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Current Status of Magnetic Resonance Colonography for Screening and Diagnosis of Colorectal Cancer. Radiol Clin North Am 2018; 56:737-749. [DOI: 10.1016/j.rcl.2018.04.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Levine MS, Yee J. History, evolution, and current status of radiologic imaging tests for colorectal cancer screening. Radiology 2015; 273:S160-80. [PMID: 25340435 DOI: 10.1148/radiol.14140531] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Colorectal cancer screening is thought to be an effective tool with which to reduce the mortality from colorectal cancer through early detection and removal of colonic adenomas and early colon cancers. In this article, we review the history, evolution, and current status of imaging tests of the colon-including single-contrast barium enema, double-contrast barium enema, computed tomographic (CT) colonography, and magnetic resonance (MR) colonography-for colorectal cancer screening. Despite its documented value in the detection of colonic polyps, the double-contrast barium enema has largely disappeared as a screening test because it is widely perceived as a labor-intensive, time-consuming, and technically demanding procedure. In the past decade, the barium enema has been supplanted by CT colonography as the major imaging test in colorectal cancer screening in the United States, with MR colonography emerging as another viable option in Europe. Although MR colonography does not require ionizing radiation, the radiation dose for CT colonography has decreased substantially, and regular screening with this technique has a high benefit-to-risk ratio. In recent years, CT colonography has been validated as an effective tool for use in colorectal cancer screening that is increasingly being disseminated.
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Affiliation(s)
- Marc S Levine
- From the Department of Radiology, Hospital of the University of Pennsylvania, 3400 Spruce St, Philadelphia, PA 19104 (M.S.L.); and Department of Radiology and Biomedical Imaging, University of California-San Francisco, San Francisco Veterans Affairs Medical Center, San Francisco, Calif (J.Y.)
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van der Paardt MP, Stoker J. Magnetic Resonance Colonography for Screening and Diagnosis of Colorectal Cancer. Magn Reson Imaging Clin N Am 2014; 22:67-83. [DOI: 10.1016/j.mric.2013.07.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Keeling AN, Morrin MM, McKenzie C, Farrell RJ, Sheth SG, Ngo L, Bloch BN, Pedrosa I, Rofsky NM. Intravenous, contrast-enhanced MR colonography using air as endoluminal contrast agent: Impact on colorectal polyp detection. Eur J Radiol 2012; 81:31-8. [PMID: 21131152 DOI: 10.1016/j.ejrad.2010.10.028] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2010] [Revised: 10/14/2010] [Accepted: 10/20/2010] [Indexed: 01/26/2023]
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Sambrook A, Mcateer D, Yule S, Phull P. MR colonography without bowel cleansing or water enema: a pilot study. Br J Radiol 2011; 85:921-4. [PMID: 22167505 DOI: 10.1259/bjr/26473479] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVES The value of screening for colorectal cancer has been well demonstrated, and national programmes are being implemented. At present the primary imaging modality is colonoscopy, which has an associated morbidity and mortality. CT colonography (CTC) has been proposed as an alternative, but this is associated with radiation exposure and generally requires bowel preparation. The aim of this pilot study was to assess the feasibility of MR colonography (MRC) without bowel preparation or water enema for the detection of colorectal neoplasia. METHODS Patients scheduled for colonoscopy were invited to participate in the study; informed consent was obtained. MRC (with oral barium faecal tagging and colonic air distension) was performed 1-2 weeks before the colonoscopy. Axial T(2) weighted single-shot fast spin-echo (prone and supine) and axial T(1) weighted fast spoiled gradient-recalled (pre- and post-iv gadolinium) supine MRI sequences were performed. The examinations were reported by two gastrointestinal radiologists by consensus. Colonoscopy following standard bowel preparation was performed by a single endoscopist blinded to the MRC results. Significant lesions were defined as polyps or masses >10 mm in diameter. RESULTS 29 patients were studied. Colonoscopy revealed 25 mass lesions in 13 patients. MRC correctly identified four of the nine lesions >10 mm in diameter (sensitivity 44%; specificity 100%). Although specificity remained high for smaller lesions, sensitivity was poor. CONCLUSION This pilot study has demonstrated the feasibility of performing MRC without bowel preparation or water enema. This would seem to be a promising modality for colorectal cancer screening. Larger studies are required to determine the accuracy of this modality for the detection of colorectal neoplasia.
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Affiliation(s)
- A Sambrook
- Department of Radiology, Aberdeen Royal Infirmary, Aberdeen, UK
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Magnetic resonance colonography: comparison between T1 high-resolution isotropic volume excitation (THRIVE) and balanced fast field echo (bFFE) using an air enema or water-gadolinium enema. Clin Radiol 2010; 65:319-24. [PMID: 20338400 DOI: 10.1016/j.crad.2009.11.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2009] [Revised: 10/23/2009] [Accepted: 11/23/2009] [Indexed: 12/12/2022]
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Abstract
The bowel is a common site for pathologic processes, including malignancies and inflammatory disease. Colorectal cancer accounts for 10% of all new cancers and 9% of cancer deaths. A significant decrease in the incidence of colorectal cancer and cancer death rates has been attributed to screening measures, earlier detection, and improved therapies. Virtual colonoscopy (VC), also known as computed tomography colonography, is an effective method for detecting polyps. However, in light of increasing concerns about ionizing radiation exposure from medical imaging and potential increased risk of future radiation-induced malignancies, magnetic resonance imaging (MRI) is seen as an increasingly attractive alternative. Improvements in MRI technology now permit three-dimensional volumetric imaging of the entire colon in a single breath hold at high spatial resolution, making VC with MRI possible.
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Affiliation(s)
- Lewis K Shin
- Department of Radiology, Stanford University School of Medicine, 300 Pasteur Drive, Room H-1307, Stanford, CA 94305-5105, USA.
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Achiam MP, Løgager VB, Chabanova E, Eegholm B, Thomsen HS, Rosenberg J. Diagnostic accuracy of MR colonography with fecal tagging. ACTA ACUST UNITED AC 2009; 34:483-90. [PMID: 18452023 DOI: 10.1007/s00261-008-9402-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
BACKGROUND MR colonography (MRC) is a non-invasive method of examining the colon, but it is still only used in a few specialized centers on a daily basis. The purpose of this study was to evaluate the performance of MRC with improved fecal tagging vs. conventional colonoscopy (CC). METHODS Between March 2006 and February 2007, consecutive patients who received first-time referrals to CC were asked to participate in the study. Two days prior to MRC, a new contrast mixture (barium/ferumoxsil) was ingested together with four meals each day. Standard bowel cleansing was performed before CC. MRC was evaluated by two blinded observers. MRC results were compared with CC. RESULTS A total of 56 patients were included. The per-polyp sensitivity was 85.7% for polyps 6-10 mm and 81.3% for polyps >10 mm. The per-patient sensitivity/specificity was 100%/80% for polyps >6 mm and 100%/91.4% for polyps >10 mm. CONCLUSION MRC showed acceptable per-patient sensitivities, but the per-polyp sensitivities are still compromised by the fecal tagging. MRC may be implemented, but at the present time MRC with fecal tagging is not ready for widespread use, although it remains a very promising diagnostic tool.
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Affiliation(s)
- Michael Patrick Achiam
- Department of Diagnostic Radiology, Copenhagen University Hospital Herlev, Herlev, Denmark.
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Bakir B, Acunas B, Bugra D, Yamaner S, Asoglu O, Salmaslioglu A, Balik E. MR colonography after oral administration of polyethylene glycol-electrolyte solution. Radiology 2009; 251:901-9. [PMID: 19318587 DOI: 10.1148/radiol.2513081061] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
This prospective study was approved by the local institutional ethics committee, and written informed consent was obtained from all patients. The aim of this study was to determine whether the oral administration of a polyethylene glycol (PEG)-electrolyte solution induces adequate luminal distention for magnetic resonance (MR) colonography to be performed and to assess patient acceptance of this procedure. Fifty-five patients (26 women, 29 men; mean age, 60.5 years +/- 14 [standard deviation]; age range, 40-75 years) who were referred for optical colonoscopy (OC) owing to symptoms and findings that included rectal bleeding, altered bowel habits, and positive fecal occult blood test results participated in this study. Standard bowel preparation was performed 1 day before the procedure. MR colonography was performed and followed by OC on the same day. Before undergoing MR colonography, the patients received 2.0-2.5 L of the PEG-electrolyte solution orally. Adequate distention of all colonic segments was achieved in 50-53 (91%-96%) of patients imaged in the supine position and in 51-53 (93%-96%) of patients imaged in the prone position. Oral administration of the solution yielded uniform luminal darkening and sufficient colonic distention for MR colonography in 91%-96% of patients.
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Affiliation(s)
- Baris Bakir
- Department of Radiology, Istanbul University, Istanbul Medical School, Capa, 34390 Istanbul, Turkey.
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Magnetic Resonance Colonography for the Evaluation of Colonic Inflammatory Bowel Disease. J Comput Assist Tomogr 2008; 32:848-54. [DOI: 10.1097/rct.0b013e31815b63ff] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Morrin MM, Pedrosa I, McKenzie CA, Farrell RJ, Bloch N, Solazzo S, Ngo L, Goldberg SN, Rofsky NM. Parallel imaging enhanced MR colonography using a phantom model. J Magn Reson Imaging 2008; 28:664-72. [DOI: 10.1002/jmri.21357] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
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Zhang S, Peng JW, Shi QY, Tang F, Zhong MG. Colorectal neoplasm: Magnetic resonance colonography with fat enema-initial clinical experience. World J Gastroenterol 2007; 13:5371-5. [PMID: 17879409 PMCID: PMC4171329 DOI: 10.3748/wjg.v13.i40.5371] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To assess Magnetic resonance colonography with fat enema as a method for detection of colorectal neoplasm.
METHODS: Consecutive twenty-two patients underwent MR colonography with fat enema before colonoscopy. T1-weighted three-dimensional fast spoiled gradient-echo with inversion recovery sequence was acquired with the patient in the supine position before and 75 s after Gadopentetate Dimelumine administration. Where by, pre and post MR coronal images were obtained with a single breath hold for about 20 s to cover the entire colon. The quality of MR colonographs and patients' tolerance to fat contrast medium was investigated. Colorectal neoplasms identified by MR colonography were compared with those identified on colonoscopy and sensitivity of detecting the lesions was calculated accordingly.
RESULTS: MR colonography with fat enema was well tolerated without sedation and analgesia. 120 out of 132 (90.9%) colonic segments were well distended and only 1 (0.8%) colonic segment was poor distension. After contrast enhancement scan, mean contrast-to-noise ratio (CNR) value between the normal colonic wall and lumen was 18.5 ± 2.9 while mean CNR value between colorectal neoplasm and lumen was 20.2 ± 3.1. By Magnetic resonance colonography, 26 of 35 neoplasms (sensitivity 74.3%) were detected. However, sensitivity of MRC was 95.5% (21 of 22) for neoplasm larger than 10 mm and 55.6% (5 of 9) for 5-10 mm neoplasm.
CONCLUSION: MR colonography with fat enema and T1-weighted three-dimensional fast spoiled gradient-echo with inversion recovery sequence is feasible in detecting colorectal neoplasm larger than 10 mm.
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Affiliation(s)
- Shuai Zhang
- Department of Radiology, Fudan University Cancer Hospital Shanghai 200032, China
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Florie J, Birnie E, van Gelder RE, Jensch S, Haberkorn B, Bartelsman JF, van der Sluys Veer A, Snel P, van der Hulst VPM, Bonsel GJ, Bossuyt PMM, Stoker J. MR Colonography with Limited Bowel Preparation: Patient Acceptance Compared with That of Full-Preparation Colonoscopy. Radiology 2007; 245:150-9. [PMID: 17885188 DOI: 10.1148/radiol.2451061244] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To prospectively evaluate participants' experience and preference of magnetic resonance (MR) colonography with limited bowel preparation compared with full-preparation colonoscopy in participants at increased risk for colorectal cancer. MATERIALS AND METHODS This study had institutional review board approval; all participants gave written informed consent. In this multicenter study, consecutive participants undergoing conventional colonoscopy because of a personal or family history of colorectal cancer or adenomatous polyps underwent MR colonography 2 weeks prior to colonoscopy. They all followed a low-fiber diet and were given lactulose and an oral contrast agent (fecal tagging with gadolinium) 2 days before colonography. Before imaging, spasmolytics were administered intravenously, and a water-gadolinium chelate mixture was administered rectally for distention of the colon. Breath-hold T1- and T2-weighted sequences were performed in the prone and supine positions. Participant experience in terms of, for example, pain and burden was determined by using a five-point scale and was evaluated with a Wilcoxon signed rank test; participant preference was determined by using a seven-point scale and was evaluated with the chi2 statistic after dichotomizing. RESULTS Two hundred nine participants (77 women, 132 men; mean age, 58 years; range, 23-84 years) were included. One hundred forty-eight participants received sedatives (midazolam) and/or analgesics (fentanyl) during colonoscopy. Participants rated the MR colonography bowel preparation as less burdensome (P<.001) compared with the colonoscopy bowel preparation (10% and 71% of participants rated the respective examinations moderately to extremely burdensome). Participants also experienced less pain at MR colonography (P<.001) and found MR colonography less burdensome (P<.001). Immediately after both examinations, 69% of participants preferred MR colonography, 22% preferred colonoscopy, and 9% were indifferent (P<.001, 69% vs 22%). After 5 weeks, 65% preferred MR colonography and 26% preferred colonoscopy (P<.001). CONCLUSION Participants preferred MR colonography without extensive cleansing to colonoscopy immediately after both examinations and 5 weeks later. Experience of the bowel preparation and of the procedure was rated better.
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Affiliation(s)
- Jasper Florie
- Department of Radiology, Academic Medical Center, Meibergdreef 9, 1105 AZ Amsterdam, the Netherlands.
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Saar B, Meining A, Beer A, Settles M, Helmberger H, Frimberger E, Rummeny EJ, Rösch T. Prospective study on bright lumen magnetic resonance colonography in comparison with conventional colonoscopy. Br J Radiol 2007; 80:235-41. [PMID: 17329681 DOI: 10.1259/bjr/83959666] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The aim of this prospective trial was to evaluate sensitivity and specificity of bright lumen magnetic resonance colonography (MRC) in comparison with conventional colonoscopy (CC). A total of 120 consecutive patients with clinical indications for CC were prospectively examined using MRC (1.5 Tesla) which was then followed by CC. Prior to MRC, the cleansed colon was filled with a gadolinium-water solution. A 3D GRE sequence was performed with the patient in the prone and supine position, each acquired during one breathhold period. After division of the colon into five segments, interactive data analysis was carried out using three-dimensional post-processing, including a virtual intraluminal view. The results of CC served as a reference standard. In all patients MRC was performed successfully and no complications occurred. Image quality was diagnostic in 92% (574/620 colonic segments). On a per-patient basis, the results of MRC were as follows: sensitivity 84% (95% CI 71.7-92.3%), specificity 97% (95% CI 89.0-99.6%). Five flat adenomas and 6/16 small polyps (< or =5 mm) were not identified by MRC. MRC offers high sensitivity and excellent specificity rates in patients with clinical indications for CC. Improved MRC techniques are needed to detect small polyps and flat adenomas.
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Affiliation(s)
- B Saar
- Department of Diagnostic, Interventional and Pediatric Radiology, University Hospital of Berne, Inselspital, Switzerland.
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Purkayastha S, Athanasiou T, Tekkis PP, Constantinides V, Teare J, Darzi AW. Magnetic resonance colonography vs computed tomography colonography for the diagnosis of colorectal cancer: an indirect comparison. Colorectal Dis 2007; 9:100-11. [PMID: 17223933 DOI: 10.1111/j.1463-1318.2006.01126.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
OBJECTIVE The primary aim of this study was to use meta-regression techniques to compare the diagnostic accuracy of computed tomography colonography (CTC) and magnetic resonance colonography (MRC), compared with conventional colonoscopy for patients presenting with colorectal cancer (CRC). METHOD Quantitative meta-analysis was performed using prospective studies reporting comparative data between CTC and MRC individually to conventional colonoscopy. Study quality was assessed and sensitivities, specificities, diagnostic odds ratios (DOR) were calculated. Summary receiver operating characteristic (SROC) curves and sensitivity analysis were utilized. Meta-regression was used to indirectly compare the two modalities following adjustment for patient and study characteristics. RESULTS Overall sensitivity and specificity for CTC (0.96, 95% CI 0.92-0.99; 1.00, 95% CI 0.99-1.00 respectively) and MRC (0.91, 95% CI 0.79-0.97; 0.98, 95% CI 0.96-0.99 respectively) for the detection of CRC was similar. Meta-regression analysis showed no significant difference in the diagnostic accuracy of both modalities (beta=-0.64, P=0.37 and 95% CI of 0.12-2.39). Both tests showed high area under the SROC curve (CTC=0.99; MRC=0.98), with high DORs (CTC=1461.90, 95% CI 544.89-3922.30; MRC=576.41, 95% CI 135.00-2448.56). Factors that enhanced the overall accuracy of MRC were the use intravenous contrast, faecal tagging and exclusion of low-quality studies. No factors improved diagnostic accuracy from CTC except studies with more than 100 patients (AUC=1.00, DOR=2938.35, 95%CI 701.84-12 302.91). CONCLUSION This meta-analysis suggested that CTC and MRC have similar diagnostic accuracy for detecting CRC. Study quality, size and intravenous/intra-luminal contrast agents affect diagnostic accuracies. For an exact comparison to be made, studies evaluating CTC, MRC and colonoscopy in the same patient cohort would be necessary.
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Affiliation(s)
- S Purkayastha
- Department of Biosurgery & Surgical Technology, Imperial College, St Mary's Hospital, London, UK
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Wong TYY, Lam WWM, So NMC, Lee JFY, Leung KL. Air-inflated magnetic resonance colonography in patients with incomplete conventional colonoscopy: Comparison with intraoperative findings, pathology specimens, and follow-up conventional colonoscopy. Am J Gastroenterol 2007; 102:56-63. [PMID: 17100979 DOI: 10.1111/j.1572-0241.2006.00891.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND To assess the usefulness of air-inflated magnetic resonance colonography (MRC) in patients with incomplete conventional colonoscopy (CC). METHODS From September 2001 to December 2004, 51 patients (25 male and 26 female, age range 32 to 85 years) with incomplete colonoscopy were recruited to have MRC performed. Half-fourier single short turbo spin echo (HASTE) axial, coronal, and three dimensional fat suppressed gradient echo sequence (VIBE) coronal images in both the prone and supine positions were performed for each patient. MRC was reviewed by two radiologists for detection of synchronous colonic lesion. The location and size of lesions were recorded and were compared with the findings of CC. Patients were managed according to the clinical situation and intraoperative findings were compared with MRC findings. Follow-up colonoscopy was performed in 29 patients. The follow-up colonoscopy findings were then compared with the MRC findings. RESULTS Forty-four patients had incomplete colonoscopy because of an obstructing tumor. The other seven patients had incomplete colonoscopy because of excessive bowel looping. Apart from one patient suffering from chronic obstructive airway disease with resulting nondiagnostic MRC, all other patients had MRC successfully performed. Each colon was divided into six bowel segments for analysis. All 300 segments were of diagnostic quality and were assessed by the MRC. MRC correctly identified all 44 obstructing tumors demonstrated by initial CC. Synchronous tumors in proximal colonic segments were identified in two patients by MRC. In addition, MRC identified two colonic tumors located in bowel segments inaccessible by CC because of excessive looping. CONCLUSIONS MRC is useful for detection of colonic pathology and assessment of proximal colon in patients with colonic cancer after incomplete colonoscopy.
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Affiliation(s)
- Tammy Yuen-yee Wong
- Department of Diagnostic Radiology and Organ Imaging, Prince of Wales Hospital, Shatin, NT, Hong Kong
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Florie J, van Gelder RE, Haberkorn B, Birnie E, Lavini C, Reitsma JB, Stoker J. Magnetic resonance colonography with limited bowel preparation: A comparison of three strategies. J Magn Reson Imaging 2007; 25:766-74. [PMID: 17340636 DOI: 10.1002/jmri.20880] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE To prospectively compare three strategies of magnetic resonance colonography (MRC) with fecal tagging. MATERIALS AND METHODS Three strategies were compared: (S1) gadolinium as oral tagging agent and a gadolinium-water mixture for rectal filling (bright lumen), (S2) oral barium and water rectally, and (S3) oral barium and air rectally. In S2 and S3 (both dark lumen) gadolinium was injected intravenously. Three-dimensional (3D) T1-weighted and two-dimensional (2D) T2-weighted sequences were used. Two observers scored diagnostic confidence and image quality (contrast, homogeneity, artifacts), analyzed by chi-squared and Fisher's exact test. Patient experience and preference were determined by questionnaire (Mann-Whitney test). RESULTS A total of 45 patients were included, 15 were randomly assigned per strategy. Diagnostic confidence of S1 and S3 is significantly better than for S2. S1 has the additional advantage of showing significantly better contrast between bowel wall and lumen, and showing significantly better homogeneity on both T1- and T2-weighted sequences, but with significantly more artifacts on the T1-weighted sequences. S3 showed significantly better contrast and homogeneity than S2 on the T2-weighted sequences. Bowel preparation of S1 was rated significantly better. Patient preference was comparable. CONCLUSION Image quality was best using the bright lumen strategy or the dark lumen strategy using air for rectal filling. Although bowel preparation was rated best using the bright lumen strategy, patient preference was comparable.
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Affiliation(s)
- Jasper Florie
- Department of Radiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
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Wessling J, Fischbach R, Borchert A, Kugel H, Allkemper T, Osada N, Heindel W. Detection of Colorectal Polyps: Comparison of Multi–Detector Row CT and MR Colonography in a Colon Phantom. Radiology 2006; 241:125-31. [PMID: 16908674 DOI: 10.1148/radiol.2411050292] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To compare multi-detector row (four- and 16-section) computed tomography (CT), including a low-dose protocol, with high-field-strength (1.5- and 3.0-T) magnetic resonance (MR) imaging for reader detection of colorectal polyps in a colon phantom. MATERIALS AND METHODS A colon phantom with simulated haustral folds and 10 polyps of varying size (2.0-8.0 mm) was imaged at four- and 16-section CT (section thicknesses of 1.25 and 0.75 mm, reconstruction increments of 0.8 and 0.7 mm, and 100 and 10 mAs, respectively, and 120 kV for both) and at 1.5- and 3.0-T MR imaging (three-dimensional gradient-recalled echo sequence, section thickness of 1.4 mm). Three-dimensional endoluminal images were assessed by 10 reviewers for each modality regarding polyp detection. Comparisons of sensitivities were performed by using logistic regression. RESULTS Overall, polyps were detected with a sensitivity of 87% (95% confidence interval [CI]: 80%, 94%) at four-section CT, 92% (95% CI: 87%, 97%) at 16-section CT, 56% (95% CI: 46%, 66%) at 1.5-T MR imaging, and 55% (95% CI: 45%, 65%) at 3.0-T MR imaging. The detection of polyps at least 4 mm in diameter was not influenced by the modality or radiation dose (sensitivity of 100%). CT performed in low-dose mode depicted all polyps with a diameter of at least 3 mm. Polyps smaller than 3 mm in diameter were detected with a sensitivity of 7.5% (1.5-T MR imaging), 22.5% (3.0-T MR imaging), and 20% (low-dose CT); detection rates were significantly greater (P < .001) with normal-dose CT (four section, 67.5%; 16 section, 82.5%). Increased spatial resolution (with CT) and higher field strength (with MR imaging) had no significant effect on polyp detection. CONCLUSION With both multi-detector row CT and MR imaging, readers detected polyps above the clinically relevant threshold diameter of 6 mm, with similar sensitivities.
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Affiliation(s)
- Johannes Wessling
- Department of Clinical Radiology and Medical Informatics and Biomathematics, University of Muenster, Albert-Schweitzer-Str 33, 48149 Muenster, Germany.
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Haykir R, Karakose S, Karabacakoglu A, Sahin M, Kayacetin E. Three-dimensional MR and axial CT colonography versus conventional colonoscopy for detection of colon pathologies. World J Gastroenterol 2006; 12:2345-50. [PMID: 16688823 PMCID: PMC4088068 DOI: 10.3748/wjg.v12.i15.2345] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To evaluate the sensitivity and specificity of MR colonography (MRC) and CT performance in detecting colon lesions, and to compare their sensitivity and specificity with that of conventional colonoscopy.
METHODS: Forty-two patients suspected of having colonic lesions, because of rectal bleeding, positive fecal occult blood test results or altered bowel habits, underwent the examinations. After insertion of a rectal tube, the colon was filled with 1000-1500 mL of a mixture of 9 g/L NaCl solution, 15-20 mL of 0.5 mmol/L gadopentetate dimeglumine and 100 mL of iodinized contrast material. Once colonic distension was achieved, three-dimensional gradient-echo (3D-GRE) sequences for MR colonography and complementary MR images were taken in all cases. Immediately after MR colonography, abdominal CT images were taken by spiral CT in the axial and supine position. Then all patients were examined by conventional colonoscopy (CC).
RESULTS: The sensitivity and specificity of MRC for colon pathologies were 96.4% and 100%, respectively. The percentage of correct diagnosis by MRC was 97.6%. The sensitivity and specificity of CT for colon pathologies were 92.8%, 100%, respectively. The percentage of correct diagnosis by CT was 95.2%.
CONCLUSION: In detecting colon lesions, MRC achieved a diagnostic accuracy similar to CC. However, MRC is minimally invasive, with no need for sedation or analgesics during investigation. There is a lower percentage of perforation risk, and all colon segments can be evaluated due to multi-sectional imaging availability; intramural, extra-intestinal components of colonic lesions, metastasis and any additional lesions can be evaluated easily. MRC and CT colonography are new radiological techniques that promise to be highly sensitive in the detection of colorectal mass and inflammatory bowel lesions.
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Affiliation(s)
- Rahime Haykir
- Department of Radiology, Selcuk University Meram Medical Faculty, Konya 42080, Turkey
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23
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Bielen DJLE, Bosmans HTC, De Wever LLI, Maes F, Tejpar S, Vanbeckevoort D, Marchal GJF. Clinical validation of high-resolution fast spin-echo MR colonography after colon distention with air. J Magn Reson Imaging 2006; 22:400-5. [PMID: 16106357 DOI: 10.1002/jmri.20397] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
To evaluate the feasibility of MR colonography (MRC) with air using two-dimensional (2D) T1-weighted fast spin-echo (T1wFSE) in patients scheduled for conventional colonoscopy (CC) after classic bowel preparation, and assess the ability of the technique to detect colonic lesions. The distention was sufficient for diagnosis, and the technique provided adequate delineation of the wall in the majority of segments. Residual fluid obscured the wall in different segments, especially in the ascending and descending colon (supine position) and in the cecum, transverse, and sigmoid colon (prone position). These findings were consistent with CT colonography. MRC visualized three lesions, missed one lesion >10 mm, visualized none of four lesions <5 mm, and yielded one false-positive lesion (5-10 mm). Missed lesions can be due to inconsistency in the slice positions between consecutive breath-holds, which is inherent to the multishot technique. Residual fluid may have obscured the smaller lesions. The shortcomings of the technique are limited coverage and signal drop-off at the borders of the field of view (FOV). Before multishot 2D T1wFSE colonography can become a valid screening method, improved patient preparation and a more practical technique are needed.
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Affiliation(s)
- Didier J L E Bielen
- Department of Radiology, University Hospital Gasthuisberg K.U. Leuven, Leuven, Belgium.
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24
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Purkayastha S, Tekkis PP, Athanasiou T, Aziz O, Negus R, Gedroyc W, Darzi AW. Magnetic resonance colonography versus colonoscopy as a diagnostic investigation for colorectal cancer: a meta-analysis. Clin Radiol 2005; 60:980-9. [PMID: 16124980 DOI: 10.1016/j.crad.2005.04.015] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2004] [Revised: 03/30/2005] [Accepted: 04/14/2005] [Indexed: 01/16/2023]
Abstract
AIMS Magnetic resonance colonography (MRC) is emerging as a potential complementary investigation for the diagnosis of colorectal cancer (CRC) and also for benign pathology such as diverticular disease. A meta-analysis reporting the use of MRC is yet to be performed. The aim of this study was to evaluate the diagnostic accuracy of MRC compared with the gold-standard investigation, conventional colonoscopy (CC). METHODS A literature search was carried out to identify studies containing comparative data between MRC findings and CC findings. Quantitative meta-analysis for diagnostic tests was performed, which included the calculation of independent sensitivities, specificities, diagnostic odds ratios, the construction of summary receiver operating characteristic (SROC) curves, pooled analysis and sensitivity analysis. The study heterogeneity was evaluated by the Q-test using a random-effect model to accommodate the cluster of outcomes between individual studies. RESULTS In all, 8 comparative studies were identified, involving 563 patients. The calculated pooled sensitivity for all lesions was 75% (95% CI: 47% to 91%), the specificity was 96% (95% CI: 86% to 98%) and the area under the ROC curve was 90% (weighted). On sensitivity analysis, MRC had a better diagnostic accuracy for CRC than for polyps, with a sensitivity of 91% (95% CI: 97% to 91%), a specificity of 98% (95% CI: 66% to 99%) and an area under the ROC curve of 92%. There was no significant heterogeneity between the studies with regard to the diagnostic accuracy of MRC for CRC. CONCLUSION This meta-analysis suggests that MRC is an imaging technique with high discrimination for cases presenting with colorectal cancer. The exact diagnostic role of MRC needs to be clarified (e.g. suitable for an elderly person with suspected CRC). Further evaluation is necessary to refine its applicability and diagnostic accuracy in comparison with other imaging methods such as computed tomography colonography.
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Affiliation(s)
- S Purkayastha
- Department of Surgical Oncology, Imperial College of Science, Technology and Medicine, St Mary's Hospital, London, UK
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25
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Lauenstein TC, Ajaj W, Kuehle CA, Goehde SC, Schlosser TW, Ruehm SG. Magnetic resonance colonography: comparison of contrast-enhanced three-dimensional vibe with two-dimensional FISP sequences: preliminary experience. Invest Radiol 2005; 40:89-96. [PMID: 15654253 DOI: 10.1097/01.rli.0000149489.56736.39] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
PURPOSE The purpose of this study was to compare a dark-lumen magnetic resonance colonography (MRC) approach with a True FISP-based bright-lumen technique concerning presence of artifacts and the detection rate of colorectal pathologies. MATERIALS AND METHODS Thirty-seven patients with suspected colorectal lesions were included in this trial. The colon was filled with 2500 mL of tap water. Two-dimensional True FISP datasets as well as T1-weighted GRE sequences (pre- and post intravenous contrast) were acquired. The detection rate of colorectal masses and inflammatory lesions was determined for both techniques separately. Besides, image quality was assessed. All patients underwent conventional colonoscopy as the standard of reference. RESULTS By means of dark-lumen MRC datasets, all polyps >5 mm were correctly diagnosed, whereas 4 polyps <5 mm were missed. Sensitivity of dark-lumen MRC amounted to 78.9%. There were no false-positive results: residual stool could correctly be differentiated from colorectal masses. The True FISP-based bright-lumen MRC, however, failed to detect 2 additional polyps resulting in a sensitivity of 68.4%. Furthermore, bright-lumen MRC led to false-positive results in 5 patients. Both techniques visualized inflammatory bowel disease in 5 patients. However, image quality of True FISP was rated superior to that of dark-lumen MRC. CONCLUSION Dark-lumen MRC proved to be superior over bright-lumen MRC regarding the detection of colorectal masses. However, True FISP imaging can turn out to be helpful as a result of high image quality and motion insensitivity.
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Affiliation(s)
- Thomas C Lauenstein
- Department of Diagnostic and Interventional Radiology, University Hospital Essen, Germany.
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26
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Jardine VL, Sala E, Lomas DJ. MR colonography: baseline appearance of the unprepared rectosigmoid. Br J Radiol 2005; 78:202-6. [PMID: 15730984 DOI: 10.1259/bjr/15237296] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
A retrospective review of 100 routine pelvic MR examinations was conducted to evaluate the appearance of the unprepared rectosigmoid colon, with the aim of informing future strategies for minimal preparation MR colonography. All examinations were reviewed by two observers in consensus, and included matched-location axial T1 weighted and T2 weighted fat suppressed fast spin echo (FSFSE) images. Analysis revealed that the overall appearance of the faecal material in the colon could simulate tumour in 80% of T1 weighted and 17% of T2 weighted images. By matching the images from the two sequences for each patient the faeces had an overall appearance that would mimic tumour in only 7% of cases. However, luminal tumour-mimicking foci of signal occurred frequently, present in 91% of T1 weighted and 85% of T2 weighted studies. The results indicate that if bowel-cleansing regimens are to be avoided for MR colonography, effective strategies such as dietary restriction and use of oral contrast agents will be required to reduce luminal signal on T2 weighting and eliminate polyp-mimicking foci. The results also suggest that T2 weighted strategies should be further investigated and that combination with T1 weighted imaging may improve discrimination of lesions from normal faecal material.
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Affiliation(s)
- V L Jardine
- Department of Radiology, University of Cambridge & Addenbrooke's Hospital, Cambridge, UK
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27
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Lomas DJ, Habib SH, Joubert IJ, Sala E, Graves MJ. CO2 as a distending medium for gastric and small bowel MRI: a feasibility study. Eur Radiol 2005; 15:672-6. [PMID: 15703949 DOI: 10.1007/s00330-004-2580-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2004] [Accepted: 10/15/2004] [Indexed: 11/29/2022]
Abstract
This work evaluates carbon dioxide as a contrast medium for magnetic resonance imaging of the stomach and small bowel. Twelve healthy volunteers underwent rapid magnetic resonance imaging after oral administration of a carbon dioxide generating agent using a combination of breath-hold and interactive fluoroscopic imaging during breathing. Diagnostic-quality images were obtained in 100% of cases for the stomach and in 92, 75, 67 and 42% of cases for the duodenal segments 1-4, respectively. Visualisation of the jejunum and ileum proved unacceptable for clinical use and anti-peristaltic agents did not significantly influence the results. Further development of fast imaging and magnetic resonance interactive fluoroscopic methods may allow the use of carbon dioxide as a contrast medium for clinical imaging of the stomach and duodenum.
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Affiliation(s)
- D J Lomas
- Department of Radiology, University of Cambridge and Addenbrooke's NHS Trust, Hills Road, Cambridge, CB2 2QQ, UK.
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28
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Ajaj W, Lauenstein TC, Pelster G, Holtmann G, Ruehm SG, Debatin JF, Goehde SC. MR colonography in patients with incomplete conventional colonoscopy. Radiology 2004; 234:452-9. [PMID: 15591429 DOI: 10.1148/radiol.2342032001] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
PURPOSE To assess dark-lumen magnetic resonance (MR) colonography for the evaluation of colonic segments in patients in whom conventional colonoscopy could not be completed. MATERIALS AND METHODS Institutional review board approval and written informed consent were obtained. Within 24 hours of incomplete conventional colonoscopy, 37 patients (22 women, 15 men; age range, 25-63 years) underwent MR colonography. Contrast material-enhanced T1-weighted three-dimensional images were collected after rectal administration of water for colonic distention. Data from MR colonography were evaluated by two radiologists. With a three-point scale, image quality was characterized in terms of colonic distention (1 = good; 2 = moderate, diagnostic; and 3 = poor, nondiagnostic) and presence of artifacts (1 = none; 2 = moderate, diagnostic; and 3 = extensive, nondiagnostic). Depiction of colorectal disease was assessed according to the following colonic segments: cecum, ascending colon, transverse colon, descending colon, sigmoid colon, and rectum. RESULTS Four patients had history of colorectal cancer, and each had undergone partial colonic resection of two segments. Hence, 214 segments were evaluated. Conventional colonoscopy failed in assessment of 127 of 214 potentially visible colonic segments in the 37 patients. MR image quality was rated diagnostic in 35 patients and permitted assessment of 206 of 214 potentially visible segments. Nondiagnostic image quality in two patients was attributed to inadequate distention of prestenotic colonic segments owing to high-grade tumor stenosis. All inflammation- and tumor-induced stenoses and all five polyps identified at conventional colonoscopy in poststenotic segments were correctly detected at MR colonography. However, MR-based assessment of prestenotic segments revealed two lesions suspected of being carcinoma, five polyps, and four segments affected by colitis. CONCLUSION MR colonography proved reliable in evaluating the majority of colonic segments inaccessible with conventional colonoscopy. The identification of additional disease at MR colonography underscores the need for a second diagnostic step in the setting of incomplete conventional colonoscopy.
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Affiliation(s)
- Waleed Ajaj
- Department of Diagnostic and Interventional Radiology, University Hospital Essen, Hufelandstrasse 55, 45122 Essen, Germany.
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29
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Saar B, Beer A, Rösch T, Rummeny EJ. Magnetic resonance colonography: a promising new technique. Curr Gastroenterol Rep 2004; 6:389-94. [PMID: 15341715 DOI: 10.1007/s11894-004-0055-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/30/2023]
Abstract
Colorectal carcinoma is still the second leading cause of cancer-related death, although it arises mostly from benign adenomas. Numerous screening methods are available, but none of them is accepted as ideal. Ultrafast three-dimensional data sets acquired by cross-sectional imaging modalities (CT or magnetic resonance ) in combination with new post-processing modes, known as virtual colonoscopy, have led to a new discussion of screening tests for colorectal cancer. Recently published results indicate a high sensitivity for CT colonography and for MR-based colonography (MRC), with detection rates of greater than 90% for colorectal lesions greater than 10 mm in size. Three-dimensional data acquisition for MRC is performed in less than 1 minute, and no severe complications have been reported. The main advantages of MRC are the lack of ionizing radiation, the low risk of the procedure, and low patient discomfort. MRC has become an attractive diagnostic procedure for colorectal lesions that can also be used as a screening method.
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Affiliation(s)
- Bettina Saar
- Department of Radiology, Klinikum Rechts der Isar, Technical University of Munich, Ismaningerstr. 22, D-81675 München, Germany.
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30
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Vogt C, Cohnen M, Beck A, vom Dahl S, Aurich V, Mödder U, Häussinger D. Detection of colorectal polyps by multislice CT colonography with ultra-low-dose technique: comparison with high-resolution videocolonoscopy. Gastrointest Endosc 2004; 60:201-9. [PMID: 15278045 DOI: 10.1016/s0016-5107(04)01684-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
BACKGROUND This prospective study compared multislice CT colonography with ultra-low-dose technique to high-resolution videocolonoscopy as the standard for detection of colorectal cancer and polyps. METHODS After standard bowel preparation, 115 patients underwent multislice CT colonography with an ultra-low-dose multislice CT colonography protocol immediately before videocolonoscopy. After noise reduction by using a mathematical algorithm, ultra-low-dose multislice CT colonographic images were analyzed in blinded fashion, and the results were compared with the results of high-resolution videocolonoscopy. RESULTS A total of 150 lesions were detected by high-resolution videocolonoscopy in 115 patients. For ultra-low-dose multislice CT colonography, sensitivities for detection of polyps less than 5 mm in size, 5 to 10 mm, and greater than 10 mm in diameter were 76%, 91%, and 100%, respectively. Although the sensitivity for detection of flat lesions was only 50%, the sensitivity and the specificity for detection of polyps 5 mm or greater in size were 94% and 84%, respectively. For adenomatous lesions greater than 5 mm in size, sensitivity was 94% and specificity was 92%. The overall specificity was 79%. The calculated effective radiation dose ranged between 0.75 and 1.25 mSv. CONCLUSIONS Compared with high-resolution videocolonoscopy, ultra-low-dose multislice CT colonography has excellent sensitivity and specificity for detection of colorectal lesions 5 mm or greater in size, and the radiation exposure is relatively low. However, before this technique can be generally recommended for colorectal screening, further improvement in the detection of flat and extremely small lesions must be achieved.
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Affiliation(s)
- Christoph Vogt
- Division of Medicine, Department of Gastroenterology, Hepatology and Infectious Diseases, Institute of Diagnostic Radiology, Heinrich-Heine-University of Düsseldorf, Moorenstrasse 5, D-40225 Düsseldorf, Germany
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31
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Lam WWM, Leung WK, Wu JKL, So NMC, Sung JJY. Screening of colonic tumors by air-inflated magnetic resonance (MR) colonography. J Magn Reson Imaging 2004; 19:447-52. [PMID: 15065168 DOI: 10.1002/jmri.20028] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
PURPOSE To assess the accuracy of air-inflated magnetic resonance (MR) colonography for the detection of colonic lesions. MATERIALS AND METHODS A total of 36 patients underwent both colonoscopy and air-inflated MR colonography. Breath-hold sequences (volumetric interpolated breath-hold examination (VIBE) coronal, and half-Fourier acquisition single-shot turbo spin-echo (HASTE) axial and coronal, both supine and prone) were performed with a 1.5T scanner. The detection of colonic lesions by MR colonography was then correlated with the findings from the colonoscopy performed on the same day. RESULTS Two patients were unable to complete the MR colonography examination. Analysis was based on the results from 34 patients (17 males and 17 females, 38-70 years old, mean age = 54.9 years) who completed both examinations. MR colonography depicted two of two colonic tumors, one of one P4 (> 2 cm) polyp, one of two P2 (0.5-1 cm) polyps, and two of 11 P1 (< 0.5 cm) polyps. False-positive MR colonography interpretations were noted for one P1 polyp and two P2 polyps. The overall sensitivity, positive predictive value, and accuracy of MR colonography were 38%, 67%, and 46.2%, respectively. For the detection of endoluminal lesions > 5 mm, air-inflated MR colonography yielded a sensitivity of 75%, specificity of 93.3%, accuracy of 91.2%, positive predictive value of 60%, and negative predictive value of 96.6%. CONCLUSION Air-inflated MR colonography is a new technique that deserves further investigation.
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Affiliation(s)
- Wynnie W M Lam
- Department of Diagnostic Radiology and Organ Imaging, Prince of Wales Hospital, Chinese University of Hong Kong, Shatin, Hong Kong.
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32
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Ajaj W, Lauenstein TC, Pelster G, Goehde SC, Debatin JF, Ruehm SG. MR colonography: How does air compare to water for colonic distention? J Magn Reson Imaging 2004; 19:216-21. [PMID: 14745756 DOI: 10.1002/jmri.10455] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
PURPOSE To prove the feasibility of air-distended magnetic resonance colonography (MRC) and compare it with water-based distention. MATERIALS AND METHODS In five volunteers, the colon was imaged twice: once after distending the colon with air and a second time after distending the colon with water. A total of 50 patients, who had been referred to colonoscopy for a suspected colorectal pathology were randomized into water-distention (N = 25) and air-distention (N = 25) groups. A contrast-enhanced T1-weighted three-dimensional volume interpolated breath-hold (VIBE) sequence was collected. Comparative analysis was based on qualitative ratings of image quality and bowel distention, as well as contrast-to-noise ratio (CNR) measurements for the colonic wall with respect to the colonic lumen. In addition, patient acceptance was evaluated. RESULTS Inflammatory changes and colorectal masses were correctly identified on MRC in eight patients each. One 4-mm polyp identified at colonoscopy was missed on water-distended MRC. There were no false positive findings. No significant differences were found between air- and water-distention regarding discomfort levels and image quality. The presence of air in the colonic lumen was not associated with susceptibility artifacts. CNR of the contrast-enhanced colonic wall, as well as bowel distention, were superior on air-distended three-dimensional data sets. CONCLUSION MRC can be performed using either water or air for colonic distention. Both techniques permit assessment of the colonic wall and identification of colorectal masses. While discomfort levels are similar for both agents, MRC with air provides higher CNR and better colonic distention.
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Affiliation(s)
- Waleed Ajaj
- Department of Diagnostic and Interventional Radiology, University Hospital, Essen, Germany.
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Geenen RWF, Hussain SM, Cademartiri F, Poley JW, Siersema PD, Krestin GP. CT and MR colonography: scanning techniques, postprocessing, and emphasis on polyp detection. Radiographics 2004; 24:e18. [PMID: 14527992 DOI: 10.1148/rg.e18] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
In the last decade, computed tomographic (CT) and magnetic resonance (MR) colonography, two new cross-sectional techniques for imaging of the colon, emerged. Both techniques show promising initial results in the detection of polyps equal to or greater than 1 cm in diameter in symptomatic patients. Imaging protocols are still mostly under development and prone to change. Both CT and MR colonography generate a large number of source images, which have to be read carefully for filling defects and, if intravenous contrast material is used, enhancing lesions. An important postprocessing technique is multiplanar reformatting, which allows the viewer to see potential lesions in an orientation other than that of the source images. Virtual endoscopy, a volume rendering technique that generates images from within the colon lumen, is used for problem solving. CT and MR colonography have potential advantages over colonoscopy and double-contrast barium enema examination: multiplanar capabilities, detection of enhancing lesions that make the distinction between fecal residue and true lesion possible, and ante- and retrograde virtual colonoscopy. Currently, a number of studies suggest that patients have a preference for CT colonography over colonoscopy. Patients consider bowel cleansing the most uncomfortable part of any colon examination; hence, from the acceptance point of view, fecal tagging techniques are promising. Before CT and MR colonography can be implemented in daily practice, they must show approximately the same accuracy as colonoscopy for polyp detection in both symptomatic and screening patients.
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Affiliation(s)
- Remy W F Geenen
- Department of Radiology, Erasmus Medical Center, Dr Molenwaterplein 40, 3015 GD Rotterdam, The Netherlands.
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Leung WK, Lam WWM, Wu JCY, So NMC, Fung SSL, Chan FKL, To KF, Yeung DTK, Sung JJY. Magnetic resonance colonography in the detection of colonic neoplasm in high-risk and average-risk individuals. Am J Gastroenterol 2004; 99:102-8. [PMID: 14687150 DOI: 10.1046/j.1572-0241.2003.04008.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVES Magnetic resonance colonography (MRC) is a new noninvasive diagnostic modality for colorectal cancer. However, the use of MRC in the detection of colorectal neoplasm in average-risk individuals remains unknown. This study determined the performance and the patient's preference of MRC in the detection of colorectal neoplasm. METHODS Both high-risk (i.e., symptoms suggestive of colorectal neoplasm, positive fecal occult blood test, history of colorectal cancer in one or more first-degree relatives) and average-risk (i.e., asymptomatic individuals >50 yr) individuals were recruited. MRC was performed immediately prior to conventional colonoscopy (CC) by using air inflation without contrast. The finding on CC together with histology was used as a gold standard. Patients' pain and discomfort score were recorded immediately and 24 h after the procedure. They were also asked about their preferences for the two procedures. RESULTS A total of 165 patients (79 average risk and 86 high risk) were recruited. Eight patients had incomplete MRC and one patient had failed CC. Of the remaining 156 patients, 4 were found to have colonic cancer and 31 were found to have 67 polyps. MRC correctly identified 3 cancers (sensitivity 75%, specificity 99.3%) and 4 patients with colonic polyps (sensitivity 12.9% and specificity 97.6%). Sensitivity of MRC tended to be lower in polyps <10 mm in size and in average-risk individuals. The mean procedure time of CC was significantly shorter than MRC (13.6 +/- 6.7 vs 20.6 +/- 2.7 min, p < 0.001). Although there was no significant difference in the pain and discomfort scores of the 2 procedures, 75% of patients preferred CC to MRC. CONCLUSIONS The performance of MRC when used in the detection of colonic neoplasm in average-risk individuals is unsatisfactory.
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Affiliation(s)
- Wai K Leung
- Department of Medicine & Therapeutics, the Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong, China
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Ajaj W, Pelster G, Treichel U, Vogt FM, Debatin JF, Ruehm SG, Lauenstein TC. Dark lumen magnetic resonance colonography: comparison with conventional colonoscopy for the detection of colorectal pathology. Gut 2003; 52:1738-43. [PMID: 14633953 PMCID: PMC1773877 DOI: 10.1136/gut.52.12.1738] [Citation(s) in RCA: 124] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
BACKGROUND The purpose of this study was to assess the feasibility and usefulness of a new magnetic resonance (MR) colonography technique for the detection of colorectal pathology in comparison with conventional colonoscopy as the standard of reference. PATIENTS AND METHODS A total of 122 subjects with suspected colorectal disease underwent "dark lumen" MR colonography. A contrast enhanced T1w three dimensional VIBE sequence was collected after rectal administration of water. The presence of colorectal masses and inflammatory lesions were documented. Results were compared with those of a subsequently performed colonoscopy. RESULTS MR colonography was found to be accurate regarding detection of clinically relevant colonic lesions exceeding 5 mm in size, with sensitivity and specificity values of 93%/100%. CONCLUSION Dark lumen MR colonography can be considered as a promising alternative method for the detection of colorectal disease. In addition, it allows assessment of extraluminal organs.
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Affiliation(s)
- W Ajaj
- Department of Diagnostic and Interventional Radiology, University Hospital, Essen, Germany.
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36
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Blomqvist L. Preoperative staging of colorectal cancer--computed tomography and magnetic resonance imaging. Scand J Surg 2003; 92:35-43. [PMID: 12705549 DOI: 10.1177/145749690309200106] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Cross-sectional imaging techniques are increasingly being used in the preoperative evaluation of patients with colorectal cancer. Both computed tomography (CT) and magnetic resonance (MR) imaging have been improved with significant advances of the technological hard- and software. This has contributed to high patient acceptance due to shorter examination times and more open configuration of the systems, consistent high quality images with better delineation of the normal abdomino-pelvic anatomy and pathology. New techniques such as CT-colonography have emerged from a research application to a clinical tool which can be used in different clinical settings. Phased-array receiver coils have significantly increased the usefulness of MR in the evaluation of rectal neoplasms due to the high resolution that can be obtained. New organ specific contrast agents for magnetic resonance imaging have facilitated the preoperative evaluation of liver metastases in favour of more invasive techniques with similar sensitivities. However, preoperative staging criteria for colorectal cancer using computed tomography and magnetic resonance imaging has to be updated and the results of new techniques have to be confirmed in large trials. In the future, further development of CT and MR may offer 'one-stop-shopping' protocols for both diagnosis, local and distant staging of colorectal cancer. Diffusion weighted MR-imaging, in vivo spectroscopy as well as further targeted imaging, such as with lymph node specific agents for MR may also prove to be helpful in the preoperative evaluation of patients with colorectal cancer.
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Affiliation(s)
- L Blomqvist
- Department of Diagnostic Radiology, Karolinska Hospital, Stockholm, Sweden.
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So NMC, Lam WWM, Mann D, Leung KL, Metreweli C. Feasibility study of using air as a contrast medium in MR colonography. Clin Radiol 2003; 58:555-9. [PMID: 12834640 DOI: 10.1016/s0009-9260(03)00126-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
AIM To evaluate the feasibility of using air as intraluminal contrast medium in magnetic resonance (MR) colonography. MATERIALS AND METHODS Twenty-two patients underwent MR colonography (MRC) using air before colonoscopy. All patients were imaged in prone and supine positions. Each colon was divided into five segments. Two radiologists reviewed the images for the degree of colonic distension, image quality and colonic lesions. The colonic lesions identified using MR were compared with those identified on colonoscopy. RESULTS Eight men and 14 women with mean age of 55.5 years were studied. All patients completed the MR examination. One hundred and five out of 110 (95.5%) colonic segments were well distended in both prone and supine positions. Image quality was good in all cases. Colonoscopy detected 16 lesions: three > or = 1 cm, one 7 mm lesion and 12 lesions < or = 5 mm. All lesions 1 cm or larger were detected by MRC. CONCLUSION MRC using air and the single-shot half-Fourier rapid acquisition with refocused echoes (RARE) technique is feasible. But in this small pilot study, it had low sensitivity for the detection of polyps less than 1 cm in diameter.
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Affiliation(s)
- N M C So
- Department of Diagnostic Radiology and Organ Imaging, Prince of Wales Hospital, Hong Kong, People's Republic of China.
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38
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Abstract
BACKGROUND Colorectal cancer is the second most frequent cancer and adenomas are widely accepted as precursors to colorectal cancer. Diagnosis and removal of adenomas are recommended to reduce cancer incidence and mortality. The current diagnostic methods include sigmoidoscopy and colonoscopy. Lately, CT- and MR colonography have emerged as non-invasive methods for colon imaging. METHODS At present, CTC and MRC require bowel preparation. However, preliminary studies have been carried out without colon preparation. After the colon has been filled with air or contrast, the patient is scanned in the supine and prone positions. Data are then downloaded to a workstation for post processing and image-analysis. RESULTS Results have shown a high sensitivity and specificity for polyps > or = 10 mm, comparable to the sensitivity of conventional colonoscopy and superior to double contrast barium enema. CONCLUSIONS With the exponential development in computer processing power, CT- and MR colonography holds the promise for future colon examination with the advantages of non-invasiveness, no need for sedation, and probably no bowel preparation. A major disadvantage, however, is the radiation dose during CT colonography. Future developments with the use of "intelligent" computers, better resolution and faster examinations will make CT and/or MR colonography realistic options to replace conventional diagnostic colonoscopy.
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Affiliation(s)
- M P Achiam
- Department of Surgical Gastroenterology, H:S Hvidovre Hospital, DK -2650 Hvidovre, Denmark.
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39
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40
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Abstract
This review focuses on the technical aspects that have allowed the development of practical bowel imaging using magnetic resonance imaging, including the acquisition methods and improvements in the underlying technology. An overview of the current techniques for small and large bowel magnetic resonance examinations is provided and the scene set for the more detailed examination of specific technical aspects such as contrast media and fecal tagging addressed in other later articles in this issue.
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Affiliation(s)
- David J Lomas
- Department of Radiology, University of Cambridge and Addenbrooke's Hospital, United Kingdom
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41
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Saar B, Rösch T, Rummeny EJ. Colorectal cancer screening: a challenge for magnetic resonance colonography. Top Magn Reson Imaging 2002; 13:427-34. [PMID: 12478022 DOI: 10.1097/00002142-200212000-00006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The high incidence of colorectal carcinoma and the fact that colorectal cancer mostly arises from benign adenomas have led to recommendations for screening programs. The introduction of ultrafast three-dimensional datasets acquired by cross-sectional imaging modalities (computed tomography or magnetic resonance imaging) in combination with new postprocessing modes, known as virtual endoscopy, has led to new discussion on the recommendation of screening tests for colorectal cancer. Published results have indicated a high sensitivity for computed tomographic colonography and magnetic resonance-based colonography. Both techniques currently must be combined with colon cleansing. Three-dimensional data acquisition for magnetic resonance-based colonography is less than 1 minute using three-dimensional gradient-echo sequences. The lack of ionizing radiation, the low risk and discomfort to patients, and new techniques of minimized patient preparation make this magnetic resonance technique an attractive diagnostic procedure for colorectal lesions, with many aspects for use as a screening method.
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Affiliation(s)
- Bettina Saar
- Department of Radiology, Technical University of Munich, Germany.
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42
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Lauenstein TC, Debatin JF. Magnetic resonance colonography with fecal tagging: an innovative approach without bowel cleansing. Top Magn Reson Imaging 2002; 13:435-44. [PMID: 12478023 DOI: 10.1097/00002142-200212000-00007] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
To date, virtual colonography mandates bowel cleansing in a manner similar to colonoscopy. Because more than half of patients undergoing bowel preparation complain about negative side effects, patient acceptance is negatively impacted. To assure high patient acceptance of MR colonography, bowel cleansing needs to be eliminated. This can be accomplished by fecal tagging, a concept based on altering the signal intensity of stool by adding contrast-modifying substances to regular meals. This article describes different fecal tagging approaches and points out both advantages and limitations of these strategies.
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Affiliation(s)
- Thomas C Lauenstein
- Department of Diagnostic and Interventional Radiology, University Hospital Essen, Germany.
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43
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Affiliation(s)
- Judy Yee
- Department of Radiology, Veterans Affairs Medical Center and University of California School of Medicine, San Francisco, California 94121, USA.
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44
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Abstract
Computerized tomographic colonography (CT colonography) is a new, non-invasive technique that has been developed over the last few years; it looks at the large bowel in detail. In this chapter we look at how the examination is performed and we consider how the images are displayed. We describe the normal features of the colon, as seen using this technique, as well as the features of common pathological conditions. We will discuss screening for colorectal cancer and the performance of CT colonography; we compare the latter with other procedures currently employed in the screening and diagnosis of colorectal pathology. We consider the difficulties in interpreting these CT colonographic images and look at ways to overcome such difficulties. Finally we discuss future developments of this exciting, new technique.
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Affiliation(s)
- Clare S Smith
- Department of Radiology, Mater Misercordiae Hospital, Eccles Street, Dublin 7, Ireland
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45
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Abstract
Virtual colonoscopy (CT colonography) promises to become a primary method for colorectal cancer screening and return radiologists to a major role in colon cancer prevention. Results from major centers in the United States show accuracy to be comparable to conventional colonoscopy for detection of polyps of significant size--that is, greater than 10 mm--with few false-positives. The advent of virtual colonoscopy has also heightened awareness of the natural history of colonic polyps, particularly in terms of identifying an appropriate target size for detection in colorectal screening programs. Small polyps (<10 mm) are often either hyperplastic on histology or are unlikely to progress to frank cancer in the patient's lifetime and are therefore of little clinical significance for the average adult. Thus, the rationale for detecting and removing each and every colonic polyp regardless of size has come under increasing scrutiny in the context of cost-benefit analysis of various test strategies for colorectal cancer screening. Virtual colonoscopy may allow patients to obtain reliable information about the status of their colonic mucosa noninvasively and thus make a more informed decision as to whether to proceed to conventional colonoscopy for polypectomy.
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Affiliation(s)
- J T Ferrucci
- Department of Radiology, Boston Medical Center, Boston University School of Medicine, 88 E. Newton St., Boston, MA 02118, USA
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46
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Abstract
CT colonography is an evolving noninvasive imaging technique that allows detection of colorectal polyps and cancers. When assessing the clinical results of this test, several points need to be emphasized. First, as computed tomography (CT) technology improves, so will clinical results. Therefore, earlier results reporting the accuracy of CT colonography may not be applicable to the current state of the art. Second, as clinical experience has grown, an understanding of the limitations and pitfalls of the technique has increased. A learning curve is involved and, with increased experience, results should improve. This article will focus on the evolving clinical results of CT colonography.
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Affiliation(s)
- M Macari
- Department of Radiology, Abdominal Imaging, New York University Medical Center, Tisch Hospital, New York 10016, USA.
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