Imaging of the gastrointestinal tract-novel technologies

Table 1 Most frequently used imaging modalities in the study of the gastrointestinal tract: Overview of main advantages and shortcomings

Modality	Advantages	Shortcomings
Multidetector computed tomography (MDCT)	High temporal and spatial resolution	High radiation exposure
	Fast image acquisition without motion artefacts	Less suitable for research in healthy subjects
	Total evaluation of entire intestine and its surroundings	No direct functional information
	3D reconstructions and virtual endoscopy Possibility for image guided intervention	Low risk of nephropathy due to intravenous iodised contrast media
Ultrasound (US)	High soft tissue resolution	Relatively high interobserver variability
	No radiation exposure	Intestinal gas lowers image quality
	Ideal for repeated examination and research	Artifacts may be difficult to interpret
	Evaluation of intestinal wall and surroundings	Total visualisation of the entire intestine is difficult
	Information on motility, function and flow directly available using special techniques
	Possibility for intraluminal imaging
	Ideal for image guided intervention
Magnetic resonance imaging (MRI)	Good soft tissue imaging capabilities	Motion artifacts due to intestinal motility
	No radiation exposure	Long image acquisition
	Ideal for repeated examinations and research Total evaluation of entire intestine and its surroundings	Image resolution less than CT making 3D reconstructions and virtual endoscopy cumbersome
	Functional and motility information directly available using special techniques	Potential long term effects of gadolinium-based contrast media (nephrogenic systemic fibrosis)
Conventional radiography	High temporal and spatial resolution	Only direct visualisation of luminal/mucosal properties
	Fast image acquisition	Radiation exposure
	Motility and function easily studied using intraluminal contrast	No 3D image data
Endoscopy	Direct visualisation of the mucosa	Invasive procedure
	Possibility for intervention (biopsies, polypectomy and endoscopic surgery)	Discomfort and potential intestinal perforation No visualisation of deeper wall layers and surroundings