Advances in endoscopic ultrasound-guided shear wave elastography: A comprehensive review of its clinical applications

Table 1 Endoscopic ultrasound-guided shear wave elastography in pancreatic diseases

Ref.	Design	Population	Techniques	Reference standard	Results
Kojima et al[39]	Single-center, retrospective observational study (pilot + SWE sub-study)	Diagnostic EUS in 16 cases (normal pancreas, IPMN, CP, PC, etc.); SWE study: 32 PC, 17 AIP, 14 controls	EUS-SWE (10 measurements, ROI 5 mm × 10 mm; Vs and VsN measured)	Clinical diagnosis (PC, AIP; normal controls)	PC: Vs not significantly different vs controls (2.22 m/second vs 1.96 m/second, P = 0.063), but VsN significantly lower in lesions (21% vs 87%, P < 0.001); AUROC 0.918 for VsN cut-off 50%. AIP: Vs not significantly different vs controls (2.35 m/second vs 1.96 m/second, P = 0.065), but VsN significantly lower (17% vs 87%, P < 0.001); AUROC 0.929. Treatment monitoring: In AIP, Vs and VsN improved after 16 weeks of steroid therapy
Shintani et al[31]	Retrospective, single-center	657 screened; 22 patients with ECP vs 22 matched controls (JPSC)	EUS-SWE (≥ 5 measurements in pancreatic body, ROI 10 mm × 5 mm; VsN > 50% considered reliable)	JPSC 2019 for ECP	Mean Vs significantly higher in ECP vs normal (2.31 ± 0.67 m/second vs 1.59 ± 0.40 m/second, P < 0.001). Optimal cut-off 2.24 m/second (AUROC 0.82, 95%CI: 0.69-0.94). Vs strongly correlated with number of EUS findings (rs = 0.626, P < 0.001). Independent predictors of high Vs: History of acute pancreatitis and ≥ 2 positive EUS findings
Shintani et al[30]	Retrospective, single-center	50 patients with CP or suspected CP	EUS-SWE in three pancreatic regions (head, body, tail; ≥ 5 measurements per site, ROI 10 mm × 5 mm, VsN > 50%)	RC	Vs values significantly higher in CP vs non-CP across all regions. Diagnostic accuracy highest in pancreatic body: AUROC 0.87 (cut-off 2.33 m/second; sensitivity 824%, specificity 87.5%). Head and tail AUROCs 0.79 and 0.81, respectively. Vs correlated with number of RC features in all regions (strongest in body, rs = 0.55). Lobularity with honeycombing was independent predictor of stiffness
Yamashita et al[34]	Prospective, single-center	49 patients with suspected/confirmed CP	EUS-SWE vs EUS-SE	CT, RC, JPSC 2019, pancreatic exocrine dysfunction	EUS-SWE values positively correlated with RC and JPSC severity grades and number of EUS features; EUS-SE showed no correlation. Diagnostic accuracy (AUROC SWE vs SE): CT 077 vs 0.61; RC 0.85 vs 0.56; JPSC 0.83 vs 0.53; exocrine dysfunction 0.78 vs 0.61
Abboud et al[38]	Prospective, single-center	117 consecutive patients undergoing EUS for various indications (cysts, CP, recurrent acute pancreatitis, mass, screening)	EUS-SWE (10 measurements in head, body, tail; ROI 5-15 mm; VsN > 50% considered reliable)	Not disease-specific (technical feasibility/reproducibility study)	Safety/feasibility: 3320 measurements, 100% success, no peri-procedural complications. Reliability: Higher in head (85.1% reliable), vs body (75.5%) and tail (64.2%). Reproducibility: ICC good across all sites (0.80-0.89)
Yamashita et al[33]	Prospective, single-center	40 patients (normal, early, probable, and definite CP)	EUS-SWE (10 measurements in pancreatic body; ROI 5 mm × 10 mm)	JPSC 2010; BT-PABA for exocrine function; DM for endocrine dysfunction	EUS-SWE positively correlated with JPSC stages and with pancreatic function diagnostic test. Diagnostic accuracy: CP AUROC 0.92 (cut-off 1.96 m/second; sensitivity 83%, specificity 100%); exocrine dysfunction AUROC 0.78 (cut-off 1.96 m/second; sensitivity 90%, specificity 65%); DM AUROC 0.63 (cut-off 2.34 m/second; sensitivity 75%, specificity 64%)
Ohno et al[35]	Retrospective, single-center	64 patients with solid pancreatic lesions (43 PC, 9 MFP, 9 PanNEN, 3 metastases)	EUS-SWE vs EUS-SE	Histology or ≥ 12 months clinical follow-up	Vs: No significant difference between PC, MFP, PanNEN, metastases (PC 2.19 m/second vs MFP 2.56 m/second, P = 0.57); AUROC for PC vs non-PC = 0.56. VsN: Low across SPLs (PC 19%, MFP 13%, PanNEN 18%). Strain histogram: Mean strain significantly lower in PC vs MFP (45.4 vs 74.5, P = 0.0007); AUROC = 0.68
Yamashita et al[32]	Retrospective, single-center	52 patients (normal, indeterminate, suggestive, and consistent CP)	EUS-SWE (10 measurements in pancreatic body; ROI 5 mm × 10 mm)	RC; DM as marker of endocrine dysfunction	EUS-SWE values significantly correlated with RC stages (rs = 0.81) and number of EUS features (rs = 0.72). Diagnostic performance: CP AUROC 0.97 (cut-off 2.19 m/second; sensitivity 100%, specificity 94%); DM AUROC 0.75 (cut-off 2.78 m/second; sensitivity 70%, specificity 56%)
Ohno et al[29]	Prospective, single-center exploratory study	160 patients undergoing EUS; subgroup: 14 with AIP, 16 normal controls	EUS-SWE (≥ 5-10 measurements in pancreatic head, body, tail; ROI 5 mm × 10 mm; VsN reliability index, ≥ 50% accepted)	International Consensus Diagnostic Criteria for AIP	Overall feasibility: 97.6% success rate (3743/3837 measurements). Median Vs in AIP group significantly higher than controls (2.57 m/second vs 1.89 m/second, P = 0.0185). In 6 patients, Vs decreased after steroid therapy (3.32 m/second to 2.46 m/second, P = 0.0234), paralleling pancreatic size reduction

SWE: Shear wave elastography; EUS: Endoscopic ultrasound; IPMN: Intraductal papillary mucinous neoplasm; CP: Chronic pancreatitis; PC: Pancreatic cancer; AIP: Autoimmune pancreatitis; ECP: Early chronic pancreatitis; MFP: Mass-forming pancreatitis; PanNEN: Pancreatic neuroendocrine neoplasms; ROI: Region of interest; Vs: Shear wave velocity; VsN: Net effective shear wave velocity; SE: Strain elastography; JPSC: Japanese diagnostic criteria 2019; RC: Rosemont criteria; CT: Computed tomography; BT-PABA: N-benzoyl-L-tyrosyl-p-aminobenzoic acid; DM: Diabetes mellitus; AUROC: Area under the receiver operating characteristic; CI: Confidence interval; ICC: Intraclass correlation coefficient; SPLs: Solid pancreatic lesions.

Table 2 Endoscopic ultrasound-guided shear wave elastography in liver diseases

Ref.	Design	Population	Techniques	Reference standard	Results
AbiMansour et al[27]	Prospective, single-center	Patients undergoing EUS for various indications; subset analyzed for liver disease staging	EUS-SWE performed in the left lobe of the liver during EUS	VCTE and clinical diagnosis of advanced liver disease	Patients with advanced liver disease showed higher values of EUS-SWE compared to healthy control: LHL 17.6 kPa vs 12.7 kPa (P < 0.001); RHL 24.8 kPa vs 11.0 kPa (P < 0.001)
Yousaf et al[45]	Prospective + retrospective, single-center	25 patients with suspected chronic liver disease	EUS-SWE (right lobe), EUS-PPG, and concomitant EUS-liver biopsy	Histology (METAVIR), clinical/radiologic criteria	Mean EUS-SWE 24.1 kPa. Significant fibrosis (F2-F4) associated with higher PPG (5.9 mmHg vs 2.5 mmHg, P = 0.003) and higher stiffness (30.0 kPa vs 15.6 kPa, P = 0.02). Advanced fibrosis (F3-F4) vs non-advanced: PPG 6.0 mmHg vs 3.4 mmHg (P = 0.01), EUS-SWE 32.0 kPa vs 18.8 kPa (P = 0.04)
Del Valle et al[40]	Single-center, cross-sectional diagnostic trial (case-control)	59 patients: 29 cirrhosis, 30 controls	EUS-SWE (ROI 10 mm, ≥ 10 measurements in both lobes) vs VCTE	Gold standard: 2-lobe EUS-guided liver biopsy (Kleiner/METAVIR)	Cirrhosis 27 kPa (RHL)/25 kPa (LHL) vs controls 5.6/6.5 kPa (P < 0.001). Accuracy: AUROC 0.97 (RHL), 0.98 (LHL), 0.95 (VCTE). Performance: Se 966% (both lobes), Sp 90% (RHL), 96.7% (LHL). Cut-offs: 10.7 kPa (RHL), 14 kPa (LHL). Agreement: Higher with LHL-EUS-SWE (96.6%) vs RHL (93.2%) and VCTE (91.5%)
Diehl et al[36]	Prospective pilot cohort	52 patients undergoing EUS-guided liver biopsy for abnormal liver function tests or fibrosis staging	EUS-SWE (10 measurements per lobe, VsN > 60% reliable); compared with VCTE	Bilobar EUS-guided liver biopsy (histology, Kleiner/METAVIR)	Correlation with histology: RHL SWE r = 0.57 (P < 0.0001), LHL r = 0.37 (P = 0.0079). Accuracy: AUROC advanced fibrosis F3-4: 0.98 (RHL), 0.95 (LHL), 0.99 (VCTE), no significant differences. Cut-offs: RHL 25.5 kPa (Se 60%, Sp 98%), LHL 22.5 kPa (Se 60%, Sp 83%). Reproducibility: Variance 35 × higher in LHL vs RHL; RHL more reliable
Wang et al[37]	Multicenter, cross-sectional (prospective data)	62 obese patients (BMI ≥ 30) with suspected MASLD/MASH undergoing liver biopsy	EUS-SWE (ROI < 2 cm from transducer, 10 measurements, ROI ≤ 1.5 cm; minimal probe pressure)	Liver biopsy (Brunt criteria); subset comparison with VCTE (n = 19) and FIB-4	Stiffness increased with fibrosis stage (Kruskal-Wallis P < 0.0001). Accuracy (AUROC): F ≥ 20.87, F ≥ 30.93, F4 0.95. Cutoffs (90% Se/90% Sp): F ≥ 27.50/9.82 kPa (PPV/NPV 0.74/0.89 at Se-prioritized; 0.91/0.78 at Spprioritized); F ≥ 38.48/10.20 kPa (PPV/NPV 0.73/0.94; 0.80/0.88); F4 11.30/14.60 kPa (PPV/NPV 0.56/1.00; 0.67/0.98). Comparators: EUSSWE superior to FIB4 for F ≥ 2 and F ≥ 3 (AUROC 0.87 vs 0.61, P = 0.0048; 0.93 vs 0.63, P < 0.0001); vs VCTE in reliable subgroup (n = 19): EUSSWE AUROC 0.93/0.89/0.93 (F ≥ 2/F ≥ 3/F4) vs VCTE 0.84/0.61/0.60 with superiority for F ≥ 3 (P = 0.0067) and F4 (P = 0.0022). Feasibility/safety: No adverse events; IQR/M > 30% in 29%, VsN < 50% in 12.9% (accuracy unchanged in Se analyses)
AbiMansour et al[51]	Prospective, single-center	142 patients undergoing clinically indicated EUS; 13 (9.2%) with CSPH	EUS-SWE of spleen (ROI 1-1.5 cm from probe, ≥ 10 reliable readings, VsN > 60%)	Clinical and radiologic criteria for CSPH	Mean spleen stiffness significantly higher in CSPH vs non-CSPH (37.6 ± 8.5 kPa vs 29.1 ± 9.9 kPa; P = 0.003). AUROC 0.74 for CSPH detection; optimal cut-off 37.6 kPa (Se 692%, Sp 79.8%). Spleen stiffness correlated with liver stiffness measured by EUS-SWE (P = 0.001) and MRE (P = 0.003)
Kohli et al[44]	Single-center, prospective tandem study	42 patients undergoing liver biopsy	EUS-SWE (left and right lobes separately) vs VCTE	Liver biopsy (histology, fibrosis staging)	AUROC for advanced fibrosis: VCTE 0.87, EUS-SWE left lobe 080, right lobe 078. AUROC for cirrhosis: VCTE 0.90, EUS-SWE left lobe 096, right lobe 090. VCTE unreliable in 8 patients who all had successful EUS-SWE

EUS: Endoscopic ultrasound; BMI: Body mass index; MASLD: Metabolic dysfunction-associated steatotic liver disease; MASH: Metabolic dysfunction-associated steatohepatitis; CSPH: Clinically significant portal hypertension; SWE: Shear wave elastography; PPG: Portal pressure gradient; ROI: Region of interest; VCTE: Vibration-controlled transient elastography; VsN: Net effective shear wave velocity; FIB-4: Fibrosis-4 index; RHL: Right hepatic lobe; LHL: Left hepatic lobe; AUROC: Area under the receiver operating characteristic; Se: Sensitivity; Sp: Specificity; PPV: Positive predictive value; NPV: Negative predictive value; IQR/M: Interquartile range-to-median ratio; MRE: Magnetic resonance elastography.