Is pocket-size ultrasound a reliable tool for bowel investigation? A study on its feasibility, reproducibility and diagnostic accuracy

Magnetic Resonance Enterography and Intestinal Ultrasound for the Assessment and Monitoring of Crohn's Disease

Magnetic resonance enterography [MRE] and intestinal ultrasound [IUS] have developed rapidly in the past few decades, emerging as the primary non-invasive options for both diagnosing and monitoring Crohn's disease [CD]. In this review, we evaluate the pertinent data relating to the use of MRE and IUS in CD. We summarise the key imaging features of CD activity, highlight their increasing role in both the clinical and the research settings, and discuss how these modalities fit within the diagnostic pathway. We discuss how they can be used to assess disease activity and treatment responsiveness, including the emergence of activity scores for standardised reporting. Additionally, we address areas of controversy such as the use of contrast agents, the role of diffusion-weighted imaging, and point-of-care ultrasound. We also highlight exciting new developments, including the applications of artificial intelligence. Finally, we provide suggestions for future research priorities.

Reproducibility and accuracy of a pocket-size ultrasound device in assessing liver steatosis

BACKGROUND

This diagnostic prospective study compared the feasibility and diagnostic accuracy of Pocket-size Ultrasound Devices (PUDs) against standard ultrasound (US) in detecting liver steatosis using the controlled attenuation parameter (CAP) and liver biopsy as reference standards.

MATERIALS AND METHODS

Consecutive patients with chronic liver diseases were assessed for the presence of steatosis using PUD and US. A CAP cut-off value >275 dB/m was applied to establish ≥S1. A 26-patient subgroup underwent liver biopsy. PUD reproducibility was evaluated using Cohen's k statistic. Diagnostic accuracy of PUD and US was given as Sensibility (Sn), Specificity (Sp), Positive and Negative Predictive Values (PPV, NPV), positive and negative Likelihood Ratio (LR+, LR-).

RESULTS

81 consecutive patients (69% males) with multiple etiologies were enroled. PUD inter-observer agreement was good (k 0.77, 95%CI 0.62-0.93). PUD and US identified ≥S1 according to CAP values respectively with Sn 0.87, Sp 0.61, PPV 0.49, NPV 0.91, LR+ 2.04, LR- 0.07, AUROC 0.74 and Sn 0.96, Sp 0.54, PPV 0.47, NPV 0.97, LR+ 2.10, LR- 0.07, AUROC 0.75.

CONCLUSIONS

PUD shows good reproducibility and diagnostic accuracy in ruling liver steatosis out, representing a useful point-of-care tool to avail of hepatologists interested in excluding NAFLD, but with basic US skills.

David Against Goliath: Direct Comparison of Handheld Bowel Sonography and Magnetic Resonance Enterography for Diagnosis of Crohn's Disease

BACKGROUND

Diagnosis of Crohn's disease (CD) requires ileo-colonoscopy (IC) and cross-sectional evaluation. Recently, "echoscopy" has been used effectively in several settings, although data about its use for CD diagnosis are still limited. Our aim was to evaluate the diagnostic accuracy of handheld bowel sonography (HHBS) in comparison with magnetic resonance enterography (MRE) for CD diagnosis.

METHODS

From September 2019 to June 2021, we prospectively recruited consecutive subjects attending our third level IBD Unit for suspected CD. Patients underwent IC, HHBS, and MRE in random order with operators blinded about the result of the other procedures. Bivariate correlation between MRE and HHBS was calculated by Spearman coefficient (r). To test the consistency between MRE and HHBS for CD location and complications, the Cohen's k measure was applied.

RESULTS

Crohn's disease diagnosis was made in 48 out of 85 subjects (56%). Sensitivity, specificity, positive predictive values, and negative predictive values for CD diagnosis were 87.50%, 91.89%, 93.33%, and 85% for HHBS; and 91.67%, 94.59%, 95.65%, and 89.74% for MRE, without significant differences in terms of diagnostic accuracy (89.41% for HHBS vs 92.94% for MRE, P = NS). Magnetic resonance enterography was superior to HHBS in defining CD extension (r = 0.67; P < .01) with a better diagnostic performance than HHBS for detecting location (k = 0.81; P < .01), strictures (k = 0.75; P < .01), abscesses (k = 0.68; P < .01), and fistulas (k = 0.65; P < .01).

CONCLUSION

Handheld bowel sonography and MRE are 2 accurate and noninvasive procedures for diagnosis of CD, although MRE is more sensitive in defining extension, location, and complications. Handheld bowel sonography could be used as effective ambulatory (or out-of-office) screening tool for identifying patients to refer for MRE examination due to high probability of CD diagnosis.