The accuracy of 64-slice MDCT for determining the perforation site of the gastrointestinal tract: ROC analysis

Multidetector CT findings in gastrointestinal tract perforation that can help prediction of perforation site accurately

AIM

To assess the accuracy, sensitivity, and specificity of multidetector computed tomography (MDCT) findings by comparing the locations of free air in the abdomen and imaging findings with the site of gastrointestinal perforation.

MATERIALS AND METHODS

Ninety-three patients with acute abdominal pain who visited the emergency department between January 2015 and October 2018 were included in the study. There were 59 male and 34 female patients with a mean age of 50.5 years. The site of perforation was based on surgical findings in all cases.

RESULTS

Among specific air distributions, periportal free air and subphrenic free air were statistically significant in differentiating upper gastrointestinal tract perforation. Whereas free air in the minor pelvis, right lower quadrant free air, left lower quadrant free air, and air in the mesentery were statistically significant in differentiation of lower gastrointestinal tract perforation.

CONCLUSION

Multidetector findings may help to predict the site of gastrointestinal perforation, which would change the treatment plan.

Management of Giant Gastric Ulcer Perforation: Report of a Case and Review of the Literature

Giant gastric ulcer (GGU) is defined as an ulcer more than 3 cm in diameter. Now infrequent in clinical practice, in the pre-H2 receptor antagonist (H2RA) era, the incidence of GGU varied between 12 and 24% of all gastric ulcers. Proton pump inhibitors reportedly achieve better healing rates and symptom relief in comparison to H2RA. The GGU is associated with high incidence of serious complications such as hemorrhage. A perforated GGU though rare (<2%) offers serious challenges in management. We report one such case wherein the role of multidetector CT scan (MDCT) for diagnosis and treatment planning, surgical options for GGU perforations, and factors affecting outcome are discussed.

Gastrointestinal tract perforation: evaluation of MDCT according to perforation site and elapsed time

OBJECTIVES

To evaluate multidetector computed tomography (MDCT) for the prediction of perforation site according to each gastrointestinal (GI) tract site and elapsed time.

METHODS

One hundred and sixty-eight patients who underwent MDCT before laparotomy for GI tract perforation were enrolled and allocated to an early or late lapse group based on an elapsed time of 7 h. Two reviewers independently evaluated the perforation site and assessed the following CT findings: free air location, mottled extraluminal air bubbles, focal bowel wall discontinuity, segmental bowel wall thickening, perivisceral fat stranding and localised fluid collection.

RESULTS

The overall diagnostic accuracy was 91.07 % and 91.67 % for reviewers 1 and 2, respectively, with excellent agreement (kappa 0.86). Accuracies (98.97 % and 97.94 %) and agreements (kappa 0.894) for stomach and duodenum perforation were higher than for other perforation sites. Strong predictors of perforation at each site were: focal bowel wall discontinuity for stomach, duodenal bulb and left colon, mottled extraluminal air bubbles for retroperitoneal duodenum and right colon, and segmental bowel wall thickening for small bowel. The diagnostic accuracy was not different between the early- and late-lapse groups.

CONCLUSIONS

MDCT can accurately predict upper GI tract perforation with high reliability. Elapsed time did not affect the accuracy of perforation site prediction.

KEY POINTS

Perforation of the stomach and duodenum can be accurately predicted with MDCT. Knowledge of CT findings predicting perforation site can improve diagnostic accuracy. Elapsed time does not significantly affect accuracy in predicting perforation sites.

[Use of multidetector computed tomography for locating the site of gastrointestinal tract perforations]

INTRODUCTION

The purpose of this study was to evaluate the accuracy of multidetector computed tomography (MDCT) for locating the site of gastrointestinal tract perforations and to determine the most predictive signs in this diagnosis.

MATERIAL AND METHODS

A total of 98 patients with pneumoperitoneum on MDCT were retrospectively analysed. Two experienced radiologists reviewed the presence or absence of direct signs (extravasation of oral contrast, focal defect in the bowel wall, focal defect with multiplanar reformations images) and indirect signs (free air in supramesocolic, inframesocolic, supramesocolic and inframesocolic compartments, concentration of extraluminal air bubbles adjacent to the bowel wall, extraluminal fluid, segmental bowel-wall thickening, perivisceral fat stranding, abscess) to identify the site of the perforation. The Kappa index was evaluated between radiologists to determine the site of perforation and for each predictive sign, as well as Kappa index between the site of perforation detected with MDCT and the site proven at surgery. The frequency, sensitivity, specificity and positive and negative predictive value (PPV and NPV, respectively) were calculated.

RESULTS

The perforation site was identified correctly in 80.4% of cases. Kappa index between radiologists to identify the site was excellent (0.919), varying between 0.5-1.0 for each radiological sign. The most frequent site of perforation at surgery (33.7%) and in MDCT (40.82%) was the sigmoid colon/rectum. Concentration of extraluminal air bubbles adjacent to the bowel wall was the most sensitive (91%) sign and "segmental bowel-wall thickening" had the highest PPV (90%).

CONCLUSION

MDCT is useful for locating the site of GI perforation, with a high sensitivity (80%) and an excellent agreement between radiologists.