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

The role of radiology in diagnosing gastrointestinal tract perforation

Spontaneous, iatrogenic or surgical perforation of the whole gastrointestinal wall can lead to serious complications, resulting in increased morbidity and mortality. Optimal patient management requires early clinical appraisal and prompt imaging evaluation. Both radiologists and referring clinicians should recognize the importance of choosing the ideal imaging modality and the usefulness of oral and rectal contrast medium. Surgeons and radiologists should be familiar with CT and fluoroscopy findings of the normal and pathologic anatomy after esophageal, stomach or colon surgery. Specifically, they should be able to differentiate innocuous from clinically-relevant, life-threatening postoperative complications to guide appropriate treatment. Advantages of esophagram, CT-esophagram, CT after rectal contrast enema and other imaging modalities are discussed.

Graham Patch Repair of a Prepyloric Ulcer Complicated by Recurrent Abdominal Abscesses and Leukocytosis: A Case Report

This case report describes the clinical course of a 51-year-old Caucasian woman with a history of anemia who presented to the emergency department with worsening diffuse abdominal pain and weakness two days after dental surgery. The patient's condition rapidly deteriorated, manifesting as tachycardia, diaphoresis, and a peritonitic abdomen. A CT scan revealed a perforated gastric ulcer, prompting emergent laparoscopy, Graham patch repair, and abdominal washout. Postoperatively, the patient developed leukocytosis, and imaging indicated the formation of an abscess. Despite initial attempts at percutaneous drainage, a subsequent exploratory laparotomy was performed. The patient's leukocytosis eventually resolved, and she was discharged after 21 days with outpatient follow-up. The discussion delves into the declining incidence of peptic ulcer disease but a constant rate of complications, emphasizing the role of factors such as nonsteroidal anti-inflammatory drug use. The diagnostic approach using CT scans in suspected perforated peptic ulcers is highlighted. The study also explores risk stratification scoring systems, with a preference for operative management. The laparoscopic omental patch repair (Graham patch) is discussed, citing its safety and efficacy. The case presented an uncommon occurrence of failed primary percutaneous abscess drainage, leading to subsequent surgical drainage. The discussion concludes by noting variables that may contribute to drainage failure and emphasizes the need for further research to understand such complications.

Liver Trauma: Until When We Have to Delay Surgery? A Review

Liver involvement after abdominal blunt trauma must be expected, and in up to 30% of cases, spleen, kidney, and pancreas injuries may coexist. Whenever hemodynamics conditions do not contraindicate the overcoming of the ancient dogma according to which exploratory laparotomy should be performed after every major abdominal trauma, a CT scan has to clarify the liver lesions so as to determine the optimal management strategy. Except for complete vascular avulsion, no liver trauma grade precludes nonoperative management. Every attempt to treat the injured liver by avoiding a strong surgical approach may be considered. Each time, a nonoperative management (NOM) consisting of a basic “wait and see” attitude combined with systemic support and blood replacement are inadequate. Embolization should be considered to stop the bleeding. Percutaneous drainage of collections, endoscopic retrograde cholangiopancreatography (ERCP) with papilla sphincterotomy or stent placement and percutaneous transhepatic biliary drainage (PTBD) may avoid, or at least delay, surgical reconstruction or resection until systemic and hepatic inflammatory remodeling are resolved. The pathophysiological principle sustaining these leanings is based on the opportunity to limit the further release of cell debris fragments acting as damage-associated molecular patterns (DAMPs) and the following stress response associated with the consequent immune suppression after trauma. The main goal will be a faster recovery combined with limited cell death of the liver through the ischemic events that may directly follow the trauma, exacerbated by hemostatic procedures and surgery, in order to reduce the gross distortion of a regenerated liver.

Fatal Case of Perforated Cytomegalovirus Colitis: Case Report and Systematic Review

Objective: We describe a patient with history of heart transplant on maintenance immunosuppression who presented with sigmoid colon perforation from cytomegalovirus (CMV) colitis and performed a systematic review of outcomes after perforated CMV colitis. Background: Cytomegalovirus enterocolitis is uncommon among solid organ transplant patients and can result in small or large bowel perforation. Methods: We systematically reviewed articles describing patients with CMV enterocolitis with small or large bowel perforations from PubMed, Embase, and Web of Science from database inception to February 2021. Results: Seventy-seven articles were identified containing 84 patients with perforated CMV enterocolitis. The most prevalent comorbid diagnosis was human immunodeficiency virus (HIV; 27 patients, 32%), and 37 patients (44%) were taking corticosteroids at time of presentation. The ileum was the most common location for a perforation (26 patients, 31%). Odds of survival were lower for patients with small bowel perforation (odds ratio [OR], 0.38; 95% confidence interval [CI], 0.14-0.98) and HIV/acquired immunodeficiency syndrome (AIDS; OR, 0.32; 95% CI, 0.11-0.88). Odds of survival were higher for patients with large bowel perforation (OR, 2.64; 95% CI, 1.03-7.09), radiographically diagnosed perforation (OR, 3.45; 95% CI, 1.12-11.60) and those who received a CMV antiviral (OR, 9.19; 95% CI, 3.26-28.48). Conclusions: Perforated CMV enterocolitis is uncommon even in immunocompromised hosts. Clinicians should maintain a high level of suspicion for CMV-induced bowel perforation in this population because antiviral treatment is associated with increased odds of survival.

Seasonal Variation of Presentation of Perforated Peptic Ulcer Disease: An Overview of Patient Demographics, Management and Outcomes

Background

Perforated peptic ulcer disease (PUD) is one of the most common causes of acute peritonitis. It carries significant mortality and morbidity. Several previous studies have reported a seasonal variation in the presentation of patients with perforated ulcers. Here we present this study from our experience in a Northern Irish acute district hospital.

Methods

A retrospective cohort study was conducted on perforated peptic ulcer patients who presented to Altnagelvin Area Hospital emergency department between 2015 to 2020. Data on patient demographics, clinical presentation, investigations, management and outcomes were collected. Primary outcome was to investigate if seasonality was associated with the incidence of perforated peptic ulcers. Follow-up data were also collected. Seasons were defined as per UK Met Office.

Results

A total of 50 patients presented with perforated PUD. Male to female ratio was approximately 3:2. Peaks were noted in spring and winter. April was the most common month for presentation followed by December. Smoking was the most common risk factor followed by alcohol abuse. Fourteen patients (28%) were either very frail or had contained perforations and were conservatively managed. Three deaths were noted (6%). Thirteen patients (26%) required ICU admission at some stage in their management.

Conclusion

Slight seasonal variation was noted in the presentation of perforated peptic ulcers in our study with a higher incidence in the winter and spring months. The month of April was noted to have the peak incidence of the disease in our study.

Accuracy of specific free air distributions in predicting the localization of gastrointestinal perforations

PURPOSE

To evaluate the role of specific distributions of free air in predicting the location of gastrointestinal (GI) tract perforation.

MATERIALS AND METHODS

One hundred and fifteen patients with surgically proven GI tract perforation between January 2015 and June 2019 were included in the study. The site of perforation was based on surgical findings in all cases. Two radiologists retrospectively interpreted the computed tomography (CT) images of these patients for extraluminal free air distribution. Perforation sites were demonstrated intraoperatively in all cases and were categorized as follows: stomach and duodenum, jejunum and ileum, proximal colon (cecum, ascending colon, and transverse colon), distal colon (descending colon and sigmoid colon), rectum, and appendix.

RESULTS

There were 79 male and 36 female patients with a mean age of 56.4 years. Periportal, perihepatic, and perigastric free air were statistically significant in predicting gastroduodenal perforation. Mesenteric free air was significant in predicting both small bowel and distal colon perforations. Pelvic free air was statistically significant in distal colon perforations. Periappendiceal free air was found to be a strong predictor of acute perforated appendicitis.

CONCLUSION

Specific free air distributions may help to predict the site of gastrointestinal perforation, which would change the treatment plan.

Laparoscopy in Emergency: Why Not? Advantages of Laparoscopy in Major Emergency: A Review

A laparoscopic approach is suggested with the highest grade of recommendation for acute cholecystitis, perforated gastroduodenal ulcers, acute appendicitis, gynaecological disorders, and non-specific abdominal pain (NSAP). To date, the main qualities of laparoscopy for these acute surgical scenarios are clearly stated: quicker surgery, faster recovery and shorter hospital stay. For the remaining surgical emergencies, as well as for abdominal trauma, the role of laparoscopy is still a matter of debate. Patients might benefit from a laparoscopic approach only if performed by experienced teams and surgeons which guarantee a high standard of care. More precisely, laparoscopy can limit damage to the tissue and could be effective for the reduction of the overall amount of cell debris, which is a result of the intensity with which the immune system reacts to the injury and the following symptomatology. In fact, these fragments act as damage-associated molecular patterns (DAMPs). DAMPs, as well as pathogen associated molecular patterns (PAMPs), are recognised by both surface and intracellular receptors of the immune cells and activate the cascade which, in critically ill surgical patients, is responsible for a deranged response. This may result in the development of progressive and multiple organ dysfunctions, manifesting with acute respiratory distress syndrome (ARDS), coagulopathy, liver dysfunction and renal failure. In conclusion, none of the emergency surgical scenarios preclude laparoscopy, provided that the surgical tactic could ensure sufficient cleaning of the abdomen in addition to resolving the initial tissue damage caused by the “trauma”.

An Overview of Gastroduodenal Perforation

Gastroduodenal perforation may be spontaneous or traumatic and the majority of spontaneous perforation is due to peptic ulcer disease. Improved medical management of peptic ulceration has reduced the incidence of perforation, but still remains a common cause of peritonitis. The classic sub-diaphragmatic air on chest x-ray may be absent and computed tomography scan is a more sensitive investigation in the stable patient. The management of perforated peptic ulcer disease is still a subject of debate. The majority of perforated peptic ulcers are caused by Helicobacter pylori, so definitive surgery is not usually required. Perforated peptic ulcer is an indication for operation in nearly all cases except when the patient is asymptomatic or unfit for surgery. However, non-operative management has a significant incidence of intra-abdominal abscesses and sepsis. Primary closure is achievable in traumatic perforation, but the management follows the Advanced Trauma Life Support (ATLS) principles.

Noncontrast MRI of acute abdominal pain caused by gastrointestinal lesions: indications, protocol, and image interpretation

Gastrointestinal tract lesions are major causes of acute abdominal pain. A rapid, accurate, and reliable diagnosis is required to manage patients. Magnetic resonance imaging (MRI) is a nonionizing modality that is beneficial for pregnant women, children, and young adults who are sensitive to ionizing radiation. For patients with renal impairment who are not accurately diagnosed with noncontrast computed tomography, noncontrast MRI can serve as an alternative diagnostic modality. MRI protocols used for acute abdominal pain are supposed to be optimized and prioritized to shorten scanning times. Single-shot T2-weighted and fat-suppressed T2-weighted imaging are important pulse sequences that are used to reveal pathology and inflammation in the gastrointestinal tract. Diffusion-weighted imaging clearly depicts inflammation and abscesses as hyperintense lesions. Most acute gastrointestinal tract lesions, including inflammation, ischemia, obstruction, and perforation, demonstrate bowel wall thickening. Bowel obstruction and adynamic ileus present bowel dilatation, and perforation and penetration show bowel wall defects. MRI can be used to reveal these pathological findings with some characteristics depending on their underlying pathophysiology. This review article discusses imaging modalities for acute abdominal pain, describes a noncontrast MRI protocol for acute abdominal pain caused by gastrointestinal tract lesions, and reviews MRI findings of acute gastrointestinal tract lesions.

Clinical characteristics of pneumoperitoneum with pneumatosis intestinalis detected using computed tomography: A descriptive study

Pneumoperitoneum has always been considered a surgical emergency as it represents a perforation of the gastrointestinal tract. Although several cases of pneumoperitoneum with pneumatosis intestinalis (PI) have been reported, the characteristics of such cases remain unclear. The current study aimed to clarify the clinical characteristics of pneumoperitoneum cases with PI detected using computed tomography (CT).This descriptive study was conducted at a single center. In a total of 18,513 abdominal CT scans obtained between January 2010 and February 2017, extraluminal free air was detected in 254 examinations of 182 cases. The medical records and CT images of these 182 patients were retrospectively analyzed.Pneumoperitoneum with PI was detected through 23 examinations in 21 cases, and the average age of the patients was 80.1 years. The frequency was 0.12% in all abdominal CT examinations, but 24.7% in the 85 cases with extraluminal free air, excluding iatrogenic air. PI was classified as benign in 20 cases and as life-threatening in 1 case. The majority of cases with benign PI showed good general and local findings and little leukocytosis, while the case with life-threatening PI showed severe conditions. No evidence of bowel wall discontinuity, segmental bowel-wall thickening, perivisceral fat stranding, and abscesses were observed. Ascites were detected less frequently in the cases with PI than in the other pneumoperitoneum cases (P < .01). Pneumoperitoneum and PI occasionally recurred, and PI and/or extraluminal free air generally disappeared quickly.Pneumoperitoneum with PI is a relatively common condition in older patients, and the majority of cases are caused by benign PI. The characteristics of pneumoperitoneum cases with benign PI include well-maintained physical conditions, normal laboratory data, absence of CT findings indicative of peritonitis, and infrequent ascites. In pneumoperitoneum cases with PI, predicting whether the PI is benign or life-threatening is clinically very important, whereas the presence of extraluminal free air is considered to be insignificant.

Gastrointestinal perforation: clinical and MDCT clues for identification of aetiology

Gastrointestinal tract (GIT) perforation is a common medical emergency associated with considerable mortality, ranging from 30 to 50%. Clinical presentation varies: oesophageal perforations can present with acute chest pain, odynophagia and vomiting, gastroduodenal perforations with acute severe abdominal pain, while colonic perforations tend to follow a slower progression course with secondary bacterial peritonitis or localised abscesses. A subset of patients may present with delayed symptoms, abscess mimicking an abdominal mass, or with sepsis.

Direct multidetector computed tomography (MDCT) findings support the diagnosis and localise the perforation site while ancillary findings may suggest underlying conditions that need further investigation following primary repair of ruptured bowel. MDCT findings include extraluminal gas, visible bowel wall discontinuity, extraluminal contrast, bowel wall thickening, abnormal mural enhancement, localised fat stranding and/or free fluid, as well as localised phlegmon or abscess in contained perforations.

The purpose of this article is to review the spectrum of MDCT findings encountered in GIT perforation and emphasise the MDCT and clinical clues suggestive of the underlying aetiology and localisation of perforation site.

[Acute abdomen - gastrointestinal causes]

CLINICAL/METHODICAL ISSUE

Diagnostic imaging plays a crucial role in the assessment and stratification of pathologic conditions causing acute abdomen. This report provides information on etiology, clinical manifestations and therapeutic options for six common diseases resulting in acute abdomen-appendicitis, cholecystitis, bowel obstruction, diverticulitis, acute pancreatitis, and viscus perforation.

PERFORMANCE

Besides initial ultrasound, CT scans often represent the imaging gold standard for the diagnostic evaluation of acute abdomen.

PRACTICAL RECOMMENDATIONS

Depending on the underlying pathologic condition, sonography or CT is suitable for the stratification of the gastrointestinal disease causing acute abdomen.

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.

Evaluation of risk factors for perforated peptic ulcer

Background

The aim of this study was to evaluate the prediction factors for perforated peptic ulcer (PPU).

Methods

At St. Luke’s International Hospital in Tokyo, Japan, a case control study was performed between August 2004 and March 2016. All patients diagnosed with PPU were included. As control subjects, patients with age, sex and date of CT scan corresponding to those of the PPU subjects were included in the study at a proportion of 2 controls for every PPU subject. All data such as past medical histories, physical findings, and laboratory data were collected through chart reviews. Univariate analyses and multivariate analyses with logistic regression were conducted, and receiver operating characteristic curves (ROCs) were calculated to show validity. Sensitivity analyses were performed to confirm results using a stepwise method and conditional logistic regression.

Results

A total of 408 patients were included in this study; 136 were a group of patients with PPU, and 272 were a control group. Univariate analysis showed statistical significance in many categories. Four different models of multivariate analyses were conducted, and significant differences were found for muscular defense and a history of peptic ulcer disease (PUD) in all models. The conditional forced-entry analysis of muscular defense showed an odds ratio (OR) of 23.8 (95% confidence interval [CI]: 5.70–100.0), and the analysis of PUD history showed an OR of 6.40 (95% CI: 1.13–36.2). The sensitivity analysis showed consistent results, with an OR of 23.8–366.2 for muscular defense and an OR of 3.67–7.81 for PUD history. The area under the curve (AUC) of all models was high enough to confirm the results. However, anticoagulants, known risk factors for PUD, did not increase the risk for PPU in our study. The conditional forced-entry analysis of anticoagulant use showed an OR of 0.85 (95% CI: 0.03–22.3).

Conclusions

The evaluation of prediction factors and development of a prediction rule for PPU may help our decision making in performing a CT scan for patients with acute abdominal pain.

Natural History of Pneumoperitoneum After Laparotomy: Findings on Multidetector-Row Computed Tomography

BACKGROUND

Postoperative pneumoperitoneum after abdominal surgery represents a diagnostic challenge. This study was designed to analyze the appearance of pneumoperitoneum on computed tomography after uncomplicated abdominal surgery through laparotomy.

METHODS

The database of the department of digestive surgery was retrospectively queried to identify all patients who underwent abdominal surgery through laparotomy during a 13-month period. This initial search retrieved a total of 384 consecutive patients. Criteria for inclusion in this study were: (a) the operation was performed in our institution, (b) the patient had computed tomography examination postoperatively, and (c) the patient had no postoperative grade ≥3 complication.

RESULTS

Postoperative pneumoperitoneum was visible in 38/80 patients (47.5 %), with a mean volume of 15 ± 22.8 (SD) cm³ and multiple locations in 32/38 patients (84 %). Postoperative pneumoperitoneum was observed in 22/26 patients (85 %) until day 5 postoperative, 14/34 patients (41 %) between day 6 and day 15 postoperative, and in 2/21 patients (9.5 %) after day 15 postoperative. Its volume decreased when the time interval between surgery and computed tomography increased. Results of multivariate analysis showed that the time interval between surgery and computed tomography was the single independent variable that was associated with the presence of postoperative pneumoperitoneum.

CONCLUSIONS

Postoperative pneumoperitoneum is a frequent finding on computed tomography in the early period following abdominal surgery and commonly with multiple locations. Although commonly observed before day 5 postoperative, its presence must be considered as an alarming finding after day 7 postoperative, if present in a single location with a volume >20 cm³.

Can multidetector CT detect the site of gastrointestinal tract injury in trauma? - A retrospective study

PURPOSE

We aimed to assess the performance of computed tomography (CT) in localizing site of traumatic gastrointestinal tract (GIT) injury and determine the diagnostic value of CT signs in site localization.

METHODS

CT scans of 97 patients with surgically proven GIT or mesenteric injuries were retrospectively reviewed by radiologists blinded to surgical findings. Diagnosis of either GIT or mesenteric injuries was made. In patients with GIT injuries, site of injury and presence of CT signs such as focal bowel wall hyperenhancement, hypoenhancement, wall discontinuity, wall thickening, extramural air, intramural air, perivisceral infiltration, and active vascular contrast leak were evaluated.

RESULTS

Out of 97 patients, 90 had GIT injuries (70 single site injuries and 20 multiple site injuries) and seven had isolated mesenteric injury. The overall concordance between CT and operative findings for exact site localization was 67.8% (61/90), partial concordance rate was 11.1% (10/90), and discordance rate was 21.1% (19/90). For single site localization, concordance rate was 77.1% (54/70), discordance rate was 21.4% (15/70), and partial concordance rate was 1.4% (1/70). In multiple site injury, concordance rate for all sites of injury was 35% (7/20), partial concordance rate was 45% (9/20), and discordance rate was 20% (4/20). For upper GIT injuries, wall discontinuity was the most accurate sign for localization. For small bowel injury, intramural air and hyperenhancement were the most specific signs for site localization, while for large bowel injury, wall discontinuity and hypoenhancement were the most specific signs.

CONCLUSION

CT performs better in diagnosing small bowel injury compared with large bowel injury. CT can well predict the presence of multiple site injury but has limited performance in exact localization of all injury sites.

Perforated peptic ulcer - an update

Peptic ulcer disease (PUD) affects 4 million people worldwide annually. The incidence of PUD has been estimated at around 1.5% to 3%. Perforated peptic ulcer (PPU) is a serious complication of PUD and patients with PPU often present with acute abdomen that carries high risk for morbidity and mortality. The lifetime prevalence of perforation in patients with PUD is about 5%. PPU carries a mortality ranging from 1.3% to 20%. Thirty-day mortality rate reaching 20% and 90-d mortality rate of up to 30% have been reported. In this review we have summarized the current evidence on PPU to update readers. This literature review includes the most updated information such as common causes, clinical features, diagnostic methods, non-operative and operative management, post-operative complications and different scoring systems of PPU. With the advancement of medical technology, PUD can now be treated with medications instead of elective surgery. The classic triad of sudden onset of abdominal pain, tachycardia and abdominal rigidity is the hallmark of PPU. Erect chest radiograph may miss 15% of cases with air under the diaphragm in patients with bowel perforation. Early diagnosis, prompt resuscitation and urgent surgical intervention are essential to improve outcomes. Exploratory laparotomy and omental patch repair remains the gold standard. Laparoscopic surgery should be considered when expertise is available. Gastrectomy is recommended in patients with large or malignant ulcer.

Complications of endoscopic polypectomy, endoscopic mucosal resection and endoscopic submucosal dissection in the colon

Endoscopic resection (ER), including endoscopic polypectomy (EP), endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) are used to remove superficial neoplasms from the colon. Snare resection is used for EP and EMR, whereas endoscopic knives are used to perform dissection in the submucosal space in ESD. 80-90% colonic polyps are <10 millimetres (mm) and are effectively managed by conventional EP. Increasingly cold snare polypectomy is preferred. Large laterally spreading lesions (LSLs) and sessile polyps ≥20 mm are primarily removed by EMR. ESD may be used when superficial invasive disease is suspected and for some LSLs, particularly non-granular subtypes. Resection of colonic lesions by ER is associated with a small but definite incidence of significant complications, most commonly bleeding and perforation. This review discusses complications of ER with a particular focus on their prevention, early recognition and management. In many cases, complications from all three procedures share similar mechanisms and management principles and these are described at the start of each section, followed by a description of specific aspects for individual procedures.

Small Bowel Perforations: What the Radiologist Needs to Know

The incidence of small bowel perforation is low but can develop from a variety of causes including Crohn disease, ischemic or bacterial enteritis, diverticulitis, bowel obstruction, volvulus, intussusception, trauma, and ingested foreign bodies. In contrast to gastroduodenal perforation, the amount of extraluminal air in small bowel perforation is small or absent in most cases. This article will illustrate the main aspects of small bowel perforation, focusing on anatomical reasons of radiological findings and in the evaluation of the site of perforation using plain film, ultrasound, and multidetector computed tomography equipments. In particular, the authors highlight the anatomic key notes and the different direct and indirect imaging signs of small bowel perforation.

The relationship between computed tomography findings and the locations of perforated peptic ulcers: it may provide better information for gastrointestinal surgeons

BACKGROUND

Computed tomography (CT) plays an important role in diagnosing gastrointestinal perforation. This study explored the relationship between CT findings and the locations of perforated peptic ulcers (PPUs), which may help further surgical planning.

METHODS

During a 34-month period, 175 patients had CT scans. We categorized those 175 patients into 2 groups: patients with and without a PPU at a difficult ulcer site for a laparoscopic approach. Both clinical data and the CT images were reviewed and analyzed.

RESULTS

Based on the univariate analysis results, we conducted multivariate analyses of 3 factors: age, American Society of Anesthesiologists classification of 3 or more, and positive lesser sac image findings. The positive lesser sac findings in CT were the only independent factor that was correlated to the PPU site.

CONCLUSIONS

Positive lesser sac CT findings may help to predict PPUs in sites where a laparoscopic approach might be difficult. Our study re-evaluates the additional value of CT scanning in diagnosing PPU, and the results may assist with surgical planning in clinical practice.

The emergency room diagnosis of gastrointestinal tract perforation: the role of CT

Computed tomography (CT) plays an important role in the evaluation of patients presenting to the emergency department with a suspected spontaneous gastrointestinal tract (GIT) perforation. Prospective identification of the site of perforation helps the emergency department physician plan the appropriate treatment in a potentially unstable patient. The purpose of this pictorial essay is to review the CT approach a radiologist should take when evaluating the patient with suspected perforation in the emergent setting. A series of patients presenting to the emergency department with surgically proven GIT perforations were retrospectively reviewed, and key images were obtained. For the purposes of this review, the anatomy of the abdominal cavity in relation to sites of GIT perforation will be discussed. CT findings of perforation will be described, including free intraperitoneal/extraperitoneal air, bowel wall discontinuity, and localized inflammatory changes. The use of a bone window setting to increase the free air conspicuity will be emphasized. The mimics of pneumoperitoneum will be demonstrated, including pneumothorax, pneumomediastinum, and venous air. Using a systematic approach, CT can precisely determine the presence and site of a gastrointestinal perforation in a majority of patients. This greatly assists the surgeon in planning the correct surgical approach.

Computed tomography scan is superior to x-ray plain film in the diagnosis of gastrointestinal tract perforation

Gastrointestinal (GI) tract perforation is one of the most severe acute abdomens. In clinical practice, abdominal x-ray plain film remains the first-line diagnostic modality for this entity. A proportion of the perforated patients, however, do not exhibit a classic x ray sign: free air at the subphrenic area. This insufficiency can bring difficulties to the diagnosis, delay appropriate treatments, and even cause lethal consequences. We describe herein a case of GI tract perforation, which was not detected by the abdominal x-ray plain film initially. Strikingly, the abdominal computed tomographic (CT)scan established the diagnosis and predicted the site and cause of the perforation, which were consistent with the intraoperative findings and pathological examination. In addition, CT scan was useful in monitoring the progression of the disease. Given the high performance of CT scan in the present case, we recommend it as a preferred diagnostic modality for patients who are suspected of GI perforation,especially when the abdominal x-ray plain film is inconclusive.