Tailored helical CT evaluation of acute abdomen

An Assessment of the Etiologies Associated With Acute Abdomen Subjected to Exploratory Laparotomy: A Study From a Rural Area of Himachal Pradesh

Background The aim of this retrospective study is to establish a correlation between clinical features, surgical diagnosis, and the final diagnosis of laparotomies, as well as to establish the relationship between preoperative delay on the outcomes of surgery in the form of mortality and morbidity. Emergency surgery is high-risk in patients with acute abdomen with uncertain diagnosis. The results of surgery are remarkable and provide quick relief to the suffering and agony of patients with the dreadful condition of acute generalized peritonitis. Methodology Patients presenting with complaints of acute abdomen who needed laparotomy based on clinical judgment and investigations were included in this study. The study data were reviewed from April 2007 to January 2011 and March 2014 to February 2016 in a government hospital. Results A total of 174 patients with acute abdomen in whom there was an indication of laparotomy based on clinical judgment and radiological investigations were selected. Most patients had gastrointestinal perforation (n = 115) and acute intestinal obstruction (n = 23). The most important clinical features analyzed were abdominal tenderness (n = 160), guarding (n = 153), distention (n = 75), and tachycardia (n = 63). Conclusions Among the total patients, 150 underwent surgery within 24 hours of the presentation in the emergency and the remaining after 24 hours. The most common cause of laparotomy was a duodenal perforation in 79 patients and gastric perforation in 24 patients. A total of 114 patients developed no complications postoperatively. Among patients who developed postoperative complications, wound sepsis and acute respiratory distress syndrome were the most common. Mortality was noted in three patients.

The Diagnostic Performance of Multi-Detector Computed Tomography (MDCT) in Depiction of Acute Spondylodiscitis in an Emergency Department

Background: The diagnosis of acute spondylodiscitis can be very difficult because clinical onset symptoms are highly variable. The reference examination is MRI, but very often the first diagnostic investigation performed is CT, given its high availability in the acute setting. CT allows rapid evaluation of other alternative diagnoses (e.g., fractures), but scarce literature is available to evaluate the accuracy of CT, and in particular of multi-detector computed tomography (MDCT), in the diagnosis of suspected spondylodiscitis. The aim of our study was to establish MDCT accuracy and how this diagnostic method could help doctors in the depiction of acute spondylodiscitis in an emergency situation by comparing the diagnostic performance of MDCT with MRI, which is the gold standard. Methods: We searched our radiological archive for all MRI examinations of patients who had been studied for a suspicion of acute spondylodiscitis in the period between January 2017 and January 2021 (n = 162). We included only patients who had undergone MDCT examination prior to MRI examination (n = 25). The overall diagnostic value of MDCT was estimated, using MRI as the gold standard. In particular, the aim of our study was to clarify the effectiveness of CT in radiological cases that require immediate intervention (stage of complications). Therefore, the radiologist, faced with a negative CT finding, can suggest an elective (not urgent) MRI with relative serenity and without therapeutic delays. Results: MDCT allowed identification of the presence of acute spondylodiscitis in 13 of 25 patients. Specificity and positive predictive value were 100% for MDCT, while sensitivity and negative predictive value were 68% and 50%, respectively, achieving an overall accuracy of 76%. In addition, MDCT allowed the identification of paravertebral abscesses (92%), fairly pathognomonic lesions of spondylodiscitis pathology. Conclusions: The MDCT allows identification of the presence of acute spondylodiscitis in the Emergency Department (ED) with a satisfactory accuracy. In the case of a positive CT examination, this allows therapy to be started immediately and reduces complications. However, we suggest performing an elective MRI examination in negative cases in which pathological findings are hard to diagnose with CT alone.

A Deep Residual U-Net Algorithm for Automatic Detection and Quantification of Ascites on Abdominopelvic Computed Tomography Images Acquired in the Emergency Department: Model Development and Validation

Background

Detection and quantification of intra-abdominal free fluid (ie, ascites) on computed tomography (CT) images are essential processes for finding emergent or urgent conditions in patients. In an emergency department, automatic detection and quantification of ascites will be beneficial.

Objective

We aimed to develop an artificial intelligence (AI) algorithm for the automatic detection and quantification of ascites simultaneously using a single deep learning model (DLM).

Methods

We developed 2D DLMs based on deep residual U-Net, U-Net, bidirectional U-Net, and recurrent residual U-Net (R2U-Net) algorithms to segment areas of ascites on abdominopelvic CT images. Based on segmentation results, the DLMs detected ascites by classifying CT images into ascites images and nonascites images. The AI algorithms were trained using 6337 CT images from 160 subjects (80 with ascites and 80 without ascites) and tested using 1635 CT images from 40 subjects (20 with ascites and 20 without ascites). The performance of the AI algorithms was evaluated for diagnostic accuracy of ascites detection and for segmentation accuracy of ascites areas. Of these DLMs, we proposed an AI algorithm with the best performance.

Results

The segmentation accuracy was the highest for the deep residual U-Net model with a mean intersection over union (mIoU) value of 0.87, followed by U-Net, bidirectional U-Net, and R2U-Net models (mIoU values of 0.80, 0.77, and 0.67, respectively). The detection accuracy was the highest for the deep residual U-Net model (0.96), followed by U-Net, bidirectional U-Net, and R2U-Net models (0.90, 0.88, and 0.82, respectively). The deep residual U-Net model also achieved high sensitivity (0.96) and high specificity (0.96).

Conclusions

We propose a deep residual U-Net–based AI algorithm for automatic detection and quantification of ascites on abdominopelvic CT scans, which provides excellent performance.

Review of COVID-19, part 1: Abdominal manifestations in adults and multisystem inflammatory syndrome in children

The coronavirus disease 2019 (COVID -19) pandemic caused by the novel severe acute respiratory syndrome coronavirus (SARS-CoV-2) has affected almost every country in the world, resulting in severe morbidity, mortality and economic hardship, and altering the landscape of healthcare forever. Although primarily a pulmonary illness, it can affect multiple organ systems throughout the body, sometimes with devastating complications and long-term sequelae. As we move into the second year of this pandemic, a better understanding of the pathophysiology of the virus and the varied imaging findings of COVID-19 in the involved organs is crucial to better manage this complex multi-organ disease and to help improve overall survival. This manuscript provides a comprehensive overview of the pathophysiology of the virus along with a detailed and systematic imaging review of the extra-thoracic manifestation of COVID-19 with the exception of unique cardiothoracic features associated with multisystem inflammatory syndrome in children (MIS-C). In Part I, extra-thoracic manifestations of COVID-19 in the abdomen in adults and features of MIS-C will be reviewed. In Part II, manifestations of COVID-19 in the musculoskeletal, central nervous and vascular systems will be reviewed.

Negative surgical exploration in suspected gastrointestinal perforation: trend, preoperative predictors, and etiologies

Background

Despite the rapid improvement of clinical science and imaging technology including computed tomography, the entity of negative surgical exploration in suspected gastrointestinal perforation (N-GIP) still exist. However, few studies have focused on this issue and most studies are case reports. We undertook this study to investigate the rates of N-GIP, and explore a set of possible preoperative predictors associated with N-GIP.

Methods

This was a retrospective study performed at the department of general surgery in our treatment center. All patients included were suspected gastrointestinal perforation (GIP) cases, aged 14 years and over, and underwent emergency surgery between 2009 and 2019. A predictive multivariable model of the presence of N-GIP was developed using logistic regression analysis.

Results

A total of 973 patients were identified and 30 (3.1%) were found to have no evidence of perforated gastrointestinal tract. The mean age of patients was 59.74 (range, 14–97) years, and 67.2 percent of the patients were males. The rates of N-GIP did not have a significant change over time (P=0.212 for trend). In multivariable analysis, absence of generalized peritonitis, duration of abdominal pain >19.6 hours, and neutrophil-to-lymphocyte ratio (NLR) <3.80 were significant predictors of N-GIP. N-GIP was more common in patients with gastrointestinal tumors and foreign bodies. Five patients (16.7%) in N-GIP group experienced complications and the 90-day mortality rate was 6.7%.

Conclusions

The rates of N-GIP did not change significantly over time. N-GIP was associated with the absence of generalized peritonitis, duration of abdominal pain >19.6 hours, and NLR <3.80.

Influence of clinical suspicion on CT accuracy of acute mesenteric ischemia: Retrospective study of 362 patients

PURPOSE

Acute mesenteric ischemia (AMI) may be underdiagnosed when not clinically suspected before CT is performed. We assessed the influence of a clinical suspicion of AMI on the CT accuracy.

METHOD

This retrospective single-centre study included patients who underwent CT in 2014-2019 and had clinically suspected AMI and/or confirmed AMI. CT protocols were adapted based on each patient's presentation and on findings from unenhanced images. The CT protocol was considered optimal for AMI when it included arterial and portal venous phases. CT protocols, accuracy of reports, and outcomes were compared between the groups with and without suspected AMI before CT.

RESULTS

Of the 375 events, 337 (90 %) were suspected AMI and 66 (18 %) were AMI, including 28 (42 %) with and 38 without suspected AMI. These two groups did not differ significantly regarding the medical history, clinical presentation, or laboratory tests. The CT protocol was more often optimal for AMI in the group with suspected AMI (26/28 [93 %] vs. 28/38 [74 %], p = 0.046). Diagnostic accuracy was not different between groups with and without suspected AMI (26/28 [93 %] vs. 34/38 [90 %], p = 1.00). However, it was lower in the group without suspicion of AMI when the CT protocol was not optimal for AMI (27/28 [96 %] vs 7/10 [70 %], p = 0.048).

CONCLUSIONS

The negative influence of not clinically suspecting AMI can be mitigated by using a tailored CT protocol.

A fistulating incarcerated incisional hernia: a case report

An incisional hernia is usually a defect in the scar of an abdominal surgery. The natural history is intestinal obstruction with the risk of strangulation. We report a case of a long-term conservative management of an incisional hernia with an abdominal corset. This resulted in fistulation from pressure necrosis that required an en-bloc excision of the incarcerated fistulating bowel with the hernia sac. The defect was managed using the Jenkin's 'mass closure' technique with no recurrence of the hernia.

Role of computed tomography and magnetic resonance imaging in local complications of acute pancreatitis

Acute pancreatitis (AP) represents a pancreas inflammation of sudden onset that can present different degrees of severity. AP is a frequent cause of acute abdomen and its complications are still a cause of death. Biliary calculosis and alcohol abuse are the most frequent cause of AP. Computed tomography (CT) and magnetic resonance imaging (MRI) are not necessary for the diagnosis of AP but they are fundamental tools for the identification of the cause, degree severity and AP complications. AP severity assessment is in fact one of the most important issue in disease management. Contrast-enhanced CT is preferred in the emergency setting and is considered the gold standard in patients with AP. MRI is comparable to CT for the diagnosis of AP but requires much more time so it is not usually chosen in the emergency scenario. Complications of AP can be distinguished in localized and generalized. Among the localized complications, we can identify: acute peripancreatic fluid collections (APFC), pseudocysts, acute necrotic collections (ANC), walled off pancreatic necrosis (WOPN), venous thrombosis, pseudoaneurysms and haemorrhage. Multiple organ failure syndrome (MOFS) and sepsis are possible generalized complications of AP. In this review, we focus on CT and MRI findings in local complications of AP and when and how to perform CT and MRI. We paid also attention to recent developments in diagnostic classification of AP complications.

Triple phase computed tomography of the pancreas in healthy cats

While the availability and use of computed tomography (CT) continues to grow, no study has described the size and multiphase CT appearance of the normal feline pancreas. This information is important to not only allow more accurate identification and differentiation of disease, but it may also be useful in assessing pancreatic function. In this prospective analytical study, we described a triple phase CT protocol of the pancreas for use in sedated cats and the attenuation, enhancement pattern, size, and volume of the pancreas for a group of healthy cats. Fifteen healthy cats were enrolled in the study and a standardized protocol for acquiring arterial, portal, and delayed phase CT images of the pancreas was developed and described. The pancreas was hypo to isoattenuating to both the liver and spleen in all phases in the majority of cats with a homogenous enhancement pattern noted in all 15. Mean pancreatic attenuation was 48, 79, 166, and 126 Hounsfield units (HU) respectively on precontrast, arterial, portal, and delayed phase images. In addition, mean height, length, and width of the left lobe of the pancreas were larger than the right lobe in all 15 cats. There were no associations between volume and volume: body weight ratio with age (P = 0.6518, P = 0.6968) or sex (P = 0.7013, P = 0.2043). This baseline information may be beneficial for use in future studies characterizing pancreatic disease in cats as well as future research studies evaluating pancreatic endocrine function.

Unindicated multiphase CT scans in non-traumatic abdominal emergencies for women of reproductive age: a significant source of unnecessary exposure

PURPOSE

To determine the frequency of unindicated CT phases and the resultant excess of absorbed radiation doses to the uterus and ovaries in women of reproductive age who have undergone CT for non-traumatic abdomino-pelvic emergencies.

MATERIALS AND METHODS

We reviewed all abdomino-pelvic CT examinations in women of reproductive age (40 years or less), between 1 June 2012 and 31 January 2015. We evaluated the appropriateness of each CT phase on the basis of clinical indications, according to ACR appropriateness criteria and evidence-based data from the literature. The doses to uterus and ovaries for each phase were calculated with the CTEXPO software, taking into consideration the size-specific dose estimate (SSDE) after measuring the size of every single patient.

RESULTS

The final cohort was composed of 76 female patients with an average age of 30 (from 19 to 40 years). In total, 197 CT phases were performed with an average of 2.6 phases per patient. Out of these, 93 (47%) were unindicated with an average of 1.2 inappropriate phases per patient. Unindicated scans were most frequent for appendicitis and unlocalized abdominal pain. The excesses of mean radiation doses to the uterus and ovaries due to unindicated phases were, respectively, of 38 and 33 mSv per patient.

CONCLUSION

In our experience, unindicated additional CT phases were numerous with a significant excess radiation dose without an associated clinical benefit. This excess of radiation could have been avoided by widespread adoption of the ACR appropriateness criteria and evidence-based data from the literature.

Diagnosing acute pancreatitis-Clinical and radiological characterisation of patients without threefold increase of serum lipase

OBJECTIVES

Diagnosing acute pancreatitis (AP) may be challenging in patients with acute abdominal pain but missing threefold increased serum lipase levels (Lip-). This studyaims both to characterize these patients using clinical, radiological and mortality data, and to assess the group of patients who need contrast-enhanced computed tomography (CECT).

METHODS

In this retrospective, IRB approved study 234 consecutive patients with AP were investigated. Inclusion criteria were single (SAP) and recurrent attacks (RAP) of AP and CECT ≥72h after onset of symptoms. Severity of AP was assessed by C-reactive protein at 48h after hospital admission and using 3 CT-based scores (CTSI, mCTSI, EPIC) by 2 observers. Mortality rates from pancreatic and non-pancreatic causes were noted with regard to lipase increase. Results were compared with paired t-test and Wilcoxon signed-rank test.

RESULTS

64/234 (27%) patients belonged to Lip- group and 170/234 (73%) patients were allocated to Lip+ group. Significantly more male patients (78% in Lip- vs. 63% in Lip+, p<0.05) with RAP (63% in Lip- vs. 21% in Lip+, p<0.001) were observed in the Lip- group. EPIC was significantly lower in Lip- group compared to Lip+ group (3(IQR 2-5) vs. 2(IQR 1-3), p<0.001). Mortality from pancreatic and non-pancreatic causes was comparable in Lip- and Lip+ group (pancreatic causes: 9% vs. 6%, p=0.60; nonpancreatic causes: 8% vs. 5%, p=0.58).

CONCLUSIONS

27% of all patients with AP presented without threefold increase of lipase levels. Thus, they would be underdiagnosed without confirming CECT, which revealed significantly lower counts of pleural effusions and ascites. Male patients with RAP were found significantly more often among the Lip- group. Hence, they would benefit the most from CECT for diagnosing AP.

Emergency Laparotomies at a Tertiary Care Center-a Hospital-Based Cross-Sectional Study

Emergency laparotomy is a common high-risk surgical procedure, but with a few outcome data and few data on postoperative care. This was a hospital-based descriptive study of 376 consecutive emergency midline laparotomies performed in a tertiary care center. The aim of the study was to identify the clinical presentation, surgical indications, preoperative delay, intraoperative findings, and postoperative complications. Majority of the patients belonged to the 40-80-year age group. Broadly, the indications could be divided into acute abdomen and trauma. Most of the cases (82 %) presented with acute abdomen, out of which 57 % cases had gastrointestinal perforation, and 33 % had intestinal obstruction. In trauma laparotomies, 63 % of cases were done for blunt abdominal trauma and the rest for penetrating injury. The clinical features were analyzed, of which most frequent were abdominal tenderness (88.8 %), abdominal distension (88 %), tachycardia (74.2 %), and guarding (70.7 %). Nearly three fourths of the patients underwent laparotomy within 24 h of entry to the casualty. The most common condition that resulted in an emergency laparotomy was duodenal perforation which was seen in 93 patients, followed by gastric perforation in 60 patients. Postoperatively, 54.5 % of patients did not develop any complication. The most common complication encountered was wound infection (26.6 %). Mortality following emergency laparotomy was 13 %. Age-specific mortality was maximum in patients with age more than 80 years. The diagnosis-specific mortality was higher for large bowel perforation and mesenteric ischemia among the acute abdomen cases, and liver injury or great vessel injury among the trauma cases.

Small bowel diverticulitis: an imaging review of an uncommon entity

In this review, we discuss the clinical and radiologic findings of small bowel diverticulosis, which is infrequently encountered during practice and far less common than colonic diverticulosis. Small bowel diverticulosis can present with a range of emergent symptomatic complications including diverticulitis, perforation, or hemorrhage. Here, we focus on the clinical features, pathogenesis, radiologic findings, and treatment of small bowel diverticulitis. Although not routinely considered in the differential diagnosis of an acute abdomen, prospective radiologic diagnosis of small bowel diverticulitis is important and can lead to conservative treatment thus preventing unnecessary exploratory laparotomy.

Evaluating Patients with Left Upper Quadrant Pain

Imaging plays a major role in the evaluation of patients who present to the emergency department with acute left upper quadrant (LUQ) pain. Multidetector computed tomography is currently the primary modality used for imaging these patients. The peritoneal reflections, subperitoneal compartment, and peritoneal spaces of the LUQ are key anatomic features in understanding the imaging appearance of acute diseases in this area. Diseases of the stomach, spleen, pancreas, and splenic flexure are encountered in patients with acute LUQ pain. Optimization of the imaging protocol is vital for accurate diagnosis and characterization of these diseases in the acute setting.

Multidetector CT in emergency radiology: acute and generalized non-traumatic abdominal pain

Multidetector CT (MDCT) is an imaging technique that provides otherwise unobtainable information in the diagnostic work-up of patients presenting with acute abdominal pain. A correct working diagnosis depends essentially on understanding the individual patient's clinical data and laboratory findings. In haemodynamically stable patients with acute severe and generalized abdominal pain, MDCT is now the preferred imaging test and gives invaluable diagnostic information, also in unstable patients after stabilization. In this descriptive review, we focus our attention on acute, severe and generalized or undifferentiated non-traumatic abdominal pain. The main differential diagnoses are acute pancreatitis, gastrointestinal perforation, ruptured abdominal aneurysm and acute mesenteric ischaemia. We will provide radiologist readers with a technical guide to optimize MDCT imaging protocols and list the major CT signs essential to reach a correct diagnosis and guide the best treatment.

Acute Pancreatitis (AP)

All of these conditions can be associated with acute pancreatitis,except?

Multidetector computed tomography for the assessment of adnexal mass: is unenhanced CT scan necessary?

OBJECTIVE

To compare the diagnostic performance and radiation dose between contrast-enhanced CT (ECT) alone, and combined unenhanced and contrast-enhanced CT (UE + ECT) for the assessment of adnexal mass.

MATERIALS AND METHODS

This retrospective study was approved by the Institutional Review Board. A total of 146 consecutive patients (mean age, 41.1 years) who underwent preoperative unenhanced and contrast-enhanced multidetector CT of the pelvis and had adnexal masses found at surgery were included. Two readers independently evaluated the likelihood of adnexal malignancy on a 5-point scale on two different imaging datasets (ECT alone and UE + ECT). The area under the receiver operating characteristic curve (AUC) was used to evaluate diagnostic performance. Radiation dose to patients was calculated by the volume CT dose index (CTDIvol) and the dose length products (DLP) on each dataset.

RESULTS

Of the total 178 adnexal masses, 133 masses were benign and 45 masses were malignant. For both readers, there is no significant difference of AUC values between ECT alone and UE + ECT for the detection of adnexal malignancy (reader 1, 0.93 vs. 0.95; reader 2, 0.92 vs. 0.91) (p > 0.05). The mean CTDIvol (12.6 ± 2.2 mGy) and DLP (641.2 ± 137.2 mGy) of ECT alone was significantly lower than the mean CTDIvol (21.5 ± 2.7 mGy) and DLP (923.6 ± 158.8 mGy) of UE + ECT (p < 0.0001).

CONCLUSION

The use of unenhanced CT scan in addition to contrast-enhanced CT scan does not improve the detection of adnexal malignancy, but increases radiation exposure.

Comparison between survey radiography, B-mode ultrasonography, contrast-enhanced ultrasonography and contrast-enhanced multi-detector computed tomography findings in dogs with acute abdominal signs

Contrast-enhanced multi-detector computed tomography (CE-MDCT) is used routinely in evaluating human patients with acute abdominal symptoms. Contrast-enhanced ultrasound (CEUS) continues to be in its infancy as it relates to evaluation of the acute abdomen. The purpose of this study was to compare survey radiography, B-mode ultrasound, CEUS, and CE-MDCT findings in canine patients presenting with acute abdominal signs; with a focus on the ability to differentiate surgical from non-surgical conditions. Nineteen dogs were prospectively enrolled. Inclusion required a clinical diagnosis of acute abdominal signs and confirmed surgical or non-surgical causes for the clinical signs. Agreement for the majority of recorded imaging features was at least moderate. There was poor agreement in the identification of pneumoperitoneum and in the comparison of pancreatic lesion dimensions for B-mode vs. CEUS. The CT feature of fat stranding was detected in cases including, but not limited to, gastric neoplasia with perforation, pancreatitis, and small intestinal foreign body. Ultrasound underestimated the size and number of specific lesions when compared with CE-MDCT. Contrast-enhanced ultrasound was successful in detecting bowel and pancreatic perfusion deficits that CE-MDCT failed to identify. Accuracy for differentiation of surgical vs. non-surgical conditions was high for all modalities; 100%, 94%, and 94% for CE-MDCT, ultrasonography and survey radiography respectively. Findings indicated that CE-MDCT is an accurate screening test for differentiating surgical from non-surgical acute abdominal conditions in dogs. Focused CEUS following CE-MDCT or B-mode ultrasonography may be beneficial for identifying potentially significant hypoperfused lesions.

Flank pain, nausea, vomiting and hypotension in a chronic hemodialysis patient with a spontaneous perirenal hemorrhage

Decreases in blood pressure develop in response to a wide range of clinical disorders. Various factors have been implicated in the development of hemodialysis-associated hypotension, including an impairment of the compensatory processes, an autonomic dysfunction or cardiac failure. The additional presence of concomitant acute abdomen may result in a diagnostically challenging situation. We herein report our experience with a chronic hemodialysis patient who developed severe hypotension with acute flank pain due to spontaneous bleeding around the kidney. Concerns regarding the management of the disease are also discussed.

The etiology of pneumoperitoneum in the 21st century

BACKGROUND

We sought to determine the origin of free intraperitoneal air in this era of diminishing prevalence of peptic ulcer disease and imaging studies. In addition, we attempted to stratify the origin of free air by the size of the air collection.

METHODS

We queried our hospital database for "pneumoperitoneum" from 2005 to 2007 and for proven gastrointestinal perforation from 2000 to 2007. Massive amount of free air was defined as any air pocket greater than 10.0 cm.

RESULTS

Among patients with free air, the predominant causes were perforated viscus (41%) and postoperative (<8 days) residual air (37%). For patients with visceral perforation, only 45% had free air on imaging studies, and for these patients, the predominant cause was peptic ulcer (16%), diverticulitis (16%), trauma (14%), malignancy (14%), bowel ischemia (10%), appendicitis (6%), and endoscopy (4%). The likelihood that free air was identified on an imaging study by lesion was 72% for perforated peptic ulcer, 57% for perforated diverticulitis, but only 8% for perforated appendicitis. The origin of massive free air was equally likely to be gastroduodenal, small bowel, or colonic perforation.

CONCLUSION

The cause of free air when surgical pathology is the source has substantially changed from previous reports.

LEVEL OF EVIDENCE

Epidemiologic study, level IV.

Evaluating the accuracy of emergency medicine resident interpretations of abdominal CTs in patients with non-traumatic abdominal pain

Abdominal computed tomography (CT) is widely used as a diagnostic tool in emergency medicine (EM) to accurately diagnose abdominal pain. EM residents must be able to offer preliminary interpretations of CT imaging. In this study, we evaluated the preliminary interpretation ability of a sample of emergency residents presented with adult abdominal CT images, and compared their results with those of radiology residents. We conducted a prospective observational study from November 16, 2008 to June 30, 2009. During this time, we gathered preliminary interpretations of consecutive abdominal CT made by emergency and radiology residents. We assessed the discrepancy rates of both samples by comparing their findings to the final reports from attending radiologists. A total of 884 cases were enrolled in the present study. The discrepancy rates of emergency and radiology residents were 16.7% and 12.2%, respectively. When female genital organs, peritoneum, adrenal glands, or the musculoskeletal system were abnormal, we found that emergency residents' preliminary interpretations of CT images were insufficient compared to those of radiology residents. Therefore more formal education is needed to emergency residents. If possible, the preliminary interpretations of radiology attending physicians are ideal until improving the ability of interpretations of emergency residents in abdomen CT.

Feasibility for using dual-phase contrast-enhanced multi-detector helical computed tomography to evaluate awake and sedated dogs with acute abdominal signs

Canine patients with acute abdominal signs are often clinically unstable and need a rapid and accurate diagnosis. Contrast-enhanced multi-detector computed tomography (CT) is the current modality of choice for evaluating acute abdominal pain in people. We hypothesized that contrast-enhanced multi-detector CT would be a feasible and safe technique for use in awake and lightly sedated dogs with acute abdominal signs. Eighteen client-owned dogs were enrolled, all presenting with acute abdominal signs. Dogs were scanned using a dual-phase protocol that included precontrast, arterial, and portal venous phases. Eight dogs were scanned awake and ten were given light sedation as chosen by the primary care clinician. Two observers who were unaware of clinical findings and sedation status scored image quality for each scan by consensus opinion. Mean serum creatinine in the sedated group was higher than in the awake group but was within the normal reference range. Other laboratory and physiologic measures did not differ between awake and sedated groups. No IV contrast-related adverse reactions were seen. Median scan time for all patients was less than 10 min. Sixteen of 18 contrast-enhanced multi-detector CT scans were scored fair to excellent in diagnostic quality, with no statistical difference in diagnostic quality for awake vs. sedated patients. Causes for two poor quality diagnostic scans included severe beam hardening from previously administered barium contrast agent and severe motion artifacts. We conclude that dual-phase contrast-enhanced multi-detector CT is a feasible and safe technique for evaluating awake and minimally sedated dogs presenting with acute abdominal signs.

Uncommon causes of acute abdominal pain: multidetector computed tomography pearls and pitfalls for the radiologist on call

We review uncommon causes of acute abdominal pain in which inconclusive multidetector computed tomography (MDCT) studies were followed by emergency surgery and unexpected diagnoses. Despite dedicated protocols and technical advances, MDCT of uncommon causes of acute abdominal pain still represents a significant challenge for the radiologist on call. We emphasize diagnostic pearls and pitfalls that may help the radiologist on call identify or suspect these uncommon causes of acute abdominal pain on MDCT.

Rare cause of acute surgical abdomen with free intraperitoneal air: Spontaneous perforated pyometra. A report of 2 cases

BACKGROUND

The acute abdomen accounts for up to 40% of all emergency surgical hospital admissions and a large proportion are secondary to gastrointestinal perforation. Studies have shown the superiority of the abdominal CT over upright chest radiographs in demonstrating free intraperitoneal air. Spontaneous perforated pyometra is a rare cause of the surgical acute abdomen with free intraperitoneal air. Only 38 cases have been reported worldwide.

CASE REPORT

We report 2 cases of spontaneously perforated pyometra in our hospital's general surgery department. Both underwent exploratory laparotomy: one had a total hysterectomy and bilateral salpingo-oophorectomy, while the other had an evacuation of the uterine cavity, primary repair of uterine perforation and a peritoneal washout. A literature search was conducted and all reported cases reviewed in order to describe the clinical presentations and management of the condition. Of the 40 cases to date, including 2 of our cases, the most common presenting symptoms were abdominal pain (97.5%), fever (37.5%) and vomiting (25.0%). The main indication for exploratory laparotomy was pneumoperitoneum (97.5%).

CONCLUSIONS

Pyometra is an unusual but serious condition in elderly women presenting with an acute abdomen. A high index of suspicion is needed to make the appropriate diagnosis.

[Cecal volvulus: imaging features]

OBJECTIVE

To determine the sensitivity of plain-film radiography and computed tomography (CT) in the diagnosis of cecal volvulus.

MATERIAL AND METHODS

We reviewed the clinical histories of 11 patients diagnosed with cecal volvulus at endoscopy or surgery. Two radiologists working in consensus analyzed the findings at plain-film radiography and at CT and calculated the sensitivities. The plain-film and CT studies were retrospectively classified as certain, probable, or indeterminate for cecal volvulus on the basis of the presence or absence of previously reported signs. Signs of wall suffering at CT were compared to the histologic findings.

RESULTS

The most sensitive findings at plain-film radiography were the presence of a disproportionately dilated bowel loop and a pattern of distal small bowel occlusion (91%), followed by a single air-fluid level in the cecum and collapse of the distal colon (82%). At CT, the "coffee bean" sign with a single air-fluid level and collapse of the left colon had a sensitivity of 100%. The whirl sign was present in 86%. Retrospectively, 36% of the plain-film studies and 86% of the CT studies were classified as certain for cecal volvulus. Although all cases with ischemia had signs of vascular compromise on CT, no significant correlation was observed between these variables.

CONCLUSIONS

The plain-film signs reported for cecal volvulus enable a certain diagnosis in a third of all cases; the CT signs enable a certain diagnosis in most cases. The evaluation of additional findings increases the chances of reaching the correct diagnosis.

Emergency and urgent surgery

Patients presenting with general surgical emergencies are hypovolemic, and require early aggressive resuscitative efforts. Although these efforts may safely be accomplished preoperatively in a select subset of patients, it is often the combined task of surgeons, anesthesiologists, and internists to optimize these critically ill patients in the intraoperative and postoperative period. Early surgical consultation and intervention can be lifesaving. This article presents the current state of emergency surgical care in the United States and the approach to the patient with an emergency surgical illness. The aggressiveness of the surgical intervention is patient- and disease-specific and requires frequent and open communication between all health care providers, the patient, and his or her family. In addition to aggressive resuscitation, life-threatening general surgical conditions often require specific diagnostic and therapeutic interventions.

Emergency and urgent surgery

Patients presenting with general surgical emergencies are hypovolemic, and require early aggressive resuscitative efforts. Although these efforts may safely be accomplished preoperatively in a select subset of patients, it is often the combined task of surgeons, anesthesiologists, and internists to optimize these critically ill patients in the intraoperative and postoperative period. Early surgical consultation and intervention can be lifesaving. This article presents the current state of emergency surgical care in the United States and the approach to the patient with an emergency surgical illness. The aggressiveness of the surgical intervention is patient- and disease-specific and requires frequent and open communication between all health care providers, the patient, and his or her family. In addition to aggressive resuscitation, life-threatening general surgical conditions often require specific diagnostic and therapeutic interventions.

Diagnosis of acute appendicitis with sliding slab ray-sum interpretation of low-dose unenhanced CT and standard-dose i.v. contrast-enhanced CT scans

OBJECTIVE

The purpose of this study was to compare low-dose unenhanced CT with standard-dose i.v. contrast-enhanced CT in the diagnosis of appendicitis.

MATERIALS AND METHODS

Two hundred seven adults with suspected appendicitis underwent CT with mean effective doses of both 4.2 and 8.0 mSv. Two radiologists retrospectively reviewed thin-section images by sliding a 5-mm-thick ray-sum slab. They rated the likelihood of appendicitis and appendiceal visualization on 5- and 3-point scales, respectively, and proposed alternative diagnoses. Likelihood > or = 3 was considered a positive diagnosis. Receiver operating characteristics analysis, the McNemar test, and the Wilcoxon's signed-rank test were used.

RESULTS

Seventy-eight patients had appendicitis. The values of the area under the receiver operating characteristics curve were 0.98 for the low-dose unenhanced acquisition and 0.97 for the standard-dose contrast-enhanced acquisition for reader 1 (95% CI for the difference, -0.02 to 0.03) and 0.99 and 0.98 (-0.02 to 0.02) for reader 2. Sensitivity was 98.7% for low-dose unenhanced CT and 100% for standard-dose contrast-enhanced CT for reader 1 (p = 1.00) and 100% for both techniques for reader 2. Specificity was 95.3% and 93.0% (p = 0.25) and 96.9% and 96.9%. The interpretation was indeterminate (score 3) in 0.5% and 1.4% of cases for reader 1 (p = 0.63) and 0.5% and 0% for reader 2 (p = 1.00). A normal appendix was not visualized in 5.4% and 3.9% of cases by reader 1 (p = 0.63) and 3.9% and 2.3% of cases by reader 2 (p = 0.50). None of the patients whose appendix was not visualized had appendicitis. Diagnostic confidence, visualization score for a normal appendix, and correct alternative diagnosis tended to be compromised with use of low-dose unenhanced CT, showing a significant difference for a reader's confidence in the diagnosis of appendicitis (p = 0.004). The two techniques were comparable in the diagnosis of appendiceal perforation.

CONCLUSION

Low-dose unenhanced CT is potentially useful in the diagnosis of appendicitis.

[Multidetector computed tomography in abdominal emergencies]

Abdominal emergencies encompass traumatic events in the region of the abdomen as well as the clinical term acute abdomen. Multidetector CT (MDCT) represents one of the most important imaging modalities for detection and correct diagnosis in such abdominal emergencies. Based on the acquired data MDCT allows a stable imaging of the abdomen in an extremely short time even in critically ill patients. Multiplanar reconstructions can be created based on the high resolution data allowing an impressive visualization of the pathology. In this review article the most important abdominal pathologies of the abdomen diagnosed by MDCT are presented with special emphasis on the liver, bile ducts, spleen and kidneys as well as the gastro-intestinal tract. Additionally, MDCT imaging of the individual organ regions will be dealt with in detail.

Acute Renal Infarction With Heritable Coagulopathy and Patent Foramen Ovale

We present the case of a 27-year-old woman who presented to the emergency department with the acute onset of left sided abdominal pain. Initial CT examination showed multiple renal infarcts in the lower pole of the left kidney, and an angiogram showed thrombus in a segmental branch of the left renal artery. Subsequent transesophageal echocardiogram demonstrated a small patent foramen ovale with bidirectional shunting, and serum coagulopathy evaluation demonstrated a G20210A prothrombin gene mutation. We conclude that the renal infarctions were caused by a paradoxical embolic event in the setting of an inherited coagulopathy and a patent foramen ovale.

Acute Renal Infarction With Heritable Coagulopathy and Patent Foramen Ovale

We present the case of a 27-year-old woman who presented to the emergency department with the acute onset of left sided abdominal pain. Initial CT examination showed multiple renal infarcts in the lower pole of the left kidney, and an angiogram showed thrombus in a segmental branch of the left renal artery. Subsequent transesophageal echocardiogram demonstrated a small patent foramen ovale with bidirectional shunting, and serum coagulopathy evaluation demonstrated a G20210A prothrombin gene mutation. We conclude that the renal infarctions were caused by a paradoxical embolic event in the setting of an inherited coagulopathy and a patent foramen ovale.

Multislice CT angiography in the follow-up of fenestrated endovascular grafts: effect of slice thickness on 2D and 3D visualization of the fenestration stents

PURPOSE

To investigate the effect of multislice computed tomography (CT) protocols on the visualization of target vessel stents in patients with abdominal aortic aneurysm (AAA) treated with fenestrated endovascular grafts.

METHODS

Twenty-one patients (19 men; mean age 75 years, range 63-86) undergoing fenestrated endovascular repair of AAA were retrospectively studied. Multislice CT angiography was performed with several protocols, and the section thicknesses used in each were compared to identify any relationship between slice thickness and target vessel stents visualized on 2-dimensional (2D) axial, multiplanar reformatted (MPR), and 3-dimensional (3D) virtual intravascular endoscopy (VIE) images. Image quality was assessed based on the degree of artifacts and their effect on the ability to visualize the configuration, intra-aortic location, and intraluminal appearance of the target vessel stents and measure their protrusion into the aortic lumen.

RESULTS

There were 7 different multislice CT scanning protocols employed in the 21 patients (25 datasets, with 2 sets of follow-up images in 4 patients). The slice thicknesses and numbers (n) of studies included were 0.5 (n=3), 0.625 (n=6), 1.0 (n=1), 1.25 (n=9), 2.5 (n=3), 3.0 (n=1), and 5.0 mm (n=2). Of these CT protocols, images (especially 2D/3D reconstructions) acquired at 2.5, 3.0, and 5.0 mm were significantly compromised by interference from artifacts. Images acquired with a slice thickness of 1.0 or 1.25 mm were scored equal to or lower than those acquired with a submillimeter section thickness (0.5 or 0.625 mm), with minor degrees of artifacts resulting in acceptable image quality.

CONCLUSION

Visualization of the target vessel stents depends on the appropriate selection of multislice CT scanning protocols. Our results showed that studies performed with a slice thickness of 1.0 or 1.25 mm produced similar image quality to those with a thickness of 0.5 or 0.625 mm. Submillimeter slices are not recommended in imaging patients treated with fenestrated stent-grafts, as they did not add additional information to the visualization.

O valor da fase sem contraste na tomografia computadorizada do abdome

OBJETIVO: Determinar o valor agregado da fase sem meio de contraste da tomografia computadorizada do abdome em pacientes sem diagnóstico determinado ou em estadiamento tumoral. MATERIAIS E MÉTODOS: Estudo prospectivo e transversal em 100 pacientes consecutivos submetidos a tomografia computadorizada abdominal sem e com meio de contraste intravenoso. Dois examinadores avaliaram todos os exames, procurando estabelecer, através da fase com meio de contraste intravenoso (primeira análise) e posteriormente através da fase sem contraste (segunda análise), o diagnóstico principal e os secundários em função da indicação clínica do exame. Mediu-se a freqüência de mudança diagnóstica decorrente da análise combinada das fases pré- e pós-contraste intravenoso. Casos que tiveram mudança diagnóstica foram avaliados por especialistas clínicos para determinar se implicaria mudanças de conduta. RESULTADOS: Diagnósticos principal e secundário foram modificados em 1 e 18 casos, respectivamente (p = 1,000; p = 0,143). Os diagnósticos modificados foram: esteatose, definição de nódulo em adrenal, nefrolitíase, classificação de cistos renais e calcificação hepática. Nos casos em que a fase sem contraste modificou o diagnóstico, os especialistas mudaram sua conduta em 14/19 (73%) dos pacientes (p = 0,038). CONCLUSÃO: A fase sem contraste não modificou significativamente o diagnóstico principal ou secundário. Porém, as mudanças nos diagnósticos secundários influenciaram na conduta adotada pelos especialistas.

Jejuno-ileal diverticulitis with localized perforation: CT and US findings

PURPOSE

To describe the computed tomography and ultrasound findings of five cases of small bowel diverticulitis with localized perforation.

MATERIAL AND METHODS

Our database, from April 2003 to August 2007, was reviewed and five cases of small bowel diverticulitis were identified.

RESULTS

Jejuno-ileal diverticulitis with covered perforation usually presents as wall thickening of a small bowel loop and an adjacent inflammatory mass containing air bubbles.

CONCLUSION

Small bowel diverticula are rare and mostly asymptomatic. They become clinically relevant when complications arise, such as diverticulitis. The symptoms of jejuno-ileal diverticulitis are non-specific and the diagnosis is performed mainly by imaging studies.

Gastrointestinal perforation and the acute abdomen

The acute abdomen accounts for up to 40% of all emergency-surgical hospital admissions and is considered in the differential in the more than 7 million visits to the emergency department annually for abdominal pain in the United States. A large percentage of these cases are secondary to perforation or impending gastrointestinal perforation. Gastrointestinal perforation causes considerable mortality and usually requires emergency surgery.Rapid diagnosis and treatment of these conditions is essential to reduce the high morbidity and mortality of late-stage presentation. Successful treatment requires a thorough understanding of the anatomy, microbiology, and pathophysiology of this disease process and in-depth knowledge of the therapy, including resuscitation,antibiotics, source control, and physiologic support.

Detection of biliary duct narrowing and choledocholithiasis: accuracy of portal venous phase multidetector CT

PURPOSE

To retrospectively evaluate the sensitivity and specificity of 64-detector computed tomography (CT) in the portal venous phase by using transverse images and both multiplanar and minimum intensity reformations for the detection of biliary duct narrowing and choledocholithiasis, with magnetic resonance cholangiopancreatography (MRCP) or endoscopic retrograde cholangiopancreatography (ERCP) as the reference standard.

MATERIALS AND METHODS

Approval from institutional review board was obtained for this HIPAA-compliant retrospective study; informed consent was waived. The study included all patients (42 men, 52 women; mean age, 61 years) who underwent abdominal 64-detector CT within 2 months of MRCP and/or ERCP. All patients underwent portal venous phase intravenous contrast material-enhanced abdominal CT. Sixty-one patients underwent MRCP and 54 patients underwent ERCP (21 patients underwent both). Two radiologists, blinded to the reference standard, independently evaluated the CT images, including multiplanar and minimum intensity reformations, for biliary duct narrowing and choledocholithiasis. Standard of reference examinations were used to calculate sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV).

RESULTS

Twenty-three (24%) of 94 patients had a biliary duct narrowing at reference examinations. For detecting biliary duct narrowing, observer 1 had a sensitivity of 78.2%, specificity of 100%, PPV of 100%, and NPV of 93.4% and observer 2 had a sensitivity of 69.6%, specificity of 100%, PPV of 100%, and NPV of 91.0%. In 18 (19%) of 94 patients, choledocholithiasis was detected at reference examinations. For detecting choledocholithiasis, observer 1 had a sensitivity of 77.8%, specificity of 96.1%, PPV of 82.4%, and NPV of 94.8% and observer 2 had a sensitivity of 72.2%, specificity of 96.1%, PPV of 81.2%, and NPV of 93.6%.

CONCLUSION

Portal venous phase multidetector CT images are highly specific and moderately sensitive for the detection of biliary duct narrowing and choledocholithiasis.

Advances in vascular imaging

Advances in vascular surgery have mirrored advances in diagnostic imaging. Indeed, the endovascular revolution has been made possible largely by advances in computed tomography, magnetic resonance imaging, and vascular ultrasound. As technology allows better noninvasive vascular diagnosis, conventional angiography, once the gold standard for the diagnosis of vascular disease, is now reserved largely for intervention. This article discusses the current state of vascular imaging. Specific emphasis is placed on the comparative clinical utility of different imaging modalities in the detection and management of vascular disease.

A randomized, controlled trial of routine early abdominal computed tomography in patients presenting with non-specific acute abdominal pain

AIM

To compare the effect of an initial early computed tomography (CT) examination versus standard practice (SP) on the length of hospital stay, diagnostic accuracy, and mortality of adults presenting with acute abdominal pain.

MATERIALS AND METHODS

Two hundred and five adults presenting with acute abdominal pain were randomized to undergo an early CT examination or current SP, which comprised supine abdominal and erect chest radiography. One hundred and ninety-eight patients (99 in each arm) were included in the analysis. The primary endpoint was the duration of inpatient stay; secondary endpoints were diagnostic certainty and mortality.

RESULTS

There was no significant difference in the length of hospital stay between the two arms (p=0.20). At randomization 36% (35 of 96) of CT patients and 49% (48 of 98) of SP patients were correctly diagnosed; 24h after randomization the correct diagnosis had been established in 84% of CT patients and 73% of SP patients. This refinement in diagnostic certainty was significantly better in the CT group (p<0.001). There was no difference in mortality between the two trial arms (p=0.31).

CONCLUSION

Early abdominal CT in patients with acute abdominal pain improves diagnostic certainty, but does not reduce the length of hospital stay and 6 month mortality.