Use of MDCT to Differentiate Autoimmune Pancreatitis From Ductal Adenocarcinoma and Interstitial Pancreatitis.

OBJECTIVE: The purposes of this study were to identify the most common imaging features of autoimmune pancreatitis and to evaluate the utility of MDCT for differentiating autoimmune pancreatitis from two more frequently encountered differential diagnoses--pancreatic ductal adenocarcinoma and acute interstitial pancreatitis. MATERIALS AND METHODS: Dual-phase contrast-enhanced MDCT images of 91 patients (39 with autoimmune pancreatitis, 25 with pancreatic ductal adenocarcinoma, 27 with acute interstitial pancreatitis) were evaluated by two radiologists in consensus for distribution of pancreatic abnormality, sausage shape, low-attenuation halo, pancreatic duct dilatation, peripancreatic stranding, lymphadenopathy, biliary abnormality, vascular involvement, and renal lesions. Chi-square tests, multiple logistic regression analysis, and ROC analysis were performed. RESULTS: The most common imaging features of autoimmune pancreatitis were sausage shape (25/39 [64%]) and low-attenuation halo (23/39 [59%]). Pancreatic duct dilatation (20/25 [80%]) and biliary dilatation (11/25 [44%]) were most frequent in pancreatic ductal adenocarcinoma. Peripancreatic stranding (22/27 [81%]) was most frequent in acute interstitial pancreatitis. Sausage shape, low-attenuation halo, and absence of a pancreatic duct or biliary dilatation differentiated autoimmune pancreatitis from pancreatic ductal adenocarcinoma with an accuracy of 0.88. Sausage shape and absence of peripancreatic stranding differentiated autoimmune pancreatitis from acute interstitial pancreatitis with an accuracy of 0.82. There was no significant difference in the frequency of vascular involvement or of lymphadenopathy among these diagnoses. CONCLUSION: Typical cases of autoimmune pancreatitis can be accurately differentiated from pancreatic ductal adenocarcinoma and acute interstitial pancreatitis on the basis of characteristic MDCT features. However, autoimmune pancreatitis should be considered in the presence of atypical features.

Migration of intrauterine devices: radiologic findings and implications for patient care.

Intrauterine devices (IUDs) are a commonly used form of contraception worldwide. However, migration of the IUD from its normal position in the uterine fundus is a frequently encountered complication, varying from uterine expulsion to displacement into the endometrial canal to uterine perforation. Different sites of IUD translocation vary in terms of their clinical significance and subsequent management, and the urgency of communicating IUD migration to the clinician is likewise variable. Expulsion or intrauterine displacement of the IUD leads to decreased contraceptive efficacy and should be clearly communicated, since it warrants IUD replacement to prevent unplanned pregnancy. Embedment of the IUD into the myometrium can usually be managed in the outpatient clinical setting but occasionally requires hysteroscopic removal. Complete uterine perforation, in which the IUD is partially or completely within the peritoneal cavity, requires surgical management, and timely and direct communication with the clinician is essential in such cases. Careful evaluation for intraabdominal complications is also important, since they may warrant urgent or emergent surgical intervention. The radiologist plays an important role in the diagnosis of IUD migration and should be familiar with its appearance at multiple imaging modalities.

Performance of multidetector computed tomographic angiography in determining surgical resectability of pancreatic head adenocarcinoma.

OBJECTIVE: To evaluate the performance of multidetector computed tomographic angiography (MDCTA) in assessing the surgical resectability of pancreatic head adenocarcinoma. METHODS: With institutional review board approval, radiographic, surgical, and pathological records of 203 consecutive patients with adenocarcinoma of the pancreatic head were analyzed retrospectively. Patients were imaged with MDCT scanners using our institution's CTA pancreatic protocol. Images were compared with surgical outcomes to determine the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of MDCTA in determining resectability. RESULTS: Data were analyzed twice, once with equivocal findings on MDCTA assumed as resectable and again with equivocal cases assumed as unresectable. All equivocal cases were ultimately unresectable; when this was assumed, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were determined to be 100%, 71%, 85%,100% and 89%. Twelve patients deemed resectable by preoperative MDCTA were found to be unresectable on surgical exploration owing to vascular involvement (n = 4), liver metastases (n = 4), and peritoneal involvement (n = 4). CONCLUSIONS: Multidetector CT angiography offers accurate and valuable preoperative assessment of surgical resectability of pancreatic ductal adenocarcinoma. Liver and peritoneal metastases and vascular invasion still remain important pitfalls in preoperative evaluation.

Thoracic and abdominal devices radiologists should recognize: pictorial review.

OBJECTIVE: Surgical, interventional, and diagnostic devices are continually being developed and often have unexpected radiographic appearances. The purpose of this article is to familiarize the radiologist with several devices that may be placed in the thorax and abdomen. CONCLUSION: The radiologist's familiarity with the radiographic appearance of devices placed in the chest and abdomen is essential for accurate image interpretation and identification of postprocedure complications.

Thoracic and abdominal devices radiologists should recognize: self-assessment module.

The educational objectives for this self-assessment module are for the participant to exercise, self-assess, and improve his or her understanding of thoracic and abdominal devices.

Selective approach to use of upper gastroesophageal imaging study after laparoscopic Roux-en-Y gastric bypass.

BACKGROUND: Many institutions routinely perform upper gastroesophageal imaging (UGI) studies on their laparoscopic Roux-en-Y gastric bypass (LRYGB) patients after surgery. We had routinely studied our patients with UGI on postoperative day 1 to rule out an anastomotic leak or obstruction, until recently when we abandoned this practice. As previously reported, we found that routine UGI did not contribute significantly to patient care. The purpose of this study was to determine whether patient outcomes were affected by this change in protocol. METHODS: From March 2004 to September 2005, 508 LRYGB cases were performed at our institution. Linear cutting staplers were used to create both the gastrojejunostomy and the jejunojejunostomy. In each case, the Roux limb was brought up in an antecolic, antegastric configuration. Before changing our protocol, 194 LRYGB cases were performed, and each patient underwent a routine UGI study (group 1). After abandoning this practice, 314 LRYGB cases were performed (group 2), and an UGI study was obtained only if clinical indicators (e.g., tachypnea, tachycardia, nausea, vomiting, low urine output, and/or abdominal pain) were present. The patient demographics, including gender, age, body mass index, length of hospital stay, and complications were recorded in our bariatric database and reviewed retrospectively. RESULTS: A postoperative UGI study was obtained in 204 patients--in 194 patients routinely (group 1) and in 10 patients because of clinical indications (group 2). No obstructions or leaks were found in any of these 204 patients. In group 2, 304 patients were discharged without an UGI series and did well without any leak or obstruction, except for 1 patient who returned 3 months postoperatively with a stricture at his jejunojejunostomy. No statistically significant differences were found between the 2 groups. CONCLUSION: The results of our study have shown that routine UGI studies after LRYGB do not contribute significantly to postoperative patient care at our institution. We now perform them selectively according to clinical indications, without this change adversely affecting our clinical outcomes.

Routine postoperative upper gastroesophageal imaging is unnecessary after laparoscopic Roux-en-Y gastric bypass.

Routine early postoperative upper gastroesophageal imaging (UGI) is often used in laparoscopic Roux-en-Y gastric bypass (LRYGB) procedures to confirm anastomotic patency and to exclude leaks. The aim of our study was to assess the usefulness of this practice. From January 2003 to November 2004, 322 LRYGB cases were performed using linear staplers for the gastrojejunostomy and jejuno-jejunostomy anastomoses. As part of our protocol, all patients received a Gastrograffin (Mallinkrodt, Inc., St Louis, Missouri) UGI on postoperative Day 1. The same radiological techniques were used and the same radiological team reviewed all films. Abnormal films were identified. In addition, patient demographics, time to discharge, and complications were collected and analyzed in a prospective database. There were no anastomotic leaks or obstructions. However, 42 of 322 (13%) studies demonstrated delayed gastric emptying. There were no statistically significant differences between patients with normal and delayed UGI studies. Routine UGI studies did not contribute significantly to patient care, and its routine use was subsequently abandoned.

Pancreatic and peripancreatic diseases mimicking primary pancreatic neoplasia.

A variety of anatomic variants and pathologic conditions in and around the pancreas may simulate primary pancreatic neoplasia at routine abdominal cross-sectional imaging. An ambiguous lesion whose appearance suggests a pancreatic origin requires a broad differential diagnosis that can subsequently be narrowed on the basis of both clinical history and features at optimal computed tomography (CT) and magnetic resonance (MR) imaging. Pancreas-specific multidetector CT and MR imaging techniques with thin collimation, multiplanar and multiphasic scans, and newly introduced curved planar reformation may help avoid potential diagnostic pitfalls. These techniques can help identify and characterize a mass in multiple viewing planes, thereby helping distinguish a true pancreatic neoplasm from peripancreatic adenopathy or from a tumor of the adjacent duodenum or small bowel. They can also help determine the cause of a tumor. It is important that the radiologist be familiar with the wide spectrum of anatomic variants and disease entities that can mimic primary pancreatic neoplasia in order to initiate the appropriate lesion-specific work-up and treatment and avoid unnecessary tests or procedures, including surgery.

Portal vein aneurysms: a case series with literature review.

Portal vein aneurysms are a relatively uncommon entity and often an incidental, asymptomatic finding. Recognition of this finding can help to avoid potential confusion with abdominal masses of other etiologies. We would like to present four cases of portal vein aneurysms, and discuss the natural history, imaging findings, and treatment of this condition. One of the cases of portal vein aneurysm presented occurred after liver transplantation, which, to the best of our knowledge, has only been described once in the English-language literature.

Accuracy of nonfocused helical CT for the diagnosis of acute appendicitis: a 5-year review.

OBJECTIVE: The clinical usefulness of routine, nonfocused helical CT was evaluated in diagnosing acute appendicitis or providing an alternative diagnosis in patients presenting to the emergency department with acute lower abdominal pain. MATERIALS AND METHODS: We reviewed CT reports and clinical records of 650 consecutive adult patients who presented between January 1996 and December 2000 with right lower quadrant pain or lower abdominal pain and clinical findings suggestive of appendicitis. Helical CT was performed with oral contrast material in 610 cases (93.8%) and IV contrast in 572 cases (88.0%). Both vascular and enteric contrast media were administered in 544 cases (83.7%). Rectal contrast material was administered in 52 cases (8.0%). The abdomen was helically scanned from the dome of the diaphragm to the iliac crests with a collimation of 7 mm, from the iliac crests to the acetabular roof at a 5-mm collimation, from the acetabular roof to the symphysis pubis with a collimation of 5-10 mm. The surgical or clinical record was used for follow-up. RESULTS: Of the 650 patients, 552 (84.9%) had adequate clinical follow-up. There were 137 true-positive, eight false-positive, five false-negative, and 402 true-negative cases. The sensitivity, specificity, and accuracy of nonfocused helical CT were 96.5%, 98.0%, 97.6%, respectively. The positive and negative predictive values were 94.5% and 98.8%, respectively. In patients without acute appendicitis, CT suggested an alternative diagnosis, which clinically explained the patient's acute abdominal pain in 266 patients (66.2%). CONCLUSION: Nonfocused helical CT was highly accurate in diagnosing acute appendicitis or suggesting an alternative diagnosis in patients with acute lower abdominal pain or right lower quadrant pain.

Patient gender-related performance of nonfocused helical computed tomography in the diagnosis of acute appendicitis.

OBJECTIVE: To determine the impact of patient gender on the performance of helical computed tomography (CT) in the diagnosis of acute appendicitis. MATERIALS AND METHODS: From January 1, 1996 to December 31, 2000, 650 consecutive nonfocused helical abdominal CT scans were performed in adult patients presenting with acute lower abdominal pain. In general, most patients received both intravenous and oral contrast with 5-mm scan collimation through the lower abdomen and pelvis; details regarding technique and overall accuracy have been published previously. We subanalyzed results with respect to patient gender-related differences, especially in false-positive and false-negative cases. A chi2 analysis was performed to determine if significant gender-related differences were present in major or minor CT diagnostic criteria for acute appendicitis, extra-appendiceal findings, sensitivity, specificity, and accuracy. RESULTS: Of the 650 patients, 552 had adequate clinical follow-up. The sensitivity for diagnosing acute appendicitis was 100% (65/65) in men and 93.6% (74/79) in women (P < 0.05); specificity was 96.2% (130/135) in men and 98.9% (272/275) in women (P > 0.05); and accuracy was 97.5% (193/198) in men and 97.6% in women (346/354) (P > 0.05). A thickened appendix and periappendiceal stranding were seen in 92.1% of men and 84.5% of women (P = 0.15) All 5 false-negative results were in thin women. In patients without acute appendicitis, CT was able to provide a relevant alternative diagnosis in 183 of 272 women (67.3%) and 81 of 130 men (62.3%) (P > 0.05). CONCLUSION: Nonfocused helical CT was highly accurate for diagnosing acute appendicitis in both men and women, although there was a slight but significant decrease in sensitivity in thin women.