Pancreas Ductal Adenocarcinoma and its Mimics: Review of Cross-sectional Imaging Findings for Differential Diagnosis.

Ductal adenocarcinoma is the most common pancreatic neoplasm. A variety of pancreatic lesions mimic pancreas ductal adenocarcinoma (PDAC), such as high-grade neuroendocrine tumors, small solid pseudopapillary tumors, metastases, focal autoimmune pancreatitis, and groove pancreatitis. These occasionally look similar in images, but they have differential diagnosis points. Familiarity with the imaging features of PDAC and its mimics is paramount for correct diagnosis and management of patients. In this essay, we describe imaging findings of PDAC and its mimics for differential diagnosis.

The many faces of Meckel's diverticulum and its complications.

Meckel's diverticulum is the most frequent congenital malformation of the gastrointestinal tract, occurring in 2% of the general population. Meckel's diverticulum is usually asymptomatic and found incidentally. However, the lifetime risk of complications is 4-40%. In this essay, we describe the clinical and imaging findings in 12 cases of Meckel's diverticula with complications over a 5-year period, which were confirmed pathologically. The major complications of Meckel's diverticulum include gastrointestinal bleeding, bowel obstruction, perforation and inflammation. Small bowel follow-through (SBFT), computed tomography (CT) including CT enterography and RI scintigraphy can be used to show typical imaging features of Meckel's diverticulum and its complications. Knowledge of the clinical and radiologic findings of Meckel's diverticulum can aid in the early and accurate diagnosis of this anomaly and its complications.

The bright rim sign on MRI for anterior talofibular ligament injury with arthroscopic correlation.

OBJECTIVE: The purpose of this article is to determine whether bright rim lesions on MRI are a marker for anterior talofibular ligament injury. MATERIALS AND METHODS: The study included 34 patients who had an ankle injury and underwent arthroscopic surgery. All patients underwent 3-T MRI for the diagnosis of anterior talofibular ligament injury. If MRI revealed nonvisualization of the ligament, ligament discontinuity, and unusual ligament thickening (criterion 1) or the bright rim sign (criterion 2), the injury was considered to be a ligament disruption. After MRI, ankle arthroscopy was performed in all patients for a definitive diagnosis. RESULTS: Arthroscopy showed anterior talofibular ligament disruption in 33 patients. When the MRI diagnosis was based on criterion 1, anterior talofibular ligament disruption was diagnosed with a sensitivity of 60.6-66.7% and an accuracy of 58.8-67.6%. When the MRI diagnosis was based on both criteria 1 and 2, anterior talofibular ligament disruption was diagnosed with a sensitivity of 90.9-97.0% and an accuracy of 88.2-94.1%. By adding criterion 2 to the diagnosis, the sensitivity for anterior talofibular ligament injury was increased significantly (p < 0.01), and 8-12 additional patients with anterior talofibular ligament injury were diagnosed, most of whom exhibited a partial tear of the anterior talofibular ligament on arthroscopy. The interobserver agreement rate for the presence of anterior talofibular ligament disruption using criterion 1, both criteria, and the bright rim sign was fair to excellent. CONCLUSION: A cortical defect with bright dotlike or curvilinear high-signal-intensity lesions on T2-weighted MRI may be an additional morphologic feature to increase the diagnostic performance of detecting anterior talofibular ligament injuries, including those with partial tears.

A case of intrapancreatic accessory spleen mistaken as a pancreatic mass due to different enhancing pattern from normal spleen.

Most cases of accessory spleen show similar features as normal spleen in imaging studies. However, some accessory spleen has unusual scan feature which can be misdiagnosed. We present a case of intrapancreatic accessory spleen that was discovered incidentally during a workup for abdominal pain in a 47-year-old woman. CT and MRI revealed a different enhancing pattern from that of the spleen. Further evaluation with endoscopic ultrasonography failed to identify the pancreatic mass. Therefore, it was surgically removed and diagnosed pathologically as an accessory spleen.