Sung Hye Koh

Diagnostic Performance of CT in the Detection of Intestinal Ischemia Associated With Small-Bowel Obstruction Using Maximal Attenuation of Region of Interest

OBJECTIVE The purpose of this study was to assess the diagnostic performance of CT in the detection of intestinal ischemia associated with small-bowel obstruction using the maximal attenuation of a region of interest (ROI). MATERIALS AND METHODS Abdominal CT scans of 60 patients with small-bowel obstruction were retrospectively reviewed. The reference standard of the clinicopathologic groups was classified into four categories: no bowel necrosis, mucosal-submucosal necrosis, superficial muscle necrosis, and transmural necrosis. The viability of the small bowel on CT was evaluated by visual assessment using five categories (i.e., definitely intestinal ischemia, probably intestinal ischemia, possibly intestinal ischemia, equivocal CT results, and no intestinal ischemia) and by measurement of the maximal attenuation of an ROI at selected obstructed small-bowel loops on contrast-enhanced and unenhanced CT scans. Diagnostic performances were evaluated by one-way analysis of variance and receiver operating characteristic (ROC) curve analysis. RESULTS The sensitivity, specificity, positive and negative predictive values, and accuracy of visual assessment for intestinal ischemia were 91.7% (33/36), 66.7% (16/24), 80.5% (33/41), 84.2% (16/19), and 81.7% (49/60), respectively. The maximal attenuation of the ROIs on contrast-enhanced CT and the subtraction value between the maximal attenuation on contrast-enhanced CT and that on unenhanced CT scans at selected bowel were significantly different according to clinicopathologic group (p < 0.001). The area under the ROC curve of the maximal attenuation subtraction values between contrast-enhanced and unenhanced CT scans (0.995) was higher than that of visual assessment (0.908) for the detection of intestinal ischemia. CONCLUSION The quantification of bowel wall enhancement using the maximal attenuation of an ROI was a reliable and useful method for the diagnosis of intestinal ischemia and showed good correlation with pathology results.

CT evaluation of local leakage of bone cement after percutaneous kyphoplasty and vertebroplasty

Background: Percutaneous injection of bone cement (acrylic cement) during percutaneous kyphoplasty and vertebroplasty can cause symptomatic or asymptomatic complications due to leakage, extravasation or vascular migration of cement. Purpose: To investigate and to compare the incidence and site of local leakage or complications of bone cement after percutaneous kyphoplasty and vertebroplasty using bone cement. Material and Methods: We retrospectively reviewed 473 cases of percutaneous kyphoplasty or vertebroplasty performed under fluoroscopic guidance. Of the 473 cases, follow-up CT scans that covered the treated bones were available for 83 cases (59 kyphoplasty and 24 vertebroplasty). Results: The rate of local leakage of bone cement was 87.5% (21/24) for percutaneous vertebroplasty and 49.2% (29/59) for kyphoplasty. The most common site of local leakage was perivertebral soft tissue (n=8, 38.1%) for vertebroplasty. The most common site of local leakage was a perivertebral vein (n=7, 24.1%) for kyphoplasty. Two cases of pulmonary cement embolism developed: one case after kyphoplasty and one case after vertebroplasty. Conclusion: Local leakage of bone cement was more common for percutaneous vertebroplasty compared with kyphoplasty (P<0.005). The most common sites of local leakage were perivertebral soft tissue and perivertebral vein.

Chest CT findings of toxocariasis: Correlation with laboratory results

AIM To assess the relationship between chest computed tomography (CT) findings of patients with toxocariasis and levels of serological markers. MATERIALS AND METHODS A total of 38 cases of patients diagnosed with toxocariasis by enzyme-linked immunosorbent assay (ELISA), CT, and serological markers were retrospectively reviewed. The presence of nodule with or without ground-glass opacity (GGO) halo, consolidation, focal GGO, pleural effusion, and lymphadenopathy at chest CT were evaluated. Statistical analysis was performed with the Fishers exact test. RESULTS The most common chest CT findings were nodule (n = 12, 31.6%) and focal GGO (n = 12, 31.6%). In patients with normal eosinophil levels, focal GGO (n = 9, 37.5%) was the most common finding. In contrast, nodule with a GGO halo (n = 7, 50%) was the most common finding in the eosinophilia group. Nodule with a GGO halo was more common in the eosinophilia group, with a statistically significant difference (p = 0.017). Nodule was more common in the eosinophilia group, and focal GGO was more common in the normal eosinophil group. CONCLUSION The most common chest CT findings in toxocariasis were nodule with or without GGO halo, and focal GGO. In the eosinophilia group, nodule with a GGO halo was significantly more frequent. Other CT findings did not show a statistically significant relationship with serological markers.

What determines the periportal free air, and ligamentum teres and falciform ligament signs on CT: can these specific air distributions be valuable predictors of gastroduodenal perforation?

PURPOSE The purpose of this retrospective study was to determine what gives rise to the periportal free air, and ligamentum teres and falciform ligament signs on CT in patients with gastrointestinal (GI) tract perforation, and whether these specific air distributions can play a clinically meaningful role in the diagnosis of gastroduodenal perforation. MATERIAL AND METHODS Ninety-three patients who underwent a diagnostic CT scan before laparotomy for a GI tract perforation were included. The readers assessed the presence of specific air distributions on CT (periportal free air, and ligamentum teres and falciform ligament signs). The readers also assessed the presence of strong predictors of gastroduodenal perforation (focal defects in the stomach and duodenal bulb wall, concentrated extraluminal air bubbles in close proximity to the stomach and duodenal bulb, and wall thickening at the stomach and duodenal bulb). The specific air distributions were assessed according to perforation sites, and the elapsed time and amount of free air, and then compared with the strong predictors of gastroduodenal perforation by using statistical analysis. RESULTS All specific air distributions were more frequently present in patients with gastroduodenal perforation than lower GI tract perforation, but only the falciform ligament sign was statistically significant (p<0.05). The presence of all three specific air distributions was demonstrated in only 13 (20.6%) of 63 patients with gastroduodenal perforation. Regardless of the perforation sites, the falciform ligament sign was present significantly more frequently with an increase in the amount of free air on multiple logistic regression analysis (adjusted odds ratio, 1.29; p<0.001). The sensitivity, specificity, accuracy, and positive predictive and negative predictive values of each strong predictor for the diagnosis of gastroduodenal perforation were higher than those of specific air distributions. The focal wall thickening (accuracy, 95.7%) was the most useful parameter for the diagnosis of gastroduodenal perforation. CONCLUSION The prediction of the perforation site of the GI tract on CT should be based on the presence of strong predictors of the site of bowel perforation, and the specific free air distribution should be regarded as complementary predictors.

Lymphoma Involving the Ulnar Nerve Sonographic Findings

We report a case of a 70-year-old man with lymphoma of the ulnar nerve that presented as a palpable mass on his left forearm and wrist. He had a history of oral lymphoma with complete remission after chemotherapy and radiotherapy. The lesion appeared sonographically as a hypoechoic mass mimicking a cyst encasing the ulnar nerve. However, the mass showed vascularity on color Doppler sonography. Lymphoma involving the peripheral nervous system is very rare. 1 To the best of our knowledge, there has been no report of sonographic findings that describe lymphoma involving the peripheral nerves. In this report, we describe the sonographic features of a case involving lymphoma of the ulnar nerve and correlate sonography with magnetic resonance image, positron emission tomography/computed tomography, and histopathologic examination.