Kyu Ho Choi

N-butyl-2-cyanoacrylate pulmonary embolism after endoscopic injection sclerotherapy for gastric variceal bleeding.

Purpose The purpose of this work was to describe the radiologic and clinical manifestations of n-butyl-2-cyanoacrylate pulmonary embolism (PE) after endoscopic injection sclerotherapy (EIS) for gastric variceal bleeding. Method From 1992 to 1999, the medical records of 140 patients who had undergone EIS using n-butyl-2-cyanoacrylate were reviewed for identification of respiratory symptoms and amount of injection, and their pre-and postprocedure chest radiographs were reviewed to identify PE. In patients with PE, pre-and postprocedure chest radiographs (6/6), chest CT scans (3/6), lung perfusion scans (3/6), and follow-up chest radiographs (6/6) were analyzed retrospectively. Results Radiographically evident PE was observed in 6 (4.3%) of 140 patients. In comparison with patients without emboli, these patients received a higher mean volume of injection (4.2 vs. 1.8 ml) (p = 0.0011). Four of the six patients with pulmonary emboli had respiratory symptoms. Chest radiographs and CT scans showed unusual tubular or nodular, radiopaque pulmonary emboli along the pulmonary vessels. Multiple peripheral, wedge-shaped, subsegmental perfusion defects were seen on perfusion lung scans. In five of six patients, the radiographic abnormalities showed complete or partial resolution. There were no fatalities directly associated with PE. Conclusion Radiographically evident PEs are uncommonly observed following EIS and appear to be more common in patients receiving a higher volume of liquid acrylate. Affected patients were either mildly symptomatic or asymptomatic, and there were no direct fatalities of this complication.

Blunt traumatic rupture of the diaphragm: sonographic diagnosis

Ultrasonographic features of seven patients with diaphragmatic rupture due to blunt trauma were analyzed. The ruptures occurred at the left hemidiaphragm in four patients and at the right in three. Direct ultrasonographic findings were as follows: disrupted diaphragm in four patients; nonvisualized diaphragm in three patients; floating diaphragm in two patients; and herniation of the liver or bowel loops through the diaphragmatic defect in three patients. Indirect sonographic findings included pleural effusion or subphrenic fluid collection in five patients and splenic laceration in one. Although the number of patients was limited, ultrasonography was very useful for the diagnosis of diaphragmatic rupture.

MRI of Tuberculous pyomyositis

PURPOSE The purpose of this article is to describe the findings of MRI in tuberculous pyomyositis (PM). METHOD The MR images of four proven cases of tuberculous PM were retrospectively reviewed and analyzed with clinical and laboratory findings. The location, signal intensity on T1- and T2-weighted spin echo images, presence of abscess, signal intensity of peripheral rim, patterns of contrast enhancement, and associated findings were evaluated. RESULTS On MR images, all cases demonstrated low signal intensity on T1-weighted images and high signal intensity on T2-weighted images in a single muscle. Abscess was seen in all cases. Peripheral rim showed subtle hyperintensity on T1-weighted images and hypointensity on T2-weighted images. After gadolinium infusion, peripheral rim enhancement was observed in all cases. Cellulitis was associated in one case. The patients clinically presented with a palpable mass of long duration. CONCLUSION Tuberculous PM shows characteristic findings of a well demarcated abscess with rim enhancement at MRI and can be distinguished from other soft tissue masses.

Prognostic Value of Metabolic Tumor Volume Measured by 18F-FDG PET/CT in Locally Advanced Head and Neck Squamous Cell Carcinomas Treated by Surgery

PurposeWe assessed the prognostic value of metabolic tumor volume (MTV) measured using18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) inpatients with locally advanced head and neck squamous cell carcinoma (HNSCC).MethodsWe retrospectively reviewed 56 patients (51 men, five women; mean age 56.0 ± 8.8years) who had locally advanced HNSCC and underwent FDG PET/CT for initial evaluation. All patients had surgical resection and radiotherapy with or without concurrent chemotherapy. The peak standardized uptake value (SUVpeak) and MTV of the target lesion, including primary HNSCC andmetastatic cervical lymph nodes, were measured from FDG PET/CT images. We compared SUVpeak, MTV, and clinicopathologic variables such as age, Eastern Cooperative Oncology Group (ECOG) performance status, pN stage, pT stage, TNM stage, histologic grade and treatment modality to disease-free survival (DFS) and overall survival (OS).ResultsOn the initial FDG PET/CT scans, the median SUVpeak was 7.8 (range, 1.8-19.0) and MTV was17.0 cm3 (range, 0.1-131.0 cm3). The estimated 2-year DFS and OS rates were 67.2% and 81.8%. The cutoff points of SUVpeak 6.2 and MTV 20.7 cm3 were the best discriminative values for predicting clinical outcome. MTV and ECOG performance status were significantly related to DFS and OS on univariate and multivariate analyses (p < 0.05).ConclusionThe MTV obtained from initial FDG PET/CT scan is a significant prognostic factor for disease recurrence and mortality in locally advanced HNSCC treated with surgery and radiotherapy with or without chemotherapy.

Eosinophilic cholangitis: US, CT, and cholangiography findings.

We report a case of eosinophilic cholangitis, with US, CT, and cholangiographic findings. The lesion showed marked wall thickening of cystic and common bile ducts on US and CT together with mild diffuse narrowing of the common duct on cholangiography.

Intraventricular Hemorrhage Caused by Lateral Ventricular Meningioma: A Case Report

Meningiomas causing intracranial hemorrhage are rare, and hemorrhage from a lateral ventricular meningioma seems to be even rarer. We report a case of trigonal meningioma in a 43-year-old woman who presented with intraventricular hemorrhage, and describe the CT, MRI and angiographic findings.

Unusual Acute Encephalitis Involving the Thalamus: Imaging Features

Objective To describe the brain CT and MR imaging findings of unusual acute encephalitis involving the thalamus. Materials and Methods We retrospectively reviewed the medical records and CT and/or MR imaging findings of six patients with acute encephalitis involving the thalamus. CT (n=6) and MR imaging (n=6) were performed during the acute and/or convalescent stage of the illness. Results Brain CT showed brain swelling (n=2), low attenuation of both thalami (n=1) or normal findings (n=3). Initial MR imaging indicated that in all patients the thalamus was involved either bilaterally (n=5) or unilaterally (n=1). Lesions were also present in the midbrain (n=5), medial temporal lobe (n=4), pons (n=3), both hippocampi (n=3) the insular cortex (n=2), medulla (n=2), lateral temporal lobe cortex (n=1), both cingulate gyri (n=1), both basal ganglia (n=1), and the left hemispheric cortex (n=1). Conclusion These CT or MR imaging findings of acute encephalitis of unknown etiology were similar to a combination of those of Japanese encephalitis and herpes simplex encephalitis. In order to document the specific causative agents which lead to the appearance of these imaging features, further investigation is required.

Osteonecrosis Mimicking Bone Metastasis in Femoral Head on 18F-FDG PET/CT: A Case Report

A 77-year-old woman underwent chemotherapy, radiotherapy, and brachytherapy for cervical cancer 9 years ago. On a follow-up 18F-fluorodeoxyglucose (FDG) PET/CT image, focal FDG uptake was noted in a focal osteolytic lesion in the right femoral head. During magnetic resonance imaging, this lesion showed subchondral dark-signal-intensity rim on T1-weighted image and double line sign on T2-weighted image, suggestive of osteonecrosis. The lesion was pathologically confirmed as osteonecrosis after surgery. This case demonstrates that osteonecrosis of the femoral head may demonstrate focal FDG uptake mimicking bone metastasis.

CT and MR findings of neuronal migration anomalies

Neuronal migration anomalies(NMA) are congenital malformations cau sed by insults to m igrating neuroblast during the third to fifth gestational months . We reviewed CT and MR findings of 17 patients with NMA to evaluate their usefulness in various migration a nomalies Of 17 patients ‘ 9 had only CT ‘ 3 had only MR, a nd 5 had both CT and MR. We diagnose 5 cases of schizencephaly. 3 cases of he te rotopic gray matter , 3 cases of lissencephaly and 6 cases of polymicrogyria. Clinically , these patie n ts presented with se izure ‘ motor deficit and mental retardation The main findings of each anomaly were as follows:( 1) Schizen cephaly was cha racterized by full-thickness cleft extending from cortical surface to ventricles with or without intervening CSF;(2) heterotopic gray matter was characterized by ectopically located gray matter;(3) lissencephaly was characterized by f1a t, thick cortex with decreased sulci ‘ and(4) polymicrogyria was characterized by many tiny gyri with incomplete sulc i. MR was superior to CT in detecting NMA because of its multiplanar display capabilities. exceptional gray-white matter differentiation . and absen ce of bony artifac t.