Language Lateralization by Functional MRI: A Comparison with Wada Test-preliminary Results

PURPOSE: To evaluate the usefulness of functional MR imaging (fMRI) for the determination of languagedomi-nance and to assess differences in language lateralization according to activation task or activated area. MATERIALS AND METHODS: Functional maps of the language area were obtained during word generation tasks (noun andverb) and a reading task in ten patients (9 right handed, 1 left handed) who had undergone the Wada test. MRexaminations were performed using a 1.5T scanner and the EPI BOLD technique. The SPM program was employed for thepostprocessing of images and the threshold for significance was set at p<0.001 or p<0.01. A lateralization indexwas calculated from the number of activated pixels in three hemispheric re-gions (whole hemisphere, frontal lobe,and temporoparietal lobe), and the results were compared with those of Wada tests. The results for lateralizationof language area were compared among stimulation tasks and regions and used for calculation of lateralizationindices. RESULTS: During the Wada test, nine patients were left dominant and one patient was right dominant forlan-guage. Language dominance based on activated signals in each hemisphere was consistent with the results of theWada test in 87.5% (verb and noun generation tasks) and 90% (reading task) of patients. Language domi-nancedetermined by activated signals in the frontal lobe was consistent in 87.5%, 75%, and 80% of patients in eachstimulation task (verb generation, noun generation, and reading), respectively. The consistency rate of ac-tivatedsignals in the temporoparietal lobe was 87.5%, 87.5% and 80% of patients in each task. The mean val-ue of thelateralization index, calculated on the basis of activated signals in the temporoparietal lobe was higher thanthat in the hemisphere or frontal lobe. The verb generation task showed a higher lateralization index than thenoun generation or reading task. CONCLUSION: The lateralization index was higher in the verb generation task andin the region of the tem-poroparietal lobe than in other stimulation tasks or regions. fMRI is a potentiallyuseful non-invasive method for the determination of language dominance.

functional MRI of Language Area

PURPOSE: To evaluate the usefulness of functional MR imaging(fMRI) for language mapping and determination of language lateralization. MATERIALS AND METHODS: Functional maps of the language area were obtained during word generation tasks and decision task in ten volunteers(7 right handed, 3 left-handed). MR examination were performed at 1.5T scanner with EPI BOLD technique. Each task consisted of three resting periods and two activation periods with each period of 30 seconds. Total acquisition time was 162sec. SPM program was used for the postprocessing of images. Statistical comparisons were performed by using t-statistics on a pixel-by-pixel basis after global normalization by ANCOVA. Activation areas were topographically analyzed(p<0.001) and activated pixels in each hemisphere were compared quantitatively by lateralization index. RESULTS: Significant activation signals were demonstrated in 9 of 10 volunteers. Activation signals were found in the premotor and motor cortices, the inferior frontal, inferior parietal, and mid-temporal lobes during stimulation tasks. In the right handed seven volunteers, activation of language areas was lateralized to the left side. Verb generation task produced stronger activation in the language areas and higher value of lateralization index than noun generation task or decision task. CONCLUSION: fMRI could be a useful non-invasive method for language mapping and determination of language dominance.

Lymphangitic Carcinomatosis of the Lung: Serial Changes on High-Resolution CT

PURPOSE: To present initial and follow-up HRCT findings of lymphangitic carcinomatosis of the lung. MATERIALS AND METHODS: Both initial and follow-up HRCT scans were obtained in 18 patients with lymphangitic carcinomatosis of the lung. After dividing the patients into two groups (with anticancer chemotherapy (n=12) and without chemotherapy (n=6), changes of pulmonary parenchymal abnormalities (percentile increase or decrease in the extent of each pattern) were assessed and compared on initial and follow-up HRCTs. RESULTS: Findings on initial CT were interlobular septal thickening (n=18) (smooth in 15 and mixed smooth and nodular in three), thickening of bronchovascular bundles (n=17), areas of ground-glass opacity (n=15), polygonal lines (n=15), and nodules (n=10). With chemotherapy, the finding of polygonal lines decreased by 20/3%, while findings of ground-glass opacity, bronchovascular bundle thickening, septal thickening, and nodules remained stable. Without chemotherapy, all CT patterns of abnormalities except nodules increased by 45-88%. In three patients who did not undergo chemotherapy, smooth interlobular septal thickening changed to nodular thickening. CONCLUSION: Lymphangitic carcinomatosis of the lung manifests initially as smooth thickening of the interlobular septae, bronchovascular bundle thickening,areas of ground-glass opacity, and polygonal lines, as seen on HRCT. Without chemotherapy, the extent of CT findings increases and there is a tendency for smooth septal thickening to change to nodular thickening. Chemotherapy induces improvement or cessation of the progression of CT findings.

Mediastinal Interfaces and Lines: Clinical Significance and Radiographic-CT Correlation

Mediastinal interfaces on a chest radiograph result from contact between mediastinal structures and the adjacent lung, while mediastinal lines result from contact between the two lungs across the midline. A variation of mediastinal interface is mediastinal stripe, a narrow band produced by contact of both sides of a mediastinal structure with the lungs. Alterations in mediastinal interfaces and lines may be due to variations in normal anatomy, or may reflect the presence of abnormalities within the mediastinum. Familiarity with the various normal mediastinal interfaces and lines, and the changes that occur with disease is important for the interpretation of the chest radiograph and in the diagnosis of mediastinal abnormalities. The purpose of this pictorial essay is to illustrate the most important normal and abnormal interfaces and lines and also to correlate radiographic and CT findings.

Placement of Central Venous Access via Subclavian Vein under Fluoroscopic Guidance with Intravenous Contrast Injection

PURPOSE: To evaluate the safety and efficacy of Hickman catheter placement via the subclavian vein under fluoroscopic guidance with intravenous contrast injection. MATERIALS AND METHODS: During an eleven-month period, 187 Hickman catheters were percutaneously placed in 167 consecutive patients in an interventional radiology suite. Subclavian venous puncture was made with injection of contrast medium into the peripheral venous line. After subclavian venous access had been obtained, a subcutaneous tunnel was created using a peel-away sheath or a tunneler. The Hickman catheters were inserted through a peel-away sheath, the distal tip of which was at the junction of the right atrium and the superior vena cava. RESULTS: One hundred and eighty-six Hickman catheters were successfully placed; the one failure was due to an atomical tortuosity of the vein(0.53%). Complications included one case of subclavian vein occlusion (0.53%); three of line occlusion by thrombus (1.6%); one of oozing at the suture site (0.53%); six of infection or inflammation (3.2%); eight of natural removal (4.2%); one case of air embolism (0.53%) and two of malposition (0.1%). Major complications such as pneumothorax or arterial puncture leading to mediastinal hemorrhage did not, however, occur. CONCLUSION: The authors concluded that radiologic Hickman catheter placement offers advantages over traditional approaches in terms of safety, convenience, and time and cost savings.

Primary Epiploic Appendagitis: 4 Case Report

Primary epiploic appendagitis of the colon is a rare cause of abdominal pain and is a self-limiting disease. Double contrast barium enema showed a smooth extrinsic compression located anterolateraly to the involved colon. Ultrasonography revealed a non-compressible echogenic ovoid mass attached to the colon wall. On abdominal CT, all lesions were seen as pedunculated ovel fatty masses with surrounding streaky densities connected to the serosal surface of the adjacent colon. Follow up CT performed 13-25(mean 18) days later showed that during this intrval, the volume of the mass and extent of surrounding infiltrations had decreased.

Adenosquamous Carcinoma of the Liver: A Case Report

A case of primary adenosquamous carcinoma of the liver is reported. A large cystic mass with irregular enhancing wall was seen in the left lobe of the liver; multiple hepatic cysts and metastatic nodules were scattered in both lobes. Sonoguided needle biopsy was performed and on histopathology, adenosquamous carcinoma was diagnosed. The radiologic and pathologic relationships of this unusual neoplasm are discussed.

Malignant and Benign Diffuse Pleural Disease: Utility of FDG PET in Differential Diagnosis and Comparison with CT

PURPOSE: To assess the utility of 2-[18F] fluoro-2-deoxy-D-glucose (FDG) PET in differentiating malignant and benign diffuse pleural disease, and to compare it with CT. MATERIALS AND METHODS: Both FDG PET and CT scans were performed in 20 consecutive patients with diffuse pleural disease (13 malignant and seven benign cases). In FDG PET, peak standardized uptake value (SUV) as well as visual assessment of abnormally increased uptake in the pleura was evaluated. The results were compared with CT findings. RESULTS: With only visual assessment of PET images, sensitivity, specificity, and accuracy for malignancy were 92%, 43%, and 75%, respectively. With peak SUV of 4.8 or more, the corresponding figures were 100%, 57%, and 85%, respectively, and on CT interpretation, were100%, 57%, and 85%, respectively. Tuberculous empyema simulated malignant pleural disease both on FDG PET (3/6 patients with peak SUV more than 4.8) and CT (3/6 patients). CONCLUSION: For the differentiation of malignant and benign diffuse pleural disease, FDG PET and CT are equally accurate. Combined visual and quantitative assessments of PET images enhance discriminatory ability. Tuberculous empyema simulates malignant pleural disease both on FDG PET and CT.

High-Resolution PACS Work station: Diagnostic Performance and Comparison with Laser-Printed CR Films in Chest Diseases

OBJECTIVES: To compare the diagnostic performance of a high-resolution picture archiving and communications system (PACS) workstation directly interfaced with computed radiography(CR) with laser-printed CR films in chest diseases. MATERIALS AND METHODS: Chest radiographs with (n=91) and without (n=25) abnormalities were included. Atotal of 100 abnormalities from 91 radiographs consisted of irregular lines, pneumothoraces, nodules and consolidations (25 of each). Laser-printed hard copies with dynamic range compression (DRC) were produced. InPACS, soft copies of 1760 X 2140 X 10 bits CR images were displayed on 1536 X 2048 with 8 bit gray-scale monitors.The performance of four observers was compared between laser-printed hard copies and CR images displayed on a workstation according to receiver operating characteristic analysis. RESULTS: Overall, no significant difference sin observer performance were observed between laser-printed hard copies and CR images displayed on a workstation(p=.2454). Even though statistically not significant, the former was slightly superior to the latter for lesions of irregular lines, pneumothoraces, and consolidations, whereas for nodules, the latter was slightly better than the former. CONCLUSION: The diagnostic performance of a high-resolution PACS workstation in chest radiographs is acceptable and comparable to CR hard copies printed with DRC processing mode.