Although it is rare, the right atrium can be encroached on by abnormal mediastinal structures, including aortic aneurysms, carcinomas, hepatic cysts and diaphragmatic paralysis. Extrinsic compression of the right atrium causes significant hemodynamic compromise and can lead to fatal outcomes. We describe the case of a 66-year old man with a past history of pulmonary tuberculosis that had undergone right pneumonectomy 40 years previously. He then presented with signs and symptoms of right-sided heart failure. These new signs and symptoms were recognized to be secondary to extrinsic compression of the right atrium, which was due to late-onset postpneumonectomy empyema, and the signs and symptoms were successfully relieved by performing open drainage of the empyema.
Aortic Aneurysm ; Drainage ; Empyema ; Empyema, Pleural ; Fatal Outcome ; Heart ; Heart Atria ; Heart Failure ; Hemodynamics ; Pneumonectomy ; Respiratory Paralysis ; Tuberculosis, Pulmonary

PURPOSE: To compare free-breathing and respiratory-triggered diffusion-weighted imaging on 1.5-T MR system in the detection of hepatic lesions. MATERIALS AND METHODS: This single-institution study was approved by our institutional review board. Forty-seven patients (mean 57.9 year; M:F = 25:22) underwent hepatic MR imaging on 1.5-T MR system using both free-breathing and respiratory-triggered diffusion-weighted imaging (DWI) at a single examination. Two radiologists retrospectively reviewed respiratory-triggered and free-breathing sets (B50, B400, B800 diffusion weighted images and ADC map) in random order with a time interval of 2 weeks. Liver SNR and lesion-to-liver CNR of DWI were calculated measuring ROI. RESULTS: Total of 62 lesions (53 benign, 9 malignant) that included 32 cysts, 13 hemangiomas, 7 hepatocellular carcinomas (HCCs), 5 eosinophilic infiltration, 2 metastases, 1 eosinophilic abscess, focal nodular hyperplasia, and pseudolipoma of Glisson's capsule were reviewed by two reviewers. Though not reaching statistical significance, the overall lesion sensitivities were increased in respiratory-triggered DWI [reviewer1: reviewer2, 47/62(75.81%):45/62(72.58%)] than free-breathing DWI [44/62(70.97%):41/62(66.13%)]. Especially for smaller than 1 cm hepatic lesions, sensitivity of respiratory-triggered DWI [24/30(80%):21/30(70%)] was superior to free-breathing DWI [17/30(56.7%):15/30(50%)]. The diagnostic accuracy measuring the area under the ROC curve (Az value) of free-breathing and respiratory-triggered DWI was not statistically different. Liver SNR and lesion-to-liver CNR of respiratorytriggered DWI (87.6+/-41.4, 41.2+/-62.5) were higher than free-breathing DWI (38.8+/-13.6, 24.8+/-36.8) (p value <0.001, respectively). CONCLUSION: Respiratory-triggered diffusion-weighted MR imaging seemed to be better than free-breathing diffusion-weighted MR imaging on 1.5-T MR system for the detection of smaller than 1 cm lesions by providing high SNR and CNR.
Abscess ; Carcinoma, Hepatocellular ; Diffusion ; Eosinophils ; Ethics Committees, Research ; Focal Nodular Hyperplasia ; Hemangioma ; Humans ; Liver ; Neoplasm Metastasis ; Retrospective Studies ; ROC Curve

PURPOSE: To compare free-breathing and respiratory-triggered diffusion-weighted imaging on 1.5-T MR system in the detection of hepatic lesions. MATERIALS AND METHODS: This single-institution study was approved by our institutional review board. Forty-seven patients (mean 57.9 year; M:F = 25:22) underwent hepatic MR imaging on 1.5-T MR system using both free-breathing and respiratory-triggered diffusion-weighted imaging (DWI) at a single examination. Two radiologists retrospectively reviewed respiratory-triggered and free-breathing sets (B50, B400, B800 diffusion weighted images and ADC map) in random order with a time interval of 2 weeks. Liver SNR and lesion-to-liver CNR of DWI were calculated measuring ROI. RESULTS: Total of 62 lesions (53 benign, 9 malignant) that included 32 cysts, 13 hemangiomas, 7 hepatocellular carcinomas (HCCs), 5 eosinophilic infiltration, 2 metastases, 1 eosinophilic abscess, focal nodular hyperplasia, and pseudolipoma of Glisson's capsule were reviewed by two reviewers. Though not reaching statistical significance, the overall lesion sensitivities were increased in respiratory-triggered DWI [reviewer1: reviewer2, 47/62(75.81%):45/62(72.58%)] than free-breathing DWI [44/62(70.97%):41/62(66.13%)]. Especially for smaller than 1 cm hepatic lesions, sensitivity of respiratory-triggered DWI [24/30(80%):21/30(70%)] was superior to free-breathing DWI [17/30(56.7%):15/30(50%)]. The diagnostic accuracy measuring the area under the ROC curve (Az value) of free-breathing and respiratory-triggered DWI was not statistically different. Liver SNR and lesion-to-liver CNR of respiratorytriggered DWI (87.6+/-41.4, 41.2+/-62.5) were higher than free-breathing DWI (38.8+/-13.6, 24.8+/-36.8) (p value <0.001, respectively). CONCLUSION: Respiratory-triggered diffusion-weighted MR imaging seemed to be better than free-breathing diffusion-weighted MR imaging on 1.5-T MR system for the detection of smaller than 1 cm lesions by providing high SNR and CNR.
Abscess ; Carcinoma, Hepatocellular ; Diffusion ; Eosinophils ; Ethics Committees, Research ; Focal Nodular Hyperplasia ; Hemangioma ; Humans ; Liver ; Neoplasm Metastasis ; Retrospective Studies ; ROC Curve

A mesothelial cyst of the round ligament is a rare cause of an inguinal mass. Clinically, it is frequently misdiagnosed as one of commoner diseases such as an inguinal hernia, femoral hernia, lipoma, and lymphadenopathy upon physical examination. Some previous reports elaborated the sonographic features of a mesothelial cyst of the round ligament. However, to our knowledge, few reports have described the CT features of a mesothelial cyst. We illustrated here the sonographic and multidetector CT features of a case of a mesothelial cyst of the round ligament that presented as an inguinal palpable mass and mimicked a metastasis in a patient with a Sertoli-Leydig cell tumor of the ovary.
Abdominal Neoplasms/*diagnosis/secondary ; Aged ; Contrast Media/diagnostic use ; Cysts/*radiography/*ultrasonography ; Diagnosis, Differential ; Epithelium/radiography/ultrasonography ; Female ; Humans ; Ovarian Neoplasms/*pathology ; Radiographic Image Enhancement/methods ; Round Ligament/*radiography/*ultrasonography ; Sertoli-Leydig Cell Tumor/*pathology ; Tomography, X-Ray Computed/methods

BACKGROUND/AIMS: Invasive coronary angiography remains the gold standard in the diagnosis of coronary artery disease. However, multidetector CT (MDCT) coronary angiography is an emerging technique that is available for the non-invasive detection of coronary artery stenoses. While the diagnostic accuracy of first generation MDCT is limited, recently released 64-slice MDCT has yielded promising results due to increased temporal and spatial resolution. The objective of this study was to investigate the diagnostic accuracy of non-invasive 64-slice MDCT for coronary artery disease. METHODS: One hundred one patients (63 males and 38 females; mean age, 63.7+/-10.5 years) undergoing conventional coronary angiography were included in this study. All coronary arteries, including the distal segments and side branches, were analyzed for the presence of significant stenosis (> or =50% diameter stenosis) and compared with of the quantitative coronary angiographic findings. RESULTS: Of the 1,440 coronary artery segments studied, 1,348 segments were assessed quantitatively by both MDCT and conventional coronary angiography (94%). Two hundred nine significant stenoses were detected by conventional coronary angiography. On a segment-based analysis, the senisitivity, specificity, and positive and negative predictive values of 64-slice MDCT were 96, 97, 85, and 99%, respectively. On a vessel-based analysis, the sensitivity, specificity, and positive and negative predictive values of 64-slice MDCT were 96, 97, 85, and 99%, respectively. The corresponding values obtained on a patient-based analysis were 100, 94, 97, and 100%, respectively. Coronary calcification was the major cause of false-positive findings. CONCLUSIONS: This study demonstrated that 64-slice MDCT coronary angiography is of similar accuracy as conventional coronary angiography for the detection of coronary artery disease. In selected groups of patients, 64-slice MDCT may replace the more invasive coronary angiography.
Constriction, Pathologic ; Coronary Angiography ; Coronary Artery Disease ; Coronary Stenosis ; Coronary Vessels ; Humans ; Male ; Sensitivity and Specificity

We report here on a case of primary extraskeletal mesenchymal chondrosarcoma that arose from the pancreas. A 41-year-old man was evaluated by CT to find the cause of his abdominal pain. The CT scans showed a heterogeneously enhancing necrotic mass with numerous areas of coarse calcification, and this was located in the left side of the retroperitoneal space and involved the body and tail of the pancreas. Portal venography via the celiac axis also showed invasion of the splenic vein. Following excision of the mass, it was pathologically confirmed to be primary extraskeletal mesenchymal chondrosarcoma that arose from the pancreas.
Abdominal Pain/etiology ; Adult ; Chondrosarcoma, Mesenchymal/complications/*diagnosis/surgery ; Contrast Media/administration & dosage ; Diagnosis, Differential ; Humans ; Iohexol/analogs & derivatives/diagnostic use ; Male ; Necrosis ; Pancreas/pathology/radiography ; Pancreatic Neoplasms/complications/*diagnosis/surgery ; Portal Vein/radiography ; Radiographic Image Enhancement/methods ; Rare Diseases ; Retroperitoneal Space/radiography ; Splenic Vein/radiography ; Tomography, X-Ray Computed/methods

Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a rare cancer and it is widely regarded as being distinct from the other subtypes of peripheral T-cell lymphoma. SPTCL commonly presents with subcutaneous nodules that resembles panniculitis. The clinicopathologic features of SPTCL have recently been described. However, only a few cases with their CT and sonographic findings have been reported in the radiologic literature. We illustrate here the MR findings of this rare tumor in one case that presented with a popliteal mass.
Lymphoma, T-Cell* ; Lymphoma, T-Cell, Peripheral ; Panniculitis ; Subcutaneous Tissue ; T-Lymphocytes* ; Ultrasonography

Solitary fibrous tumor (SFT) is a benign mesenchymal neoplasm of a spindle-cell origin, and it usually involves the pleura. It's occurrence in various organs of the body has recently been described. Meningeal SFT is very rare. Radiologically, it is a strongly enhancing solid mass and is undistinguishable from fibrous meningioma and hemangiopericytoma. Yet we report here on a case of SFT with massive cystic degeneration that arose from the meninges of the left occipital region.
Hemangiopericytoma ; Meninges* ; Meningioma ; Pleura ; Solitary Fibrous Tumors*

PURPOSE: We wanted to evaluate the usefulness of venous color Doppler with performing a Valsalva maneuver for chassifing primary varicose vein of the lower extremity. MATERIALS AND METHODS: From September 2002 to March 2005, 207 patients and 288 extremities that were clinically suggestive of primary varicose vein in the lower extremity underwent venous color Doppler with performing a Valsalva maneuver. The patients included 133 women and 74 men aged between 20-79 years (mean age: 51 year). Color Doppler study was performed in the great and small saphenous veins. We used a 5 point grading system, Grade (Gr.) 0 was no evidence of reflux, Gr. I was early reflux within 3 seconds after the Valsalva maneuver, Gr. II was continuous reflux without dilatation during the Valsalva maneuver, Gr. III was continuous reflux with dilatation during the Valsalva maneuver and Gr. IV was reflux at a resting state. To find a relationship between the rate of operation and the grading system, we retrospectively reviewed the patient's medical records and the grading system. RESULTS: In the great saphenous vein, Gr. 0 was noted in 42 cases, Gr. I was noted in 68 cases, Gr. II was noted in 23 cases, Gr. III was noted in 104 cases and Gr. IV was noted in 51 cases. In the small saphenous vein, Gr. 0 was noted in 98 cases, Gr. I was noted in 60 cases Gr. II was noted in 38 cases, Gr. III was noted in 36 cases and Gr. IV was noted 56 cases. Among these cases, 2 cases of Gr. 0, 9 cases of Gr. I, 3 cases of Gr. II, 85 cases of Gr. III and 44 cases of Gr. IV of the great saphenous vein were operated on. 3 cases of Gr. 0, 4 cases of Gr. I, 4 cases of Gr. II, 23 cases of Gr. III and 37 cases of Gr. IV of the small saphenous vein were also operated on. Consequently, the operation rate was 76.5% in the severe cases over Gr. III. CONCLUSION: Color Doppler with performing a Valsalva maneuver and our new grading system is a useful method to determine the rate of operation for the patients suffering with primary varicose vein.
Dilatation ; Extremities ; Female ; Humans ; Lower Extremity ; Male ; Medical Records ; Retrospective Studies ; Saphenous Vein ; Valsalva Maneuver* ; Varicose Veins*

PURPOSE: We wanted to evaluate an acceptable compression rate of JPEG2000 for long term archiving of CT and MR images in PACS. MATERIALS AND METHODS: Nine CT images and 9 MR images that had small or minimal lesions were randomly selected from the PACS at our institute. All the images are compressed with rates of 5:1, 10:1, 20:1, 40:1 and 80:1 by the JPEG2000 compression protocol. Pairs of original and compressed images were compared by 9 radiologists who were working independently. We designed a JPEG2000 viewing program for comparing two images on one monitor system for performing easy and quick evaluation. All the observers performed the comparison study twice on 5 mega pixel grey scale LCD monitors and 2 mega pixel color LCD monitors, rspectively. The PSNR (Peak Signal to Noise Ratio) values were calculated for making quantitative comparisons. RESULTS: On MR and CT, all the images with 5:1 compression images showed no difference from the original images by all 9 observers and only one observer could detect a image difference on one CT image for 10:1 compression on only the 5 mega pixel monitor. For the 20:1 compression rate, clinically significant image deterioration was found in 50% of the images on the 5M pixel monitor study, and in 30% of the images on the 2M pixel monitor. PSNR values larger than 44 dB were calculated for all the compressed images. CONCLUSION: The clinically acceptable image compression rate for long term archiving by the JPEG2000 compression protocol is 10:1 for MR and CT, and if this is applied to PACS, it would reduce the cost and responsibility of the system.
Data Compression ; Noise