Late-onset postpneumonectomy empyema presenting as right-sided heart failure: extrinsic right atrial compression.

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.

Multidetector computed tomography (MDCT) images with soft tissue and bone algorithm reconstruction in head and facial trauma.

We aimed to evaluate the usefulness of multidetector CT (MDCT) scan images with soft tissue and bone algorithm reconstruction in nine patients for investigation of head and facial trauma. We compared these MDCT scans with the conventional brain CT scans and facial bone CT scans of eight patients with head and facial trauma. The overall radiation dose did not differ significantly between the two groups (Mann-Whitney test, p=0.370) but the MDCT scans with soft tissue and bone algorithm reconstruction avoided overlapping scan range radiation exposure, especially to the eye and lower half of the brain.

Mesothelial cyst of the round ligament mimicking a metastasis: a case report.

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.

Frequency of myocardial bridges and dynamic compression of epicardial coronary arteries: a comparison between computed tomography and invasive coronary angiography.

BACKGROUND: The objective of the present study was to describe the relative frequency of myocardial bridging and dynamic compression of the coronary arteries as assessed by CT angiography and conventional angiography. METHODS AND RESULTS: A total of 311 patients (208 men, 103 women; mean age 63 years) who received both 64-section CT angiography and conventional angiography were reviewed retrospectively for myocardial bridging of the left anterior descending coronary artery. Myocardial bridging was considered when the left anterior descending coronary artery was within the interventricular gorge and was classified as either myocardial bridging with partial encasement or myocardial bridging with full encasement, according to the extent of vessel encasement by the myocardium. The length, location, and depth of myocardial bridging were correlated with the presence, length, and degree of dynamic compression observed at conventional angiography. Among the 300 patients studied (11 were excluded), myocardial bridging was observed at CT angiography in 174 (58%) as partial encasement (n=57) or full encasement (n=117). Conventional angiography revealed dynamic compression in 40 patients (13.3%; partial encasement in 1 patient and full encasement in 39). The length of the dynamic compression was considerably longer than the respective tunneled segment in all patients. Total length correlated (P=0.003) with the dynamic compression, but depth did not (P=0.283). CONCLUSIONS: The frequency of myocardial bridging observed by CT angiography was 58%, and conventional angiography revealed dynamic compression in 13.3% of total patients. Dynamic compression occurred almost exclusively (97.5% of the time) in patients with full encasement of the left anterior descending coronary artery, regardless of the presence of overlying muscle.

A case of very late stent thrombosis facilitated by drug eluting stent fracture: comparative images before and after stent fracture detected by 64-multidetector computed tomography.

A stent fracture (SF) is one of the responsible factors for in-stent restenosis after a percutaneous coronary intervention. Factors that have an important role for a SF are vessel tortuosity, the presence of a right coronary artery lesion, overlapping stents, and the use of a drugeluting stent (DES) such as a sirolimus-eluting stent. Unlike with the use of bare metal stents, most SFs have occurred with the use of DES, and a DES may be a possible factor for a SF. A SF can cause clinical problems that range from stable angina to acute coronary syndrome. We experienced a case of acute myocardial infarction that was combined with a SF. We describe here the coronary angiography findings and the 64-multidetector computed tomography images before and after the SF.

Coronary stent fracture: detection with 64-section multidetector CT angiography in patients and in vitro.

PURPOSE: To evaluate 64-section multidetector coronary computed tomographic (CT) angiography for the depiction of coronary stent fracture in patients and in vitro. MATERIALS AND METHODS: This retrospective study was approved by the institutional review board, and informed patient consent was waived. The coronary CT angiograms obtained in 371 consecutive patients (268 men, 103 women; mean age, 62.9 years) with 545 stents were reviewed. All patients with stent fractures underwent conventional coronary angiography and/or fluoroscopy as part of their medical care. In phantom studies, magnified radiographs of three types of drug-eluting stents in their fully expanded, maximally bent, and unrolled states were obtained. CT angiography and fluoroscopy of a water phantom that contained two drug-eluting stents--Cypher and Taxus devices--with four fractures each were performed, and two radiologists blinded to the fracture information evaluated the images. RESULTS: Twenty-four stents with fractures were identified. Eighteen fractured stents (13 Cypher, four Taxus, one S670) in 14 patients were detected with CT angiography; six (33%; two Cypher, four Taxus) of these 18 stents in five (36%) patients were not detected on conventional angiograms at the initial readings. Six fractured stents showed significant (>50%) recurrent in-stent stenosis. Of 58 arteries with overlapping stent placements, eight (14%) had fractures involving 11 stents. In the in vitro studies, 57 stent fractures (31 Cypher, 26 Taxus) were detected with CT angiography and 38 (18 Cypher, 20 Taxus) were detected with fluoroscopy. CONCLUSION: Coronary CT angiography depicts stent fractures in patients and phantoms, even those fractures that are not clearly depicted by conventional angiography. SUPPLEMENTAL MATERIAL: http://radiology.rsnajnls.org/cgi/content/full/249/3/810/DC1.

Coronary-to-bronchial artery fistula: demonstration by 64-multidetector computed tomography with retrospective electrocardiogram-gated reconstructions.

OBJECTIVE: The aim of this study was to evaluate the incidence of coronary-to-bronchial artery fistula (CBF) and clinical significance in 1300 patients examined with 64-multidetector computed tomography (MDCT) coronary angiography. METHODS: One thousand three hundred ten patients underwent coronary MDCT for atypical chest pain or screening. Volume-rendering and multiplanar reconstruction images were reviewed, and subsequent cineangiographies were compared. RESULTS: Eight cases of CBF were detected-6 originated from the left circumflex artery, and 2 originated from the right coronary artery. A hypertrophied anomalous branch of left circumflex artery was observed in 1 case, and underlying bronchiectasis was noted. Seven cases had a thin-wall communicating vessel. Subsequent cineangiography revealed identical appearance with MDCT reconstruction images. CONCLUSIONS: The incidence of CBF (0.61%) in this study is similar to those of a few cineangiographic studies in the literature. Our study showed that 64-MDCT coronary angiography is an accurate and noninvasive tool for detection of CBF.

Primary extraskeletal mesenchymal chondrosarcoma arising from the pancreas.

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.

Uniform image quality achieved by tube current modulation using SD of attenuation in coronary CT angiography.

OBJECTIVE: The objective of our study was to evaluate whether the SD of CT attenuation values obtained from unenhanced scans of the left atrium is a reliable parameter for the individual modulation of tube current to achieve uniform image quality in coronary CT angiography (CTA). MATERIALS AND METHODS: One hundred patients (59 men and 41 women) who were suspected to have coronary artery disease underwent coronary CTA using a 64-MDCT scanner. In addition to clinical studies, we also performed measurements on water phantoms. Tube current was modulated by the SD of the CT attenuation values measured from the left atrium on unenhanced images scanned at 300 mA. A modulation table was created from data obtained from the studies of water phantoms scanned at various tube currents. Other scanning parameters were identical to those used to obtain unenhanced and contrast-enhanced studies of the 100 patients. The SD values were measured from images scanned at an adjusted tube current, and the images of normal coronary and internal mammary arteries were graded. Radiation doses measured using the volume CT dose index (CTDI(vol)) were compared between the SD of the CT attenuation values and the modulation parameters suggested by the manufacturer of the scanner. RESULTS: Image quality was rated as grade 3 (low mottle) on a 4-grade scale by four observers for 92-94 of the 100 patients (average, 92.5%). The mean SD value at an adjusted tube current was 12.1 H with an SD of 0.758 H (target SD = 12 H). A radiation dose reduction of 9-45% was achieved in patients grouped by weight who weighed less than 70 kg, and a reduction of up to 71% was seen in individual cases. CONCLUSION: Modulating tube current using the SD of CT attenuation values from the left atrium is a highly reliable method of achieving uniform image quality in coronary CTA.

An ROC study of chest radiographs: 2K Versus 4K high-resolution soft-copy images.

Computed radiography of chest with a 4K image array was recently introduced. We performed a multiobserver study to compare the diagnostic accuracy of 2K (standard) and 4K (high quality) chest radiographs displayed on a 5-mega-pixel monitor (2K monitor). One hundred cases of posteroanterior chest radiographs (a total of 200 images) were selected by two chest radiologists. Those radiographs included pneumothorax (n = 14), nodules (n = 15), interstitial disease (n = 10), or neither abnormality (n = 61). These were interpreted by four radiologists in two separate sessions. They recorded their confidence scale for the presence or absence of abnormality. Diagnostic accuracy was determined by receiver operating characteristic (ROC) analysis for each observer. ROC analysis showed no statistically significant difference between the 2K and 4K modes for the detection of any of the different abnormalities by individual readers. Our preliminary study suggests that 2K mode would be sufficient for the detection of abnormality on chest radiograph and there is no considerable validity to incline toward the 4K mode in current picture archiving and communication system environment using 2K monitor. However, we think that additional investigation using more subtle parenchymal or rib lesion should be followed.

CT of nasal-type T/NK cell lymphoma in the lung.

Nasal-type T-cell/natural killer cell lymphoma is a new distinctive clinicopathologic entity with a characteristic immunophenotypic expression of CD56. Most cases show a predilection for the nasopharyngeal region and are referred to as nasal T/NK-cell lymphoma. Few cases occur in areas other than the nose. To the best of our knowledge, nasal type T/NK cell lymphoma with isolated lung involvement has not been reported. We illustrate here the CT findings of this rare tumor occurring primarily in the lung.

Low-grade fibromyxoid sarcoma: CT, sonography, and MR findings in 3 cases.

Low-grade fibromyxoid sarcoma (LGFMS) is a distinctive variant of fibrosarcoma characterized by deceptively bland histologic features and a paradoxically aggressive clinical course. The radiologic finding of this uncommon tumor has not been described to date. In this report, 3 cases of LGFMS occurring in axilla, chest wall, and pleura are presented with CT, MRI, and sonographic findings.