Gham Hur

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.

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.

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.

CT features of torsion of benign cystic teratoma of the ovary

PURPOSE The purpose of this work was to evaluate the usefulness of CT scans for distinguishing torsed from uncomplicated benign cystic teratoma (BCT). METHOD Retrospective analysis was performed in 14 torsed BCTs (14 patients) and in 23 uncomplicated BCTs (20 patients) for comparison. The features on CT scans were compared to the pathologic findings. RESULTS CT findings indicating torsed BCT were the presence of eccentric wall thickening of >1 cm, peritumoral infiltration, and presence of enlarged solid tubal mass adjacent to the uterus (p < 0.05). CONCLUSION The present study suggests that CT is useful in differentiating torsed from uncomplicated BCT. Although CT findings are not specific for some patients, detection of certain CT findings could increase the diagnostic accuracy.

Percutaneous insertion of Zilver stent in malignant biliary obstruction

BackgroundWe evaluated the clinical efficacy and technical feasibility of the percutaneously inserted self-expandable nitinol stent (Zilver stent) for palliation of malignant biliary obstruction.MethodsSeventeen patients with malignant tumors involving the intra- or extrahepatic bile duct who presented with obstructive jaundice underwent percutaneous insertion of a self-expandable nitinol stent. We retrospectively reviewed the hospital records of patients and evaluated the technical feasibility on stent placement, complications, patient survival, and duration of stent patency.ResultsPercutaneous biliary stenting with 27 Zilver stents was performed in 17 patients with malignant biliary obstruction. Technical success was 95%. Malposition of the stent was encountered in one patient. Minor technical problems were encountered in two patients: the introducer tip was broken during stent insertion, so endoscopic removal was done. Mean follow-up period for the 17 patients was 182 days (range 29–485 days): nine patients died of progressive disease at a mean follow-up of 151 days (range 61–371days) after stent insertion and eight patients remained alive at the final follow-up of 216 days (range 29–485 days). The median survival period for all patients was 277 days. The stent occlusion rate was 26% and the mean patency period was 280 days. In five patients, seven stents were obstructed by tumor ingrowth and overgrowth. Stent patency rates were 100%, 100%, 75%, 61%, and 41% at 1, 2, 3, 6, and 12 months, respectively. A late complication, erosive bleeding of the hepatic artery by the stent, developed in one patient.ConclusionPercutaneous biliary stenting using the nitinol stent is technically feasible and safe and clinically efficacious treatment for malignant biliary obstruction, even with a minor technical problem during stent insertion.

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.

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.

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.

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.