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Multidetector row CT has been established as a noninvasive method for the detection of coronary artery disease. In previous studies, the diagnostic accuracy of 64-slice CT for the detection of in-stent restenosis usually displayed high sensitivity and negative predictive value, while specificity and positive predictive values were too low to allow its utilization in clinical practice. Especially in small stents-with a diameter below 3.0 mm-the accuracy of CT angiography to detect in stent stenosis has been low. Recently, CT systems with improved in-plane spatial resolution (high-definition CT, HDCT) have become commercially available. Furthermore, an experimental CT (fine-cell detector CT, FDCT) has been developed using half pitch dimension detector cells in both X and Z directions compared with 64-slice CT. Compared with that in conventional 64-slice CT, the spatial resolution was 30% improved in HDCT and 60% improved in FDCT, and the lumen visibility was 1.3 times improved in HDCT and 1.5 times improved in FDCT. The diagnostic accuracy of in-stent restenosis with HDCT was higher than 90% in both sensitivity and specificity, moderate (77%) in positive predictive value, and very high (98%) in negative predictive value. FDCT is not yet applicable to patients, however, further improvement of diagnostic accuracy in the evaluation of in-stent restenosis is expected in FDCT. In the near future, cardiac CT could reach the diagnostic performance to replace invasive catheter angiography, and would be the appropriate noninvasive technique for diagnosis of in-stent restenosis. [ABSTRACT FROM AUTHOR]

Hemosuccus pancreaticus, which is generally due to the rupture of a splenic artery aneursym into the pancreatic duct, is a rare cause of intermittent upper gastrointestinal hemorrhage. Segmental arterial mediolysis (SAM) is a rare arteriopathy. We report a 53-year-old man with hemosuccus pancreaticus due to a splenic artery aneurysm associated with SAM. The patient, who also had a celiac artery aneurysm affected by SAM, was successfully treated by both coil embolization and aortic stent grafting for complete coverage of the celiac artery. SAM is a very rare cause of hemosuccus pancreaticus, and endovascular treatment may be favorable for hemosuccus pancreaticus. [ABSTRACT FROM AUTHOR]

Objective: To compare two MR sequences at 1.5 T-T2-weighted and contrast-enhanced T1-weighted images-by using macroscopic sections to determine which image type enables the most accurate assessment of cervical carcinoma.Methods: Forty consecutive patients (mean age, 39.2 years) with biopsy-proven cervical carcinoma were included. Each MR sequence was assessed for tumour localisations, tumour margins, and cancer extent with the consensus of two readers, and tumour margins were rated on a five-point scale. MR findings were correlated with histopathological findings. Contrast-to-noise ratios (CNRs) obtained with each image were compared using nonparametric tests.Results: Thirty-one of 40 patients underwent hysterectomies and nine of 40 underwent trachelectomies. In 36 patients, lesions were identified on at least one sequence. The tumours at stage 1B or higher were detected in 94.7% on contrast-enhanced T1-weighted images and in 76.3% on T2-weighted images (P < 0.05). Tumour margins appeared significantly more distinct on contrast-enhanced T1-weighted images than on T2-weighted images (P < 0.001). The CNRs obtained using contrast-enhanced T1-weighted images were significantly higher (P < 0.001) than those obtained using T2-weighted images.Conclusion: Contrast-enhanced T1-weighted imaging is more useful for assessing cervical carcinoma than T2-weighted imaging. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to assess the body weight-tailored contrast material injection protocol for 64-detector computed tomography (CT) to maintain optimal coronary CT attenuation. Materials and methods: A total of 60 patients who underwent CT coronary angiography were assigned to one of three groups: protocol A, total of 0.7 ml kg with 300 mg I/ml iodine concentration; protocol B, total of 0.6 ml kg with 350 mg I/ml; protocol C, total of 0.7 ml kg with 350 mg I/ml. The injection duration was 10 s in all patients. The proportion of intracoronary attenuation values >325 HU was compared on a pervessel and per-patient basis. Results: The attenuation value was significantly more likely to exceed 325 HU with protocol C (95% for reader 1 and 90% for reader 2) than with protocol A or B on the per-vessel analysis ( P < 0.05). The attenuation value also signifi cantly exceeded 325 HU with protocol C (95% and 90%, respectively) more often than with protocol A or B on the per-patient analysis ( P < 0.05). Conclusion: A total of at least 0.7 ml kg contrast material with 350 mg/ml iodine concentration is required to achieve optimal coronary CT attenuation (>325 HU) with 64-detector CT when using an injection duration of 10 s. [ABSTRACT FROM AUTHOR]

Malignant transformation or tumor rupture is a rare complication of ovarian mature cystic teratomas. We present computed tomography (CT) images of a 52-year-old woman that revealed a large, predominantly cystic mass filled with fat and enhanced solid components located in the lower abdomen. Ten days later, the cystic mass ruptured, and massive ascites was observed on magnetic resonance imaging (MRI). Resulting from the rupture, MRI revealed reduced size and thickening wall of the tumor. After resection, the mass ruptured, and malignant transformation (squamous cell carcinoma) was observed. To our knowledge, there are no reports describing before and after images of a ruptured cystic teratoma with malignant transformation. [ABSTRACT FROM AUTHOR]

Background: The coronary sinus (CS) including the great cardiac vein is an important anatomic structure that is considered a landmark for the mitral annulus (MA) and also a target for catheter ablation. Objective: This study evaluated the anatomical relationship between the CS and its surrounding structures visualized by multi-detector computed tomography (MDCT). Methods: We performed MDCT on 42 patients, and the ranges of the coronary arteries (CAs) and esophagus that ran closest (<5 mm) to the CS were examined. In addition, the distances between the CS and the MA and left ventricle and left atrium were compared with the amplitudes of the local atrial and ventricular electrograms in the CS at the most lateral point (3 o''clock) and the inferior point (6 o''clock) in the CS. Results: The distal portion of the right CA ran near the antero-inferior side of the CS ostium in 92% of the patients. The esophagus and the left circumflex CA proximity to the CS ran from 15 to 41 mm and from 53 to 104 mm from the ostium in all patients. At the 3 o''clock and 6 o''clock position of the MA, the distance between the center of the CS and MA was 12 and 13 mm, respectively, and showed negative correlation with the ratio of atrial and ventricular electrograms. Conclusion: The right CA, the left circumflex CA, and the esophagus were frequently located near the CS. The CS was shifted away from the MA, and the CS–MA distance could be predicted with intracardiac electrograms. [Copyright &y& Elsevier]

Purpose: The purpose of this study was to evaluate the frequency of tracheobronchomalacia (TBM) associated with pulmonary emphysema with paired inspiratory-expiratory multidetector computed tomography (MDCT) using a low-dose technique.Materials and Methods: This study included 56 consecutive patients (55 men, 1 woman; mean age 68.9 years) with pulmonary emphysema who had undergone paired inspiratory-expiratory CT scanning with a low-dose technique (40 mA). All images were retrospectively examined by two thoracic radiologists in a blinded fashion. The diagnosis of TBM was based on the standard criterion of >50% reduction in the cross-sectional area of the tracheobronchial lumen at the end-expiratory phase. A mild TBM criterion of >30% reduction was also reviewed. All patients underwent pulmonary function tests. The relation between the forced expiratory volume in 1 s (FEV(1.0%)) and TBM was statistically analyzed.Results: Four (7.1%) and eight (14.3%) patients were diagnosed as TBM based on the standard and mild criteria, respectively. In four patients, the percentages of luminal narrowing were 63.4% and 51.2%, respectively for tracheomalacia and 59.2% and 62.0%, respectively, for bronchomalacia. The FEV(1.0%) values between patients with and without TBM showed no statistical difference.Conclusion: The incidence of TBM associated with pulmonary emphysema was 7.1% with the standard criterion. It is possible that TBM has been underdiagnosed in a number of patients with pulmonary emphysema. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate the clinical value of bilateral breast magnetic resonance (MR) imaging (MRI) in patients showing suspicious microcalcifications on mammography and negative ultrasound findings. Fifty patients underwent MRI before stereotactic vacuum-assisted breast biopsy (SVAB). MR findings were classified into five types for interpretation, and types 4 and 5 were considered malignant. SVAB revealed 13 carcinomas and 37 benign lesions. Malignant lesions were more frequently found in cases of positive MRI diagnoses than in negative MRI diagnoses (P < 0.001). Mammography had a sensitivity of 100%, a specificity of 24% and an accuracy of 44%, whereas mammography plus MRI had a sensitivity of 85%, a specificity of 100% and an accuracy of 96%. In the evaluation of mammographically detected microcalcifications, bilateral breast MRI is of good diagnostic value and may alter the indications for SVAB. [ABSTRACT FROM AUTHOR]

Background/Aims: Early evaluations of patients presenting with acute chest pain remain difficult. We examined the diagnostic capacity of multidetector computed tomography (MDCT) for acute coronary syndrome (ACS) in patients presenting with acute chest pain. Methods/Results: We examined 36 consecutive patients presenting with acute chest pain with neither diagnostic ECG changes nor elevated biomarkers. 64-slice MDCT was performed, and we evaluated the presenceof significant coronaryartery stenosis (>50% reduction in lumen diameter). Significant stenosis was detected in 15 patients by MDCT. Among them, 11 patients were diagnosed as having ACS based on the findings of coronary angiography or myocardial perfusion single photon emission computed tomography (positive predictive value 73%). All 21 patients without significant stenosis by MDCT, except only one, were regarded as not having ACS (negative predictive value 95%). Sensitivity and specificity were 92 and 83%, respectively. In patients without a history of coronary artery disease (CAD), both the specificity and positive predictive value improved to 100% (sensitivity 90%; negative predictive value 95%). In patients with neither a history of CAD nor coronary calcification, the diagnostic accuracy of MDCT was 100%. Conclusions: MDCT has high diagnostic capacity for the early evaluation of ACS, especially in patients without a history of CAD or coronary calcification. Copyright © 2008 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

The aim of this study was to determine the diagnostic performance of stress and rest perfusion magnetic resonance imaging (MRI) and late gadolinium-enhanced (LGE) MRI for identifying patients with obstructive coronary artery disease (CAD). A total of 50 patients with suspected CAD underwent stress-rest perfusion MRI, followed by LGE MRI with a 1.5-T system. Stress-rest perfusion MRI resulted in an area under the receiver-operating characteristic curve (AUC) of 0.92 for observer 1 and 0.84 for observer 2 with sensitivity and specificity of 89% (32/36) and 79% (11/14) by observer 1, 83% (30/36) and 71% (10/14) by observer 2, respectively, showing a moderate interobserver agreement (Cohen's kappa = 0.49). While combination of stress-rest perfusion and LGE MRI did not result in improved accuracy for the prediction of flow-limiting obstructive CAD (AUC 0.81 for observer 1 and 0.80 for observer 2), the sensitivity was increased to 92% in both observers with a substantial interobserver agreement (kappa = 0.70). Stress-rest myocardial perfusion MRI is an accurate diagnostic test for identifying patients with obstructive CAD. [ABSTRACT FROM AUTHOR]

We report the case of a sporadic gastric submucosal neurofibroma underneath a T1 stage cancer. A 61-year-old man underwent gastroscopy because of epigastralgia and was diagnosed as having T1 stage gastric cancer by an experienced gastroenterologist. Subsequently performed computed tomography (CT) showed poorly circumscribed wall thickening underneath the converged folds on three-dimensional images. On a dynamic enhancement study, the thickened wall was seen to be enhanced gradually from the arterial phase to the equilibrium phase. Based on these findings, we diagnosed stage T2 cancer. Total gastrectomy was performed, and the surgically removed specimen revealed that the wall thickening was caused by a submucosal neurofibroma and that cancer existed in this neurofibroma, invading the submucosa. This patient had no family history of neurofibromatosis, and so the lesion was diagnosed as early gastric cancer with a sporadic submucosal neurofibroma. Coexistence of gastric cancer and a submucosal tumor is rare, but such a case is one of the pitfalls of a CT diagnosis of T stage gastric cancer. [ABSTRACT FROM AUTHOR]

A 76-year-old man had undergone aneurysm exclusion and ascending abdominal aortic extraanatomical bypass for a thoracoabdominal aortic aneurysm in 1978. In 1983 hemoptysis occurred, and resection and closure of the central stump of the aorta and a left lower lobectomy were performed. Dilatation (ϕ50 mm) of a prosthetic graft (Cooley Graft ϕ18 mm) used for extraanatomical bypass was noted in 2001 and was repaired by placement of an Inoue stent graft. However, the aneurysm diameter increased further (ϕ70 mm), although no endoleak was noted: Placement of an Inoue stent graft covering the whole length of the prosthetic graft was repeated in 2006. The postoperative course was smooth, no endoleak occurred, and the patient was discharged 2 weeks after surgery. [ABSTRACT FROM AUTHOR]

Purpose To evaluate the clinical value of diffusion-weighted imaging (DWI) and dynamic MRI in combination with T2-weighted imaging (T2W) for the detection of prostate cancer. Materials and Methods A total of 83 patients with elevated serum prostate specific antigen (PSA) levels (>4.0 ng/mL) were evaluated by T2W, DWI, and dynamic MRI at 1.5 T prior to needle biopsy. The data from the results of the T2W alone (protocol A), combination of T2W and DWI (protocol B), and the combination of T2W+DWI and dynamic MRI (protocol C) were entered into a receiver operating characteristic (ROC) curve analysis, under results of systemic biopsy as the standard of reference. Results Prostate cancer was pathologically detected in 44 of the 83 patients. The sensitivity, specificity, accuracy, and the area under the ROC curve (Az) for the detection of prostate cancer were as follows: 73%, 54%, 64%, and 0.711, respectively, in protocol A; 84%, 85%, 84%, and 0.905, respectively, in protocol B; and 95%, 74%, 86%, and 0.966, respectively, in protocol C. The sensitivity, specificity, and accuracy were significantly different between the three protocols ( P < 0.01). Conclusion In patients with elevated serum PSA levels, the combination of T2W, DWI, and dynamic MRI may be a valuable tool for detecting prostate cancer and avoiding an unnecessary biopsy without missing prostate cancer. J. Magn. Reson. Imaging 2007. © 2006 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

Abstract: Superparamagnetic iron oxide (SPIO) particles are as MR contrast media composed of iron oxide crystals coated with dextran or carboxydextran. These particles are sequestered by phagocytic Kupffer cells in normal reticuloendothelial system (RES), but are not retained in tumor tissue. Consequently, there are significant differences in T2/T2* relaxation between normal RES tissue and tumors, which result in increased lesion conspicuity and detectability. The introduction of SPIO has been expected to substantially increase the detectability of hepatic metastases. For focal hepatocellular lesions, it has been documented that SPIO-enhanced MR imaging exhibits slightly better diagnostic performance than dynamic helical CT in the detection of hypervascular hepatocellular carcinoma (HCC). A combination of dynamic and static MR imaging technique using T1- and T2 imaging criteria appears to provide clinically more useful patterns of enhancement. SPIO-enhanced MR imaging also provides information useful for differential diagnosis, via enhancement of RES-containing tumors. With the exploitation of rapid T2*-sensitive sequences, SPIO-enhanced dynamic MR imaging may become comparable to gadolinium-enhanced dynamic MR imaging and dynamic studies with multidetector-row CT. SPIO-enhanced MR imaging plays an important role in therapeutic decision-making for patients with HCC. [Copyright &y& Elsevier]

Objective: Cryoablation of pulmonary metastases might be a useful therapy for nonsurgical candidates. Methods: The procedure was performed after achievement of local anesthesia for 35 tumors in 20 patients (12 male and 8 female patients; mean age, 57 years). The primary end point was the safety and feasibility of cryoablation, and the secondary end point was tumor control assessed by follow-up dynamic computed tomographic scanning performed every 3 months. Results: Of the 22 sessions of cryoablation, pneumothorax occurred in 11, hemoptysis occurred in 8, and there was 1 case of phrenic nerve palsy. The mean hospital stay was 2.6 days. There was local recurrence of 7 (20%) tumors in 7 (35%) patients during a 9- to 28-month (median, 21 months) follow-up period. One-year survival according to the Kaplan-Meier method was 89.4%. Conclusion: Percutaneous cryoablation therapy for metastatic lung tumors is feasible and minimally invasive, with satisfactory local control. [Copyright &y& Elsevier]

Purpose: To investigate the mechanism of ring enhancement on ferumoxides-enhanced T1-weighted (T1W) gradient echo images in malignant focal hepatic lesions.Materials and Methods: Eighteen patients with hepatocellular carcinoma (HCC) underwent breath-hold T1-, T2-, and T2*-weighted magnetic resonance (MR) images at 1.5-Tesla after ferumoxides administration. The existence of ring enhancement on T1W, and the maximum size of the area showing decreased phagocytic activity on T2W and T2*W, and that of the area showing ring enhancement on T1W were evaluated. The Kupffer cell (KC) density of HCC itself and peritumoral liver parenchyma was assessed with KC stain sections.Results: Ring enhancement was noted in 13 of 18 HCC (72%). Peritumoral KC density was increased in the ring enhancement (+) group as compared with the ring enhancement (-) group. In the ring enhancement (+) group, the tumor size measured on T2W was smaller than that measured on either T1W or T2*W, suggesting a sustained T1 relaxation effect and a decreased T2* relaxation effect in the peritumoral regions.Conclusion: Ring enhancement on superparamagnetic iron oxide (SPIO)-enhanced T1W may correlate with increased KC density and decreased SPIO clustering in KC in peritumoral regions. [ABSTRACT FROM AUTHOR]

This report describes an in-stent restenosis of the infrarenal aorta in a patient with Takayasu's arteritis in a nonactive state. A 10-mm-diameter Wallstent had been deployed 42 months previously. The stented restenosed segment was replaced by a surgical graft. Histopathological examination of the excised aortic segment showed a thin layer of fibrocellular neointima and massive organized and calcified thrombus. To our knowledge, this is the first histopathological report of a late in-stent restenosis of the abdominal aorta in Takayasu's arteritis. [ABSTRACT FROM AUTHOR]

Pathologically, restenotic lesions after stenting were investigated by use of atherectomized tissues of seven coronary and seven iliac arteries. The mean interval of the stent deployment to restenosis was 9.1 months for the coronary artery and 33.7 months for the iliac artery, indicating a 3.7-fold longer interval for the latter. This study does not include cases of acute thrombotic occlusion. The atherectomized tissue from restenotic coronary arteries showed abundant neointima with a-actin-positive and ultrastructually synthetic-type smooth muscle cells in a rich myxomatous extracellular matrix. In the iliac arteries, the predominant component of restenosis consisted of organized thrombi. The neointima of the iliac arteries was mature, and only a small amount of spindle cells were observed in the hyalinized matrix. The tissue that developed restenosis after stenting was different in the coronary and iliac arteries included in this series. This study on the atherectomized tissue suggests that even in the chronic stage, a major cause of in-stent restenosis among the larger caliber vessels such as the iliac artery is not neointima but stent thrombosis. [ABSTRACT FROM AUTHOR]

The left-atrial appendage (LAA) is the most frequent site of thrombus formation. The most probable reason is its anatomical structure and blood stasis. We hypothesized that peak time delay should occur in the LAA with stagnant blood flow. We measured peak time delay in LAA against left atrium with the flow-mode study of electron-beam CT for 49 patients (including 23 patients with atrial fibrillation [AF]). Volume-mode scannings were also performed to detect intracardiac thrombi. Patients with atrial fibrillation showed a larger value than those with sinus rhythm ( P <0.01). Some AF patients with no filling of contrast media into the LAA and/or thrombus showed a larger value than the others. The value obtained by the flow-mode study might have the potential to assess blood stasis and to predict the jeopardized state in the LAA. [ABSTRACT FROM AUTHOR]