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PURPOSE:We aimed to evaluate the usefulness of histograms of lung perfused blood volume (HLPBV) based on the presence of pulmonary thromboembolism (PTE) and the pulmonary embolic burden.METHODS:A total of 168 patients (55 males; mean age, 62.9 years) underwent contrast-enhanced dual-energy computed tomography (DECT) between January 1 2012 and October 31 2014. Initial DECT images were three-dimensionally reconstructed, and the HLPBV patterns were divided into three types, including the symmetric type (131 patients, 78.0%), gradual type (25 patients, 14.9%), and asymmetric type (12 patients, 7.1%).RESULTS:Acute PTE was diagnosed in all 12 patients with asymmetric type (100%), 19 of the 25 patients with gradual type (76%) and 24 of the 131 patients with symmetric type (18.3%). HLPBV pattern exhibited correlations with the right/left ventricular diameter ratio (r=0.36, P = 0.007) and CT obstruction index (r=0.63, P < 0.001) in patients with PTEs. When the gradual and asymmetric types were regarded as positive for PTE, the specificity, positive predictive value, negative predictive value, and accuracy were 92.9%, 83.8%, 87.6%, and 81.0%, respectively.CONCLUSION:Histogram-pattern analysis using DECT might be a useful application to diagnose PTE.

Abstract Background Steroid therapy, a key therapy for inflammatory, allergic, and immunological disorders, is often associated with steroid myopathy as one of the side effects. Steroid therapy is considered the first-line therapy for myositis; however, there have been no reports strictly comparing the muscle mass in patients with myositis before and after steroid therapy. Thus, it is currently unclear whether steroid therapy for such patients affects muscle volume in addition to muscle strength. We aimed to determine the change in muscle mass after steroid therapy via cross-sectional computed tomography (CT) in patients with myositis. Methods Data from seven patients with myositis and eight controls, who were all treated with high doses of steroids, were assessed before and after steroid therapy. Clinical factors in patients with myositis included serum muscle enzyme levels and muscular strength. The cross-sectional area of skeletal muscle and the low muscle attenuation rate at the level of the caudal end of the third lumbar vertebra were obtained using CT and measured using an image analysis program for all patients. Data were subjected to statistical analysis using several well-established statistical tests. The Wilcoxon signed-rank test was used for comparing paired data for each patient. The Mann-Whitney U test was used to compare sets of data sampled from two groups. The Spearman’s rank correlation coefficient was used for determining the correlations between two variables. Statistical significance was set at p

Background--Recently, we reported that urinary 8-hydroxy-2'-deoxyguanosine (U-8-OHdG), an oxidative stress marker, reflected inflammatory activity in cardiac sarcoidosis (CS). Here, we investigated whether U-8-OHdG levels were associated with ventricular tachycardia (VT) in patients with CS. Methods and Results--This prospective cohort study enrolled 62 consecutive patients with CS, of whom 36 were diagnosed as having active CS based on abnormal 18F-flurodeoxyglucose accumulation in the heart on positron-emission tomography/computed tomography. The 36 patients with active CS were subdivided as having CS with sustained VT (CS-VT group; n=18) or CS without sustained VT (CS-nVT group; n=18). Twenty-seven patients diagnosed with idiopathic dilated cardiomyopathy served as heart failure controls. U-8-OHdG, brain natriuretic peptide, cardiac function indices, and immunohistological data from subendomyocardial biopsy samples were compared across groups. Immunohistochemical examination of ventricle biopsy samples revealed that the anti-8-OHdG antibody-positive area of cardiac tissue was significantly greater in CS-VT than in CS-nVT or dilated cardiomyopathy and significantly correlated with U-8-OHdG levels (n=58; R=0.61; P<0.00001), which were significantly higher in CS-VT than in CS-nVT (24.6±7.1 versus 15.2±3.8 ng/mg⋅Cr; P<0.0001). Other baseline characteristics did not differ between the groups. Multivariate analysis indicated that U-8-OHdG was an independent determinant factor for VT. Receiver operating characteristic curve analysis to identify patients with VT resulted in a U-8-OHdG cutoff value of 17.5 ng/mg ⋅Cr (sensitivity, 89%; specificity, 83%; area under the curve, 0.90). Conclusions--U-8-OHdG levels are associated with VT in patients with active CS diagnosed by 18F-flurodeoxyglucose positron-emission tomography, providing additive and relevant information about the arrhythmia substrate. [ABSTRACT FROM AUTHOR]

Background: The aim of this study is to evaluate the accuracy of a newly developed quantitative method using 64-multislice computed tomography angiography (CTA) to detect coronary in-stent restenosis (ISR). Methods and results: CTA was performed in 45 patients who underwent stent implantation (79 lesions) and the accuracy to diagnose ISR was evaluated by comparing with invasive coronary angiography (ICA). CTA was evaluated both visually and quantitatively using a new stent restenosis index (SRI) utilizing CT densities at proximal and distal artery lumen from the stented region and the correction value depending on the stent diameter. ICA showed 11 ISR (14%). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for visual evaluation were 78%, 75%, 35%, 95%, and 76%, respectively. On the other hand, the quantitative evaluation using SRI represents 82%, 93%, 64%, 97%, and 91%, respectively. Conclusions: Evaluation of ISR using SRI is superior to the visual estimation of CTA. [ABSTRACT FROM AUTHOR]

SUMMARY: The usefulness of magnetic resonance imaging (MRI) for aortic diseases is discussed, with special attention given to the MRI features of aortic dissection and Takayasu arteritis. Computed tomography (CT) and MRI provide excellent visualization of vessels and their relationship to surrounding structures; however, CT depicts the vessel lumen optimally only when contrast enhancement is used. MRI, with its inherent multiplanar imaging capability, is well suited for evaluation of the thoracic and abdominal aorta and can be used with or without contrast enhancement. Basic technical considerations in cardiac imaging, which include conventional spin-echo, fast spin-echo, cine gradient, and echo-planar imaging, with time-of-flight and phase-contrast methods, are discussed and applied to aortic aneurysm, aortic dissection, and Takayasu arteritis. The diagnostic capacity of spin-echo MRI in patients with suspected aortic dissection is enhanced when it is combined with cine MRI. Despite the ability of CT and MRI to demonstrate luminal and mural changes of aortic abnormalities, conventional angiography still may be necessary at first admission for selected patients in the late occlusive phase to provide additional information on the degree and extent of the arteritis. CT angiography and MR angiography are promising imaging techniques that will overcome difficulties in visualizing distal branch vessel lesions and obviate the need for conventional angiography in the near future. [ABSTRACT FROM AUTHOR]