Mitsuko Tsubamoto

Pathologic subgroups of nonspecific interstitial pneumonia: differential diagnosis from other idiopathic interstitial pneumonias on high-resolution computed tomography.

Objective: To determine whether the subtypes of nonspecific interstitial pneumonia (NSIP) could be differentiated from other idiopathic interstitial pneumonias (IIPs) on the basis of findings on high-resolution computed tomography (CT). Methods: Two observers evaluated the high-resolution CT findings in 90 patients with IIPs. The patients included 36 with NSIP, 11 with usual interstitial pneumonia (UIP), 8 with cryptogenic organizing pneumonia (COP), 10 with acute interstitial pneumonia (AIP), 14 with desquamative interstitial pneumonia (DIP) or respiratory bronchiolitis-associated interstitial lung disease (RB-ILD), and 11 with lymphoid interstitial pneumonia (LIP). The NSIP cases were subdivided into group 1 NSIP (n = 6), group 2 NSIP (n = 15), and group 3 NSIP (n = 15). Results: Observers made a correct diagnosis with a high level of confidence in 65% of NSIP cases, 91% of UIP cases, 44% of COP cases, 40% of AIP cases, 32% of DIP or RB-ILD cases, and 82% of LIP cases. Group 1 NSIP was misdiagnosed as AIP, DIP or RB-ILD, and LIP in 8.3% of patients, respectively. Group 2 NSIP was misdiagnosed as COP in 10% of patients, LIP in 6.7%, AIP in 3.3%, and DIP or RB-ILD in 3.3%. Group 3 NSIP was misdiagnosed as UIP in 6.7% of patients, COP in 6.7%, and DIP or RB-ILD in 3.3%. Conclusions: In most patients, NSIP can be distinguished from other IIPs based on the findings on high-resolution CT. Only a small percentage of patients with predominantly fibrotic NSIP (group 3 NSIP) show overlap with the high-resolution CT findings of UIP.

Pulmonary Cavitary Nodules on Computed Tomography : Differentiation of Malignancy and Benignancy

Objective: To establish computed tomographic findings that enable accurate differentiation between malignant and benign cavitary lung nodules. Methods: Computed tomographic scans from 39 patients with malignant cavitary nodules and from 39 patients with benign cavitary nodules were independently assessed by 2 observers. They recorded the computed tomographic findings of both types of cavitary nodules and surrounding pulmonary parenchyma. The computed tomographic findings were then compared using &khgr;2 test. Results: The notch was found in 29% of benign cavitary nodule cases and in 54% of malignant cavitary nodule cases (P < 0.01). An irregular internal wall was found in 26% of benign nodules and in 49% of malignant nodule cases (P < 0.01). A linear margin (P < 0.01), satellite nodule presence (P < 0.01), bronchial wall thickening (P < 0.05), consolidation (P < 0.05), and ground-glass attenuation (P < 0.01) were significantly more frequent in benign cavitary nodules than in malignant ones. Conclusions: Although the computed tomographic findings of benign and malignant cavitary nodules overlap, some computed tomographic findings are useful for differentiating cavitary nodules.

MR imaging of thymic epithelial tumors: correlation with World Health Organization classification.

PurposeThe aim of this study was to determine magnetic resonance imaging (MRI) features of various subtypes of thymic epithelial tumors based on the World Health Organization classification.Materials and methodsThe study included 64 patients with histologically proven thymic epithelial tumors. Two observers evaluated the MRI findings in terms of tumor size, contour, lobulation, shape, homogeneity, the presence of intratumor high- and low-signal foci, enhancement degree and pattern, the presence of capsule and septum, and associated mediastinal lymphadenopathy and pleural effusion.ResultsType A tumors were more likely to have a smooth contour, round shape, distinct capsule, and smaller size compared to any other type of thymic epithelial tumor. Thymic carcinomas demonstrated a higher prevalence of low-signal foci within the mass on T2-weighted images and mediastinal lymphadenopathy than any other types. The frequency of heterogeneous intensity on T2-weighted images increased from type A tumors to thymic carcinomas.ConclusionThe presence of a smooth contour, round shape, and capsule is highly suggestive of a type A tumor. Foci of low signal intensity in the mass on T2-weighted images and mediastinal lymphadenopathy are highly suggestive of thymic carcinomas.

Quantitative analysis for computed tomography findings of various diffuse lung diseases using volume histogram analysis.

Objectives: The aim of this study was to achieve the quantitative analysis of the characteristic computed tomography (CT) findings and course of interstitial pneumonia using the volume histogram method. Methods: Contrast (CNT), variance (VAR), and entropy (EPY) values from whole-lung volume data were compared between normal lungs and 5 diseases that have characteristic CT findings. Thirteen cases with nonspecific interstitial pneumonia (NSIP) were evaluated before and after treatment. Results: In cases with thickening of the bronchovascular bundles and interlobular thickening, ground-glass attenuation, airspace consolidation, and honeycombing, the values of VAR and EPY were greater than those in the normal cases (P < 0.05). In the cases with NSIP, the CNT value after treatment was significantly greater and the values of VAR and EPY after treatment were significantly lower than those before treatment (P < 0.05). Conclusions: Volume histogram analysis is a promising method for the evaluation of diffuse lung diseases and the effectiveness of treatment.

Evaluation of coronary artery bypass grafts using multidetector-row CT with Japanese patients

PurposeTo evaluate the patency of coronary artery bypass grafting (CABG) with multidetectorrow computed tomography (MDCT) in Japanese patients, who have narrower coronary arteries than Caucasians.Materials and MethodsNineteen patients (12 men and 7 women, mean age: 63±12 years) with 33 coronary bypass grafts were examined with three-dimensional volume rendering (3D-VR) and curved multiplanar reconstruction (MPR) of MDCT. All grafts were compared with those obtained with selective graft angiography.ResultsFor the 19 patients with 33 grafts, the overall sensitivity and specificity, compared with those for selective bypass angiography, were 96.7% and 100%, respectively.ConclusionThe patency of CABG in Japanese patients can be effectively evaluated with 3D-VR and curved MPR of MDCT.

Usefulness of newly developed interactive multiplanar reconstruction viewer for large amount of image sets by multidetector-row CT: evaluation of invasion to surrounding organs of esophageal carcinoma

The objective of this study is to evaluate usefulness of newly developed interactive multiplanar reconstruction (MPR) viewer for the evaluation of invasion to surrounding organs of esophageal carcinoma.

Time study of computer aided diagnosis—a preliminary results on temporal subtraction

Abstract In this paper, we present the results of time study of CAD (Computer-Aided Diagnosis) on temporal subtraction for ground-glass shadow on chest radiographs. Our results showed that the average reading time with the CAD system was significantly longer than without employing the CAD system. However, diagnostic accuracy with temporal subtraction images was slightly improved than without temporal subtraction (with; Az=0.96, without; Az=0.95). Consequently, we could interpret that the radiologists performance was enhanced by CAD on temporal subtraction, even with longer reading time.