Torahiko Yamanouchi

One-stop shop assessment for atrial septal defect closure using 256-slice coronary CT angiography.

ObjectivesTo investigate the feasibility and accuracy of measurement of the pulmonary to systemic blood flow ratio (Qp/Qs) and defect and rim sizes in secundum atrial septal defects (ASDs) using 256-slice CT, compared to the reference transoesophageal echocardiography (TEE) and right heart catheterization (RHC) measurements.MethodsTwenty-three consecutive adult patients with secundum ASDs who underwent retrospective ECG-gated coronary CT angiography (CCTA), TEE and RHC were enrolled in this study. Right ventricular (RV) and left ventricular (LV) stroke volumes (SV) were calculated by biventricular volumetry of CCTA. Qp/Qs-CT was defined as RVSV/LVSV. The sizes of the defect and rim were measured by multi-planar reconstruction CT images. Correlations between Qp/Qs-CT and Qp/Qs–RHC and between the defect diameter obtained by CT and TEE were analyzed by Pearson’s coefficient analysis. Rim sizes by CT and TEE were compared by paired t-test.ResultsQp/Qs-CT was significantly correlated with Qp/Qs-RHC (r = 0.83, p < 0.0001), and the defect diameter by CT was significantly correlated with that by TEE (r = 0.95, p < 0.0001). There was no significant difference between CT and TEE in measurements of rim size.Conclusions256-slice CCTA allows measuring Qp/Qs and size of defects and rims in patients with secundum ASDs, accomplishing pretreatment evaluation non-invasively and comprehensively.Key Points• Quantification of left-to-right shunting can be performed reliably and accurately by CT.• The sizes of defects and rims can be measured accurately using 256-slice CT.• 256-slice CT permits pretreatment evaluation of ASD non-invasively and comprehensively.

Prediction of post-operative pulmonary function after lobectomy for primary lung cancer: A comparison among counting method, effective lobar volume, and lobar collapsibility using inspiratory/expiratory CT

PURPOSE To compare the predictabilities of postoperative pulmonary function after lobectomy for primary lung cancer among counting method, effective lobar volume, and lobar collapsibility. METHODS Forty-nine patients who underwent lobectomy for primary lung cancer were enrolled. All patients underwent inspiratory/expiratory CT and pulmonary function tests 2 weeks before surgery and postoperative pulmonary function tests 6-7 months after surgery. Pulmonary function losses (ΔFEV1.0 and ΔVC) were calculated from the pulmonary function tests. Predictive postoperative pulmonary function losses (ppoΔFEV1.0 and ppoΔVC) were calculated using counting method, effective volume, and lobar collapsibility. Correlations and agreements between ΔFEV1.0 and ppoFEV1.0 and those between ΔVC and ppoΔVC were tested among three methods using Spearmans correlation coefficient and Bland-Altman plots. RESULTS ΔFEV1.0 and ppoΔFEV1.0insp-exp were strongly correlated (r=0.72), whereas ΔFEV1.0 and ppoΔFEV1.0count and ΔFEV1.0 and Pred. ΔFEV1.0eff.vol. were moderately correlated (r=0.50, 0.56). ΔVC and ppoΔVCeff.vol. (r=0.71) were strongly correlated, whereas ΔVC and ppoΔVCcount, and ΔVC and ppoΔVC insp-exp were moderately correlated (r=0.55, 0.42). CONCLUSIONS Volumetry from inspiratory/expiratory CT data could be useful to predict postoperative pulmonary function after lobectomy for primary lung cancer.

Quantification of coronary flow using dynamic angiography with 320-detector row CT and motion coherence image processing: Detection of ischemia for intermediate coronary stenosis.

OBJECTIVES Anatomical coronary stenosis is not always indicative of functional stenosis, particularly for intermediate coronary lesions. The purpose of this study is to propose a new method for quantifying coronary flow using dynamic CT angiography for the whole heart (heart-DCT) and investigate its ability for detecting ischemia from intermediate coronary stenosis. METHODS Participants comprised 36 patients with coronary artery disease who underwent heart-DCT using 320-detector CT with tube voltage of 80kV and myocardial perfusion scintigraphy (MPS). Heart-DCT was continuously performed at mid-diastole throughout 15-25 cardiac cycles with prospective ECG-gating after bolus injection of contrast media (12-24ml). Dynamic datasets were computed into 90-100 data sets by motion coherence image processing (MCIP). Next, time-density curves (TDCs) for coronary arteries with a diameter >3mm were automatically calculated for all phases using MCIP. On the basis of the maximum slope method, coronary flow index (CFI) was defined as the ratio of the maximum upslope of coronary artery attenuation to the upslope of ascending aorta attenuation on the TDC, and was used to quantify coronary flow. CFIs for the proximal and distal sites of coronary arteries with mild-to-moderate stenosis were calculated. Coronary territories were categorized as non-ischemic or ischemic by MPS. Receiver-operating-characteristic (ROC) analysis was performed to determine the optimal cutoff for CFI to detect ischemia. RESULTS Distal CFI was significantly lower for ischemia (0.26±0.08) than for non-ischemia (0.50±0.17, p<0.0001). No significant difference in proximal CFI was seen between ischemia (0.55±0.23) and non-ischemia (0.62±0.24). ROC analysis revealed 0.39 as the optimal cutoff for distal CFI to detect ischemia, with C-statistics of 0.91, 100% sensitivity, and 75% specificity. CONCLUSIONS This novel imaging technique allows coronary flow quantification using heart-DCT. Distal CFI can detect myocardial ischemia derived from intermediate coronary stenosis.

Lymphomatoid Granulomatosis: Two Different Phenotypes of Computed Tomography Findings

Lymphomatoid granulomatosis (LYG) is a lymphoproliferative disease that develops mainly in the lung; typically, multiple nodules are seen in the lower lungs. Its pathogenesis is related to a reactivation of Epstein-Barr virus (EBV). Atypical B-cell lymphocytes infected by EBV and reactive T-cell lymphocytes infiltrate around the blood vessels of the lung. The nodules and associated necrosis then form granulomatous-like lesions. We present a case of LYG with variable imaging findings during the patient’s clinical course.