Yoshie Kunihiro

Added value of lung perfused blood volume images using dual-energy CT for assessment of acute pulmonary embolism

PURPOSE To investigate the added value of lung perfused blood volume (LPBV) using dual-energy CT for the evaluation of intrapulmonary clot (IPC) in patients suspected of having acute pulmonary embolism (PE). MATERIALS AND METHODS Institutional review board approval was obtained for this retrospective study. Eighty-three patients suspected of having PE who underwent CT pulmonary angiography (CTPA) using a dual-energy technique were enrolled in this study. Two radiologists who were blinded retrospectively and independently reviewed CTPA images alone and the combined images with color-coded LPBV over a 4-week interval, and two separate sessions were performed with a one-month interval. Inter- and intraobserver variability and diagnostic accuracy were evaluated for each reviewer with receiver operating characteristic (ROC) curve analysis. RESULTS Values for inter- and intraobserver agreement, respectively, were better for CTPA combined with LPBV (ICC=0.847 and 0.937) than CTPA alone (ICC=0.748 and 0.861). For both readers, diagnostic accuracy (area under the ROC curve [Az]) were also superior, when CTPA alone (Az=0.888 [reader 1] and 0.912 [reader 2]) was compared with that after the combination with LPBV images (Az=0.966 [reader 1] and 0.959 [reader 2]) (p<0.001). However, Az values of both images might not have significant difference in statistics, because Az value of CTPA alone was high and 95% confidence intervals overlapped in both images. CONCLUSION Addition of dual-energy perfusion CT to CTPA improves detection of peripheral IPCs with better interobserver agreement.

Kinematic MRI of the normal shoulder using a specially designed positioning device.

Objectives The objective of this study was to determine the normal patterns of the normal glenohumeral joint by kinematic MRI with a special positioning device. Methods Ten healthy volunteers were examined using an open MRI system. Axial three-dimensional gradient-echo images were obtained through the glenohumeral joint in the transverse axial plane by 30° increments from external rotation to internal rotation. Results The free margins of the anterior labrum (40%) and the posterior labrum (10%) were seen to be slightly mobile. Although the anterior labrum showed increased signal intensity (20%), no signal intensity changes occurred in the posterior labrum. Most of the anterior labrum was not triangular in internal rotation. The anterior joint capsule showed changes in shape (60%) in neutral and internal rotation. Conclusions Kinematic MRI can provide information on the labrocapsular ligamentous complex without the need for intraarticular injection of a contrast agent.

Assessment of volume reduction effect after lung lobectomy for cancer

BACKGROUND Lung lobectomy results in an unexpected improvement of the remaining lung function in some patients with moderate-to-severe emphysema. Because the lung function is the main limiting factor for therapeutic decision making in patients with lung cancer, it may be advantageous to identify patients who may benefit from the volume reduction effect, particularly those with a poor functional reserve. METHODS We measured the regional distribution of the emphysematous lung and normal lung using quantitative computed tomography in 84 patients undergoing lung lobectomy for cancer between January 2010 and December 2012. The volume reduction effect was diagnosed using a combination of radiologic and spirometric parameters. RESULTS Eight patients (10%) were favorably affected by the volume reduction effect. The forced expiratory volume in one second increased postoperatively in these eight patients, whereas the forced vital capacity was unchanged, thus resulting in an improvement of the airflow obstruction postoperatively. This improvement was not due to a compensatory expansion of the remaining lung but was associated with a relative decrease in the forced end-expiratory lung volume. According to a multivariate analysis, airflow obstruction and the forced end-expiratory lung volume were independent predictors of the volume reduction effect. CONCLUSIONS A combined assessment using spirometry and quantitative computed tomography helped to characterize the respiratory dynamics underlying the volume reduction effect, thus leading to the identification of novel predictors of a volume reduction effect after lobectomy for cancer. Verification of our results by a large-scale prospective study may help to extend the indications for lobectomy in patients with oncologically resectable lung cancer who have a marginal pulmonary function.

Volumetric evaluation of dual-energy perfusion CT for the assessment of intrapulmonary clot burden

AIM To evaluate the volumetric values of intrapulmonary clots (IPCs) using 64-section dual-energy perfusion computed tomography (DEpCT). MATERIALS AND METHODS A total of 174 patients suspected of having acute pulmonary embolism (PE) underwent DEpCT, and acute PE was diagnosed in 48 of these patients. DEpCT images were three-dimensionally reconstructed with four threshold ranges: 1-120 HU (V₁₂₀), 1-15 HU (V₁₅), 1-10 HU (V₁₀), and 1-5 HU (V₅). Each relative value per V₁₂₀ was expressed as %V₁₅, %V₁₀ and %V₅. These values were compared with the d-dimer, pulmonary arterial (PA) pressure, right ventricular (RV) diameter, RV/left ventricular diameter ratio, PA diameter, and CT angiographic obstruction index (CTOI). RESULTS In patients with IPCs, PA pressure, d-dimer and volumetric values of DEpCT were significantly higher (p < 0.001). Relative volumetric values at DEpCT had better correlations with the PA pressure, PA diameter, and CTOI than absolute ones, and %V₅ especially had good correlations with PA pressure (r = 0.44, p = 0.02), PA diameter (r = 0.40, p = 0.005), and CTOI (r = 0.38, p = 0.009). CONCLUSION The relative volumetric evaluation of DEpCT images with a lower attenuation threshold range may be helpful for assessing right heart strain, because these values had good correlation with CTOI, pulmonary pressure, and diameter in suggesting right heart load.

High-resolution computed tomography of chest complications in patients treated with hematopoietic stem cell transplantation

Hematopoietic stem cell transplantation (HSCT) has become a standard method for treating patients with hematological malignancies. Preconditioning chemotherapeutic drugs, total body irradiation (TBI), or chronic graft-versus-host disease (GVHD) can cause several chest complications after HSCT. Because immunosuppression is marked after HSCT, it takes at least 1 year for the immune system to recover completely. Therefore, several infectious and noninfectious complications may occur within the year after HSCT. HSCT-specific complications occur in a characteristic temporal sequence associated with the period following HSCT. During the neutropenic phase, bacterial pneumonia, fungal infection, pulmonary edema, and diffuse alveolar hemorrhage may occur. During the early phase, pneumocystis pneumonia, cytomegalovirus pneumonia, engraftment syndrome, and idiopathic pneumonia syndrome are the common complications. During the late phase, constrictive bronchiolitis and organizing pneumonia may occur probably associated with chronic GVHD. Although high-resolution CT findings lack specificity, the frequency and likelihood of occurrence of certain complications in certain phases and sometimes characteristic features (such as a CT halo sign for fungal infection) facilitate early detection of a life-threatening complication.

The low attenuation area on dual-energy perfusion CT: Correlation with the pulmonary function tests and quantitative CT measurements

PURPOSE To retrospectively investigate the distribution of the low attenuation area (LAA) on dual energy perfusion CT (DEpCT) in comparison with the results of pulmonary function tests (PFTs) and quantitative CT measurements. MATERIALS AND METHODS Twenty-eight patients (15 male and 13 female; mean age: 62.21 years) underwent DEpCT and PFTs within a 1-month interval. The ranges of the LAA on DEpCT were classified into six groups with attenuation values of 0-3, 0-5, 0-8, 0-10, 0-13 and 0-15 HU and the ratios of LAA in each group were compared with the percentage of forced expiratory volume in the 1st second (%FEV(1.0)), FEV(1.0)/forced vital capacity (FEV(1.0)/FVC) and the relative area of the lung with attenuation coefficients lower than -950 HU (RA(-950)). RESULTS The LAAs on the DEpCT images were significantly correlated with the RA(-950), %FEV(1.0) and FEV(1.0)/FVC, and the regression analysis showed that the best values of LAA on DEpCT were 0-10 HU with RA(-950) (r=0.63), 0-8 HU with %FEV(1.0) (r=-0.52) and 0-8HU with FEV(1.0)/FVC (r=-0.61) per patient. CONCLUSION The iodine disturbance on DEpCT had a moderate correlation with the results of the PFTs and RA(-950), but further examination would be needed for evaluation of iodine distribution.

The usefulness of a diagnostic method combining high-resolution CT findings and serum markers for cytomegalovirus pneumonia and pneumocystis pneumonia in non-AIDS patients.

Background The combination of high-resolution computed tomography (HRCT) findings and serum markers would be of great value in diagnosing cytomegalovirus pneumonia (CMVP) and pneumocystis pneumonia (PCP) considering low invasiveness. Purpose To compare the HRCT findings of CMVP and PCP and to evaluate the differences in HRCT findings between patients diagnosed based on pathologic evidence and serum markers. Material and Methods Two radiologists retrospectively evaluated the HRCT findings of 21 patients with CMVP and 70 patients with PCP. Eight patients with CMVP and 32 patients with PCP were diagnosed based on pathologic evidence (“Path” group), while 13 patients with CMVP and 38 patients with PCP were diagnosed based on serum markers (CMV antigenemia, β-D-glucan) (“Serum-Marker” group). A total of 19 CT morphological criteria were evaluated, and the significance of the differences between the two diseases and between the “Path” and “Serum-Marker” groups with respect to each disease was calculated. Results The presence of small nodules, the tree-in-bud pattern, and the halo sign was found more frequently in the CMVP group. Extensive ground-glass attenuation (GGA), a mosaic pattern, and a diffuse distribution were observed more frequently in the PCP group. There were significant differences between the “Path” and “Serum-Marker” groups in average extent of consolidation and distribution of consolidation in PCP, and the distribution of GGA in CMVP, respectively. Conclusion The combined use of HRCT findings and serum markers is useful for the diagnosis of CMVP and PCP in non-AIDS patients. The typical HRCT findings for the differential diagnosis included extensive GGA with mosaic pattern in PCP and nodules, nodules with or without the tree-in-bud pattern, and the halo sign in CMVP.

The Validation of a No-Drain Policy After Thoracoscopic Major Lung Resection

BACKGROUND The omission of postoperative chest tube drainage may contribute to early recovery after thoracoscopic major lung resection; however, a validation study is necessary before the dissemination of a selective drain policy. METHODS A total of 162 patients who underwent thoracoscopic anatomical lung resection for lung tumors were enrolled in this study. Alveolar air leaks were sealed with a combination of bioabsorbable mesh and fibrin glue. The chest tube was removed just after the removal of the tracheal tube in selected patients in whom complete pneumostasis was obtained. RESULTS Alveolar air leaks were identified in 112 (69%) of the 162 patients in an intraoperative water-seal test performed just after anatomical lung resection. The chest tube could be removed in the operating room in 102 (63%) of the 162 patients. There were no cases of 30-day postoperative mortality or in-hospital death. None of the 102 patients who did not undergo postoperative chest tube placement required redrainage for a subsequent air leak or subcutaneous emphysema. The mean length of postoperative hospitalization was shorter in patients who had not undergone postoperative chest tube placement than in those who had. The omission of chest tube placement was associated with a reduction in the visual analog scale for pain from postoperative day 0 until postoperative day 3, in comparison with patients who underwent chest tube placement. CONCLUSIONS The outcome of our validation cohort revealed that a no-drain policy is safe in selected patients undergoing thoracoscopic major lung resection and that it may contribute to an early recovery.

High-resolution CT findings of primary lung cancer with cavitation: a comparison between adenocarcinoma and squamous cell carcinoma

AIM To evaluate the high-resolution computed tomography (CT) findings of primary lung cancer with cavitation and compare the findings in adenocarcinoma and squamous cell carcinoma. MATERIALS AND METHODS The high-resolution CT findings of tumours with cavitation were retrospectively evaluated in 60 patients. Forty-seven of the lesions were diagnosed as adenocarcinomas; 13 were diagnosed as squamous cell carcinomas. The diameters of the tumour and cavity, the maximum thickness of the cavity wall, shape of the cavity wall, the number of cavities, and the presence of ground-glass opacity, bronchial obstruction, intratumoural bronchiectasis, emphysema, and honeycombing were evaluated. The mechanisms of cavity formation were examined according to the pathological features. RESULTS The maximum thickness of the cavity wall was significantly greater in squamous cell carcinomas than in adenocarcinomas (p=0.002). Ground-glass opacity and intratumoural bronchiectasis were significantly more common in adenocarcinomas than in squamous cell carcinomas (p<0.001 and p=0.040, respectively). Regarding the pathological findings, intratumoural bronchiectasis with or without alveolar wall destruction contributed to a significant difference between adenocarcinoma and squamous cell carcinoma (p<0.001; odds ratio [OR], 20.35; 95% confidence interval [CI], 3.87-107.10). CONCLUSION The cavity wall tends to be thicker in squamous cell carcinomas than in adenocarcinomas. The presence of ground-glass opacity and intratumoural bronchiectasis is strongly suggestive of adenocarcinoma.

Volumetric evaluation of dual-energy perfusion CT by the presence of intrapulmonary clots using a 64-slice dual-source CT

Background Dual-energy perfusion CT (DEpCT) directly represents the iodine distribution in lung parenchyma and low perfusion areas caused by intrapulmonary clots (IPCs) are visualized as low attenuation areas. Purpose To evaluate if volumetric evaluation of DEpCT can be used as a predictor of right heart strain by the presence of IPCs. Material and Methods One hundred and ninety-six patients suspected of having acute pulmonary embolism (PE) underwent DEpCT using a 64-slice dual-source CT. DEpCT images were three-dimensionally reconstructed with four threshold ranges: 1–120 HU (V120), 1–15 HU (V15), 1–10 HU (V10), and 1–5 HU (V5). Each relative ratio per V120 was expressed as the %V15, %V10, and %V5. Volumetric data-sets were compared with D-dimer, pulmonary arterial (PA) pressure, right ventricular (RV) diameter, RV/left ventricular (RV/LV) diameter ratio, PA diameter, and PA/aorta (PA/Ao) diameter ratio. The areas under the ROC curves (AUCs) were examined for their relationship to the presence of IPCs. This study was approved by the local ethics committee. Results PA pressure and D-dimer were significantly higher in the patients who had IPCs. In the patients with IPCs, V15, V10, V5, %V15, %V10, and %V5 were also significantly higher than those without IPC (P ≤ 0.001). %V5 had a better correlation with D-dimer (r = 0.30, P < 0.001) and RV/LV diameter ratio (r = 0.27, P < 0.001), and showed a higher AUC (0.73) than the other CT measurements. Conclusion The volumetric evaluation by DEpCT had a correlation with D-dimer and RV/LV diameter ratio, and the relative ratio of volumetric CT measurements with a lower attenuation threshold might be recommended for the analysis of acute PE.