Shingo Iwano

3D-CT Volumetry of the Lung Using Multidetector Row CT : Comparison with Pulmonary Function Tests

RATIONALE AND OBJECTIVES The aim of this study was to evaluate the accuracy of measurements of lung volumes reconstructed using three-dimensional computed tomographic (CT) imaging from thin-section multidetector-row CT images compared to standard pulmonary function testing. MATERIALS AND METHODS Preoperative three-dimensional CT images and pulmonary function test results of 64 patients with solitary pulmonary nodules who were considered candidates for lung resection were reviewed. On the three-dimensional CT images, total lung capacity (TLC(CTV)), emphysematous lung capacity (ELC(CTV)), and normal lung capacity (NLC(CTV)) were calculated. Total lung capacity (TLC), vital capacity, and forced expiratory volume in 1 second were measured using spirometry. RESULTS There was a strong positive correlation between estimated TLC(CTV) and measured TLC values (r = 0.87, P < .001). Estimated ELC(CTV) at the threshold value of -900 Hounsfield units was negatively correlated with forced expiratory volume in 1 second (r = -0.56, P < .001). NLC(CTV) values were more strongly correlated with vital capacity values than TLC(CTV) values (r = 0.74, P < .001). CONCLUSIONS Lung volume calculated using three-dimensional CT volumetry was well correlated with lung volume measured using spirometry. Three-dimensional CT volumetry can be used to evaluate pulmonary function.

Mediastinal atlas creation from 3-D chest computed tomography images: Application to automated detection and station mapping of lymph nodes

One important aspect of lung cancer staging is the assessment of mediastinal lymph nodes in 3-D chest computed tomography (CT) images. In the current clinical routine this is done manually by analyzing the 3-D CT image slice by slice to find nodes, evaluate them quantitatively, and assign labels to them for describing the clinical and pathologic extent of metastases. In this paper we present a method to automate the process of lymph node detection and labeling by creation of a mediastinal average image and a novel lymph node atlas containing probability maps for mediastinal, aortic, and N1 nodes. Utilizing a fast deformable registration approach to match the atlas with CT images of new patients, our method can maintain an acceptable runtime. In comparison to previously published methods for mediastinal lymph node detection and labeling it also shows a good sensitivity and positive predictive value.

What causes false-negative PET findings for solid-type lung cancer?

BACKGROUND To investigate possible causes for false-negative findings on PET scans for solid-type lung cancers, we retrospectively compared PET findings to clinical and pathological features using multivariate analysis. METHODS We reviewed PET/CT records, clinical records, preoperative thin-section CT images, and postoperative pathological records and selected only solid-type primary lung cancers with lesions ≤ 40 mm in diameter that had been definitively diagnosed by surgical resection. PET images with SUVmax of ≥ 2.5 were considered PET-positive. Logistic regression analysis was used to identify independent predictors of PET-positive or negative among five factors: body weight, blood glucose level, lesion size, location, and histological classification. RESULTS A total of 187 solid-type primary lung cancers were selected. Forty lesions (21.4%) were judged as PET-negative and 147 lesions (78.6%) were judged as PET-positive. Multivariate logistic analysis for the 187 lesions revealed that lesion size (p<0.001) and histological tumour type (p<0.001) were significant factors for determining whether PET findings were negative. CONCLUSIONS Among solid-type lung cancers, lesion size and histopathological findings were significantly associated with FDG uptake. In particular, it warrants attention that lesions ≤ 2 cm and bronchioloalveolar carcinoma and well-differentiated adenocarcinoma have a tendency for negative PET findings.

Automatic mediastinal lymph node detection in chest CT

Computed tomography (CT) of the chest is a very common staging investigation for the assessment of mediastinal, hilar, and intrapulmonary lymph nodes in the context of lung cancer. In the current clinical workflow, the detection and assessment of lymph nodes is usually performed manually, which can be error-prone and timeconsuming. We therefore propose a method for the automatic detection of mediastinal, hilar, and intrapulmonary lymph node candidates in contrast-enhanced chest CT. Based on the segmentation of important mediastinal anatomy (bronchial tree, aortic arch) and making use of anatomical knowledge, we utilize Hessian eigenvalues to detect lymph node candidates. As lymph nodes can be characterized as blob-like structures of varying size and shape within a specific intensity interval, we can utilize these characteristics to reduce the number of false positive candidates significantly. We applied our method to 5 cases suspected to have lung cancer. The processing time of our algorithm did not exceed 6 minutes, and we achieved an average sensitivity of 82.1% and an average precision of 13.3%.

3d-ct Lung Volumetry Using Multidetector Row Computed Tomography: Pulmonary Function of Each Anatomic Lobe

Purpose We sought to determine the volume of each anatomic lung lobe reconstructed using 3-dimensional computed tomography (3D-CT) imaging from multidetector CT images and to compare these with pulmonary function test results. Materials and Methods We reviewed preoperative 3D-CT images and spirometry results of 111 patients (86 men and 25 women) with pulmonary neoplasms who were considered candidates for lung resections. On a 3D-CT image, the entire lung was semiautomatically separated into 5 anatomic lobes: right upper lobe, right middle lobe, right lower lobe, left upper lobe, and left lower lobe. For each lobe, total lobar volume, emphysematous lobar volume with low attenuation values of less than −950 HU, and normal lobar volume (NLV=total lobar volume−emphysematous lobar volume) were calculated. Vital capacity, forced expiratory volume in 1 second, and diffusing capacity for carbon monoxide (DLCO) were measured by spirometry. Relationships between NLV values of each lobe and pulmonary function results were determined by the Pearson correlation coefficients and multiple regression analysis. Results The NLV values for both lower lobes (right lower lobe and left lower lobe) and the other lobes (right upper lobe, right middle lobe, and left upper lobe) were significantly correlated with vital capacity and forced expiratory volume in 1 second; lower lobes showed a stronger tendency toward these correlations. The NLV values of the lower lobes were significantly correlated with DLCO (P<0.001), although the NLV values of the other lobes were not correlated with DLCO (P=0.112). Conclusions Pulmonary function results, particularly DLCO, were primarily affected by the NLVs of the lower lobes.

Virtual bronchoscopy-guided transbronchial biopsy for aiding the diagnosis of peripheral lung cancer.

OBJECTIVE The aim of this study was to evaluate the clinical value of virtual bronchoscopy (VB) in aiding diagnosis of peripheral lung cancer by transbronchial biopsy (TBB). In addition, we sought to systematically analyze the factors that affect the diagnostic sensitivity of VB-guided TBB for the evaluation of peripheral lung cancers. MATERIALS AND METHODS A hundred and twenty-two peripheral lung cancers from 122 patients (82 men and 40 women, 38-84 years; median 68.5 years) who were performed VB-guided TBB were evaluated retrospectively. VB was reconstructed from 1- or 0.5-mm slice thickness images of multi-detector CT (MDCT). Experienced pulmonologists inserted the conventional and ultrathin bronchoscopes into the target bronchus under direct vision following the VB image. RESULTS A definitive diagnosis was established by VB-guided TBB in 96 lesions (79%). The diagnostic sensitivity of small pulmonary lesions ≤30 mm in maximal diameter (71%) was significantly lower than that of lesions >30 mm (91%, p=0.008). For small pulmonary lesions ≤30 mm (n=76), internal opacity of the lesion was the independent predictor of diagnostic sensitivity by VB-guided TBB, and the non-solid type lung cancers were significantly lower than the solid type and part-solid type lung cancers for diagnostic sensitivity (odds ratio=0.161; 95% confidence interval=0.033-0.780; p=0.023). CONCLUSION Use of an ultrathin bronchoscope and simulation with VB reconstructed by high quality MDCT images is thought to improve pathological diagnosis of peripheral lung cancers, especially for solid and partly solid types. For small pulmonary lesions ≤30 mm, the lesion internal opacity is a significant factor for predicting the diagnostic sensitivity, and the sensitivity was low for small non-solid type of lung cancers.

Clinical impact of prevalence and severity of COPD on the decision-making process for therapeutic management of lung cancer patients

BackgroundRecent studies suggest that coexistence of chronic obstructive pulmonary disease (COPD) might be independently related to a worse prognosis for lung cancer. However, because data on the substantial prevalence of COPD and its severity in Asian lung cancer patients remain limited, clinical impact of prevalence and severity of COPD among the population has not been fully evaluated. Furthermore, patients with COPD often have comorbidities. Thus, whether the decision-making process for therapeutic management of lung cancer patients might be independently affected by COPD remains elusive.MethodsClinical impact of prevalence and severity of COPD were evaluated in 270 Japanese patients with newly diagnosed lung cancer who were sequentially registered and underwent bronchoscopy from August 2010 to July 2012 at Nagoya University hospital. Furthermore, to explore whether or not the severity of airflow obstruction might affect the decision to propose thoracic surgery with curative intent, we evaluated data from patients with lung cancer at stage 1A to 3A who underwent spirometry and bronchoscopy.ResultsThe prevalence rate of COPD was 54.4% among Japanese patients with lung cancer who underwent bronchoscopy. The incidence of Global Initiative for Chronic Obstructive Lung Disease (GOLD) grades 1 and 2 was significantly higher than that of GOLD grade 3. Although COPD-related comorbidities were not independent factors for proposing thoracic surgery, the number of thoracic surgeries performed was significantly less in the COPD group than the non-COPD group. Multivariate analysis showed that more severe airway obstruction, advanced clinical staging, and higher age, were independent factors associated with the decision on thoracic surgery.ConclusionsWe demonstrated a high prevalence of COPD among Japanese lung cancer patients. Based on the knowledge that severity of COPD is one of the most important factors in the therapeutic decision, comprehensive assessment of COPD at bronchoscopy might allow us to implement the optimum management for lung cancer patients.

Three‐dimensional (3D) visualization of endolymphatic hydrops after intratympanic injection of Gd‐DTPA: Optimization of a 3D‐real inversion‐recovery turbo spin‐echo (TSE) sequence and application of a 32‐channel head coil at 3T

To enable volume visualization of endolymphatic hydrops of Ménières disease via a volume rendering (VR) technique, a three‐dimensional (3D) inversion‐recovery (IR) sequence with real reconstruction (3D‐real IR) sequence after intratympanic injection of Gd‐DTPA was optimized for higher spatial resolution using a 32‐channel head coil at 3T.

Supplemental value of diffusion-weighted whole-body imaging with background body signal suppression (DWIBS) technique to whole-body magnetic resonance imaging in detection of bone metastases from thyroid cancer

We compared the efficacy of whole‐body MRI (WBMRI) with and without diffusion‐weighted whole‐body imaging with background body signal suppression (DWIBS) using a 3.0‐T MR scanner to [18F] fluoro‐2‐D‐glucose positron emission tomography with CT (integrated FDG‐PET/CT) for the detection of bone metastases in patients with differentiated thyroid carcinoma (DTC).

Limited efficacy of (18)F-FDG PET/CT for differentiation between metastasis-free pancreatic cancer and mass-forming pancreatitis.

Objective Differentiation between metastasis-free pancreatic cancer and mass-forming pancreatitis is important to avoid unnecessary operative procedures. This study was aimed at evaluating the efficacy of PET/CT with 18F-FDG (FDG PET/CT) for the differential diagnosis between them. Patients and Methods FDG-PET/CT was performed in 47 study patients with pancreatic masses and without any detectable metastases, 33 of which cases were finally diagnosed as pancreatic cancer and the other 14 as pancreatitis, and the corresponding imaging data were evaluated retrospectively. The maximal SUV (SUVmax) within the masses were determined at 1 hour and mostly at 2 hours after intravenous injection of FDG. Results SUVmax at 1 hour in pancreatic cancer was significantly higher than that in mass-forming pancreatitis, and the change in SUVmax from 1- to 2-hour time points was more consistent with pancreatic cancer than with mass-forming pancreatitis. However, there remained considerable overlapping between the SUVmax values of both diseases except either at the higher range for pancreatic cancer (> 7.7 at 1 hour or > 9.98 at 2 hours) or at the lower range for mass-forming pancreatitis (<3.37 at 1 hour or <3.53 at 2 hours). No obvious difference was found in the FDG uptake patterns of the mass areas between both diseases. Conclusions Differentiation between metastasis-free pancreatic cancer and mass-forming pancreatitis is difficult by FDG-PET/CT due to considerable overlapping between the SUVmax values of the two diseases, although the differential diagnosis may be possible either at the higher range of SUVmax (> 7.7 at 1 hour or > 9.98 at 2 hours) for pancreatic cancer or at the lower range of SUVmax (<3.37 at 1 hour or <3.53 at 2 hours) for mass-forming pancreatitis.