川田 奈緒子

OBJECTIVES: Structural and functional changes in pulmonary vessels are prevalent at the initial stages of chronic obstructive pulmonary disease (COPD). These vascular alterations can be assessed using cross-sectional area (CSA) of small pulmonary vessels. However, neither in non-COPD smokers nor in COPD patients it has been defined whether the structural changes of pulmonary vessels detected by paired inspiratory and expiratory CT scans are associated with emphysematous changes. We quantified the CSA and low attenuation area (LAA) and evaluated the changes in these parameters in the inspiratory and expiratory phases. MATERIALS AND METHODS: Fifty consecutive non-COPD smokers and COPD patients were subjected to multi detector-row CT and the percentage of vessels with a CSA less than 5 mm(2) as well as the percentage LAA for total lung area (%CSA<5, %LAA, respectively) were calculated. RESULTS: The %CSA<5 correlated negatively with %LAA. The %CSA<5 was lower in COPD patients with emphysema as compared with non-COPD smokers and COPD patients with or without mild emphysema. In addition, the %CSA<5 was lower in the no/mild emphysema subgroup as compared with non-COPD smokers. The respiratory phase change of %CSA<5 in COPD patients was greater than that in non-COPD smokers. CONCLUSION: The percentage of small pulmonary vessels decreased as emphysematous changes increase, and this decrease was observed even in patients with no/mild emphysema. Furthermore, respiratory phase changes in CSA were higher in COPD patients than in non-COPD smokers.

BACKGROUND: Chronic thromboembolic pulmonary hypertension (CTEPH) has been considered to be caused by single or recurrent pulmonary embolism (PE) arising from deep vein thrombosis (DVT). In Japan, female predominance and association of HLA-B*5201 with CTEPH unrelated to DVT were reported. In acute PE residual proximal DVT is associated with larger obstruction of pulmonary arteries. However, it remains uncertain whether DVT and the type of DVT are associated with clinical phenotype of CTEPH. PURPOSE: To clarify the association of DVT and DVT type with clinical phenotype of CTEPH. METHODS: Among 98 consecutive patients who underwent 16 or 64-slice multidetector CT angiography and indirect venography, 91 patients (66% female, age: 56±3 years) with adequate images were enrolled. The associations of DVT and DVT type with pulmonary hemodynamics, CT obstruction index and other clinical parameters were analyzed. RESULTS: DVT was found in 45 patients (49.5%) (distal: 12, proximal: 33), and was significantly associated with male gender and recurrent type. Furthermore, it was more frequent in HLA-B*5201-negative, and d-dimer positive patients. Compared with distal DVT, proximal DVT was associated with male gender, larger CT obstruction index (48.6±13.0 vs. 34.1±13.2%, p=0.004), and higher mean pulmonary arterial pressure (48.2±12.8 vs. 40.8±7.9 mmHg, p=0.03). Proximal DVT was significantly associated with the central type of CTEPH only in HLA-B*5201-negative patients. CONCLUSIONS: The existence and type of DVT were associated with clinical phenotype of CTEPH, and proximal DVT might contribute to the central type of CTEPH in only HLA-B*5201-negative patients.

BACKGROUND: Right-sided heart catheterization (RHC) and pulmonary digital subtraction angiography (PDSA) are the standard methods used in diagnosing suspected or defi nite chronic thromboembolic pulmonary hypertension (CTEPH). We studied the ability of 320-slice CT imaging to detect simultaneously chronic thromboembolic fi ndings in the pulmonary arteries and pulmonary hemodynamics based on the curvature of the interventricular septum (IVS) in CTEPH . METHODS: Forty-four patients with high clinical suspicion of CTEPH underwent RHC, PDSA, and enhanced double-volume retrospective ECG-gated 320-slice CT scan. We measured the sensitivity and specificity of CT imaging to detect thrombi in the pulmonary arteries compared with PDSA. We also compared IVS bowing (expressed as curvature) measured on the short-axis cine heart image with pulmonary arterial pressure (PAP) obtained by RHC. RESULTS: Compared with PDSA, the sensitivity and specificity of CT imaging to detect chronic thromboembolic findings were 97.0% and 97.1% at the main/lobar level and 85.8% and 94.6% at the segmental level, respectively. The correlation coefficients of IVS curvature with systolic PAP and mean PAP were 2 0.79 ( P , .001) and 2 0.86 ( P , .001), respectively. CONCLUSIONS: The use of 320-slice CT imaging allows for less invasive and simultaneous detection of thrombi and evaluation of pulmonary hemodynamics for the diagnostic work-up of CTEPH.

PURPOSE: To reduce the redundant acquisition range and total radiation dose for planning appropriate "triple rule-out" CT angiography (CTA) for acute chest pain, we evaluated the detailed distribution of pulmonary thromboemboli (PTE) in subjects with acute PTE. MATERIALS AND METHODS: Retrospective review of CTA n 75-subjects (48-females; 57 ± 16 years) with proven acute PTE was performed to determine whether PTE was present solely above the aortic arch or below the heart. RESULTS: 77% had PTE in the right upper lobe but none had PTE that were solely located higher than the aortic arch; 73% had PTE in the right middle lobe; 80% had PTE in the right lower lobe, but none had PTE that were solely located lower than the heart. 81% had PTE in the left upper lobe and 3% of them had PTE solely located higher than the aortic arch; both had PTE in the right upper, middle, and lower, and the left lower lobes. 75% had PTE in the left lower lobe, but none had PTE that were solely located lower than the heart. The acquisition length in limited CTPA in this population was reduced on average by 21.9% compared with full CTPA. CONCLUSIONS: In subjects with acute PTE, there were none whose PTE was located solely in the upper lobes which were higher than the aortic arch, nor solely in the lower lobes which were lower than the heart. A limited range triple rule-out CTA protocol would decrease effective doses approximately 22% relative to full chest CTA and may help the physician find all PE present.

As multi-slice CT develops, there are great expectations for an automatic and computer-support diagnoses. This research is on bronchial area which is composed of the bronchial wall regions and the air regions in the internal bronchial tube. Since to diagnose this is difficult, support diagnosis using CT images is desired. The thickness of bronchial wall changes as the airway of early lung cancer, bronchial asthma and the bronchial enhancing syndrome and others change into a malignant state. These changes are detected and the thickness of bronchial wall becomes important information. In this research, the extraction accuracy of the algorithm for bronchial wall evaluation is good. © 2009 SPIE.

BACKGROUND: The pathogenesis of daytime hypercapnia (Paco2 >or= 45 mm Hg) may be directly linked to the existence of obstructive sleep apnea syndrome (OSAS) per se, although only some patients with OSAS exhibit daytime hypercapnia. OBJECTIVE: To investigate the prevalence of daytime hypercapnia in patients with OSAS; the association of daytime hypercapnia and obesity, obstructive airflow limitation, restrictive lung impairment, and severity of sleep apnea; and the response to continuous positive airway pressure (CPAP) therapy in a subset of subjects. METHODS: The study involved 1,227 patients with OSAS who visited a sleep clinic and were examined using polysomnography. As for the response to CPAP therapy, the patients were considered good responders if their daytime Paco2 decreased >or= 5 mm Hg and poor responders if it decreased < 5 mm Hg. RESULTS: Fourteen percent (168 of 1,227 patients) exhibited daytime hypercapnia. These patients had significantly higher body mass index (BMI) and apnea-hypopnea index (AHI) values compared with normocapnic patients, while percentage of predicted vital capacity (%VC) and FEV(1)/FVC ratio did not differ between the two groups. Logistic regression analysis showed that only AHI was a predictor of daytime hypercapnia (p < 0.0001), while BMI (p = 0.051) and %VC (p = 0.062) were borderline predictors of daytime hypercapnia. Daytime hypercapnia was corrected in some patients (51%, 19 of 37 patients) with severe OSAS after 3 months of CPAP therapy. CONCLUSION: The pathogenesis of daytime hypercapnia may be directly linked to sleep apnea in a subgroup of patients with OSAS.