Atsuko Fujikawa

MRI of Pulmonary Nodules

OBJECTIVE The purpose of this article is to review the current status of MRI for evaluation of pulmonary nodules. CONCLUSION Although clinical applications of pulmonary MRI face technical limitations, currently available MRI methods have contributed to morphologic and functional evaluations of pulmonary nodules.

Quantitative CT evaluation in patients with combined pulmonary fibrosis and emphysema: correlation with pulmonary function.

RATIONALE AND OBJECTIVES The purpose of this study was to evaluate the correlations between objective quantitative computed tomography (CT) measurements of the extent of emphysematous and fibrotic lesions and the results of pulmonary function tests (PFTs) in patients with combined pulmonary fibrosis and emphysema (CPFE). MATERIALS AND METHODS This study involved 43 CPFE patients who underwent CT and PFTs. The extent of emphysematous lesions was obtained by calculating the percentage of low attenuation area (%LAA) values lower than -950 Hounsfield units (HU). Fibrotic lesions were defined as high attenuation area (HAA) using thresholds with pixels between 0 and -700 HU, and the extent of fibrosis was obtained by calculating the percentage of HAA (%HAA). The correlations of %LAA and %HAA with PFTs were evaluated by the Spearman rank correlation coefficients and multiple linear regression analysis. RESULTS A significant negative correlation was found between %HAA and diffusing capacity of the lung for carbon monoxide (DLco) %predicted (ρ = -0.747; P < .001), whereas no significant correlation was found between %LAA and DLco %predicted. On multiple linear regression analysis, although the %HAA and %LAA were independent contributors to DLco %predicted, the predictive power of %HAA was superior to that of %LAA. CONCLUSIONS In CPFE, the extent of fibrosis has a more significant impact on DLco than emphysema.

Morphological disease progression of combined pulmonary fibrosis and emphysema: comparison with emphysema alone and pulmonary fibrosis alone.

Objectives The purpose of this study was to evaluate the differences in 5-year morphological changes among the patients with combined pulmonary fibrosis and emphysema (CPFE), emphysema alone, and fibrosis alone using quantitative computed tomography evaluation. Methods This study involved 42 patients with CPFE, 45 patients with emphysema alone, and 35 patients with fibrosis alone who underwent computed tomography scans twice (initial and 5 years after the initial scan). The extent of emphysematous lesions was obtained by calculating the percentage of low attenuation area (%LAA) lower than −950 Hounsfield units. Fibrotic lesion was defined as a high attenuation area (HAA) using thresholds with pixels between 0 and −700 Hounsfield units, and the extent of fibrosis was obtained by calculating the mean percentage of HAA (%HAA). For the quantitative evaluation of the total area of emphysematous change and fibrosis, the percentage of destructed lung area (%DA) was obtained by summing %LAA and %HAA. The 5-year changes of %LAA, %HAA, and %DA were calculated. Differences were evaluated by 1-way analysis of variance, which was followed by the Tukey-Kramer test. Results The mean change of %LAA was significantly higher in CPFE (7.4% ± 3.8%) than in emphysema alone (P < 0.05). The mean change of %DA was significantly higher in CPFE (12.9% ± 5.8%) than in emphysema alone (4.9% ± 2.8%) and fibrosis alone (7.1% ± 5.7%). Conclusions Morphological disease progression in CPFE differed from that in emphysema alone or fibrosis alone. In particular, the increase in emphysematous low-attenuation lesions was significantly higher in CPFE.

Relationship Between Quantitative CT of Pulmonary Small Vessels and Pulmonary Perfusion

OBJECTIVE The relationship between morphologic alterations of pulmonary small vessels and pulmonary perfusion has not been clarified. The purpose of this study was to evaluate the relationship between the cross-sectional area (CSA) of pulmonary small vessels alterations measured on CT images and pulmonary perfusion on lung perfusion scintigraphy. MATERIALS AND METHODS This study comprised 46 subjects who underwent both CT and lung perfusion scintigraphy. We measured CSA of pulmonary small vessels less than 5 mm(2) and 5-10 mm(2) using CT images and obtained the percentage of the right lung to whole lung in each CSA group (CSA<5,R/W and CSA5-10,R/W, respectively). Using (99m)Tc-macroaggregated albumin (MAA) lung perfusion scintigraphy, we obtained right and total lung counts and calculated the percentage of the right to whole-lung counts (MAAR/W). Those CT and scintigraphy measurements were also calculated separately each in right upper, right lower, left upper, and left lower zones. The correlations of CSA<5,R/W and CSA5-10,R/W with MAAR/W, the correlation between the percentage of each lung zone to whole-lung CSA<5 and the percentage of each corresponding lung zone to whole-lung MAA were evaluated. RESULTS The mean CSA<5,R/W was 58.1% ± 11.2%, and the mean MAAR/W was 59.3% ± 17.9%. CSA<5,R/W had a significant correlation with MAAR/W (ρ = 0.865, p < 0.0001), whereas significant correlation was found but was relatively weak between CSA5-10,R/W and MAAR/W (ρ = 0.512, p = 0.0003). The percentage of each lung zone to whole-lung CSA<5 had significant correlations with the percentage of each corresponding lung zone to whole-lung MAA. CONCLUSION Pulmonary small vessels alteration, as measured by CSA on CT images, significantly correlated with pulmonary perfusion.

Pulmonary arterial enlargement in patients with acute exacerbation of interstitial pneumonia.

The purpose of this study was to evaluate change in the size of the main pulmonary (PA) artery in patients with acute exacerbation of interstitial pneumonia (IP). Twenty-nine patients underwent computed tomography at baseline and at the time of acute IP exacerbation for the measurement of the diameters of the main PA and the ascending aorta. We found that the diameter of the main PA was significantly larger at the time of acute IP exacerbation than at baseline, which might reflect the alterations in pulmonary circulation.

Usefulness of Coronal Reconstruction CT Images for Quantitative Evaluation of the Cross-Sectional Area of Small Pulmonary Vessels

RATIONALE AND OBJECTIVES Cross-sectional area <5 mm(2) (CSA<5) is a computed tomography (CT) metric that has been used for the evaluation of pulmonary vessel alterations and perfusion. CSA<5 is calculated from three axial slices; thus, whether CSA<5 represents the small pulmonary vessel alterations in the whole lung remains unclear. The purpose of this study was to compare the measurements of CSA<5 using three axial slices and coronal reconstructed slices in the relationship between the measured CSA<5 and pulmonary perfusion measured using lung perfusion scintigraphy. MATERIALS AND METHODS This study comprised 28 subjects who underwent both noncontrast CT and lung perfusion scintigraphy. The present study measured CSA<5 using both three axial CT images and coronal reconstruction images and then obtained the percentage of the CSA in right lung to that in whole lung (R/W-CSA<5). Using anteroposterior and posteroanterior projections on technetium-99m macroaggregated albumin (MAA) lung perfusion scintigraphy, we obtained right and total lung counts and calculated the percentage of the right to whole lung counts (R/W-MAA). The correlations of the R/W-CSA<5 calculated using three axial slices (R/W-CSA(A)x<5) and coronal reconstructed slices (R/W-CSA(COR)<5) with R/W-MAA were evaluated using Spearman rank correlation analysis. RESULTS Both R/W-CSA(Ax)<5 and R/W-CSA(COR)<5 were significantly correlated with R/W-MAA; however, the correlation coefficient with R/W-CSA(COR)<5 (ρ = 0.842, P < .0001) was greater than that with R/W-CSA(Ax)<5 (ρ = 0.631, P = .0004). CONCLUSIONS Coronal reconstruction images appear suitable for quantitative measurement of CSA of small pulmonary vessels.

Cost-Effectiveness Analysis of Percutaneous Vertebroplasty for Osteoporotic Compression Fractures.

Study Design: Single-center, single-arm, prospective time-series study. Objective: To assess the cost-effectiveness and improvement in quality of life (QOL) of percutaneous vertebroplasty (PVP). Summary of Background Data: PVP is known to relieve back pain and increase QOL for osteoporotic compression fractures. However, the economic value of PVP has never been evaluated in Japan where universal health care system is adopted. Methods: We prospectively followed up 163 patients with acute vertebral osteoporotic compression fractures, 44 males aged 76.4±6.0 years and 119 females aged 76.8±7.1 years, who underwent PVP. To measure health-related QOL and pain during 52 weeks observation, we used the European Quality of Life–5 Dimensions (EQ-5D), the Rolland-Morris Disability Questionnaire (RMD), the 8-item Short-Form health survey (SF-8), and visual analogue scale (VAS). Quality-adjusted life years (QALY) were calculated using the change of health utility of EQ-5D. The direct medical cost was calculated by accounting system of the hospital and Japanese health insurance system. Cost-effectiveness was analyzed using incremental cost-effectiveness ratio (ICER): &Dgr; medical cost/&Dgr; QALY. Results: After PVP, improvement in EQ-5D, RMD, SF-8, and VAS scores were observed. The gain of QALY until 52 weeks was 0.162. The estimated lifetime gain of QALY reached 1.421. The direct medical cost for PVP was ¥286,740 (about 3061 US dollars). Cost-effectiveness analysis using ICER showed that lifetime medical cost for a gain of 1 QALY was ¥201,748 (about 2154 US dollars). Correlations between changes in EQ-5D scores and other parameters such as RMD, SF-8, and VAS were observed during most of the study period, which might support the reliability and applicability to measure health utilities by EQ-5D for osteoporotic compression fractures in Japan as well. Conclusions: PVP may improve QOL and ameliorate pain for acute osteoporotic compression fractures and be cost-effective in Japan.

Quantitative computed tomography assessment of air trapping in relapsing polychondritis: correlations with spirometric values.

Objective The purpose of this study was to evaluate the relationship between quantitative computed tomography (CT) parameters of air trapping obtained with inspiratory and expiratory CT and pulmonary function tests (PFTs) in patients with relapsing polychondritis (RP). Materials and Methods This study included 23 patients with RP who underwent both CT and PFTs. In each patient, the mean lung density (MLD) was obtained by averaging CT attenuation of the lung parenchyma on both inspiratory and expiratory CT. The ratio of expiratory MLD to inspiratory MLD (E/I ratio) was also calculated. Correlations between those quantitative CT measurements and the results of PFTs were evaluated using Spearman rank correlation. Results The expiratory MLD and E/I ratio were significantly correlated with forced expiratory volume in 1 second (FEV1) %predicted, ratio of FEV1 to FVC (FEV1/FVC), and the mid expiratory phase of forced expiratory flow (FEF25%–75%) %predicted (expiratory MLD: FEV1 %predicted, r = 0.764, P < 0.0001; FEV1/FVC, r = 0.764, P < 0.0001; FEF25%–75% %predicted, r = 0.674, P < 0.001, respectively; the E/I ratio: FEV1 %predicted, r = −0.689, P < 0.001; FEV1/FVC, r = −0.689, P < 0.001; FEF25%–75% %predicted, r = −0.586, P < 0.01, respectively). The correlation between inspiratory MLD and PFTs did not reach statistical significance. Conclusions In RP patients, air trapping demonstrated on expiratory CT correlated with airway obstruction. This study may assist further refinement of the use of CT as quantitative evaluation for small and large airway obstruction in RP.

Correlations between computed tomography findings and clinical manifestations of Streptococcus pneumoniae pneumonia.

PurposeThe aim of this study was to characterize the imaging features and compare computed tomography (CT) findings with clinical features of patients with Streptococcus pneumoniae pneumonia.Materials and methodsWe retrospectively reviewed 75 patients (44 men, 31 women; mean age 67 years) diagnosed with S. pneumoniae pneumonia who underwent chest CT scanning at our institution between January 2007 and August 2008. Diagnoses were based on detection of the S. pneumoniae antigen in urine.ResultsChest CT scans revealed abnormalities in all patients. The predominant opacity patterns were an airspace pneumonia pattern (48%) and a bronchopneumonia pattern (48%), followed by an interstitial pneumonia pattern (4%). Consolidation was observed most frequently (84%) followed by ground glass opacity (82.7%), bronchial wall thickening (61.3%), and centrilobular nodules (49.3%). Airway dilatation (21.6%), pleural effusion (33.3%), lymphadenopathy (34.8%), and pulmonary emphysema (21.3%) were also observed. Pulmonary emphysema was significantly less frequent in patients with the bronchopneumonia pattern than in those without (p = 0.007). The clinical features and CT findings did not differ significantly.ConclusionCT image analysis showed that patients with S. pneumoniae pneumonia exhibited the bronchopneumonia and airspace pneumonia patterns with equal frequency. Bronchopneumonia pattern was less common in patients with preexisting emphysema.

Fluid collection in the retropharyngeal space: A wide spectrum of various emergency diseases

Fluid collections in the retropharyngeal space (RPS) result from a wide spectrum of diseases, including retropharyngeal abscess, cervical osteomyelitis, and calcific tendinitis of the longus colli muscle. These conditions should be managed by different specialties; beginning with care in the emergency room, physicians from orthopedics, pediatrics, otolaryngology, and oncology are in charge of the treatment. Since these diseases demonstrate similar fluid collections in the RPS on computed tomography (CT) and magnetic resonance imaging (MRI), the radiologists diagnosis based on the characteristic imaging findings is very important to identify the primary disease. Also, since some of the diseases require immediate surgical intervention to avoid life-threatening mediastinitis or airway obstruction, radiologists must distinguish these diseases correctly and provide recommendations for their management to physicians. Understanding clinical features and imaging findings of these fluid collections in the RPS is crucial for the best care.