Tae Iwasawa

Magnetic resonance analysis of abnormal diaphragmatic motion in patients with emphysema

The purpose of this study was to quantitatively evaluate paradoxical diaphragmatic motion using magnetic resonance (MR) imaging. A total of 27 subjects were examined, including 12 normal young adults, six control individuals, and nine patients with emphysema. With subjects in the supine position, 30 sequential sagittal MR images of the entire right lung were obtained during tidal and deep slow breathing. Diaphragmatic movement between sequential images was estimated as the displacement area and the total diaphragmatic movement in a respiratory cycle was calculated. The paradoxical motion of the diaphragm, representing the inverted movement to increase or decrease lung area, since paradoxical movement ratio (Mpr=(total paradoxical diaphragmatic movement/total diaphragmatic movement)×100), was evaluated. In patients with emphysema, paradoxical diaphragmatic motion was observed on MR images during deep breathing. The mean Mpr in emphysematous patients during deep breathing was 10±4%, which was significantly higher than 0.5±0.2% in young adults (p<0.05), and 1.2±0.6% in aged-matched controls (p<0.05). The present results indicate that magnetic resonance images could be used to detect paradoxical diaphragmatic motion in patients with emphysema.

Prediction of postoperative pulmonary function using perfusion magnetic resonance imaging of the lung.

To assess semiquantitatively the regional distribution of lung perfusion using magnetic resonance (MR) perfusion imaging.

CT analysis of the effect of pirfenidone in patients with idiopathic pulmonary fibrosis

PURPOSE Pirfenidone is a new, anti-fibrotic drug used for the treatment of idiopathic pulmonary fibrosis (IPF). The aim of this study was to evaluate the utility of computed tomography (CT) in the imaging assessment of the response to pirfenidone therapy. MATERIALS AND METHODS Subjects were 78 patients with IPF who underwent CT on two occasions with one-year interval (38 consecutive patients treated with pirfenidone and 40 age-matched control). Changes in the fibrous lesion on sequential CTs were assessed as visual score by two radiologists. We measured the volume and change per year of fibrous pattern (F-pattern) quantitatively using a computer-aided system on sequential CTs. RESULTS The baseline vital capacity (%pred VC) was 74.0 ± 14.0% in the pirfenidone group and 74.6 ± 16.6% in controls (p=NS). Deterioration of respiratory status was defined as 10% or greater decline in %pred VC value after 12-month treatment. A significantly larger proportion of pirfenidone-treated patients showed stable respiratory status (21 of 38, 65.6%) than the control (15 of 40, 37.5%). The change in fibrous lesion was significantly smaller in the pirfenidone group than the control in both of visual score (p=0.006) and computer analysis (p<0.001). The decline in VC correlated significantly with the increase in fibrotic lesion (p<0.001). CONCLUSION CT can be used to assess pirfenidone-induced slowing of progression of pulmonary fibrosis.

Distinct characteristics of pleuroparenchymal fibroelastosis with usual interstitial pneumonia compared with idiopathic pulmonary fibrosis.

BACKGROUND Pleuroparenchymal fibroelastosis (PPFE) is a rare form of interstitial pneumonia and sometimes coexists with a histologic usual interstitial pneumonia (UIP) pattern. This study aimed to describe the distinct clinical features of PPFE with UIP pattern compared with idiopathic pulmonary fibrosis (IPF). METHODS We conducted a retrospective review of the medical records of 110 consecutive patients with IPF with a histologic UIP pattern on surgical lung biopsy specimen. Patients meeting radiologic criteria for the diagnosis of PPFE based on high-resolution CT scan and with a histologic UIP pattern were included. RESULTS Nine of eleven patients meeting radiologic criteria for the diagnosis of PPFE were histologically confirmed as having PPFE with UIP pattern. The PPFE with UIP pattern group showed a significantly higher residual volume (1.8 L vs 1.3 L, P < .01), higher Paco2 (44.6 mm Hg vs 41.7 mm Hg, P = .04), and higher complication rate of pneumothorax and pneumomediastinum than the 99 patients with IPF/UIP. The ratio of anteroposterior to transthoracic diameter in patients with PPFE with UIP pattern was significantly lower than that in patients with IPF/UIP (P = .04). Survival time tended to be shorter in patients with PPFE with UIP pattern. CONCLUSIONS The results support the view that PPFE with UIP pattern is a disease entity distinct from IPF/UIP and may well be classified as PPFE.

Paradoxical motion of the hemidiaphragm in patients with emphysema.

The authors evaluate paradoxical diaphragmatic motion using magnetic resonance (MR) imaging in patients with emphysema. The subjects were 12 healthy volunteers and 10 male patients with moderate to severe air flow obstruction. With subjects in the supine position, 30 sequential sagittal images of the bilateral lungs were obtained during quiet and forced breathing using a 1.5T MR unit with a body coil. The sequence was single shot fast spin echo (SSFSE) with half Fourier transformation. Subtraction images were made from the original images (by subtracting a given image from the preceding image), which visualized the chest wall motion as white or black bands on the edge of the lung fields. The authors evaluated both the original and subtraction images. MR imaging showed abnormal hemidiaphragmatic motion during forced breathing: the ventral portion of the hemidiaphragm moved downward while the dorsal part moved upward like a seesaw in 6 patients. MR images also revealed abnormal ribcage motion; the ventral ribcage moved anteriorly when the hemidiaphragm moved upward in 7 patients. No abnormal motion was observed in healthy volunteers. MR is a noninvasive and useful tool for evaluating the asynchronous respiratory motion in patients with emphysema.

Impairment of Coronary Flow Reserve Evaluated by Phase Contrast Cine‐Magnetic Resonance Imaging in Patients With Heart Failure With Preserved Ejection Fraction

Background Phase contrast (PC) cine‐magnetic resonance imaging (MRI) of the coronary sinus allows for noninvasive evaluation of coronary flow reserve (CFR), which is an index of left ventricular microvascular function. The objective of this study was to investigate coronary flow reserve in patients with heart failure with preserved ejection fraction (HFpEF). Methods and Results We studied 25 patients with HFpEF (mean and SD of age: 73±7 years), 13 with hypertensive left ventricular hypertrophy (LVH) (67±10 years), and 18 controls (65±15 years). Breath‐hold PC cine‐MRI images of the coronary sinus were obtained to assess blood flow at rest and during ATP infusion. CFR was calculated as coronary sinus blood flow during ATP infusion divided by coronary sinus blood flow at rest. Impairment of CFR was defined as CFR <2.5 according to a previous study. The majority (76%) of HFpEF patients had decreased CFR. CFR was significantly decreased in HFpEF patients in comparison to hypertensive LVH patients and control subjects (CFR: 2.21±0.55 in HFpEF vs 3.05±0.74 in hypertensive LVH, 3.83±0.73 in controls; P<0.001 by 1‐way ANOVA). According to multivariable linear regression analysis, CFR independently and significantly correlated with serum brain natriuretic peptide level (β=−68.0; 95% CI, −116.2 to −19.7; P=0.007). Conclusions CFR was significantly lower in patients with HFpEF than in hypertensive LVH patients and controls. These results indicated that impairment of CFR might be a pathophysiological factor for HFpEF and might be related to HFpEF disease severity.

Correlation of lung parenchymal MR signal intensity with pulmonary function tests and quantitative computed tomography (CT) evaluation: a pilot study.

To evaluate the effect of ventilatory impairment on MR signal intensity of the lung parenchyma.

Prognostic Factors in Interstitial Lung Disease Associated with Primary Sjögren's Syndrome: A Retrospective Analysis of 33 Pathologically-Proven Cases

Introduction Interstitial lung disease associated with primary Sjögren’s syndrome (pSS–ILD) shows several patterns such as nonspecific interstitial pneumonia (NSIP) and usual interstitial pneumonia (UIP). Although UIP is a well–recognized prognostic determinant in idiopathic interstitial pneumonias, whether this is also the case in pSS–ILD is unclear. The objectives of this study were to evaluate the prognostic effect of UIP, and to identify the prognostic factors in pSS–ILD. Methods A retrospective review of medical records identified 33 consecutive patients with pathologically–proven pSS–ILD. Each patient was classified into each ILD pattern by multidisciplinary analysis. Baseline clinical–radiologic–pathologic characteristics and survival rates were compared between the ILD patterns. Finally, the prognostic factors in pSS–ILD were assessed by univariate and subsequent multivariate analyses using Cox’s proportional hazards regression model. Results pSS–ILD patients were diagnosed with NSIP (n = 22) or UIP (n = 11). The median follow–up period was 110 months, and five-year survival rate was 87.3% in the total patient population. The prognosis of the UIP patients was not significantly different from that of the NSIP patients (NSIP to UIP, hazard ratio [HR]: 0.77, 95% confidence interval [CI]: 0.18–3.36, P = 0.73). Multivariate analysis identified PaCO2 (HR: 1.68 per 1 Torr increase, 95% CI: 1.24–2.28, P < 0.01), extent of reticular abnormality on high–resolution CT (HR: 4.17 per 1-grade increment, 95% CI: 1.18–14.73, P = 0.03), and severity of fibroblastic foci (HR: 9.26 per 1-grade increment, 95% CI: 1.74–49.35, P < 0.01) as prognostic factors in pSS–ILD. Conclusions UIP in pSS–ILD was not related to poorer prognosis than NSIP. Assessment of detailed clinical–radiologic–pathologic findings is more important than distinguishing UIP to evaluate prognosis in this disease.

Influence of the distribution of emphysema on diaphragmatic motion in patients with chronic obstructive pulmonary disease.

PurposeWe investigated whether the distribution of emphysema on computed tomography (CT) images can affect chest wall motion in patients with chronic obstructive lung disease (COPD).Materials and methodsThe subjects were 35 male patients with COPD (age, 69.7 ± 6.2 years). The RA-950 (the ratio of lung volume under −950 HU to total lung volume on CT) was measured separately for the upper and lower halves of the lung. We analyzed the flatness of the diaphragm (Kdome) and its motion (ΔLappo) using dynamic magnetic resonance imaging. Paradoxical motion (Mpr) represented the ratio of the paradoxical diaphragmatic movement (downward or upward) when the lung area decreased or increased, respectively, to he total diaphragm movement (expressed as a percent). These parameters were analyzed in correlation with pulmonary function tests and St. George Respiratory Questionnaire (SGRQ) scores.ResultsThe RA-950 of the lower lung zone correlated significantly with the Kdome (P = 0.033), ΔLappo (P = 0.006), Mpr (%) (P = 0.001), forced expiratory volume at 1 s (% predicted; P < 0.001), and activity score of the SGRQ (p = 0.017). The RA-950 of the upper lung zone did not correlate with these parameters.ConclusionIn COPD patients, the distribution of emphysema on CT correlates with airflow obstruction and abnormal diaphragmatic motion.

Normal In-plane respiratory motion of the bilateral hemidiaphragms evaluated by sequentially subtracted fast magnetic resonance images

The purpose of this study was to demonstrate hemidiaphragmatic motion using magnetic resonance imaging. The subjects were 13 healthy, nonsmoking volunteers. The sequence consisted of a fast gradient-recalled echo for coronal images and a single-shot fast spin echo with half Fourier transformation for sagittal images. The coronal and sagittal acquisition times were 0.83 msec and 0.58 msec per image, respectively. Thirty sequential images were obtained during quiet, deep respiration. Two series of subtraction images were made from these original sequential images (a given image was subtracted from the preceding or the next image in the original series). Hemidiaphragmatic motion was visualized as white or black bands on subtraction images. In the coronal plane through the left ventricle, there was a difference in motion between the right and left hemidiaphragms in 10 subjects during tidal respiration and in 12 subjects during deep respiration. On the sagittal images, the dorsal part of the hemidiaphragm moved more rapidly during quiet, deep respiration, especially on the left side.