In the helium gas dilution method, functional residual capacity (FRC) is calculated from a helium concentra- tion equilibrium curve. In this study, we analyzed the helium concentration equilibrium curves of healthy patients, clarified the determinants of the equilibrium concentration, and studied the effects of an uneven lung distribution. We collected data from 200 patients (92 males and 108 females) whose FRC values had been measured at our institution over the past 6 years. Their FRC values ranged from 80% to 120%, and theit other pulmo- nary function values were within the normal range. In the compartmental model analysis, we discovered that the helium concentration equilibrium curve was composed of one compartment, and that it did not have a polyphasic structure. Each 0.25-minute (15-second) segment of the helium concentration equilibrium curve obtained from the patients was evaluated using univariate and multivariate regression analyses. The helium concentration equilibrium curve decreased exponentially over the time course of the analysis, and the multiple correlation coefficient for the relationship between the 0.25-minute to 0.75-minute segments and the 1.00-minute to 1.50-minute segments in the final model was 0.949. Finally, we examined the influence of an uneven peripheral lung distribution. A model based on the con- centration change seen between the initial and middle periods during at rest ventilation indicated that the latter parameter was not affected by the ventilation volume of the peripheral lung. [Original].

There have been a number of inconsistent previous reports indicating that mood disorder patients are relatively sensitive or conversely insensitive to physical pain. However, there have been few such studies examining pain using neurophysiological techniques. The present study was performed to investigate the differences in tactile sense recognition between mood disorder patients and control subjects using a tactile sense recognition P300 measuring system. Tactile stimuli were delivered to the index finger as frequent stimuli and to the ring finger as infrequent stimuli. Subjects were requested to press a button promptly and accurately in response to infrequent stimuli. N140 and P300 were measured in the event-related potential to infrequent stimulus paradigm. The subjects evaluated stimuli on a visual analog scale (VAS). The amplitudes of P300 were smaller for the mood disorder patients than for control subjects. The VAS scores of mood disorder patients were significantly higher than those of control subjects. In mood disorder patients, the amplitude of P300 was negatively correlated with the HAM-D score. These results suggest dysfunction of tactile sense recognition in mood disorder patients. In addition, the amplitude of P300 may be useful as a biological marker for psychological conditions in mood disorder patients.

OBJECTIVE:Partial expiratory flow-volume curves have the potential to detect mild bronchoconstriction because they are not affected by the modulatory effects of deep inspiration. The aim of this study was to investigate the relationship between the efficacy of bronchodilator therapy (BDT) in treating the cough and to assess the increase in the expiratory flow of the partial flow-volume curve at 40% above the residual volume level (PEF40) caused by treatment with a short-acting beta-2 agonist (SABA) in patients with chronic nonproductive cough.METHODS:We measured the reversibility of PEF40 caused by a SABA in 42 patients with chronic nonproductive cough at visit 1 (day 0). The patients received BDT for six days. The visual analogue scale (VAS) was used to assess the efficacy of BDT in treating coughing at visit 2 (day 7) (0 mm, 'no cough;' 100 mm, 'no change in coughing').RESULTS:Reversibility of the PEF40 was correlated (r=0.690, p<0.001) with the VAS score determined at visit 2 and was higher in the patients with cough variant asthma (CVA) (44.9 ± 18.3%) than in those with atopic cough (13.4 ± 10.4%) (p<0.01).CONCLUSION:Reversibility of the PEF40 predicted the efficacy of BDT in patients with chronic nonproductive cough and helped to identify patients with CVA.

Interrupter respiratory resistance (Rint) measurement is useful for evaluating lung function in patients who cannot perform traditional pulmonary function tests. However, data on the prediction formulas for Rint in healthy Japanese adults are lacking. Our aims were to examine the relationship between Rint and sex, age, height, and weight, to establish prediction formulas, and to evaluate our new prediction formula (%Rint) in patients with asthma. Rint measurement was performed in 1,536 healthy adult subjects aged 21-80 years. This study was conducted according to ATS guidelines, which recommend obtaining 10 measurements to ensure a minimum of 5 technically acceptable interruptions (Am J Respir Crit Care Med 2007). Stepwise multiple linear regression analysis indicated that height was the most significant variable independently correlating with Rint. The Rint prediction formulas for our cohort based on height were: RintE = -0.03168 x height + 8.204084 and Rinti = -0.02985 x height + 7.920835. Both %RintE and %Rinti were significantly higher in patients with asthma than in normal subjects (%RintE; 135.2 +/- 26.4 vs. 98.6 +/- 25.5, %RintI; 142.4 +/- 30.4 vs. 98.6 +/- 27.4; p < 0.0001). We established prediction formulas of Rint for healthy Japanese adults. %Rint is useful in screening for asthma.

The aim of the present study was to examine whether there is a relationship between autonomic function and post-challenge hyperglycemia in patients with type 2 diabetes. Subjects included 122 Japanese patients newly diagnosed with type 2 diabetes. Autonomic nerve function was assessed using coefficients of variation of the R-R intervals on electrocardiograms (CVRR). Unlike anthropometry, insulin secretion and insulin resistance, age (r = -0.209, P < 0.021) and post-challenge plasma glucose at 120 min (PG120; r = -0.219, P < 0.015) were the only variables significantly correlated with CVRR. Age was not significantly correlated with PG120. In multiple regression analyses, CVRR Z-score, but not age, was significantly correlated with PG120. The present results suggest that autonomic function affects post-challenge blood glucose levels independently of age. (J Diabetes Invest, doi: 10.1111/j.2040-1124.2010.00098.x, 2011)

Despite recent advances in uncovering the neural signature of memory processing in humans, spatiotemporal characteristics of cerebral activity during mental transformation of the visual (color) memory to the visuo-spatial memory has not been studied. The aim of this study was to investigate the electrophysiological correlates of internal memory transformation based on the event-related potential analysis using a root mean square (RMS) and a standardized low resolution electromagnetic tomography (sLORETA). Eleven healthy human subjects completed a modified delayed matching-to-sample test in which the visual(color) short-term memory had to be transformed into the visuo-spatial memory according to the matching probe. In comparison with a non-memory control condition, identifiable RMS peak was observed 352ms after the matching probe presentation in the condition of memory transformation. In this time, sLORETA demonstrated the higher current density in the prefrontal region. Our results suggested that the prefrontal region is associated with the internal memory transformation process depicting a spatiotemporal profile similar to P3b.

Diabetic patients suffer from systemic complications, which are generally characterized by a lack of early symptoms. In the management of diabetes, early diagnosis of complications and preventing progression are of importance. Vascular complications of diabetes are divided into microvascular and macrovascular complications. Circulatory function tests play a major role in diagnosing the presence and severity of macrovascular complications in clinical settings. In this review, we outlined the significance and precautions of each test in the diagnosis of diabetic macrovascular disease. 1) Echocardiography: Diabetic patients are often associated with ischemic heart disease, and some patients present with diffuse wall motion abnormalities due to multivessel disease. Patients with diabetic cardiomyopathy may have signs of left ventricular diastolic dysfunction with normal systolic function. 2) Carotid ultrasonography: Increase in intima-media thickness is associated with the onset of cardiovascular and cerebrovascular disease. Hypoechoic plaque and the thrombus formation have been reported to be closely related with cerebral infarction. 3) Assessment of lower extremity artery: Patients with diabetes are at a higher risk of developing peripheral artery diseases (PAD), which lead to disability. Doppler ultrasonography is widely used for noninvasive diagnosis of PAD. Information of real-time physiological blood flow is useful for disease monitoring. 4) Ankle-brachial index (ABI): ABI is a simple method recommended for screening and evaluating PAD of lower limbs. The limitation of this measurement is that pseudonormalization may occur with severe calcification of artery walls. 5) Pulse wave velocity (PWV), flow-mediated dilatation (FMD): PWV and FMD provide information for the function of blood vessels. Functional changes in peripheral arteries may precede structural changes. In this regard, these tests may play an important role in early diagnosis.

Poster: ECR 2010 / C-0837 / Quantitative pulmonary functional imaging using a dynamic flat-panel detector (FPD) by: R. Tanaka , S. Sanada, M. Fujimura, Y. Yasui, S. Tsuji, N. Hayashi, H. Okamoto, Y. Nanbu, O. Matsui; Kanazawa/JP

A 19-year-old woman with acute myeloid leukemia (M1) was treated with allogeneic hematopoietic stem cell transplantation. She was diagnosed with skin graft-versus-host disease 27 days after the transplantation. She was admitted to the Dept. of Respiratory Medicine at Kanazawa University Hospital, because she complained of progressive obstructive ventilatory impairment. A high-resolution computed tomography (CT) scan showed centrilobular small nodules. A chest CT scan (inspiratory phase and expiratory phase) revealed hyperlucent areas forming a mosaic pattern. A ventilation-perfusion scan showed matched unequal distribution. The pathological diagnosis made using biopsied lung, obtained by a right lower partial lobectomy, was constrictive bronchiolitis. Pulmonary function tests on admission showed mixed ventilatory impairment. %Residual volume(RV)/total lung capacity(TLC) was measured by the closed-circuit helium dilution method and was within the upper limit of the normal range. However, %RV/TLC measured by a body plethysmograph indicated a value of 258.1%. We believe that the difference in the %RV/TLC values reflected air trapping caused by bronchiolitis obliterans. Thus, the lung volume fraction measured by body plethysmograph was useful for diagnosing bronchiolitis obliterans in this case. [Rinsho Byori 58 : 906'-911, 2010].

Pulmonary blood flow is reflected in dynamic chest radiographs as changes in X-ray translucency, i.e., pixel values. Thus, decreased blood flow should be observed as a reduction of the variation of X-ray translucency. We performed the present study to investigate the feasibility of pulmonary blood flow evaluation with a dynamic flat-panel detector (FPD). Sequential chest radiographs of 14 subjects were obtained with a dynamic FPD system. The changes in pixel value in each local area were measured and mapped on the original image by use of a gray scale in which small and large changes were shown in white and black, respectively. The resulting images were compared to the findings in perfusion scans. The cross-correlation coefficients of the changes in pixel value and radioactivity counts in each local area were also computed. In all patients, pulmonary blood flow disorder was indicated as a reduction of changes in pixel values on the mapping image, and a correlation was observed between the distribution of changes in pixel value and those in radioactivity counts (0.7 ≤ r, 3 cases; 0.4 ≤ r < 0.7, 7 cases; 0.2 ≤ r < 0.4, 4 cases). The results indicated that the distribution of changes in pixel value could provide a relative measure related to pulmonary blood flow. The present method is potentially useful for evaluating pulmonary blood flow as an additional examination in conventional chest radiography.

Decreased ventilation is observed on chest radiographs as small changes in X-ray translucency, and ventilatory impairments can therefore be detected by analyzing the distribution of respiratory-induced changes in pixel value. This study was performed to develop a ventilatory impairment detection method based on the distribution of respiratory-induced changes in pixel values.

PURPOSE:Pulmonary ventilation and circulation dynamics are reflected on fluoroscopic images as changes in X-ray translucency. The purpose of this study was to investigate the feasibility of non-contrast functional imaging using a dynamic flat-panel detector (FPD).METHODS:Dynamic chest radiographs of 20 subjects (abnormal, n = 12; normal, n = 8) were obtained using the FPD system. Image analysis was performed to get qualitative perfusion mapping image; first, focal pixel value was defined. Second, lung area was determined and pulmonary hilar areas were eliminated. Third, one cardiac cycle was determined in each of the cases. Finally, total changes in pixel values during one cardiac cycle were calculated and their distributions were visualized with mapping on the original image. They were compared with the findings of lung perfusion scintigraphy.RESULTS:In all normal controls, the total changes in pixel value in one cardiac cycle decreased from the hilar region to the peripheral region of the lung with left-right symmetric distribution. In contrast, in many abnormal cases, pulmonary blood flow disorder was indicated as a reduction of changes in pixel values on a mapping image. The findings of mapping image coincided with those of lung perfusion scintigraphy.CONCLUSIONS:Dynamic chest radiography using an FPD system with computer analysis is expected to be a new type of functional imaging, which provides pulmonary blood flow distribution additionally.

Pulmonary ventilation and circulation dynamics are reflected on dynamic chest radiographs as changes in X-ray translucency,i.e., pixel values. The present study was performed to develop a pulmonary functional evaluation method based on the changes in pixel value, and to investigate the clinical usefulness of our method. Sequential chest radiographs of 20 subjects (abnormal,n=12; normal,n=8) during respiration were obtained with a dynamic flat-panel detector (FPD) system. The average pixel value in each local area was measured tracking the same area. To facilitate visual evaluation, the results were mapped on the original image using a grayscale in which small changes were shown in black and large changes were shown in white. In our clinical evaluation in comparison with a pulmonary scintigraphy, pulmonary ventilation disorder was indicated as a reduction of changes in pixel values. In many patients, there was a correlation between our result and a pulmonary scintigraphy (0.7<r, 4 cases; 0.4<r<or=0.7, 6 cases; 0.2<r<or=0.4, 1 case; 0<r<or=0.2, 1 case). The present method with real-time computer analysis is expected to be a rapid and simple method for evaluating pulmonary function and as an additional examination in conventional chest radiography.

OBJECTIVES:Dynamic flat panel detectors (FPD) permit acquisition of distortion-free radiographs with a large field of view and high image quality. The present study was performed to evaluate pulmonary function using breathing chest radiography with a dynamic FPD. We report primary results of a clinical study and computer algorithm for quantifying and visualizing relative local pulmonary airflow.MATERIALS AND METHODS:Dynamic chest radiographs of 18 subjects (1 emphysema, 2 asthma, 4 interstitial pneumonia, 1 pulmonary nodule, and 10 normal controls) were obtained during respiration using an FPD system. We measured respiratory changes in distance from the lung apex to the diaphragm (DLD) and pixel values in each lung area. Subsequently, the interframe differences (D-frame) and difference values between maximum inspiratory and expiratory phases (D-max) were calculated. D-max in each lung represents relative vital capacity (VC) and regional D-frames represent pulmonary airflow in each local area. D-frames were superimposed on dynamic chest radiographs in the form of color display (fusion images). The results obtained using our methods were compared with findings on computed tomography (CT) images and pulmonary functional test (PFT), which were examined before inclusion in the study.RESULTS:In normal subjects, the D-frames were distributed symmetrically in both lungs throughout all respiratory phases. However, subjects with pulmonary diseases showed D-frame distribution patterns that differed from the normal pattern. In subjects with air trapping, there were some areas with D-frames near zero indicated as colorless areas on fusion images. These areas also corresponded to the areas showing air trapping on computed tomography images. In asthma, obstructive abnormality was indicated by areas continuously showing D-frame near zero in the upper lung. Patients with interstitial pneumonia commonly showed fusion images with an uneven color distribution accompanied by increased D-frames in the area identified as normal on computed tomography images. Furthermore, measurement of DLD was very effective for evaluating diaphragmatic kinetics.CONCLUSIONS:This is a rapid and simple method for evaluation of respiratory kinetics for pulmonary diseases, which can reveal abnormalities in diaphragmatic kinetics and regional lung ventilation. Furthermore, quantification and visualization of respiratory kinetics is useful as an aid in interpreting dynamic chest radiographs.

BACKGROUND:We have established a 15-seconds tidal breathing method using our originally developed apparatus to measure cough sensitivity to capsaicin. Astograph, an apparatus to measure bronchial responsiveness to methacholine, has been widely used in clinical practice in Japan. If Astograph is available for measurement of cough sensitivity, it will contribute to promoting the spread of cough sensitivity test.METHODS:Fifteen-seconds tidal breathing methods using our original apparatus and Astograph were compared in 29 healthy subjects. To assess the agreement of the two methods, increasing concentrations of capsaicin solution were inhaled for 15 seconds until 5 or more cough were elicited and cough threshold, the lowest concentration of capsaicin eliciting 5 or more coughs, was determined by each method on 2 separate days at one week interval. On each day, the cough threshold measurement was repeated twice at one-hour interval to assess the repeatability.RESULTS:Difference and repeatability coefficient were 0.35 and 2.00 in our original method and 0.14 and 1.88 doubling concentration in Astograph method, respectively, indicating good repeatability of both methods. Difference and coefficient of agreement between the two methods was 0.30 and 2.44 doubling concentration, respectively.CONCLUSIONS:Astograph is suitable for measurement of cough sensitivity to capsaicin because of its good repeatability and agreement with our original method already established.

Electroencephalography (EEG) coherence provides a measure of functional correlations between two EEG signals. The present study was conducted to examine intrahemispheric EEG coherence at rest and during photic stimulation (PS; 5, 10 and 15 Hz) in ten unmedicated patients with presenile dementia of the Alzheimer type (AD; mean age at onset 56 years). In the resting EEG, the AD patients had significantly lower coherence than gender- and age-matched control subjects in the alpha-1, alpha-2 and beta-1 frequency bands. The EEG analysis during PS also showed that the patients had significantly lower coherence in the frequency corresponding to PS at 10 and 15 Hz. In this study, the changes in coherence from the resting state to the stimulus condition (i.e. PS-related coherence reactivity) were examined. The patients were found to show significantly smaller coherence reactivity to PS at 5 and 15 Hz. These findings suggest that, in addition to the resting state, AD patients have an impairment of intrahemispheric functional connectivity during PS. They also suggest that AD shows a failure of PS-related functional reorganization.