Yoshifumi Yasuhara

Circulating KL-6 levels in patients with drug induced pneumonitis

Background: The circulating level of KL-6/MUC1 is a sensitive marker for various interstitial lung diseases. Previous case reports have suggested that KL-6 may also be increased in some patients with drug induced pneumonitis. A study was undertaken to determine whether serum KL-6 could be a marker for particular types of drug induced pneumonitis. Methods: The findings of high resolution computed tomographic (HRCT) chest scans of 30 patients with drug induced pneumonitis were reviewed separately by two independent observers. The pneumonitis was classified into four predominant patterns: widespread bilateral consolidation (diffuse alveolar damage, DAD; n=7), fibrosis with or without consolidation (chronic interstitial pneumonia, CIP; n=11), consolidation without fibrosis (bronchiolitis obliterans organising pneumonia or eosinophilic pneumonia, BOOP/EP; n=8), and diffuse ground glass opacities without fibrosis (hypersensitivity pneumonitis, HP; n=4). Serum KL-6 levels were measured by a sandwich enzyme linked immunosorbent assay. Results: The overall sensitivity of serum KL-6 in detecting drug induced lung disease was 53.3%, which was lower than its sensitivity in detecting other interstitial lung diseases. However, the KL-6 level was increased in most patients with a DAD or CIP pattern (16/18; 88.9%) and was closely correlated with their clinical course. In contrast, serum KL-6 levels were within the normal range in all patients with a BOOP/EP or HP pattern. Conclusions: Particular patterns detected by HRCT scanning, such as DAD and CIP but not the BOOP/EP or HP patterns, are associated with increased circulating KL-6 levels in drug induced pneumonitis. Serum KL-6 levels may reflect the clinical activity of the particular disorders.

Striatal L‐DOPA Decarboxylase Activity in Parkinson's Disease In Vivo: Implications for the Regulation of Dopamine Synthesis

Abstract: L‐DOPA is a large neutral amino acid subject to transport out of, as well as into, brain tissue. Competition between dopamine synthesis and L‐DOPA egress from striatum must favor L‐DOPA egress if decarboxylation declines relatively more than transport in Parkinsons disease. To test this hypothesis, we injected patients with Parkinsons disease with a radidabeled analogue of L‐DOPA and recorded regional brain radioactivity as a function of time by means of positron emission tomography. We simultaneously estimated the activity of the decarboxylating enzyme and the amino acid transport. In the striatum of patients, we found the L‐DOPA decarboxylase activity to be reduced in the head of the caudate nucleus and the putamen. However, the rate of egress of the DOPA analogue was unaffected by the disease and thus inhibited dopamine synthesis more than predicted in the absence of L‐DOPA egress.

Three‐Dimensional Endoscopic Mode for Observation of Laryngeal Structures by Helical Computed Tomography

We produced high‐quality three‐dimensional (3D) endoscopic images of the larynx using helical scanning computed tomography. Subjects included two normal volunteers and 10 patients: five with laryngeal cancer, four with unilateral recurrent laryngeal nerve (RLN) palsy, and one with atrophied vocal folds. Two vertically split hemilaryngeal images were displayed together with the oral and tracheal views. Although motion artifacts were seen in four patients, laryngeal structures including the vocal fold, ventricular fold, and ventricle were clearly identified in all subjects. In the patients with cancer, axial images showing the extent of the tumor in each patient provided more information than 3D endoscopic images. In the patients with RLN palsy and atrophied vocal fold, combination of 3D endoscopic and cross‐sectional images offered more diagnostic information than axial images alone.

Detection of lung cancer using single-exposure dual-energy subtraction chest radiography

PurposeThe aim of this study was to evaluate the detectability of lung cancer by chest radiography with a single-exposure dual-energy subtraction (ES) method.Materials and methodsFive radiologists read two sets of chest radiographs from 77 patients (66.5 ± 9.6 years old) with histologically proven lung cancer measuring ≤3.0 cm and those from 77 normal subjects (65.7 ± 9.0 years old). The observer tests were performed in two sessions: standard computed radiography (CR) images only and a combination of CR and ES images. Receiver-operating characteristic analysis was used for statistical analysis. All tumors were classified into three groups according to the appearance on thin-section CT: (1) nonsolid: tumor shadow disappearance rate (TDR) was 100%; (2) partly solid: TDR was ≥50 but <100%; (3) solid: TDR was <50%.ResultsOverall, detectability with the ES method was significantly better than that without ES (mean Az value increased from 0.7673 to 0.8265, P < 0.05). In the subgroup analysis of the nonsolid group and the solid group detectability did not change using the ES method, whereas in the partly solid group detectability with the ES method was significantly better than that without ES (mean Az value increased from 0.7162 to 0.8209, P < 0.005).ConclusionThe ES method improves the detectability of lung cancer by chest radiography, especially of the partly solid group.

A measurement of regional portal blood flow with Xe-133 and balloon catheter in man

This investigation was undertaken to measure regional portal blood flow of the liver. The measurement was performed by injecting 133Xe into the proper hepatic artery through a balloon catheter and then occluding the proper hepatic artery with an inflated balloon. Data were collected using a gamma camera, and washout curves were generated. They were analyzed by the initial slope method and Kety Schmidt equation. The average regional portal blood flows were: 59.31±13.04 ml/100 g per min, 58.71±14.14 ml/100 g per min and 37.12±10.11 ml/100 g per min in hospital controls (11), patients with chronic hepatitis (10) and those with liver cirrhosis (56), respectively. In the patients with cirrhosis, the regional portal blood flow was significantly reduced (P<0.01). The reproducibility of this method was satisfactory. The measurement of regional portal blood flow will be useful to evaluate underlying liver injuries and determine indications of a transcatheter arterial embolization of the liver.

SPECT volume measurement using an automatic threshold selection method combined with a V filter

The volume measurement of various organs by single photon emission computed tomography (SPECT) has generally been performed by summing up the voxels lying within the outer edge of the organ determined by thresholding as a function of the maximum reconstructed counts within a volume of interest. The optimum threshold level, however, is influenced by various factors. To eliminate this problem, Mortelmans et al. (1986) proposed to use an automatic threshold selection method (ATSM) based on discriminant criteria and to correct the errors induced by the imperfect system response using the method based on linear regression analysis, which has some problems in practical application. We tried to use ATSM combined with a V filter. The correlation coefficient (r) and the regression equation between the true (x) and the calculated volume (y) obtained by experimentation using 22 phantoms with a volume ranging between 26 ml and 380 ml were as follows: r=0.994 and y(ml)=1.015x+1.09 using ATSM combined with a V filter, while r=0.993 and y(ml)=1.110x+30.55 using only ATSM. The relative error between the true and the calculated volumes decreased significantly (P<0.01) from 37.7%±26.9% to 5.5%±4.2%. The results suggest that ATSM combined with a V filter is useful for correcting the errors caused by an imperfect system response, and is available and reliable for SPECT volume determination even when the organ volume is small.

Effect of Inhalated Bronchodilators on Air Trapping in Patients with Stable Asthma

Air trapping is frequently observed during high-resolution computed tomography (HRCT) of patients with asthma, but whether the condition is reversible has not been thoroughly investigated. The aim of the present study was to evaluate reversibility of air trapping in response to bronchodilator. Ten never-smokers with stable asthma enrolled in the study. Spirometry and HRCT were performed before and after bronchodilator inhalation. Air trapping remained unchanged, although significant reversibility of FEV1 was observed. Air trapping scores correlated significantly with airway wall thickness. These observations suggest that air trapping is irreversible and that it represents structural remodeling of small airways in patients with stable asthma.

Clinical significance of the measurement of hepatic blood flow using xenon 133 and balloon catheter in patients undergoing treatment for hepatocellular carcinoma

Total hepatic blood flow and portal blood flow were measured separately using a modified xenon 133 clearance method during angiography in 71 patients with chronic liver diseases, including 40 with proven hepatocellular carcinoma, and in 12 patients without detectable chronic liver injury who served as controls. Total hepatic and portal blood flow rates in controls were 805 ±149 ml/min and 667 ± 206 ml/min, respectively. Total hepatic blood flow was significantly decreased in patients with compensated and decompensated liver cirrhosis (519 ± 156 ml/min and 317 ± 153 ml/min, respectively; P < 0.01), as was portal blood flow (399 ± 134 ml/min and 271 ± 134 ml/min, respectively; P < 0.01). Following transcatheter arterial embolization or hepatic resection (in 35 and 13 patients, respectively), hepatic failure occurred in 3 cases each. Embolization appeared contraindicated when hepatic portal blood flow was under 125 ml/min, and safe hepatic resection required an anticipated residual hepatic portal blood flow of at least 250 ml/min.

Relationship between regional severity of emphysema and coronary heart disease

We analyzed the relationship between regional severity of emphysema, which was evaluated by three-dimensional fractal analysis (3D-FA) of Technegas SPECT images, and coronary heart disease (CHD). For 22 patients with emphysema who underwent Technegas SPECT, we followed up CHD events. The follow-up period was 5.4±0.5 (mean ±SD) years. We defined the upper-lung fractal dimension (U-FD) and lower-lung fractal dimension (L-FD) obtained with 3D-FA of Technegas SPECT images as the regional severity of emphysema. FD became greater with the progression of emphysematous change. During the follow-up period, CHD events occurred in 6 (27%) of the 22 patients. The ratio of U-FD to L-FD for patients with CHD events (0.87±0.22) was significantly smaller than for patients without CHD events (1.52±0.38) (p=0.0015). These findings suggest that severer emphysema in the lower lung indicates a higher risk of CHD than that in the upper lung.

Alleviation of gallbladder complications by treatment of hepatic arterial embolization with caerulein.

SummaryTranscatheter arterial embolization (TAE) with the concurrent use of caerulein was assessed for the purpose of preventing gallbladder complications often seen after TAE of hepatic carcinoma. Ninety-six cases with primary hepatic carcinoma, who had undergone TAE in the right hepatic arterial region over the past 4 years, were divided into three groups: 22 cases for which embolization was possible on a selective basis by passing the catheter to the peripheral side beyond the bifurcated region of the cystic artery; 40 cases who had undergone TAE in which caerulein was not administered, from the central side of the bifurcated region of the cystic artery; and 34 cases given 20 μg caerulein 15–30 min before TAE. A comparison was made using the abdominal pain, pyrexia, rate of leukocytosis and the US findings of the gallbladder as the indices of the gallbladder complications. As a result, it become evident that it was possible to prevent or alleviate gallbladder complications if caerulein were administered before TAE in cases where the embolizing substances were infused in the right hepatic artery from the central side of the bifurcated region of the cystic artery. It was conclusively shown that the gallbladder blood flow decreases if the organ is contracted by caerulein, which in turn causes a decrease in the inflow of the embolizing substances whereby complications are alleviated.