Comparison between computer-aided diagnosis and radiologists: assessment of pulmonary blood flow on chest radiographs.

To evaluate the performance of a computer-aided diagnosis (CAD) scheme for estimating increased pulmonary blood flow on chest radiographs, we compared computerized assessment with findings by radiologists. Our CAD scheme extracts selectively linear opacities corresponding to vessels in regions of interest (ROIs) in the right upper and lower lung zones on digitized chest radiographs, and then calculates a radiographic index as a physical measure that reflects the area of the extracted opacities in selected ROIs. As a measure of increased pulmonary blood flow, the upper/lower radiographic index ratio was calculated for each patient. Seven radiologists estimated the degree of increased pulmonary blood flow for the same images of ROI sets presented on a cathode-ray tube monitor in a randomized order. Between the normal-pulmonary capillary wedge pressure (PCWP) group and increased-PCWP groups, there was no significant difference in performance between CAD and radiologists (p = 0.105). However, when the normal and mild PCWP groups were compared, the performance of CAD was superior to that of radiologists (p = 0.001). This study indicates that our CAD scheme is promising for quantitative estimation of increased pulmonary blood flow, especially in mild cases.

[Usefulness of helical scanning CT in assessment of left ventricular papillary muscle contractility].

Three-dimensional data on the left ventricle at quasi-end-diastole and quasi-end-systole were acquired by helical scanning CT in 12 patients. Short axial images of the left ventricle and long axial images of the papillary muscle were created using multiplanar reconstruction. Left ventricular dimensions and the length of the papillary muscle were measured, and fractional shortening of the papillary muscle was calculated. There was a good correlation between left ventricular dimensions measured by echocardiogram and helical scanning CT (end-diastole: r = 0.94: end-systole: r = 0.86; fractional shortening of left ventricular dimension: r = 0.84). Papillary muscle fractional shortening was 6.3% in the ischemic group and 21.5% in the non-ischemic group (p < 0.005). Helical scanning CT is clinically useful for the assessment of left ventricular papillary muscle function.

Regional left ventricular motion during early filling phase in patients with right ventricular pressure overload.

Global left ventricular (LV) diastolic function has been reported to be disturbed under conditions of right ventricular pressure overload (RVPO). However, from the standpoint of regional wall motion, only a little information related to the mechanism of LV diastolic dysfunction is available. Eight patients with RVPO and 7 healthy volunteers were investigated using tagged cine magnetic resonance imaging. Regional diastolic fraction (RDF) was determined in 4 segments (anterior, lateral, inferior, and septal) in the mid-ventricular short axis section and in 2 segments (septal and lateral) in the 4-chamber section. A heterogeneity index was obtained from the RDFs of the short axis section. In the RVPO group, in both short axis and 4-chamber sections, the RDF of the septal segment was depressed, and it showed an inverse correlation with the right-to-left ventricular systolic pressure (RV/LV) ratio (r = -0.74, p < 0.05) in the short axis section. In the 4-chamber section, the RDF was lower in the septal segment than in the lateral segment (p < 0.05). The heterogeneity index in the RVPO group was greater than that in the control group (p < 0.01). The index correlated positively with the RV/LV ratio (r = 0.77, p < 0.05). The altered regional diastolic motion results in increased heterogeneity in regional diastolic motion.

Visualization of air-trapping area with expiratory CT in hypersensitivity pneumonitis.

We report a case of summer-type hypersensitivity pneumonitis that demonstrated air-trapping. In this case we used images at inspiratory and expiratory volumetric HRCT, which enabled us to obtain images of the same level at inspiratory and expiratory CT.

Development and evaluation of PC-based HIS-RIS-modality-PACS coupling: the results of evaluation of initial stage with personal computer application.

A PC-based HIS/RIS/Modality/PACS coupling was developed and operated where hospital-wide PACS was closely cooperated with the HIS and RIS. Three workstations with a magneto-optical disk (MOD) juke-box for each one were used as PACS servers to collect images from eight computed radiography systems and three CT scanners. An implementation of JPEG compression reduced network load and storage volume. Twenty PACS-terminals can be connected to the PACS servers and get images from them. Functions of the terminals are magnification, tone scale modification and mensuration. The physicians can also get images on HIS-terminals employing improved HIS-terminal functions. This system has many advantages: (1) inexpensive; (2) close cooperation with the HIS and RIS which makes them easy to manage and retrieve images automatically; and (3) it is an open system, which enables us to apply new technologies. As a matter of fact the introduction of a new PC and a new OS made it possible to decrease displaying response time.

[Results of clinical study with epirubicin hydrochloride injectable solution in hepatoma].

A 10-center cooperative clinical study with a new formulation of epirubicin hydrochloride injectable solution (Epirubicin-RTU) was conducted in patients with hepatocellular carcinoma. Epirubicin-RTU 60 mg/m2 was injected into the hepatic artery and a three-week drug-free interval followed. Of 15 patients with hepatocellular carcinoma registered in this study, 14 patients were eligible, and they all completed the entire course. The objective was to investigate the safety of treatment with Epirubicin-RTU in 14 eligible patients. The adverse drug reactions frequently observed in these 14 eligible cases were leukopenia, neutropenia, thrombocytopenia, alopecia, and fever. They were all reversible and tolerable. With these results. Epirubicin-RTU was considered to be a safe pharmaceutical product to inject into the hepatic artery.

Regional ventricular systolic abnormalities caused by a rudimentary chamber in patients with univentricular hearts.

Previous studies have demonstrated that regional wall motion abnormalities are common in univentricular hearts; however, the mechanism of this abnormality and its relation to hemodynamics remain unclear. The aim of this study was to document and analyze the etiology of regional wall motion abnormality and its relation to hemodynamics in univentricular hearts. Sixteen patients (age 11+/-6 years) were examined. A tagged cine magnetic resonance imaging method that superimposes "tags" on myocardium was used to assess regional systolic motion. The tags were traced from end-diastole to end-systole, and the percent regional shortening fraction was calculated as the shortening ratio. The tags were positioned on 6 segments. Normal ranges for wall motion were established from 10 normal volunteers. An asynchrony index was calculated as the SD divided by the mean regional shortening fraction to quantify asynchronous regional motion. Hemodynamic parameters were also obtained by cardiac catheterization. In patients, regional shortening fraction was significantly lower in segments adjacent to the rudimentary chamber compared with normal values in both circumferential and longitudinal directions (p <0.05 and p <0.01, respectively). The asynchrony index was much greater in patients than in controls (62+/-25 vs 27+/-10, p <0.01). The index correlated with rudimentary chamber volume and the rudimentary/main chamber volume ratio (r = 0.58, r = 0.79, respectively). Furthermore, the index correlated with end-diastolic pressure (r = 0.82). The rudimentary chamber may play an important role in causing asynchronous regional motion, and this motion may contribute to ventricular diastolic dysfunction.

Left ventricular regional systolic motion in patients with right ventricular pressure overload.

Left ventricular regional systolic motion was investigated in patients with right ventricular pressure overload and 10 controls using tagged cine magnetic resonance imaging. The regional shortening fraction was determined in four segments (septal, lateral, inferior, and anterior) on the short-axis image. An asynchrony index, nonhomogeneity of regional shortening, was calculated. Septal shortening in these patients was depressed, and showed an inverse correlation with the right-to-left ventricular peak pressure ratio (r=-0.80, P<0.01). Lateral shortening was greater in the patients than in the controls (P<0.01). The asynchrony index was significantly greater in the patients than in the controls (P<0.01), and correlated with the right-to-left systolic pressure ratio (r=0.64, P=0.02) and the left ventricular end-diastolic pressure (r=0.79, P<0.01). The altered distribution of regional circumferential shortening results in an increased heterogeneity of regional systolic motion. These findings may have important implications for the assessment of ventricular function in patients with right ventricular pressure overload.

Fractal analysis for classification of ground-glass opacity on high-resolution CT: an in vitro study.

PURPOSE: Fractal analysis based on the fractional Brownian motion model was applied ground-glass opacity on high-resolution CT (HRCT) to investigate its usefulness in distinguishing ground-glass opacity caused by nonfibrotic disease processes and that caused by fibrotic disease processes, confirming pathology. METHOD: Twenty-one postmortem lungs inflated and fixed by Heitzman's method were evaluated. By correlating HRCT and pathology, the lungs were classified into nonfibrotic disease processes and fibrotic disease processes. Fractal analysis based on the fractional Brownian motion model provides the parameter H, which is a statistical measure related to the psychophysical perception of roughness. For regions of interest positioned over ground-glass opacities on HRCT, conventional statistics (mean value and SD) and the estimated H values were calculated using a workstation. RESULTS: Pathologically, 10 lung specimens were categorized as nonfibrotic disease processes and 11 as fibrotic disease processes. Whereas the conventional statistics had considerable overlap in two disease processes, the overlapping was drastically reduced in the H values. The H values of fibrotic disease processes (mean +/- SD, 0.423 +/- 0.064) were significantly greater than those of nonfibrotic disease processes (0.297 +/- 0.036) (p < 0.001). CONCLUSION: Fractal analysis based on the fractional Brownian motion model may provide a new promising scheme for assessing ground-glass opacity on HRCT caused by either nonfibrotic or fibrotic disease processes.

Computerized radiographic assessment of pulmonary blood flow in patients with and those without mitral stenosis.

The authors investigated whether a computerized analysis system can be used with chest radiography for estimating the redistribution of pulmonary blood flow in patients with and those without mitral stenosis (MS). Their system uses four-directional Laplacian-Gaussian filtering and binarization. As a physical measure, the radiographic index, which reflects the area of opacity in selected regions of interest (ROIs), was used. Fifteen men with MS and 15 men without MS were included in the study. ROIs were selected in the right upper and lower lung zones on radiographs, and the images were processed with the system. The radiographic indexes were determined in each ROI. As a measure of pulmonary blood flow redistribution, the upper-to-lower lung zone radiographic index ratio (U/L) was calculated. The U/L values correlated with pulmonary capillary wedge pressure values (r = .405, P = .025). The mean U/L value of the MS group was significantly higher than that of the non-MS group (1.16 +/- 0.14 vs 1.05 +/- 0.09, respectively; P = .016). These preliminary results indicate that this system can be used for quantitative estimation of the redistribution of pulmonary blood flow.

[Fast cine MR coronary angiography compared with conventional coronary angiography: criteria for coronary artery stenosis].

Magnetic resonance coronary angiography (MRA) was performed in 5 healthy volunteers and 13 patients to evaluate its diagnostic capability. Ten to 15 continuous cross sections were obtained for each coronary artery using fast cardiac cine MR (FASTCARD) with breath-hold, and reconstructed images were made. The control study showed good demonstration of the left main, proximal left anterior descending (Seg. 6) and proximal right (Seg. 1, 2) coronary arteries. Abnormal findings were classified as interruption, stenosis (severe or mild), irregularity, or decreased signal, and they were compared with the findings of conventional angiography in proximal segments (Seg. 1,2,5,6). Twelve of 15 lesions with significant stenosis (> 75%) were depicted as interruption or severe stenosis (sensitivity 80%). The sensitivity was 100% (6 of 6 lesions) in the right coronary artery and 67% (6 of 9 lesions) in the left coronary artery. The positive predictive value was 75% (12 of 16). Comparison at each segment revealed that the sensitivity, specificity and accuracy for interruption or severe stenosis were 92%, 79%, and 86%, respectively, for severe stenosis (> 90%), and 85%, 79%, and 83% for significant stenosis (> 75%). Interruption or severe stenosis on MRA is presumed to be an appropriate criterion for the detection of significant stenosis in the proximal coronary artery.

Acute interstitial pneumonia: high-resolution CT findings correlated with pathology.

OBJECTIVE: The purpose of this study was to evaluate the relation between pathologic phases and high-resolution CT (HRCT) findings in patients with acute interstitial pneumonia (AIP). MATERIALS AND METHODS: Our retrospective review found 14 patients with AIP who were included in this study. Three patients were pathologically diagnosed as having AIP by open lung biopsy, and the other 11 patients were confirmed at autopsy. In eight of the 11 autopsy patients, the postmortem lungs were inflated and fixed by Heitzman's method, and a postmortem HRCT scan was obtained on all 11 autopsy patients. Paying special attention to the disease stage, we selected 27 areas of the lung from antemortem or postmortem HRCT and correlated them with pathologic findings. RESULTS: Nine areas of the lung that showed increased attenuation without traction bronchiectasis were associated with either the exudative (n = 5) or early proliferative (n = 4) phase of AIP. Eleven areas of increased attenuation with traction bronchiectasis were associated with either the proliferative (n = 4) or fibrotic (n = 7) phase of AIP. Honey-combing, observed in one area of the lung, corresponded to restructuring of distal airspaces and dense interstitial fibrosis. Six spared areas, within or adjacent to areas of increased attenuation, showed pathologic findings of the exudative phase. CONCLUSION: HRCT findings were not specific for the pathologic findings in our patients with AIP. Nevertheless, the findings of traction bronchiectasis in areas of increased attenuation suggested the proliferative or fibrotic phase.

[Noninvasive hemodynamic assessment of internal thoracic artery grafts using duplex echocardiography from supraclavicular fossa--a comparison with Doppler catheter method].

We evaluated the usefulness of noninvasive hemodynamic assessment of internal thoracic artery grafts (ITAGs) using duplex Doppler echocardiography from the supraclavicular fossa (transcutaneous pulsed Doppler method: PD method). Eighteen ITAGs were examined by PD method in comparison with Doppler catheter method using Doppler flowire (DC method). The hemodynamic indices used were the diastolic/systolic peak velocity ratio (DSVR) and the diastolic fraction of time-velocity integral (DF) in the ITAGs. A significant linear correlation was seen both in DSVR and DF between these two methods (p < 0.01). The subjects were assigned to two groups according to angiographic findings Group A (Gr-A: 5 grafts) with string sign including significant graft stenosis and group B (Gr-B 13 grafts) with good patency. In both PD and DC methods, DSVR and DF were significantly lower in Gr-A than in Gr-B (p < 0.01). The blood flow pattern was thus systolic dominant in the grafts with string sign, while it was diastolic dominant in the grafts with good patency. In some grafts in Gr-B, however, both DSVR ad DF were as low as that in Gr-A. Responding to pacing, Gr-B further increased both DSVR and DF, but Gr-A did not. As a result, the difference between both groups was further distinguished. In summary, ITAG function can be assessed by the noninvasive PD method. Interventions such as exercise, dobutamine infusion may make it more accurate, particularly in evaluating borderline data.

Normal nonuniformity of left ventricular contraction. Assessment by cine MR imaging with presaturation myocardial tagging.

PURPOSE: To identify the normal performance of left ventricular (LV) regional contraction using cine MR imaging with presaturation myocardial tagging. MATERIAL AND METHODS: Sixteen normal volunteers were examined on a 1.5 T MR system with tagging cine sequences. Tags were applied at end-diastole as 2 parallel black lines on short-axis and 4-chamber sections, and the fractional shortenings were calculated at 7 LV locations. RESULTS: The following results were obtained with significance: a transmural gradient of contractility in the short-axis section; prolonged late-systolic endocardial shortening and epicardial early termination in the free wall; initial delay of shortening in the anterior wall; apical predominance of contractility; predominance of circumferential shortening in the free wall and of meridional shortening in the septum. These findings could be associated with myocardial fiber architecture, presumed wall stress and temporal asynergy of excitation. CONCLUSION: Cine MR imaging with myocardial tagging proved to be useful in assessing the nonuniformity of LV contraction.

Detection of subtle interstitial abnormalities of the lungs on digitized chest radiographs: acceptable data compression ratios.

OBJECTIVE: To determine acceptable compression ratios for digital radiography, we evaluated the effect of data compression on the detection of subtle interstitial lung abnormalities using digitized chest radiographs. MATERIALS AND METHODS: Screen-film chest radiographs of 38 patients with subtle interstitial lung abnormalities and 40 patients with normal lung parenchyma were digitized (spatial resolution, 0.175 mm; 2000 x 2000 pixels; 10 bits per pixel) and compressed with the discrete cosine transform method at ratios of 10:1, 20:1, and 30:1. Five chest radiologists and five radiology residents examined the uncompressed and compressed digital images and rates the presence of interstitial lung abnormalities with a five-level scale of confidence. Results were analyzed by receiver operating characteristic methods. RESULTS: Overall, the interpretation of images with a compression ratio of 30:1 was significantly less accurate than that of uncompressed images (p < .05). For the five chest radiologists, interpretation of images with a compression ratio of 20:1 or 30:1 was significantly less accurate than that of uncompressed images (p < .05). However, for the five residents, no significant difference between interpretations of compressed and uncompressed images was noted (p > or = .05). CONCLUSION: These results suggest that a 10:1 data compression ratio does not influence the detection of subtle interstitial lung abnormalities. However, information that is lost with a 20:1 data compression ratio might be essential for interpretation by experienced chest radiologists.

Usefulness of high-resolution CT for differential diagnosis of multi-focal pulmonary consolidation.

To determine whether high-resolution CT (HRCT) is useful for diagnosing patients with multi-focal pulmonary consolidation observed on chest radiography, we reviewed the HRCT scans of 80 patients with various kinds of diseases. The patients were divided into three groups: those with infectious diseases (group A, n = 28), those with non-infectious diseases in which the use of corticosteroids was the treatment of choice (group B, n = 33), and others (group C, n = 19). Centrilobular branching structure, small nodules within the consolidation, and segmental distribution were specific or more prevalent in group A. Ground-glass attenuation, air-bronchiologram, and non-segmental distribution were more prevalent in group B. Consolidation composed of central homogeneous area and its surrounding small nodules was specific for group C, especially for sarcoidosis. In conclusion, HRCT provides more useful information in diagnosing patients with multifocal consolidation than does chest radiography or conventional CT.

Dynamic range control processing of digital chest images. A clinical evaluation.

PURPOSE: The clinical usefulness of an advanced image-processing system called "dynamic range control processing" was investigated, with which selected parts of the dynamic range of digital chest images could be controlled. MATERIAL AND METHODS: A comparative study of 3 different post-processed formats of storage phosphor (SR) images was performed in 35 patients with abnormalities in the chest. The 3 formats were SR images with standard mode (SR-standard), SR images with strong edge-enhancement (SR-enhanced), and dynamic range controlled SR images (SR-controlled). RESULTS: For lung abnormalities, there was no difference among the 3 SR image formats. For normal mediastinal structures and lung abnormalities covered by the heart or diaphragm, SR-controlled and SR-enhanced images were significantly superior to SR-standard images, while no difference was found between SR-controlled and SR-enhanced images except for the trachea and bony structures. CONCLUSION: Dynamic range control processing appears to be a useful method for displaying SR chest images with an extremely wide dynamic range.

Assessment of right ventricular regional contraction and comparison with the left ventricle in normal humans: a cine magnetic resonance study with presaturation myocardial tagging.

OBJECTIVE: Right ventricular regional contractility has been thought to be difficult to assess precisely. Cine magnetic resonance imaging with presaturation myocardial tagging was employed to quantitate the contraction of the right ventricular free wall and to identify normal performance compared with the left ventricle. METHODS: Nine normal volunteers, aged 27-39 years, were examined in a 1.5 Tesla superconductive magnet, and short axis and four-chamber sections at the mid-ventricular level were imaged with cine magnetic resonance sequences. Tags, applied at end diastole as two parallel black lines, intersected the mid-portion of the free wall, dividing it into upper, centre, and lower segments in the short axis section, and anterior, middle, and posterior segments in the four-chamber section. From a series of cine magnetic resonance images at 50 ms intervals over a cardiac cycle, end diastolic, and early, mid-, and end systolic images were chosen for calculation of the endocardial, epicardial, and mean percent fractional shortening (%FS) in the six segments. RESULTS: There was (1) a gradual increase in %FS in systole in both sections (P < 0.001, < 0.005); (2) a poor transmural gradient of contractility; (3) a predominance of meridional shortening (whole length, mean end systolic %FS (SD): short axis, 17.4 (3.1)%; four-chamber, 30.1 (4.1)%; P < 0.001) in contrast to dominant circumferential shortening in the left ventricular lateral wall; (4) lower predominance of contractility in the short axis section (P < 0.001), and a middle dip of contractility in the four-chamber section (P < 0.005). CONCLUSIONS: Heterogeneity of contractility was closely correlated with the myocardial fibre architecture, and with wall stress determined by its thickness and curvature. It was proved that right ventricular regional function could be analysed non-invasively using cine magnetic resonance imaging with myocardial tagging.