Serine proteinase inhibitor 3 and murinoglobulin I are potent inhibitors of neuropsin in adult mouse brain

Extracellular serine protease neuropsin (NP) is expressed in the forebrain limbic area of adult brain and is implicated in synaptic plasticity. We screened for endogenous NP inhibitors with recombinant NP (r-NP) from extracts of the hippocampus and the cerebral cortex in adult mouse brain. Two SDS-stable complexes were detected, and after their purification, peptide sequences were determined by amino acid sequencing and mass spectrometry, revealing that target molecules were serine proteinase inhibitor-3 (SPI3) and murinoglobulin I (MUG I). The addition of the recombinant SPI3 to r-NP resulted in an SDS-stable complex, and the complex formation followed bimolecular kinetics with an association rate constant of 3.4 +/- 0.22 x 10(6) M(-1) s(-1), showing that SPI3 was a slow, tight binding inhibitor of NP. In situ hybridization histochemistry showed that SPI3 mRNA was expressed in pyramidal neurons in the hippocampal CA1-CA3 subfields, as was NP mRNA. Alternatively, the addition of purified plasma MUG I to r-NP resulted in an SDS-stable complex, and MUG I inhibited degradation of fibronectin by r-NP to 24% at a r-NP/MUG I molar ratio of 1:2. Immunofluorescence histochemistry showed that MUG I localized in the hippocampal neurons. These findings indicate that SPI3 and MUG I serve to inactivate NP and control the level of NP in adult brain, respectively.

High-spatial-resolution and real-time medical imaging using a high-sensitivity HARPICON camera

A HARPICON(TM) camera has been applied to a digital angiography system with fluorescent-screen optical-lens coupling. It uses avalanche multiplication in the photoconductive layer for high-sensitivity imaging. The limiting spatial resolutions in the 1050 scanning-line mode of the camera are about 30 and 50 micro m at input field sizes of 20 x 20 and 50 x 50 mm on the screen, respectively. For high-speed imaging, the 525 scanning-line mode at a rate of 60 images s(-1) can be selected. High-quality images of coronary arteries in dogs were obtained by intra-aortic coronary angiography and superselective coronary angiography using a single-energy X-ray above the iodine K-edge energy.

High-Spatial-Resolution Medical-Imaging System Using a HARPICON Camera Coupled with a Fluorescent Screen

A high-sensitivity HARPICON camera was developed for medical X-ray imaging using a fluorescent screen. It is an avalanche-multiplication-type image pick-up tube and is 32 times more sensitive than conventional tubes. The camera also has a wider dynamic range than conventional medical-imaging cameras because a maximum output signal current of 2.3 muA is obtained and, in high-illumination-intensity regions, photocurrent is not proportional to illumination intensity. The fluorescent screen is an intensifying screen of the type used for radiographic screen-film combinations in medical examination. An X-ray image on the screen is focused on the photoconductive layer of the pick-up tube using a coupling lens with f/0.65. Experiments were performed using monochromated X-rays at the Photon Factory. An image of a spatial resolution test chart was taken in a 525 scanning-line mode of the camera. The chart pattern of 5 line-pairs mm(-1 )(spatial resolution of 100 mum) was observed at an X-ray input field of 50 x 50 mm. Real-time digital images of the heart of a 12 kg dog were obtained at a frame rate of 60 images s(-1) after injection of a contrast medium into an artery. The images were stored in digital format at 512 x 480 pixels with 12 bits pixel(-1). High-spatial-resolution and high-contrast images of coronary arteries were obtained in aortography using X-rays with energy above that of the iodine K edge; the image quality was comparable with that of conventional selective coronary angiography.

Two-dimensional intravenous coronary arteriography using above-K-edge monochromatic synchrotron X-ray

RATIONALE AND OBJECTIVES

For intravenous (i.v.) coronary arteriography, a real-time two-dimensional (2D) imaging system is being developed using above-K-edge monochromatic X-rays alone. The potential diagnostic value of this system was examined in the current study.

METHODS

The angiographic system consisted of an asymmetric silicon (311) monocrystal, an image intensifier, and a charged-coupled device camera. It was constructed at the beam line of the Tristan Accumulation Ring. Monochromatic X-rays of 33.32 keV were used, and each image was recorded over 2 msec.

RESULTS

Ventricular wall motion and the anatomy of the coronary arteries could be seen in dogs by sequential images obtained without subtraction. The left anterior descending coronary artery, left circumflex coronary artery, and right coronary artery and the branches of these vessels were observed. The parts of the coronary arteries overlapping the aorta and left ventricle were revealed somewhat during washout of the contrast material.

CONCLUSION

For a 2D imaging system, monochromatic i.v. coronary angiography using an energy above the iodine K-edge might be able to image the coronary arteries without subtraction. However, the image quality needs to be improved by increasing the X-ray flux, decreasing background radiation scatter from the object, and decreasing contamination with 99-keV X-rays.

Phosphorus-31 nuclear magnetic resonance study on the effects of endurance training in rat skeletal muscle

To evaluate changes in muscle energetics following endurance training, we measured phosphorus-31 nuclear magnetic resonance (31P NMR) spectra on rat muscle in vivo before and after training in the same animals. The endurance training lasted for 3 months. The 31P NMR spectra were obtained serially at rest, during exercise by electrical stimulation, and during recovery. Intramuscular phosphocreatine (PCr), inorganic phosphate (P(i)), adenosine 5'-triphosphate (ATP) and pH were determined from the NMR spectra. The ratio of PCr:(PCR + P(i) at rest showed no difference between the trained and control groups even after 3 months of training. During exercise, however, this ratio was significantly higher in the trained group than in the control group. The ratio also recovered more rapidly after exercise in the trained group. The intramuscular pH decreased slightly by approximately 0.1 pH unit during exercise but did not show a significant difference between the groups. These results indicated that endurance training of 3 months duration improved the ATP supply system in the muscle. They also demonstrated that 31P NMR is a potent method for evaluating the effects of training in the same individuals.

Left atrial function in ischemic heart disease assessed by intravenous digital subtraction angiography

To investigate changes in left atrial morphology and dimensions during the cardiac cycle, the atrium was visualized by intravenous digital subtraction angiography (DSA). The study subjects consisted of 22 male patients whose average age was 54.5 +/- 8.6 years. They had ischemic heart disease without mitral valve disease and were in sinus rhythm. They were 11 patients with old myocardial infarction (OMI group) and 11 who had chest pain without evidence of infarction (AP group). DSA was performed in the continuous mode. Contrast material (35 ml) was injected at a rate of 18 ml/sec via a catheter in the superior vena cava and subtraction images were obtained at a speed of 30 frames/sec in the right anterior oblique projection. The left atrial and left ventricular margins were traced manually, their areas were calculated, and fractional changes in area were analyzed. The left ventricular ejection fraction (LVEF) was calculated by densitometry. Cardiac catheterization was performed in 16 patients and the left ventricular end-diastolic pressure (LVEDP) and mean pulmonary arterial wedge pressure (PAWP) were measured. The entire left atrium was clearly imaged using DSA. Phase analysis of the time-area curves in the right anterior oblique projection revealed that the left atrial area was maximal during left ventricular end-systole (%LA1 = 100%), it decreased during early left ventricular diastole (%LA2), and then increased slightly again during mid-diastole (%LA3). After left atrial contraction, the minimum area was obtained (%LA4). The left atrium showed a two-stage decrease in the area due to passive emptying and active contraction during left ventricular diastole. Passive emptying (%LA1-%LA2) was significantly less in the OMI group than in the AP group (6.3 +/- 3.6 vs 13.3 +/- 4.8%, p < 0.01, respectively). In all 22 subjects, passive emptying correlated with LVEF (r = 0.70, p < 0.001) and LVEDP (r = -0.58, p < 0.05). There was no difference in active contraction (%LA3-%LA4) between the 2 groups (26.0 +/- 5.7% in the OMI group, 28.2 +/- 8.4% in the AP group), and it did not correlate with LVEF or LVEDP. The ratio of passive emptying to active contraction [(%LA1-%LA2)/(%LA3-%LA4)] correlated with LVEF (r = 0.63, p < 0.01). These findings suggested that impaired left ventricular diastolic function and a relative increase in atrial contraction were present in patients with a lower LVEF. The %LA4 correlated with LVEDP and PAWP (r = 0.65, r = 0.63, p < 0.01, respectively). In conclusion, DSA proved to be a useful method for investigating left atrial morphology and function.

Tears of cruciate ligaments and menisci: evaluation with cine MR imaging

A cine magnetic resonance (MR) imaging technique, involving the acquisition of kinematic sagittal images during knee movement, was used to evaluate 52 symptomatic knee joints. Results were compared with those obtained by means of static three-dimensional (3D) MR imaging. Twenty-seven of the 28 anterior cruciate ligament (ACL) tears and 22 of 24 normal ligaments were correctly identified at cine MR imaging for a sensitivity of 96% and a specificity of 92%. Static 3D MR imaging yielded a sensitivity of 71% and a specificity of 88%. All four posterior cruciate ligament tears were identified at cine and 3D MR imaging. For meniscal tears, cine MR imaging yielded a sensitivity of 48% and a specificity of 96%; the sensitivity and specificity for 3D MR imaging were 71% and 96%, respectively. Cine MR imaging proved to be more useful than static MR imaging in assessing the tightness of cruciate ligaments, especially of those that were partially torn, and in assessing the movement of meniscal-free fragments. The increased information obtained with cine MR imaging may warrant continued investigation and clinical application.

N-isopropyl-p-[123I]iodoamphetamine SPECT in MELAS syndrome: comparison with CT and MR imaging

Regional cerebral perfusion was studied in three patients with the mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS) syndrome, using single photon emission computed tomography (SPECT) with N-isopropyl-p-[123I]iodoamphetamine (IMP). Accumulation of the tracer was relatively decreased in the parietooccipital regions and also in the frontotemporal regions after stroke-like episodes. However, quantitative regional cerebral blood flow (rCBF) measurement showed that rCBF was relatively well preserved even at these sites, and a hyperemic state was observed at the sites of normal accumulation. IMP SPECT may be useful in the diagnosis and assessment of the progress of the MELAS syndrome.

[MR imaging of the arm]

Thirty arms of healthy adults were studied with MR imaging using surface coil. Fine structures of the arm, such as muscular bundles, small vessels and nerves were clearly demonstrated. Deep fascia dividing muscular bundles appeared as high intensity on T1-weighed image due to fat deposition beneath the fascia. Aponeurosis is also flat sheet of densely arranged collagen fibers. With rather thicker layer of collagen fibers than fascia, aponeurosis appeared as low intensity sheet that was frequently demonstrated on MR images of the extremities.

Effect of strength training on the relationship between magnetic resonance relaxation time and muscle fibre composition

The effect of muscle hypertrophy on the relationship between magnetic resonance (MR) relaxation time and muscle fibre composition was investigated. Relaxation time and muscle fibre composition were measured in five subjects before and after a 20-week period of strength training. Muscle fibre composition in all subjects exhibited a significant shift to a predominance of fast-twitch (FT) fibres as a result of 20-week strength training (% area FT fibres: mean values from 49.8%, SD 17.9% to 57%, SD 5.6%; P less than 0.05). Longitudinal relaxation time (T1) and transverse relaxation time (T2) were prolonged significantly after strength training (T1 mean values from 334.9 ms, SD 13.6 to 359.0 ms, SD 9.0, P less than 0.001; T2 from 27.5 ms, SD 0.9 to 30.8 ms, SD 2.3, P less than 0.05). A constant relationship was observed in changes caused by strength training in muscle fibre composition (% area FT) and relaxation time, with a high correlation obtained between both parameters. These results indicate that MR relaxation time can be used for non-invasive estimation of muscle fibre composition.

[A case of double primary malignancy of intracranial germinoma and thymoma controlled by radiotherapy]

We report a case of double primary malignancy, in which intracranial germinoma and thymoma occurred successively and independently. As curative therapies, the former lesion was treated by definitive irradiation and the latter by postoperative irradiation. Excellent local control has been maintained for 79 and 49 months, respectively, since the beginning of the radiotherapy. The accumulated dose to the thoracic spinal cord was 63.5 Gy. No symptoms suggesting the onset of radiation myelopathy, the most critical late radiation injury, have been observed up to now. We also investigated radiobiological effect to the spinal cord assessed by the formulae of CRE and TDF.

Evaluation of exercise muscle energetics by NMR

Magnetic resonance imaging (MRI) is superior to ultrasonography and X-CT especially in density resolution in soft tissue. 31P NMR provides information on metabolism, which has not been obtained in vivo by conventional methods, such as phosphocreatine (PCr), inorganic phosphate (Pi), ATP, and intracellular pH. We used MRI and 31P NMR spectroscopy to study skeletal muscle metabolism of human and rat. These NMR results suggested that 1) estimation of muscle fiber composition, 2) evaluation of muscle ATP turnover and 3) imaging of local muscle fatigue are possible.

New trend of cardiac imaging--intravenous coronary arteriography by synchrotron radiation

Synchrotron radiation is a broadspectrum intense X-ray beam. Selected X-ray wavelength was obtained by Bragg reflex. That is a monochromatic beam, which has a high spatial resolution, and has a K-edge discontinuity in attenuation coefficient, which, by energy subtraction, contributes to improve time resolution. An attempt to apply this method to intravenous coronary arteriography was performed in 7 anesthetized dogs. The beam was obtained by synchrotron radiation from accumulation ring, was reflected by silicon crystal, and was detected by 7 inch image intensifier system. Two-dimensional real time images were recorded on video tape. Phantom experiment was also performed. In dogs, coronary arteries were clearly distinguished by synchrotron radiation, especially at real time by video system. Phantom experiment suggested that coronary arteries could be visualized even over the visualized left ventricle. In conclusion, synchrotron radiation using two-dimensional real time images is expected to be useful in intravenous coronary arteriography in man.

[Radiation tolerance of partially irradiated liver in a multidisciplinary treatment for hepatoma]

Radiation tolerance of the partially irradiated liver was studied in eight patients with primary hepatoma treated by a multimodal approach. Seven patients were treated by transarterial embolization therapy (TAE) with Lipiodol-MMC, and two patients were treated by operation, combined with radiotherapy. Six patients had liver cirrhosis and the other one had renal dysfunction. Respiration-gated irradiation was employed to reduce a treatment volume for seven patients. Radiation portals were carefully tailored using the embolized Lipiodol or a metal clip inserted into the tumor as references. Two or three portals were used for each patient. The treatment volume ranged from 64 to 1400 cm3. The target dose ranged from 50.4 Gy to 81.0 Gy, from 73.5 to 108.6 in TDF. Liver function tests (GOT, GPT, LDH, ALP, ChE and total Bilirubin) were examined for 30 weeks after initiation of irradiation. Three patients showed abnormal value in more than 5 tests. Of these three patients, the hepatic hilum was included in the treatment volume in two, and the tumor progressed during the observation period in two. Leukopenia and thrombopenia were observed, but these values were not below 2000 and 40000/mm3, respectively, although the thrombocyte count before irradiation was below 100000/mm3 in 7 patients. AFP titers decreased after the treatment in six out of seven patients with abnormally elevated pretreatment titer. The survival period after staring irradiation was 6.5 to 25 months. "The volume dose" did not correlate well with the degree of the liver function aggravation.(ABSTRACT TRUNCATED AT 250 WORDS)

Moving knee joint: technique for kinematic MR imaging

A system for magnetic resonance imaging of the knee joint during movement was developed by using a gating system and cine acquisition. The technique was used in 10 subjects: five with no history of knee pain or injury and five with tears of the anterior cruciate ligament. The normal ligaments and menisci appeared as low-intensity structures against intermediate-intensity hyaline cartilage. The ligament tears appeared discontinuous and faint against the background of the to-and-fro moving joint fluid.

The role of preoperative radiotherapy for invasive thymoma

Six patients with large invasive thymomas were treated by preoperative irradiation with 12 to 20 Gy before total or partial resection of the tumor. The responses of these 6 thymomas were estimated on the chest radiograms as follows; complete response in 2 patients, partial response in 3 and no response in one. Although the clinical responses varied, the surgical specimens of all the tumors pronounced severe fibrosis, probably not related to irradiation, and necrotic foci with a few viable tumor cells. Total resection of the thymoma was performed in 3 patients and subtotal resection in 3. Adhered or involved surrounding tissues such as the pericardium, pleura and/or veins were also resected in most patients. Preoperative radiotherapy facilitated total or subtotal resection of the invasive thymoma mass by reducing the tumor volume.

[Analysis of patients surviving for six months after irradiation of a bone metastasis]

The effects of treatment of a bone metastasis have been studied in 49 patients who survived for more than six months after radiotherapy (RT). Relief from the symptoms reached a rate as high as 91% (85/93 irradiated sites) irrespective of the primary site of the cancer. However, the survival rate and the rate of symptom relief maintenance were statistically higher in those with breast cancer (15 patients, 38 irradiated sites) than in those with a lung cancer (15, 24). The local control rate was dose dependent (TDF). High-dose irradiation, therefore is recommended to achieve a high local control rate for patients with a long life expectancy.

Irradiation synchronized with respiration gate

A respiratory gating technique was developed for radiotherapy of tumors unable to remain stable due to respiration. Irradiation was started and stopped with a microwave oscillator of a linear accelerator controlled by gating signals at specific points in the respiratory cycle. This technique was tested in a phantom specially designed to simulate a patient with lung cancer and in clinical therapy for lung tumors of seven patients. A mask was used to check ventilation in the phantom and airbags were used to measure thoracoabdominal pressure in patients and in the phantom; this enabled us to detect the excursion of the tumors. Low sensitivity film for verification demonstrated the efficacy of this technique. The gated irradiation was proved to ensure more precise radiotherapy for tumors located close to the diaphragm.

[Pulmonary infarction associated with bronchogenic carcinoma]

Pulmonary infarction may be associated with bronchogenic carcinoma. Radiopathological correlation was performed in four patients. There were two cases of squamous cell carcinoma, one case of adenocarcinoma and one case of large cell carcinoma. Infarcts in patients with squamous cell carcinoma were obscured on plain radiographs by a large primary tumor or atelectasis of the affected lobe. Infarcts in adenocarcinoma and large cell carcinoma were clearly demonstrated on plain radiographs; 1 to 2 cm in size, round or polygonal in shape, blurred in margin, and located at the periphery of the same lobe as the primary tumor. Rapid appearance of infarcts was helpful in distinguishing from intrapulmonary metastasis. Invasion of the pulmonary artery, pulmonary vein and bronchial wall in hilar region was thought to be responsible for pulmonary infarction. Pulmonary infarct should be considered in patients with centrally invasive bronchogenic carcinoma, when a small ill-defined opacity appears at the periphery of the involved lobe over a short period.

[Quantitative evaluations of left ventricular function obtained by electrocardiographically-gated magnetic resonance imaging]

Using electrocardiographically-gated magnetic resonance imaging, regional cardiac function was evaluated in 12 normal volunteers and in 10 cases of old myocardial infarction. The optimal short axis of the left ventricle was selected at the chordae tendineae level. The left ventricle was divided into 12 segments using a computer-aided system, and percentile shortening fraction (%SF) and percentile wall thickening (%WT) were calculated in each segment by the fixed coordinate method. In the normal volunteers, heterogeneity of both %FS and %WT was observed, ranging from 25 +/- 13% and 37 +/- 13%, respectively in the septal segment, to 49 +/- 13% and 60 +/- 21%, respectively in the posterior segment. In the cases of myocardial infarction, decreased %FS and %WT were detected at the affected regions. The abnormal regions revealed by %WT tended to be narrower than those revealed by %FS. Thus the MR technique at the optimal axis may be useful for quantitative evaluations of regional cardiac function.

Isoproterenol stress thallium scintigraphy for detecting coronary artery disease

The value of exercise thallium scintigraphy in detecting coronary artery disease is well established. However, there are at times situations in which the exercise test cannot be readily used. Isoproterenol (ISP) stress ECG (ISP-ECG) is reportedly a useful method in diagnosing coronary artery disease. In the present study, we assessed the diagnostic value of ISP thallium scintigraphy, comparing it with those of ISP-ECG and exercise thallium scintigraphy. The study population consisted of 24 patients who had histories of chest pain without previous myocardial infarction. ISP was given at increasing doses of 0.02, 0.04, 0.08 micrograms/kg/min at 3-minute intervals, and was terminated for any of the following reasons: angina, significant arrhythmia, significant ST segment depression (greater than or equal to 0.1 mV) or target heart rate. Thallium scintigrams were obtained immediately after terminating ISP infusion, and after a 3-hour delay, redistribution scans were obtained. Scintigrams were considered positive when a reversible defect was present. In nine patients who underwent exercise tests, exercise thallium scintigraphy was also performed. After the stress tests, coronary angiography was performed. According to the presence or absence of significant coronary artery stenosis (greater than or equal to 75%), all subjects were divided into two groups: coronary artery disease (CAD) group (n = 12) and so-called normal coronary (NC) group (n = 12). 1. Among 12 patients in the CAD group, ISP induced anginal pain in six (50%), and ISP-ECG and ISP thallium scintigraphy were positive in 10 (83%) and in 11 (92%), compared with four (33%), four (33%) and two (17%) in the NC group.(ABSTRACT TRUNCATED AT 250 WORDS)

[The relationship between N-isopropyl-p-[123I]iodoamphetamine accumulation in the brain and its dynamics in other organs]

Single photon emission computed tomography of the brain and dynamic scintigraphy of the lung and liver with N-isopropyl-p-[123I]iodoamphetamine (IMP) were performed in 21 patients with and without cerebrovascular diseases to determine the relationship between IMP accumulation in the brain and its dynamics in other organs. The D/E ratios of the lung, liver and brain were calculated dividing the counts of the delayed image by that of the early image. The brain D/E ratio in the normal hemisphere was well correlated with the lung D/E ratio. So cases which showed more rapid lung washout tended to washout faster from the brain. We thought that this fact was affected by the systemic circulation. And the values of the brain D/E ratio of the cerebrovascular disease group were larger than that of the non-cerebrovascular disease group. This suggest the frequent existence of arteriosclerotic changes in patients of the cerebrovascular disease. Because the local brain washout was depended on the amount of the cerebral blood flow there. On the other hand, the lung D/E ratio was inversely correlated with the liver D/E ratio. In other words, more washout from the lung caused more accumulation of IMP in the liver. Also the brain D/E ratio was inversely correlated with the liver D/E ratio. In conclusion, there was a close relationship between IMP dynamics in the brain and that in other organs.

Intense accumulation of indium-111 leukocytes in peritonitis carcinomatosa

In order to detect the infectious foci in a case of terminal recurrent cancer of the sigmoid colon with intense inflammation, In-111 oxine leukocyte scintigraphy was performed. Leukocytes labeled with In-111 oxine quickly localized within the region of peritonitis carcinomatosa and could be imaged after 4 hours. With time, high activity appeared in this area. And 48 hours after injection, the large intestine was clearly seen. However, no activity was seen in the main recurrent tumor. This suggested that the labeled leukocytes had accumulated in regions of inflammation rather than in malignant tissue. When performing In-111 leukocyte scintigraphy for diseases in which tumor cells and inflammation are mixed, distinguishing the two components is particularly important, and time-sequential scanning is very useful.

Ga-67 scintigraphy in chromomycosis

We examined an interesting case of chromomycosis that had a characteristic Ga-67 accumulation. This patient had had widespread chromomycosis skin lesions for 8 years. We performed Ga-67 scintigraphy in an attempt to obtain additional information on the site and extent of the lesion. Ga-67 scintigraphy revealed not only all subcutaneous nodules but also an unsuspected enlarged lymphnode and a visceral lesion. This case indicates that Ga-67 scintigraphy is a very useful method to use in detecting the site and extension of chromomycosis, especially in the nodal and the visceral lesions, and sometimes might help in differential diagnosis.

[Clinical evaluation of indium-111-labeled leukocyte imaging in bone infection]

In-111-oxine-labeled leukocyte imaging was performed on twenty-one patients suspected of having bone infection. Nine of eleven cases (82%) were diagnosed as having active infection as demonstrated by abnormal accumulation of In-111-labeled leukocytes at the site of infection. There are two false negative (18%) cases. Two cases without active infection showed abnormal uptake. Four cases revealed cold defects on the scintigraphy. Marked uptake of radiotracer was noted not only in the case of acute osteomyelitis with acute septicaemia but also in the case with persistent chronic active osteomyelitis. It was observed that for precise evaluation of the test results it was equally important to compare the imaging findings with physical signs and laboratory investigations. It is concluded that In-111-oxine-labeled leukocyte imaging is a useful tool for the evaluation of the progression of bone infection.

Evaluation of myocardial perfusion abnormality by profile analysis for digital subtraction angiogram

For quantitative estimation of ischemia, ECG-synchronized digital subtraction angiography was performed for selective coronary arteriography. The authors obtained sequential myocardial perfusion images at the arterial, capillary, and venous phases. Profile densitometry was performed along the cross section perpendicular to the long axis of the left ventricle to assess regional myocardial perfusion at the capillary phase quantitatively. By this densitometry, the volumes of vascular bed perfused by the left coronary artery could be estimated, and further, nontransmural myocardial infarction could be differentiated from transmural myocardial infarction through the profile of its density curve. This method appears to be useful for the analysis of myocardial perfusion of ischemic heart disease.

[Bone dynamic study--evaluation for factor analysis of hip joint]

Factor analysis was applied to dynamic study of Tc-99m MDP for the evaluation of hip joint disorders. Fifteen patients were examined; eight were normal, six were osteoarthritis in which one accompanied synovitis was included, and one was aseptic necrosis on the head of the femur. In normals, according to the Tc-99m MDP kinetics, three factor images and time-activity curves were obtained which were named as blood vessel, soft tissue, and bone factor images and curves. In the patient with osteoarthritis, increased accumulation of the hip joint was shown in bone factor image only. But in one patient, who took osteoarthritis with synovitis, marked accumulations of the Tc-99m MDP appeared not only on the bone factor image but also on the soft tissue. Operation revealed thickening synovial tissue around the hip joint, caused by inflammatory process. In follow-up studies of the patient with aseptic necrosis on the head of the left femur, excessive accumulations, which were seemed in his left hip joint on both bone and soft tissue factor images at first, were decreased respondently to the treatment of this lesion. In conclusion, the factor analysis was useful for differencial diagnosis of the hip joint disorders and observation of the clinical course of the hip joint disorders.

An ultrasonographic method for detection of Achilles tendon xanthomas in familial hypercholesterolemia

The diagnosis of familial hypercholesterolemia (FH) is frequently made on clinical grounds and detection of tendon xanthomas is crucial for that. In order to clarify whether ultrasonography (US) can be used as a reliable and practical method for detection of Achilles tendon xanthomas in FH, the Achilles tendon thickness in the sagittal section was examined by US in 15 patients with heterozygous FH and 34 normocholesterolemic subjects. US visualized clearly the anterior and posterior borders of the Achilles tendon. The Achilles tendon thickness determined by US correlated with that measured by conventional radiography (r = 0.99). The mean values +/- SD of the Achilles tendon thickness determined by US were 4.5 +/- 0.5 mm in the normal controls and 11.9 +/- 5.1 mm in the patients and the difference was significant (P less than 0.001). In 13 of 15 patients, US visualized thickened Achilles tendons with convex shape in the sagittal section. All the thickened Achilles tendons revealed by US were confirmed by radiography. The data indicate that US can detect Achilles tendons thickened by xanthomas. We conclude that US is a useful aid in the clinical diagnosis of FH.

Relationship between MR relaxation time and muscle fiber composition

The relationship between magnetic resonance (MR) relaxation times and muscle fiber composition was investigated in 16 men, and a high positive correlation was found. Higher proportions of fast-twitch fiber were associated with longer relaxation times, indicating that fast-twitch fiber has a longer relaxation time than slow-twitch fiber. Multiple regression analysis, conducted to investigate the suitability of relaxation time as a model of estimating muscle fiber composition, revealed that T1 and T2 were significantly related to muscle fiber composition. These results indicate that MR relaxation time may be used to estimate muscle fiber composition.

Present status of PACS activities in Japan

Three PACS organizations in Japan are: J-PACS, JAMIT-PACS and JRS-PACS. J-PACS committee is composed of representatives of manufacturing companies. Many Japanese companies are actively engaged in developing PACS-related products and services. The annual JAMIT Symposium includes an International PACS day. The JRS-PACS Committee is working to bring academics and industry closer together in developing and implementing PACS technology. MIPS has two working groups which started in 1985. The Survey Working Group issued the draft on Survey study of integral technology and present state and trends of existing systems. The Standardization Working Group, which is to complete work in 1989, issued the draft of image data format on the magnetic tape and discussion about the standardization of online digital interface for PACS. The draft of the MIPS Standard was mostly based on ACR/NEMA Standard, but simplified and reduced. However, the number of minimum parameters essential in image transfer were retained. Early experiences with PACS in Tominaga Memorial Hospital, Kyoto University Hospital and Kochi Medical School Hospital was briefly mentioned. Japan is facing a period in the early 1990s in which PACS is to be widely introduced into the university hospitals.

Tricuspid regurgitation diagnosed by intravenous digital subtraction angiography

In spite of numerous available diagnostic methods, controversies concerning the precise diagnosis of tricuspid regurgitation (TR) still remain. In right ventriculography, catheter placement may modify tricuspid valvular function. Though noninvasive Doppler echocardiography is a useful method, it is sometimes too sensitive for clinical use. Furthermore, it is not applicable to cases in which ultrasound penetration is limited. In this study, we evaluated TR using intravenous digital subtraction angiography (DSA), which can provide good images even in cases with poorly recorded echocardiograms. For this study, we placed a catheter in the superior vena cava. Cardiac DSA examinations were performed in one hundred and one patients with heart disease. We injected 35 ml of contrast medium at a speed of 18 ml/sec via a catheter introduced in the superior vena cava. DSA images by continuous mode were obtained in the RAO projection for 15-20 sec. Sequential DSA images were observed and analyzed by time-density curves of the regions of interest (ROI) which were placed in the right ventricle (RV) and inferior vena cava (IVC). Doppler echocardiography was performed for 16 cases in which TR was suspected. Of these, phonocardiography with jugular pulse tracing was recorded for 14 and contrast echocardiography were performed for six, respectively. In cases without evidence of TR, regurgitation of contrast medium into the IVC during RV systole was not recorded by the DSA method. In cases of clinically-proven TR, regurgitation into the IVC during RV systole was observed. Thus, this was considered a diagnostic feature of positive TR using the DSA method, and 13 of the 16 cases undergoing Doppler echocardiography were diagnosed as having TR using the DSA method. The severity of TR was categorized as mild, moderate and severe according to analyses of time-density curves. The severity established by the DSA method showed a close correlation with the clinical severity of TR. Doppler echocardiography was negative for TR in two of the 13 cases, but positive for TR in two of the 16 suspected cases only by the Doppler method. In cases of moderate to severe TR diagnosed by the DSA method, jugular pulse tracings showed a regurgitant wave. By contrast echocardiography, TR was evident only in cases of severe TR diagnosed by the DSA method. In conclusion, the DSA method proved useful for diagnosing TR.

[The integrated score of prognostic factors with regard to the recurrence of cervical carcinoma]

Eighty-nine patients with carcinoma of the cervix received radical radiation therapy from May 1981 through 1983 at the hospital of the National Institute of Radiological Sciences. After a 2 to 4 year follow-up, primary cancer was found to be controlled in 59 patients, a recurrence was noted in 16 patients but 12 patients had died without precise information concerning recurrence. We examined the correlation between recurrence and seven prognostic factors. Among these factors, the tumor volume, age, and the red blood corpuscle sedimentation rate showed a relatively strong correlation. A multivariable analysis (quantification methods II) was undertaken in order to integrate these prognostic factors and the score that was calculated from this analysis showed a strong correlation to local control. We believe that this score can be used for predicting recurrences and can be applied to the selection of patients for new treatments like hyperthermia or high LET irradiation.

Effects of nifedipine on left ventricular systolic and diastolic function in patients with ischemic heart disease. Radionuclide angiocardiographic studies at rest and during exercise

The purpose of this study was to evaluate the acute effects of sublingual nifedipine (10 mg) on left ventricular systolic function (ejection fraction, peak ejection rate, time to peak ejection rate) and diastolic function (peak filling rate, time to peak filling rate, filling fraction during rapid filling) at rest and during exercise using radionuclide angiography in 17 patients with ischemic heart disease. The results of the study were as follows. Diastolic indexes in the patient group were significantly different from the values in the control group at rest and during exercise. Peak filling rate and filling fraction improved significantly after nifedipine administration. These values did not show significant differences from the values in normal subjects which were obtained before nifedipine administration. The peak filling rate during exercise after nifedipine administration increased significantly, although the value was lower than that in the control group. At rest, systolic indexes in the patient group showed abnormal values, although the differences from the control values were not significant. Ejection fraction and peak ejection rate were significantly lower than those in the control group during exercise. After nifedipine administration, peak ejection rate at rest and during exercise, and ejection fraction at rest in the patient group improved significantly. Seven of 17 achieved the same exercise workloads as control conditions without symptoms or ECG changes. These data suggest that nifedipine improved left ventricular systolic and diastolic dysfunction, as well as exercise tolerance in patients with ischemic heart disease.

Variable neurohumoral and hemodynamic responses to exercise in patients with exertional angina: influence of the severity of coronary artery disease

To assess neurohumoral and hemodynamic responses to exercise in patients with exertional angina, we measured plasma norepinephrine (NE) concentrations in 23 patients with exertional angina (with no heart failure) and compared the results with their coronary arteriographic findings. The 23 patients were divided into two groups: 14 cases with multiple vessel disease (MVD) and 9 cases with one-vessel disease. At resting state there were no significant differences between the two groups in levels of NE. At maximal exercise there were no significant differences between the groups in increases of heart rate, blood pressure, and rate-pressure product, but exercise-induced increase of plasma NE (%) was significantly larger in MVD (131.6 +/- 95.4%) (mean +/- SD) than in one-vessel disease (69.0 +/- 45.3%) (p less than 0.01). In conclusion, plasma NE responses to exercise differ between patients with multiple vessel disease and patients with one-vessel disease.

Daily variations of ECG and left ventricular parameters at exercise in patients with anginal attacks but normal coronary arteriograms

In 21 patients with typical exercise-induced anginal pain but normal coronary arteriograms (group N) and in 14 patients with angiographically proved coronary stenosis (group C), symptom-limited ergometer exercise ECG and radionuclide angiocardiography were performed twice on two different days. Exercise-induced ST changes showed larger variations between the two exercise tests in group N than in group C ([delta ST1-delta ST2]: 0.07 +/- 0.06 mV in group N, 0.03 +/- 0.03 mV in group C, p less than 0.05). Rate pressure product and left ventricular ejection fraction at exercise also showed larger variations between the two tests in group N than in group C (p less than 0.001, p less than 0.05, respectively). However, substantial overlaps existed in some cases in the two groups. In conclusion, some of the patients with exercise-induced anginal pain but normal coronary arteriograms may have a variable threshold of exertional chest pain probably caused by variation in coronary vascular tone, and the other patients may have a fixed threshold of chest pain caused by other mechanisms.

Synchrotron radiation at the Photon Factory for non-invasive coronary angiography: experimental studies

Synchrotron radiation available at the Photon Factory, National Laboratory for High Energy Physics, provides a new X-ray source which is highly suitable for K-edge subtraction. This is due to its high intensity, its parallelism and its monochromaticity, available in a monochromator system. Experiments were performed using wiggler synchrotron radiation. Since the beam size is relatively-small for in-vivo imaging, a phantom coupled with a detector was moved horizontally using a scanning table. K-edge subtraction was successfully applied both to the coronary artery phantom filled with barium sulphate, and to rat angiography using iodine contrast material. The potential use and value of energy subtraction was successfully demonstrated.

Isoproterenol infusion stress two-dimensional echocardiography in diagnosis of coronary artery disease in elderly patients. Comparison with the other stress testing methods

Since a dynamic exercise stress test cannot always be performed adequately in elderly patients, an alternative method is needed for evaluation of coronary reserve. We studied two-dimensional echocardiographic (2-DE) and electrocardiographic (ECG) responses to infusion of isoproterenol (ISP) at a rate of 0.02 micrograms/Kg/min in 40 elderly patients with chest pain. The results were compared with exercise ECG (EX-ECG) tests and exercise radionuclide angiocardiography (EX-RNA) in 13 of these patients. No serious complications were encountered in the ISP test. The diagnostic sensitivity for coronary artery disease (CAD) was 71% for ISP-2-DE, 71% for ISP-ECG, 86% for EX-ECG and 71% for EX-RNA. The specificity for CAD was 83% for ISP-2-DE, 33% for ISP-ECG, 50% for EX-ECG and 100% for EX-RNA. In conclusion, the ISP-2-DE test is a safe, easily available and useful method for the assessment of coronary artery disease in elderly patients.

Digital subtraction angiography: image-sequence analysis for regional myocardial perfusion dynamics

Digital subtraction angiography with selective coronary injections of contrast media has enabled us to obtain clear images, not only of the artery, but of the capillary and venous phases of the myocardial perfusion. In the present study, densitometry was used to estimate regional myocardial perfusion dynamics in 10 control cases and 11 anterior myocardial infarction cases. The time density curve showed that contrast material increased rapidly in the arterial phase and appeared to be washed out monoexponentially in the venous phase. The time from the onset of contrast medium injection to the maximal density of the contrast medium (Tp), and the time constant obtained from the washout curve (Tc) were analyzed. In the control group, Tp in the apical region was slightly prolonged as compared with Tp in the anterobasal region, but the difference was not significant (5.2 +/- 0.5 vs 4.2 +/- 0.4 sec: mean +/- SEM). Tc did not definitely change in any portion of the myocardium (anterobasal 5.1 +/- 0.5, anterior 4.8 +/- 0.5, apex 4.6 +/- 0.5 sec, respectively). In anterior myocardial infarction, Tp in the marginal region was significantly prolonged compared to Tp in the control region (6.0 +/- 0.3 vs 4.7 +/- 0.3 sec, p less than 0.01). Tp was prolonged for more than 10 sec in the infarcted region. Tc in the marginal region was markedly prolonged compared to Tc in the control region (7.4 +/- 0.9 vs 4.4 +/- 0.5 sec, p less than 0.025). Tc could not be determined in the infarcted regions because data acquisition time of our apparatus was inadequate.(ABSTRACT TRUNCATED AT 250 WORDS)