[Cerebral blood flow and metabolism in multi-infarct dementia]

Cerebral blood flow and oxygen metabolism were studied in three aged normal volunteers and 10 patients with multi-infarct dementia (MID) by Positron Emission Tomography using O-15. The diagnosis of MID was done according to the Loeb's modified ischemic score and X-ray CT findings. The MID patients, whose X-ray CT showed localized low density areas in the subcortical white matter and basal ganglia and thalamus, were studied. No occlusion was observed at anterior cerebral artery and/or middle cerebral artery on cerebral angiography. All cases of MID were mild dementias. Regional CBF, rOEF and rCMRO2 were measured by the steady state technique described by Terry Jones et al. The values of rCBF in MID patients were significantly low compared with those of aged normal subjects in frontal, temporal, occipital, parietal cortices and thalamus. The values of CMRO2 in MID were significantly low in frontal, temporal, occipital cortices and thalamus compared with normal subjects'. The OEF was 0.46 in aged normal subjects, and 0.52 in MID patients. The MID patients in the early stage of dementia showed the increased oxygen extraction fraction, and this fact suggests that ischemia is a significant pathogenic mechanism in the production and progression of multi-infarct dementia. The decrease of CBF and CMRO2 in MID compared from normal subjects' were most remarkable in frontal cortex. The impairment of mental functions in MID should be caused by the decreased neuronal activities in frontal association cortex.

Synthesis of N-methyl and N-11C-methyl spiperone by phase transfer catalysis in anhydrous solvent

Spiperone, a butyrophenone neuroleptic drug, has been used in binding studies of dopamine receptors. Långström et al. developed N-11C-methyl spiperone, and, in cooperate with Wagner et al., made it possible to visualize the distribution of dopamine receptors in the human brain in vivo. In this paper, we independently developed another synthetic method of N-11C-methyl spiperone using the phase transfer catalyst in an anhydrous solvent. Separation of the product is feasible only by passing the reactant solution through a Millipore filter and injecting it onto high pressure liquid chromatography (HPLC). The time required for the synthesis and purification of N-11C-methyl spiperone from 11C-methyl iodide and spiperone was 20 min. Radiochemical yield exceeded 35% against 11C-methyl iodide without correcting decay of the radioactivity.

[SOL-detectability of liver SPECT--analysis by SOL detection model]

The purpose of this study is to evaluate the clinical efficacy of liver SPECT (single photon emission computed tomography). Eleven hospitals which are in or near Tokyo are participating in this study. Planar liver images and SPECT images of 134 cases which were retrospectively confirmed for its final diagnosis were collected. At the first study, the planar images (PS) were read by 13 nuclear medicine physicians. The second, the image reading by the combination of the planar images and the SPECT images (PS + SPECT) were performed. The confidence level of diagnosis for SOL (space occupying lesion) obtained by the image reading of PS and PS + SPECT has been analyzed by using the SOL detection model. The SOL detectability of PS + SPECT was higher than that of PS only. However, these differences were not statistically significant.

Benefit of transcatheter arterial embolization for ruptured hepatocellular carcinoma complicating liver cirrhosis

In 6 patients with spontaneous rupture of hepatocellular carcinoma complicating liver cirrhosis, but with no occlusion of the main portal trunk, transcatheter arterial embolization was performed within 7 days of the rupture. All 6 patients were thought to be inoperable because of shock state or severe hepatic dysfunction. In all 6 patients, the progressive decrease in the hematocrit ceased soon after the embolization. Five patients survived for 31-168 days after the embolization; 1 patient who developed septicemia died 10 days later. We conclude that transcatheter arterial embolization is beneficial as a procedure of first choice for ruptured hepatocellular carcinoma when the portal blood flow is maintained.

Transcatheter arterial embolization (TAE) in treatment for hepatoma--analysis of three-year survivors

Among 224 hepatomas treated with transcatheter arterial embolization, ten patients who survived for three years are presented. All cases had nodular lesions and the volume ratio of tumor to liver was less than 10% in nine cases. Eight cases had no large venous extension, however, one had 90% occlusion of the portal trunk and the other had tumor thrombus within the inferior vena cava. Laboratory data showed liver function was largely spared in eight cases, whereas the other two had severe liver cirrhosis. CT and/or angiography showed an increase in tumor volume in eight cases after three years of survival. Beneficial factors for long-term survival and the limitations of embolization are also discussed.

Solitary renal hamartoma not associated with tuberous sclerosis: roles of CT and angiography

CT and angiography of five solitary renal hamartomas not associated with tuberous sclerosis are reviewed. CT revealed fat in four hamartomas and was the more reliable in the differentiation from renal cancer. Bleeding from the tumour was detected in two cases and the extent of each haematoma was precisely determined by CT. Angiography showed specific findings in only one tumour. In a pararenal hamartoma, angiography was of value in clarifying the renal origin of the tumour. Though angiography may be of help when CT is inconclusive, we think it should not be relied upon as a major diagnostic tool and we utilise it mainly for preoperative mapping and embolisation. In one case CT did not detect fat and preoperative diagnosis was impossible. In one case with haematoma, detection of fat was difficult. We believe potential hamartomas with no detectable fat should be treated as malignancy until proved otherwise. There seems to be discrepancy between the vascularity of the hamartoma and the degree of contrast enhancement (CE) with a bolus injection method; hamartomas seem to show weaker CE than that expected for renal cancer of equal vascularity, a fact which may differentiate solitary hamartoma from cancer.

Hepatic tumors: differentiation by transverse relaxation time (T2) of magnetic resonance imaging

Fifty-three patients who had hepatic tumors (24 hepatomas, ten metastases, and 19 cavernous hemangiomas) underwent MR imaging using a 0.35-T superconducting imager. The transverse relaxation time (T2) was calculated from a pair of spin echo images (repetition time [TR] of 1600 msec) with echo delay times (TE) of 35 and 70 msec. The computed T2 value was obtained in a fashion similar to that used to obtain CT numbers with region-of-interest cursors. The mean T2 was 59 +/- 9 msec in hepatomas, 64 +/- 15 msec in metastases, and 100 +/- 30 msec in hemangiomas. The difference between the T2 of hemangioma and that of liver malignancies was statistically significant (P less than .001); however, differentiation between hepatoma and metastases was not possible. The T2 was shorter than 80 msec in all 24 hepatomas and in nine of ten metastases, and was longer than 80 msec in 16 of 19 hemangiomas. Forty-nine of 53 cases (92%) were correctly classified when the borderline of T2 between hemangioma and hepatic malignancies was set at 80 msec. MR with T2 calculation was valuable in differentiating between hemangioma and hepatic malignancies.

[Diagnosis of temporal lobe epilepsy by positron emission tomography]

Positron emission tomography (PET) was performed in 18 temporal lobe epileptics. About 20 mCi of 11C-glucose was perorally administered to the patients and 30 minutes later scanning was started when the transport of 11C-glucose from blood to the brain tissue reached equilibrium. At the level of 25 mm above orbitomeatal line, the slice image of the temporal lobe shows a relatively high metabolic oval ring involving the amygdala, hippocapal formation and the hippocampal gyrus medially and the T1, T2 and T3 neocortices laterally in normal subjects. The epileptic focus, when detected on PET images, was observed as a defect in this oval ring. In 15(83.3%) out of 18 cases, the location of epileptic focus was confirmed as a low metabolic defect. This diagnosis rate was higher than that of other focal epilepsy by PET study. The locations of foci were divided into three types: mesial (5 cases), lateral (4 cases) and combined (6 cases). The seizure symptoms of the patients were analyzed in terms of the correspondence to the focus types. The results showed that automatism and pseudoabsence had a close relation to the mesial and combined types and psychical, vertiginous or visual seizures correlated to the combined and lateral types. Visceral or motor seizures were induced equally by any focus types. These facts suggested that automatism and pseudoabsence were correlated with the mesial organs such as the amygdala and hippocampus and psychical, vertiginous or visual seizures had origin in lateral neocortices. Visceral or motor seizures were supposed to be the results of the spread from the temporal focus to the adjacent structures.(ABSTRACT TRUNCATED AT 250 WORDS)

MRI of brain infarction

MRI of twenty patients with cerebral infarction were reported with their X-CT. MRI with long SE mode clearly showed the ischemic lesion at 18 hours after insult, whereas X-CT performed immediately after MRI scanning showed no abnormality. The signal contrast of the lesion with long SE mode seemed to increase slightly during the patient's course, for a period of several months. The MRI images with long SE at the chronic stage were varied: small lesions appeared as hot areas, whereas large lesions appeared as cold areas and were accompanied with signal enhancement in the surrounding areas. A phantom study was also performed and it was determined that MRI was superior to X-CT in its ability to detect tissue water. One of the reasons for the high diagnostic capability of MRI for acute stroke was, therefore, attributed to this experimental result.

[Radiotherapy of metastatic bone tumor with a synthetic calcitonin derivative (Elcatonin) with irradiation]

Twenty cases of metastatic bone tumors were treated with Elcatonin together with irradiation, achieving pain relief in 47.3% of cases, improved bone scintigrams in 16.7% of cases and radiographic improvement of invaded bone in 7.7% of cases. It has reported that calcitonin is effective for pain relief in 50% of cases but for the radiographic improvement of bone lesions in only 0-10%. The life quality of patients with bone metastases is controversial since treatment techniques for advanced oncological patients has progressed remarkably. The pain relief obtained with calcitonin contributes significantly to improving the quality of life for such patients when administered in combination with conventional treatment modes.

Intraarterial digital subtraction arteriography in the diagnosis and treatment of hepatic tumors

Intraarterial digital subtraction arteriography (IADSA) was performed in 94 patients with hepatic tumors and evaluated on the following subjects: 1) visualization of small arteries in arterial phase, compared with film study, 2) visualization of faint tumor stains in hepatogram phase, compared with film study, 3) visualization of portal venous branches by intraarterial digital subtraction portography (IADSP). Interventional angiography was performed in 76 patients. Contrast dose and injection rate of IADSA was approximately a third of film study without dilution. The position of the catheter was identical in IADSA and film study. IADSPs were performed with 15-20 ml of 76% Urografin, which was injected into the superior mesenteric artery at the rate of 5 ml/sec after infusion of prostaglandin E1. Comparison in arterial phase of 67 patients showed 24 (36%) IADSAs were equal to film study. Thirty-nine (58%) were inferior but adequate for the diagnosis of hepatic tumors. Comparison in hepatogram phase showed 24 (38%) IADSAs were superior to film study and all were satisfactory for the diagnostic purposes. Ninety-eight percent of 86 IADSPs gave information about the patency of the main portal vein. Fifty-five percent of IADSPs opacified third-order portal vein branches or further. IADSA of hepatic tumors not only save time and contrast dose but was also satisfactory in image quality for interventional angiography.

Magnetic resonance imaging (MRI) of primary liver cancer--MRI-pathologic correlation

In seven primary liver cancers (HCC 5, CCC 1, mixed 1), MR images (0.35 Tesla super-conducting) were compared with macroscopic appearances, and relaxation times (T1 and T2) with microscopic characteristics. MRI was able to reveal the gross appearance of five nodular lesions, but did not reveal one diffuse HCC and one nodular HCC with marked extracapsular extension. T2-weighted SE images could not demonstrate fibrous capsules around the tumor in four nodular HCCs. The T1 and T2 values of the tumors were longer than those of the surrounding liver parenchyma, and the T1 elongation corresponded roughly to the degree of necrosis and fibrosis within the tumors.

Localization of therapeutic gelatin emboli using radiolabeling--an experimental study

Transcatheter embolization has recently gained widespread acceptance in the treatment of a variety of conditions. To clarify the localization of therapeutic gelatin particles, we have described a simple and safe technique of labeling gelatin particles with 99mTc using stannous chloride solution. This technique provides satisfactory labeling efficiency and allows excellent scintigraphic images of therapeutic gelatin emboli, thus making it possible to clarify the localization of the injected embolic material in vivo.