Hepatocellular carcinoma with sarcomatous change: characteristic findings of two-phased incremental CT

BACKGROUND

Because of its poor prognosis, the diagnosis of hepatocellular carcinoma with sarcomatous change (HCCSC) is clinically important. The purpose of this study is to elucidate the characteristic CT findings of HCCSC.

METHODS

Two-phased dynamic incremental CT images of six histologically proven HCCSC were retrospectively reviewed.

RESULTS

All tumors (100%) exhibited peripheral enhancement on delayed CT images. Lymphadenopathy was observed in 100% (six of six patients); intrahepatic metastases, in 83% (five of six). Both metastatic lesions showed findings similar to those of the primary hepatic tumors, such as peripheral enhancement. Histopathological delayed and/or prolonged peripherally enhanced areas consisted of viable cancer cells with sarcomatous changes.

CONCLUSIONS

The appearance of HCCSC on CT is that of an irregularly demarcated intrahepatic mass with delayed or prolonged peripheral enhancement, frequently with intrahepatic metastases and lymphadenopathy.

Efficient production of the C-terminal domain of secretory leukoprotease inhibitor as a thrombin-cleavable fusion protein in Escherichia coli

We have developed a high-level production system for the C-terminal domain of secretory leukoprotease inhibitor (SLPI) to investigate its pharmacological activities. A gene for the C-terminal domain of SLPI, (Asn55-Ala 107)SLPI, was constructed from chemically synthesized deoxyoligonucleotides. It was fused to a gene for the N-terminal portion of human growth hormone via a DNA sequence encoding Leu-Val-Pro-Arg, which can be cleaved by thrombin. The fused gene was expressed in Escherichia coli under the control of a trp promoter, and the fusion protein was obtained as an inclusion body. After sulfonation of the cysteine residues, the sulfonated fusion protein was cleaved at the desired site by thrombin. Sulfonated (Asn55-Ala107) SLPI was refolded in Tris buffer containing reduced and oxidized glutathione. The resulting (Asn55-Ala107) SLPI was purified by cation-exchange chromatography and reverse-phase high performance liquid chromatography. The final yield was 50 mg/I culture. (Asn55-Ala107) SLPI was as active against elastase as, but had less trypsin inhibitory activity than, native SLPI. This system is suitable for the large-scale production of the C-terminal domain of SLPI, which is an elastase-specific inhibitor.

Administration of truncated secretory leukoprotease inhibitor ameliorates bleomycin-induced pulmonary fibrosis in hamsters

The purposes of this study were to investigate the effect of our recently developed truncated secretory leukoprotease inhibitor (SLPI) on bleomycin (BLM)-induced lung injury and fibrosis in hamsters, which is widely used as a model of interstitial pulmonary fibrosis, and to assess the possible involvement of neutrophil elastase in the pathogenesis of pulmonary fibrosis. The fibrosis model was prepared by administration of BLM (10 mg/kg) intratracheally to hamsters. The truncated SLPI was administered at a dose 5 or 15 mg/kg intraperitoneally twice a day only for 10 d starting from the time of BLM administration. BLM administration resulted in decreases in body weight and survival rate. Elastase activity in the supernatant of bronchoalveolar lavage (BAL) fluids was increased at 3 and 7 d after BLM administration in parallel with the increase in the number of neutrophils in the fluids. Histopathologically, at 14 and 28 d after BLM administration, diffuse thickening and fibrosis of alveolar walls with marked cell infiltration and severe distortion of alveolar structure, including honeycomb lung, were observed to have occurred. In this model, the decreases in body weight and survival rate and the increase in elastase activity were inhibited by the truncated SLPI dose-dependently, and pulmonary fibrosis was significantly ameliorated by the administration of this shortened form of SLPI. These results suggest that neutrophil elastase may be implicated in the pathogenesis of BLM-induced pulmonary fibrosis and that the truncated SLPI might be a promising therapeutic in the treatment of interstitial pulmonary fibrosis.

Source localization of middle latency auditory evoked magnetic fields

The magnetic counterparts of middle latency auditory evoked responses (MLR) were measured for seven normal subjects with a 7-channel de superconducting quantum interference device (SQUID). The source of each component (Na, Pa, Nb and Pb) was estimated and plotted onto the individual magnetic resonance images (MRI). The source of Na, as well as those of Pa, Nb and Pb, was estimated to be in the supratemporal auditory cortex. The positions of Pa, Nb and Pb sources were compared with one another. No significant difference was observed between the positions of Pa and Nb sources. On the other hand, the source of Pb was found to be anterior to the sources of both Pa and Nb. It was suggested that there are more than two separate areas activated in the human auditory cortex during MLR.

Lymph-node metastases: efficacy for detection with helical CT in patients with gastric cancer

PURPOSE

To determine the efficacy of helical computed tomography (CT) in the detection of lymphadenopathy in patients with gastric cancer.

MATERIALS AND METHODS

Helical CT (5-mm section thickness, 5-mm/sec table incrementation) was performed in 58 patients (39 men, 19 women; mean age, 63.8 years) with gastric cancer; 1,082 lymph nodes (138 positive, 944 negative for metastasis) were resected at surgery. Findings at CT and resection were compared. Sensitivity for detecting lymph nodes was evaluated according to nodal size and presence of metastasis.

RESULTS

Seven (1.1%) of 649 lymph nodes 1-4 mm, 160 (45.1%) of 355 nodes 5-9 mm, and 56 (72%) of 78 nodes larger than 9 mm were detected at CT. For nodes of at least 5 mm, sensitivity for detecting metastasis-positive nodes (79 [75.2%] of 105 nodes) was higher than that for detecting metastasis-negative nodes (137 [41.8%] of 328; P < .01). Differences between positive and negative nodes in CT attenuation (110 HU +/- 25 vs 66 HU +/- 32) and short-to-long axis ratios (0.81 +/- 0.15 vs 0.57 +/- 0.15; P < .001) were significant.

CONCLUSION

Helical CT is effective for detection of metastatic lymphadenopathy from gastric cancer. CT attenuation and lymph-node configuration aid in diagnosis of malignant adenopathy.

[Cerebral hemodynamics and metabolism in patients with Moyamoya disease not demonstrating either cerebral infarct or hemorrhage on MRI]

We evaluated the cerebral hemodynamics and metabolism in Moyamoya patients who did not demonstrate either cerebral infarct or hemorrhage on MRI. The subjects consisted of 5 patients with Moyamoya disease (4 females and one male, aged from 15 to 40 years). The CBF, OEF and CMRO2 of the Moyamoya patients did not differ from those of the normal control subjects. The CBV did increase significantly in the cerebral cortices and striatum, but not in the cerebellum. The TT was also significantly prolonged in the frontal and parietal regions. The cerebrovascular CO2 response was markedly impaired in the frontal, temporal and parietal cortices. However, it was relatively preserved in the occipital cortex, thalamus and cerebellum. Thus, the cerebral hemodynamic reserve capacity decreased even in the Moyamoya patients not demonstrating either cerebral infarct or hemorrhage on MRI, and it should be considered in the management of these patients.

[Two cases of micrognathia caused by radiation therapy during infancy: an evaluation of their profilograms]

Two patients with micrognathia of the mandible caused by radiation therapy during infancy are reported herein. The first patient was a 25-year-old man with hemangioma of the tongue. He had previously received radiation therapy totaling 51 Gy at 1 and 2 years of age. The other patient was a 54-year-old woman who had received radiation therapy for an oral tumor during infancy. These two patients demonstrated micrognathia, and the former patient showed developmental anomaly of the teeth. In addition, the latter patient suffered from thyroid cancer at 45 years of age, and this was also thought to be radiation-related. Although reports of micrognathia caused by radiation are rare, such late effects should be taken into account when radiation therapy is planned for head and neck tumors in infants.

Epidemiological investigation of insulin resistance syndrome (syndrome X) in a city in Japan

1. In order to study the prevalence of insulin resistance syndrome (syndrome X) in Japanese subjects, inhabitants aged above 40 years living in Osaka-Sayama city from September 1992 through December 1993 were investigated. The population-based study was performed on 2498 subjects (661 males and 1837 females) constituting 10.9% of the total population aged above 40 years. 2. The prevalence of glucose intolerance was 8.7% (n = 218) in 2498 subjects. The prevalence of hypertension was 36.9% (n = 923) and that of hypertriglyceridaemia was 19.0% (n = 475). The prevalence of syndrome X as characterized by an association of glucose intolerance, hypertension and hypertriglyceridaemia was 1.6% (n = 39) in all subjects examined and 17.4% in subjects showing glucose intolerance. 3. Fasting serum insulin levels were significantly higher in patients with syndrome X than in normal subjects. Furthermore, the levels were significantly correlated with blood levels of frucutosamine, fasting glucose and triglyceride, and with body mass index as well. 4. In conclusion, insulin resistance syndrome (syndrome X) is also found among the larger Japanese population, and fasting serum insulin levels can be a useful marker of this metabolic disorder.

Nigrofrontal dopaminergic function as assessed by 18F-dopa PET

The existence of the nigrofrontal dopaminergic pathway has been demonstrated in neuroanatomical studies. We evaluated the presynaptic nigrofrontal dopaminergic function using 18F-dopa (FD) positron emission tomography (PET). The multiple time PET data in the frontal cortex from 20 to 70 min post-injection for FD were evaluated by Patlak analysis using the cerebellar time-activity curve as an input function. The frontal FD uptake rate constants could not be determined in 5 of 12 normal volunteers because of large deviations in the plots. There were no significant differences between the subjects among whom the frontal FD uptake rate constants could or could not be determined regarding the amount of FD injected, the frontal 18F counts, or whether or not they were pretreated with carbidopa. The uptake constants were determined in 9 or 12 patients with parkinsonian syndrome. While the mean (+/- S.D.) uptake constants in patients with Parkinson's disease (2.89 +/- 0.06 x 10(-3), n = 4) and in patients with progressive supranuclear palsy (2.81 +/- 0.10 x 10(-3), n = 3) were not significantly different from those in the normal volunteers (2.93 +/- 0.14 x 10(-3)), those in two patients with corticobasal degeneration (2.42 and 2.46, respectively) decreased in comparison to the control values. Differences in the nigrofrontal presynaptic dopaminergic function as assessed by FD-PET may explain the different pathogenesis and also help to differentiate between corticobasal degeneration and other parkinsonian syndromes, such as Parkinson's disease and progressive supranuclear palsy.

CT manifestations of pediatric intrathoracic desmoid tumors

We describe the CT findings in two pediatric cases of intrathoracic desmoid tumor arising from the chest wall. In both cases, CT showed heterogeneously enhanced intrathoracic masses with destruction of the ribs.

Combination chemotherapy with intra-arterial cisplatin and doxorubicin plus intravenous methotrexate and vincristine for locally advanced bladder cancer. Kyushu University Urological and Radiological Oncology Group

PURPOSE

We evaluate the usefulness of neoadjuvant chemotherapy for bladder cancer.

MATERIALS AND METHODS

The usefulness of neoadjuvant, modified methotrexate, vinblastine, doxorubicin and cisplatin chemotherapy was evaluated in 36 patients with locally advanced bladder cancer.

RESULTS

Of 36 patients 12 achieved a clinical complete response and 17 had a partial response. Of the 12 patients who achieved a clinical complete response the bladder was preserved in 11 and all patients were disease-free at a median of 33 months. No significant toxicity was observed.

CONCLUSIONS

This chemotherapy is useful for locally advanced bladder cancer and the feasibility of bladder preservation in patients with a clinical complete response was suggested.

[Selective intra-arterial injection of calcium for localization of insulinomas: proposed new criteria]

To elucidate whether noninvasive arterial stimulation venous sampling (ASVS) is helpful for localizing insulinomas, calcium gluconate (0.02-0.025 mEq Ca2+/kg) was injected directly into the gastroduodenal, splenic and superior mesenteric arteries of six patients with episodic hypoglycemia. In all six patients, there was a greater than 26-fold increase in serum insulin levels in blood samples obtained from the hepatic vein after the infusion of calcium into the artery supplying the tumor. However, in four of the six patients, such an injection into an artery not supplying the tumor resulted in a greater than twofold increase in insulin concentration. Accurate localization of the insulinomas was verified at surgery in all patients. We believe that these false positive results were caused mainly by the influx of calcium via branches of intrapancreatic anastomoses. In order to minimize false positive results, we have recommended the following new criteria for ASVS: maximum insulin concentrations exceeding 150 microU/ml in blood samples obtained from the hepatic vein, and greater than twofold increases in insulin concentration. We concluded that noninvasive ASVS is helpful in determining the location of insulinomas.

Time dependency of the acetazolamide effect on cerebral hemodynamics in patients with chronic occlusive cerebral arteries. Early steal phenomenon demonstrated by [15O]H2O positron emission tomography

BACKGROUND AND PURPOSE

The acetazolamide effect is thought to reach a maximum at 10 to 20 minutes after administration. However, we sometimes encountered patients who showed a transient deterioration of ischemic symptoms several minutes after acetazolamide administration. We therefore considered that a steal phenomenon may occur before the acetazolamide effect reaches a maximum. We evaluated the time dependency of the acetazolamide effect on cerebral hemodynamics in patients with severe stenosis or occlusion of the unilateral internal carotid artery.

METHODS

The subjects consisted of 13 patients with severe stenosis or occlusion of the unilateral internal carotid artery. Regional cerebral blood flow was measured at the resting state and at 5 and 20 minutes after the intravenous administration of 1 g acetazolamide by the use of the [15O]H2O bolus-injection method and positron emission tomography. The steal phenomenon was interpreted as positive when the regional cerebral blood flow values decreased by more than 10% after the administration of acetazolamide in more than one region of interest.

RESULTS

A steal phenomenon was observed in 5 of 13 patients at 5 minutes after acetazolamide administration on the occlusive side, whereas it was observed in only 1 patient at 20 minutes. Thus, this phenomenon was observed more frequently in the early phase of the acetazolamide test. It was also observed more frequently in patients with poorly developed collateral circulation.

CONCLUSIONS

Our acetazolamide [15O]H2O positron emission tomography study revealed an early steal phenomenon at 5 minutes after intravenous administration of acetazolamide, which may be a cause of the transient deterioration of ischemic symptoms during the acetazolamide test.

[HLA and uveitis in leprosy]

In order to investigate the role of immunogenetic factors in the pathogenesis of uveitis in leprosy, human leukocyte antigens (HLA) were analyzed among leprotics with and without uveitis. The subjects were 85 Japanese leprosy patients, 44 with uveitis and 41 without uveitis. Controls were 138 healthy subjects. A modified two-stage complement dependent microcytotoxicity test was used for typing HLA-A, -B, -C, -DR and -DQ antigens. The occurrence of HLA-DR2 antigen was significantly increased in patients as a whole (69.4%), and in the patients with uveitis (79.5%) as compared with the control subjects (35.5%). The association with DR2 was even stronger in the patients with uveitis (odds ratio = 7.1, Pc < 0.000005) than in the patients as a whole (odds ratio = 4.1, Pc < 0.0001). On the other hand, HLA-DR53 antigen was significantly decreased in the patients as a whole (43.5%) and in the patients with uveitis (36.4%) as compared with the control subjects (69.6%). No significant difference in the distribution of HLA antigens was observed in the patients without uveitis. Our results suggest that HLA-DR2 contributes to the susceptibility to uveitis in Japanese leprosy patients.

[A phase II study of FK506 (tacrolimus) on refractory uveitis associated with Behçet's disease and allied conditions]

A multicenter open study was conducted to investigate optimum dose schedule of FK506 on refractory uveitis associated with Behçet's disease and allied conditions. Fifty-three patients (41 with Behçet's and 12 with allied conditions) were enrolled in this study. A daily oral dose of FK506 was initially 0.05, 0.1, 0.15 or 0.2 mg/kg, but adjusted in more than half patients during the study based on clinical conditions of patients and/or adverse effects of FK506. The improvement rate of initial daily dose as well as final improvement rate were evaluated in the study. The improvement rate of initial daily dose was increased dose-dependently; 37.5% with 0.05 mg/kg initial daily dose group, 60.0% with 0.1 mg/kg, 91.7% with 0.15 mg/kg and 78.6% with 0.2 mg/kg. The final improvement rate was 76.5%. In patients with Behçet's disease, ocular symptoms improved in 30 (75.0%) of 40 patients evaluable for efficacy and the frequency of ocular attacks was significantly reduced. In eight (66.7%) of 12 patients with Behçet's disease in whom cyclosporin treatment had been failed, their ocular symptoms improved by FK506. Main adverse reactions of FK506 were renal impairment (28.3%), neurologic symptoms (22.6%), gastrointestinal symptoms (20.8%), hypomagnesemia (28.3%), hyperkalemia (13.2%), and hyperglycemia (13.2%. Most of the adverse effects disappeared or ameliorated after FK506 dose reduction or withdrawal from FK506 therapy. It seems that the incidence of the adverse effects depends on the dosage of FK506. The lower dosage (0.05 and 0.1 mg/kg) caused a relatively small number of adverse effects, and the higher dosage (0.15 and 0.2 mg/kg) caused them more frequently. Through level is recommended to maintain between 15-25 ng/ml during early days of treatment based on the safety and efficacy. It is also recommended that a initial daily dose is 0.15 mg/kg on the basis of the efficacy and safety results, and then adjusted based on symptoms of patients and whole blood through level of FK506.

Correlation between tumor volume doubling time and histologic findings in gastric smooth muscle tumors: clinical implications of tumor volume doubling time

To assess the clinical implications of the tumor volume doubling time of gastric smooth muscle tumors based on a comparison with the histologic findings, seven tumors (four leiomyomas and three leiomyosarcomas) were followed up by consecutive upper gastrointestinal studies between March 1985 and December 1993. The patients were four men and three women with an average age of 58 years (range: 50-71 years). The observation period ranged from 6 to 51 months, with an average of 35 months. All tumors were surgically resected and the histologic diagnosis was confirmed. The following microscopic features were evaluated: 1) mitotic rate, 2) nuclear atypia, and 3) cellularity. Each tumor was also evaluated for the presence or absence of necrosis, hemorrhage, and degeneration. The doubling time ranged from 5 to 27 months with a mean of 16 months. There was a strong negative correlation between the mitotic rate and the doubling time (r = -0.935, P = 0.0019). The doubling time was also significantly related to nuclear atypia, but the number of tumors studied was so small that its reliability was questionable. The doubling time was not related to any other histologic findings. This study shows that the doubling time is useful for estimating the malignant potential of gastric smooth muscle tumors, and that tumors with a doubling time of 16 months or less should be considered as malignant.

Immunological characterization and localization of a Porphyromonas gingivalis BApNA-hydrolyzing protease possessing hemagglutinating activity

A monoclonal antibody (mAb-PC) was produced against a BA pNA-hydrolyzing protease possessing hemagglutinating activity (Pase-C) from Porphyromonas gingivalis. Other P. gingivalis BA pNA-hydrolyzing enzymes (Pase-B and Pase-S) did not react with this antibody. By ELISA or SDS-PAGE and Western immunoblotting analysis, mAb-PC recognized all P. gingivalis and P. endodontalis strains tested but did not recognize other members of the Porphyromonas genus nor other putative periodontopathogenic organisms. Pase-C, extracellular vesicles (ECV) and human strains of P. gingivalis showed two major immunoreactive bands (44 kDa and 40 kDa), whereas a different pattern was obtained with animal strains of P. gingivalis. Biotinylarginyl chloromethane, an irreversible inhibitor of trypsin-like proteases, did not affect the reactivity of Pase-C with mAb-PC on immunoblot. By reversed-phase electronmicroscopy following immunogold labeling, the antibody was shown to bind to the cell surface of P. gingivalis. mAb-PC inhibited the hemagglutinating activity of both P. gingivalis cells and ECV whereas a monoclonal antibody against LPS of P. gingivalis did not. These results suggest that Pase-C is located on the cell surface of P. gingivalis and may participate in erythrocyte binding.

Immunohistochemical localization of C-reactive protein-binding sites in human atherosclerotic aortic lesions by a modified streptavidin-biotin-staining method

One-step fluorescein-conjugated polyclonal antibody technique has shown that C-reactive protein (CRP) was located only extracellularly in human atherosclerotic lesions. In this report a more sensitive streptavidin-biotin technique was applied to detect the localization of CRP in human atherosclerotic lesions. Immunohistochemical staining with polyclonal and monoclonal anti-human CRP antibodies both produced a brown color extracellularly in the necrotic lesions, and intracellularly in CD68+ foam cells. The latter suggests an uptake of CRP-lipid complexes by macrophages. The staining is human CRP-specific because it was eliminated by preabsorption of the monoclonal antibody with pure human CRP, or by substitution of the primary antibody with non-immune rabbit serum. By overlaid CRP-binding study, a positive stain was observed on intimal smooth muscle cells and foam cells, suggesting that they have CRP-binding sites unless the CRP-binding activity was generated de novo through the fixation procedure. Accordingly, it is hypothesized that CRP may facilitate the uptake of lipids by macrophages accumulating in atherosclerotic lesions. Further, CRP might participate in cytolysis, which enlarges the necrotic area, and/or in phagocytosis that scavenges the necrotic tissue.

Functional Rescue of photoreceptors from the damaging effects of constant light by survival-promoting factors in the rat

PURPOSE

To investigate whether and how survival-promoting agents rescue photoreceptor cell function and morphology from constant light damage, the authors recorded electroretinographic (ERG) responses and examined light micrographs of retinas in those rats given intravitreal injection of midkine (MK) and basic fibroblast growth factor (bFGF) before constant exposure.

METHODS

Albino Sprague-Dawley rats were injected with MK, bFGF, or phosphate-buffered saline (PBS) 2 days before the onset of 1 week of constant light. ERG responses were recorded using white flash stimuli with the intensity range of 4 log units, followed by histologic examinations of retinas, including quantitative assessment of the outer nuclear layer thickness as an index of photoreceptor cell loss.

RESULTS

ERG responses were barely detectable in uninjected eyes after 1 week of constant light. On the other hand, distinct responses were recordable in eyes injected intravitreally with MK and bFGF, and the degree of ERG rescue in terms of the amplitude of b-wave was approximately 40% to 60% compared with normal eyes. Intravitreally injected PBS showed slight, but noticeable, preservation of ERG responses as well. Histologic examination revealed that MK and bFGF protected photoreceptors from light damage. A good correlation was found between anatomic rescue of photoreceptors as assessed by outer nuclear layer thickness and the functional rescue as defined by the magnitude of ERG responses.

CONCLUSIONS

Functional and anatomic rescue of photoreceptors in albino rats from constant light damage is achieved by prior intravitreal injection of MK and bFGF.

[Intra-bile duct growth of hepatocellular carcinoma: value of biliary dilatation on CT]

In order to evaluate the usefulness of CT in demonstrating biliary invasion by hepatocellular carcinoma, 191 surgically proved cases were studied. Among 191 CT scans performed before surgery, six (3%) showed biliary dilatation. Pathological biliary invasion was found in eight cases (4%). Of these eight cases, four cases (50%) showed biliary dilatation on CT. In six cases with biliary dilatation on CT, pathological biliary invasion was revealed in four cases (67%). In two cases, the large (> or = 6cm) encapsulated tumors located in the hepatic hilum dilated the intrahepatic bile duct without intraductal tumor growth. We concluded that biliary dilatation on CT cannot be a sign of biliary invasion by hepatocellular carcinoma.

Radiosynthesis, rodent biodistribution, and metabolism of 1-deoxy-1-[18F]fluoro-D-fructose

Fluorine-18 labeled analog of D-fructose, 1-deoxy-1-[18F]fluoro-D- fructose (1-[18F]FDFrc), was synthesized by nucleophilic substitution of [18F]fluoride ion and the effect of the fluorine substitution on its in vivo metabolism was investigated. The tissue distributions of 1-[18F]FDFrc in rats and tumor bearing mice showed initial high uptake and subsequent rapid washout of the radioactivity in the principal sites of D-fructose metabolism (kidneys, liver and small intestine). The uptakes in the brain and tumor (fibrosarcoma) were the lowest and moderate, respectively, but tended to increase with time. The in vivo metabolic studies of 1-[18F]FDFrc and nonradioactive 1-FDFrc in mouse brain and tumor showed that the fluorinated analog remained unmetabolized in these tissues, indicating that the substitution of fluorine at the C-1 position produces a nonmetabolizable analog of D-fructose. Thus, 1-[18F]FDFrc had no features of a metabolic trapping tracer without showing any appreciable organ or tumor specific localization.

Postcontrast 3D-TOF-MR angiography of intracranial venous angiomas

The clinical value of three-dimensional time-of-flight magnetic resonance angiography (3D-TOF-MRA) was assessed in 15 patients with intracranial venous angiomas (VAs), by comparing results thereof with those of postcontrast T1-weighted MR images (MRIs). All 15 VAs were identified both on the postcontrast MRIs and MRAs. The MRAs surpassed the MRIs in imaging entire structures, including the draining veins of the supratentorial VAs. For the infratentorial VAs, the MRAs and the MRIs were of equal value. Although the addition of MRA to the MRI procedure incurs more time and expense, the complete structure of the VA can thereby be identified three-dimensionally on MRA. Conventional angiography is apparently not required for the confirmation of a VA. Thus, it is concluded that MRA is very useful for diagnosing VAs.