Dynamic 3D-CT angiography.

BACKGROUND AND PURPOSE: 3D-CT angiography (3D-CTA), a vessel-cast technique, is useful in the diagnosis of patients with brain lesions and cerebrovascular disease. However, it provides no information on blood-flow dynamics. Therefore, we developed a new technique, dynamic 3D-CTA (d3D-CTA), that yields 3D images of the vasculature and allows assessment of the hemodynamics and of the cerebral perfusion. METHODS: We subjected 12 patients to d3D-CTA; 7 had brain tumors, 4 had arteriovenous malformations (AVMs), and 1 presented with cervical internal carotid artery occlusion. d3D-CTA was performed with a multidetector-row CT scanner with 64 detectors; the parameters were 0.5-mm section thickness, 0.5 seconds per rotation, 135 kV, and 150 mA. Contrast medium (total volume, 30-35 mL) was injected at 6-7 mL/s; scanning was started after a 5-second delay. Scans were generated with volume-rendering reconstruction and displayed in cine mode. RESULTS: We succeeded in obtaining d3D-CTA scans in all cases. The scans yielded 3D information on the vascular structures and hemodynamics and on the status of the cerebral perfusion. CONCLUSION: d3D-CTA facilitates the acquisition of information on the vascular and cerebral dynamic blood flow on 3D-CTA images. Despite the relatively high radiation exposure and contrast injection speed and its limited scan range, this technique is useful for the diagnosis of patients with brain tumors or cerebrovascular disease and for treatment planning.

Sentinel node biopsy with technetium-99m colloidal rhenium sulphide in patients with breast cancer.

BACKGROUND: Sentinel node biopsy is emerging as a technique to replace routine axillary lymph node dissection. The lymphatic mapping technique is still at a developmental stage and no standard technique exists. This study used technetium-99m colloidal rhenium sulphide with a mean particle size of 100 (range 50-200) nm for sentinel node mapping. METHODS: Eighty-seven patients with breast cancer, but no clinical evidence of axillary metastasis, were studied. One day before operation technetium-99m colloidal rhenium sulphide was injected at four points into breast tissue surrounding the tumour. Lymphoscintigraphy was performed 2 h after injection, and surgery was usually performed after 20 h. A hand-held gamma probe guided sentinel node biopsy. RESULTS: Lymphoscintigraphy revealed axillary hot spots in all patients. During operation, the sentinel node was identified in all 87 patients (100 per cent). The number of sentinel nodes per patient ranged from 1 to 5 (mean 2). Metastatic sentinel nodes were identified in 37 of 87 patients. There were no false negatives. CONCLUSION: This study suggests that technetium-99m rhenium sulphide is a suitable agent for sentinel node mapping in patients with breast cancer.

New plasma-reduced synthetic media, Fukushima cocktails, for the storage of platelets for transfusion.

BACKGROUND: Donor plasma proteins are associated with non-hemolytic allergic reactions, such as urticaria or laryngeal edema, in platelet-transfusion recipients. Replacement of plasma with synthetic media from platelet concentrates (PCs) is considered to be effective in preventing such reactions. However, platelets preserved in media depleted of less than 10% plasma are reported to have functions inferior to those preserved in plasma. METHODS: Fukushima Cocktails (FCs) contain glycerol (25, 50 or 100mM), sodium acetate, glucose and other components. To test the effect and determine the most suitable concentration of glycerol for platelet preservation, functions of platelets including aggregation, hypotonic shock response and swirling pattern and released biochemicals were measured with platelets preserved in Fukushima Cocktails. The effects of residual plasma on platelet functions were also evaluated. Autologous platelets stored for 3 days in solution containing 50 mM glycerol were transfused into healthy volunteer donors to evaluate their safety and survival. RESULTS: The functions (aggregation and hypotonic shock response) of platelets preserved in Fukushima Cocktails with 10% residual plasma were preserved for 5-7 days as well as plasma controls, whereas platelets stored for 9 days in a medium lacking glycerol became swollen and beta-thromboglobulin and thromboxane B(2) increased. When the residual plasma was more than 5%, platelet functions including aggregation, hypotonic shock response and swirling pattern were well preserved for 7 days. The in vivo platelet survival rates at 24 and 48 h after transfusion of platelets stored for 3 days in Fukushima Cocktail were 77% and 60%, respectively, which were not less than autologous plasma-stored platelets. CONCLUSION: Glycerol at a concentration of around 50 mM has a beneficial effect on platelet preservation for more than 7 days. The results of these experiments indicate that platelets stored in Fukushima Cocktail should be useful clinically.

[Support system for cancer patients in the north area of Fukushima].

The purpose of this study was to elucidate the support system for cancer patients in the north area of Fukushima. The support system includes 3 general hospitals, 2 clinics with home-care hospice, 4 self-help groups, 5 volunteer groups, 3 doctors and nurses from special interest groups and 7 home-care medical services. We displayed this system on Internet (http://www.fmu.ac.jp/home/kanwa).

[Endoscopic pointing device for virtual bronchoscopy].

Virtual bronchoscopy is useful for understanding the morphology of tracheobronchial space. Because it is difficult to operate the system, we developed a new pointing device simulating the grip of a flexible bronchofiberscope. With this device, it was possible to simulate the handling of a bronchofiberscope (in or out, clockwise or counterclockwise rotation, arbitrary angle of view). We conclude this type of pointing device could prove to be a useful tool in endoscopic simulation.

[Measurement of cerebral blood flow using phase-contrast MRI].

The development of phase-contrast magnetic resonance imaging(P-C MRI) provides a noninvasive method for measurement of volumetric blood flow(VFR). The VFR of the left and right internal carotid arteries and basilar artery were measured using P-C MRI, and total cerebral blood flow(tCBF) was calculated by summing up the VFR values in three vessels. We investigated the changes in these blood flows as influenced from age, head size, height, weight, body surface area and handedness. Moreover, regional CBF(rCBF) was measured by combining with the single photon emission computed tomography(SPECT) of 123I. The blood flows were 142 +/- 58 mL/ min(mean +/- SD) in the basilar artery, 229 +/- 86 mL/min in the left, 223 +/- 58 mL/min in the right internal carotid artery, and tCBF was 617 +/- 128 mL/min(Ref. Magn Resn Imaging 14:P. 1143, 1996). Significant increases were observed in head-size-related change of VFR in the basilar artery and height-related change of tCBF. The value of rCBF was easily acquired in combination with SPECT. Phase-contrast MRI is useful for a noninvasive and rapid analysis of cerebral VFR and has potential for clinical use.

[Metabolic imaging of human brain tumors: H-1 chemical shift imaging and PET].

Positron Emission Tomography(PET) and Proton Chemical Shift Imaging(1H-CSI) has provided a cerebral metabolism. The glucose analog fluorine-18 fluorodeoxy-glucose(FDG) and amino acid analog 11C-L-methionine is the most commonly used PET tumor tracer. This time we compare with 1H-CSI and PET in gliomas and metastatic brain tumor with computer-assisted fusion images. We experienced some cases of the brain tumor. One case is metastatic brain tumor after radiation therapy, localized in right parietal hemisphere, with hemorrhage, and slightly accumulated Gd-DTPA in tumors. 11C-methionine PET demonstrates defects in tumors, but slight accumulated surrounding tumors. Accumulation of PET lesion is not elevated choline in CSI, but lactate is accumulated in tumors. Choline signal elevation seen in brain neoprasms, associated with increased cellular proliferation. Accumulation of PET and another accumulation of lactate in tumor are not demonstrate recurrence. Fusion image of PET and CSI is useful in understanding metabolism of brain tumor.

[Effectiveness of the radioactive strontium (89Sr) chloride agent, SMS.2P for pain palliation in patients with metastatic bone tumor in phase III multicenter clinical trial].

The phase III clinical trial of strontium-89 chloride agent (SMS.2P) was performed in 90 patients with painful bone metastases secondary to prostate (53), breast (18) and other types of cancer (19). Some patients experienced a transient increase in pain or nausea and vomiting. However both symptoms subsided and serious side effects were not observed in any of the patients. As reported, we confirmed some abnormal changes in peripheral blood picture. A decrease in the number of white blood cells and platelets was considered to be partly a result of bone marrow suppression due to 89Sr irradiation. Pain was substantially improved after 89Sr therapy in 58% of the patients and there was some alleviation in 12%. The release from pain was accompanied by an improved quality of life for these patients including sleep patterns and morbidity. Some patients were able to resume their former life styles. Most of the improved patients experienced pain relief from days to one week following 89Sr therapy and in half cases, this remained effective for 2 or 3 months. There were even cases in which the pain relief continued over an observation period of time of clinical study.

Cerebral oxygen and glucose metabolism and blood flow in mitochondrial encephalomyopathy: a PET study.

Cerebral blood flow (CBF), oxygen metabolism (CMRO2), and glucose metabolism (CMRGlc) were measured using positron emission tomography in five patients diagnosed as having mitochondrial encephalomyopathy. The molar ratio between the oxygen and glucose consumptions was reduced diffusely, as CMRO2 was markedly decreased and CMRGlc was slightly reduced. The CBF showed less changes. The CBF increase on hypercapnia was smaller than normal, though this was not significant. CBF with hypocapnia demonstrated a significant reduction compared with the normal. These results suggest that oxidative metabolism is impaired and anaerobic glycolysis relatively stimulated, due to a primary defect of mitochondrial function, and that mild lactic acidosis occurs in brain tissue because of impaired utilisation of pyruvate in the TCA cycle. As these findings appear to indicate directly a characteristic of this disease, such measurements may be a useful tool for assessment of the pathophysiology and for diagnosis of mitochondrial encephalomyopathy.

Three-vessel study of cerebral blood flow using phase-contrast magnetic resonance imaging: effect of physical characteristics.

The development of phase-contrast magnetic resonance imaging (P-C MRI) provides a noninvasive method for measurement of volumetric blood flow (VFR). We performed P-C MRI to study the effects of physical characteristics on cerebral blood flow. VFR of the left and right internal carotid arteries and basilar artery were measured using P-C MRI and total cerebral blood flow (tCBF) was calculated by summing up the VFR values in the three vessels. Moreover, we investigated the changes in these blood flows as influenced by age, head size, height, weight, body surface area, and handedness. The blood flows were 142 +/- 58 ml/min (mean +/- standard deviation) in the basilar artery; and 229 +/- 86 ml/min in the left, and 223 +/- 58 ml/min in the right internal carotid artery; and tCBF was 617 +/- 128 ml/min. Significant increases were observed in head size-related change of VFR in the basilar artery (p = .028) and height-related change of tCBF (p = .045). The other characteristics did not significantly influence any VFR. The results suggest that head size and height may reflect CBF, and that these effects should be considered when changes of CBF are diagnosed. Phase-contrast MRI is useful for a noninvasive and rapid analysis of cerebral VFR and has potential for clinical use.

Deuterium MR in vivo imaging of the rat eye using 2H2O.

In vivo deuterium MR imaging (2H MR) was investigated in rats after intraperitoneal administration of deuterated saline, and a dynamic study of the water movement in rat eyes was performed. Deuterium MR imaging was carried out by means of a gradient-echo (GRE) and a spin-echo (SE) pulse sequence. The rat eye was imaged in 2H MR more selectively by SE than by GRE, but a lower signal-to-noise ratio was obtained in 2H MR imaging using the SE sequence. The MR signal intensity of the rat eye was followed by a 3-compartment model, which enabled determination of the flow rate constant of the water in the eye (0.359/min). Deuterium MR imaging is useful to visualize the dynamic change of water in rat eyes using 2H MR at the same magnetic field (2 T) that can also be used for conventional MR imaging in humans.

Discrepant 99mTc-ECD images of CBF in patients with subacute cerebral infarction: a comparison of CBF, CMRO2 and 99mTc-HMPAO imaging.

Three patients with subacute ischemic cerebral infarction examined by SPECT with 99mTc-ECD and PET within the same day showed signs of luxury perfusion in the subacute phase, which is between 9 to 20 days after the onset. A 99mTc-HMPAO SPECT study was also performed within 2 days of the ECD-SPECT study. ECD-SPECT images of three patients displayed a focal decreased uptake in the infarcted lesions, while in infarcted foci, there was almost equivalent or increased CBF compared to normal and unaffected areas, decreased CMRO2, and high HMPAO uptake. The ECD-SPECT results were similar to those of CMRO2 rather than CBF, though the HMPAO-SPECT image was similar to that of CBF. In one patient, HMPAO images revealed hyperfixation of the tracer. In the chronic phase and in the acute phase before 5 days after the onset, there were no discrepancies among the ECD-SPECT, CBF, HMPAO-SPECT, and CMRO2 images. These observations indicated that 99mTc-ECD is a good indicator of damaged brain tissues in subacute ischemic infarction. They also suggested that 99mTc-ECD is a potential agent with which to evaluate cerebral tissue viability in some pathological states of cerebrovascular disease. The characteristics may be suitable for confirming the effects of thrombolytic therapy in acute ischemia, because these conditions often show signs of luxury perfusion when the therapy is successful.

Hypersensitivity of cortical muscarinic receptors in Parkinson's disease demonstrated by PET.

The status of muscarinic receptors (mAChRs) is not clear in Parkinson's disease (PD). We measured mAChR binding in the brain of eight patients with PD and eight, age-matched, healthy controls by positron emission tomography (PET) and [11C]N-methyl-4-piperidyl benzilate ([11C]NMPB). PD patients were not demented according to DSM III criteria but showed significant frontal lobe dysfunction in the Modified Wisconsin Card Sorting Test. A mean K3 value, which is an index of mAChR binding calculated by a graphical method, was 20% higher in the frontal cortex of PD patients than controls (p < 0.05). Hypersensitivity of mAChRs in the frontal cortex of PD patients may be a response to a loss of ascending cholinergic input to that region, and may relate to frontal lobe dysfunction in PD.

Serial water changes in human skeletal muscles on exercise studied with proton magnetic resonance spectroscopy and imaging.

In vivo 1H-magnetic resonance imaging (MRI) enabled us to study the distribution of water in living tissues and to document changes in human skeletal muscles during physical exercise. The purpose of the present study was to determine the total muscle water changes after exercise using water in 1H-MR spectroscopy and to compare these changes to the signal intensity change on T2*-weighted images and/or to the T2 value change. Seven young male volunteers were positioned in a 1.5 T Philips MR imaging system. They were then asked to dorsiflex their ankle joint against a 2 kg weight once every 2 seconds for 2 minutes. The peak height of water declined according to the clearance curve after exercise in all seven cases with the 1H-MRS similar to the signal intensity. The increasing rate at peak height of total muscle water exceeded both the signal intensity and the T2 value because the water peak height on the 1H-MRS included the extracellular water. In addition, we measured the changes in signal intensity in both calf muscles after walking race exercise. The time intensity curves were used to draw a clearance curve for each muscle group after exercise. It was possible to discern which muscle was used most from the T2*-weighted image that was obtained once after exercise.

[Circulation time determined by carotid angiography in patients with chronic internal carotid artery occlusion: comparison with cerebral blood flow and oxygen metabolism measured by PET].

The degree of collateral circulation in patients with unilaterally chronic internal carotid artery occlusion was estimated by mean transit time of contrast material in rapid sequence carotid angiography (Angiographic MTT), and compared with cerebral blood flow and oxygen metabolism measured by PET. In normal density region on X-ray CT, a significant negative correlation was observed between Angiographic MTT and cerebral blood flow (CBF). This indicates that cerebral blood flow can be estimated by Angiographic MTT. It has been reported that the ratio of cerebral blood volume (CBV) to CBF (CBV/CBF), i.e., mean transit time determined by PET well agreed with OEF, and is good indicator for brain circulation reserve. In this study, no significant correlation was observed between Angiographic MTT and CBV/CBF. However, a significant positive correlation was observed between Angiographic MTT and oxygen extraction fraction (OEF), and no significant correlation was observed between Angiographic MTT and oxygen consumption rate (CMRO2). These indicates that Angiographic MTT may be indicator for brain circulation reserve.

Perfusion and metabolism in predicting the survival of patients with cerebral gliomas.

BACKGROUND: Noninvasive measurements of cerebral circulation and metabolism may be useful for diagnosis in patients with brain tumors. The authors tested the prognostic significance of circulatory and metabolic values or ratios determined by positron emission tomography (PET) in patients with gliomas. METHODS: The subjects were 23 patients, who underwent a complete PET study of cerebral circulation and metabolism with long-term follow-up of at least 57 months. Regional cerebral blood flow (rCBF), blood volume (rCBV), oxygen extraction fraction, and the metabolic rates of oxygen (rCMRO2) and glucose (rCMRGl) were measured before treatment. Data regarding tumors, the contralateral gray matter and white matter, and the ratio between tumor and gray matter or between tumor and white matter were compared with survival time from the time of the PET study. Prognostic factors were tested using Cox's regression analysis. RESULTS: Among clinical parameters, histologic grade and performance status were important variables regulating survival. When survival times of patients with values or ratios equal to or higher than the median were compared to those of patients with values or ratios lower than the median, significant determinant PET measurements were tumor rCMRGl and the ratios of tumor:gray rCMRGl and tumor:white rCMRGl. Median survival time in the patients with an rCMRGl value of 4.4 mg/100ml/minute (median value) or more indicated 9 months, which was significantly shorter than greater than 113 months in the patients with a value lower than the median (P = 0.003 by the generalized Wilcoxon test). Patients with a higher value of gray rCBF, rCBV, or rCMRO2 had significantly longer survival times than those with a lower value. CONCLUSIONS: Cerebral circulation and metabolism as determined by PET can be of ancillary significance in predicting the prognosis of patients with gliomas.

Cerebral uptake of 99mTc-bicisate in patients with cerebrovascular disease in comparison with CBF and CMRO2 measured by positron emission tomography.

The regional brain uptake of 99mTc-N,N'-(1,2-ethylenediyl)bis-L-cysteine diethyl ester (99mTc-bicisate) measured by single photon emission computed tomography (SPECT) was compared with the regional CBF and CMRO2 measured by positron emission tomography in patients with cerebrovascular disease. Nine patients with the diagnosis of cerebral ischemic disorders (n = 7) or cerebral hemorrhage (n = 2) were studied. 99mTc-Bicisate brain uptake correlated with CBF and CMRO2. However, 99mTc-bicisate uptake did not reflect CBF in the single lesion showing luxury perfusion, which seemed to resemble a CMRO2 image. Though quantitative analysis showed the nonlinear correspondence of 99mTc-bicisate brain uptake with CBF and CMRO2, this correspondence could be corrected into a more linear relationship using a correction factor. 99mTc-Bicisate washout from the brain had no correlation to CBF and CMRO2. This diffuse decreasing washout rate was approximately 15% during the first hour after injection. By using the lipophilic fraction of arterial blood and a linearized correction of 99mTc-bicisate SPECT images, the feasibility of obtaining a factor-related CBF and CMRO2 was suggested from our data. These results suggested that 99mTc-bicisate had good characteristics for routine clinical use with SPECT to display the brain function in patients with neurological disorders.

Effects of fasudil hydrochloride on cerebral blood flow in patients with chronic cerebral infarction.

To evaluate the effect of the novel intracellular calcium antagonist fasudil hydrochloride, cerebral blood flow (CBF) was measured quantitatively with positron emission tomography following the intravenous administration of fasudil in five patients with chronic cerebral infarction. The hemispheric mean CBF increased significantly on both hemispheres 30, 60, and 90 min after the administration of fasudil when the CBF values were corrected according to PaCO2 level, although there was no significant change in raw CBF data. A significant increase of CBF was seen in the cerebellar hemisphere and thalamus at 30 min and in the occipital cortex at 90 min. There was no significant fall in the systemic blood pressure after the administration of fasudil.

Increased blood flow in human brain tumor after administration of angiotensin II: demonstration by PET.

To evaluate the changes of regional cerebral blood flow (CBF) in artificial hypertensive state, we investigated vascular responses to changes of arterial carbon dioxide tension (PCO2) and blood pressure by means of positron emission tomography (PET). The subjects were eight brain tumors which were histologically proven. We calculated CBF changes in hypercapnic and hypocapnic state, and then using those results, CBF changes in hypertensive state were corrected. Every patient represented a selective increase of tumor blood flow in hypertensive state induced by angiotensin II, demonstrating a loss of autoregulation in tumor. Our results suggested the possibility of enhancement of chemotherapy for brain tumors.