tadokoro masanori

RATIONALE: Radioiodine therapy improves the survival of patients with pulmonary metastases of differentiated thyroid cancer (DTC). It is controversial whether the diagnostic whole-body I-131 scan (DWS) before therapy is essential. We determined whether DWS could predict the efficacy of I-131 therapy for pulmonary metastases. METHODS: We undertook a retrospective review of records of 42 patients (28 women and 14 men, mean age 52.7 years). The patients had received 62 rounds of I-131 therapy for lung metastases of DTC at our institution between June 2002 and June 2006. On the same day that the DWS (dose of 185 MBq) (5 mCi) was completed, the patient received I-131 therapy (dose of 3700-7400 MBq) (100-200 mCi). Post-therapy whole-body scans (PWS) were performed after 3 to 4 days and 7 to 8 days. For all therapies, chest CT images were obtained before I-131 therapy, and 3 and 6 months after therapy for evaluation of therapeutic effectiveness. In addition, serum thyroglobulin (Tg) values were measured before and after the radioiodine therapy for all treatments. RESULTS: In the group demonstrating I-131 accumulation for pulmonary metastases on DWS, 72% of patients showed a reduction of pulmonary metastases on follow-up CT. On the other hand, in the group that failed to accumulate I-131 on DWS, only 5% of patients showed a reduction of pulmonary metastases. After therapy, serum Tg levels decreased significantly in the group that initially showed accumulation of I-131 in DWS (P = 0.045). In contrast, no remarkable changes between pre- and post-therapy Tg levels were observed in patients who failed to accumulate I-131 in DWS. CONCLUSION: A whole-body I-131 diagnostic scan before I-131 therapy has a predictive value for the efficacy of therapeutic radioiodine treatment for pulmonary metastases of differentiated thyroid cancer. © 2008 by Lippincott Williams &amp Wilkins.

Earlier investigations showed that N-isopropyl-p-I-123-iodoam-phetamine SPECT (I-123-IMp SPECT) is useful for the diagnosis of uveal malignant melanoma, whereas the feasibility and usefulness of F-18-FDG PET in uveal malignant melanoma have not yet been established. We compared the usefulness of I-123-IMP SPECT and 18F-FDG PET for the detection of uveal malignant melanoma on the same subjects. Methods: Nineteen patients (10 men, 9 women) with suspected uveal malignant melanoma were examined by I-123-IMP SPECT. Thirteen of them were also examined by F-18-FDG PET. I-123-IMP SPECT was performed at 15 min or at 3 and 24 h after intravenous administration of I-123-IMP. Results: In 12 of 19 study patients, I-123-IMP SPECT obtained at 24 h after intravenous administration of I-123-IMP delineated an area of increased uptake in the site corresponding to the ocular tumor. All of the ocular tumors in the 12 I-123-IMP SPECT-positive patients were confirmed histopathologically and clinically to be uveal malignant melanoma. The other 7 I-123-IMP-SPECT-negative patients have been monitored under the diagnosis of choroidal nevus, choroidal hemangioma, hyperplasia of the pigment epithelium of the retina, or idiopathic inflammatory lesions without any complications. In a total of 13 patients examined by F-18-FDG PET, 9 of whom were I-123-IMp SPECT positive and 4 were negative, only 1 patient showed abnormal uptake of F-18-FDG PET in the site corresponding to the ocular tumor. Therefore, 8 of 9 patients with uveal malignant melanoma showed false-negative results in F-18-FDG PET. The F-18-FDG PET-positive patient with uveal malignant melanoma had the largest tumor mass with a short diameter of 12 mm, a long diameter of 17 mm, and a height of 7 mm. In the other 8 F-18-FDG PET-negative patients, the tumors had a dimension of 11 x 13 x 7 mm or less. Conclusion: I-123-IMP SPECT is a sensitive and accurate method for the detection of uveal malignant melanoma, whereas the efficacy of F-18-FDG PET for this purpose is low because of a high incidence of false-negative results. I-123-IMP SPECT is far more superior in comparison with 18F-FDG PET in detecting uveal malignant melanoma.

The purpose of this study was to determine an optimal slice thickness that was efficient in differentiating malignant from benign solitary pulmonary nodules (SPNs) on high-resolution computed tomography (HRCT) images. For a total of 92 SPNs, four radiologist indicated their confidence level for the malignant or benign SPN on the CT images presented in 1-, 3-, and 5-mm slice thickness. HRCT could be used to differentiate more accurately the malignant nodules from the benign ones using 1-mm-thick sections than 3- or 5-mm-thick sections. (C) 2004 Elsevier Inc. All rights reserved.

The relationship between positron emission tomography (PET) findings and developmental or seizure outcome was examined in 17 infants (11 males, six females; mean age at onset of spasms 7 months, range 3 to 26 months) with newly diagnosed cryptogenic West syndrome. The predictive value of PET in these infants was assessed. PET was performed in the infants at the onset of spasms and 3 months after initial therapy using F-18-labelled 2-deoxy-2-fluoro-D-glucose. A third PET was performed at 18 months of age if the second scan was abnormal. All infants were followed up until at least 3 years of age. Cortical hypometabolism was detected in 11 infants on the first PET and in five infants on the second. Rate of developmental delay at the last follow-up was significantly higher in infants with hypometabolism on the second PET than in those without PET abnormalities (p<0.05). Rate of seizure occurrence after initial treatment was higher in infants with cortical hypometabolism on the second PET, but the difference was not statistically significant. Results suggest that when PET after the initial treatment shows no abnormalities, even though the first PET shows hypometabolism, infants with cryptogenic West syndrome may have a favourable developmental or seizure outcome. PET may be a useful tool in evaluating the prognosis in infants with cryptogenic West syndrome.

Background and Purpose-In major cerebral arterial steno-occlusive diseases, there can be remarkably decreased hemodynamic reserve without marked neurological impairments. In such settings, it is not known whether the neural activity is well maintained or disturbed according to the severity of cerebral ischemia. The present study was therefore undertaken to examine the neural activity under mild cerebral ischemia resulting from major cerebral arterial occlusion. Methods-Seven patients with minor neurological impairment as well as either unilateral internal carotid artery or middle cerebral artery occlusion were studied. The severity of the cortical ischemia was assessed by measuring regional cerebral blood flow (rCBF) with positron emission tomography. The change in neural activity in the ischemic brain was then evaluated by means of somatosensory evoked magnetic field with magnetoencephalography. Results-The rCBF in the primary sensory area and the strength of the initial component of somatosensory evoked magnetic field (N20 m) were significantly reduced (P<0.01) and the second component (P30 m) was significantly augmented (P<0.05) in the lesioned cerebral hemisphere as compared with the nonlesioned hemisphere. The asymmetry indexes for N20 m were positively correlated (r=0.78) and those for P30 m were inversely correlated (r=-0.92) with asymmetry indexes for rCBF. Conclusions-In patients with either unilateral internal carotid artery or middle cerebral artery occlusion and minor neural impairments, there was a reduction of afferent signal and an augmentation of the secondary response of the neurons in the primary sensory area. This showed correlation with the severity of cortical ischemia.

Background: Pendred syndrome is often associated with inner ear malformations, especially enlarged vestibular aqueduct (EVA). Recently, mutations in the Pendred syndrome gene (PDS) have been reported in patients with EVA. in addition to those with classical Pendred syndrome. Objective: The aim of this study was to investigate the genotype-phenotype correlations of PDS. Methods: Each of the 21 exons and flanking splice regions of PDS was analysed by direct DNA sequencing in nine patients with EVA: allele-specific amplification was performed to confirm the mutation. Genetic analyses were compared with thyroid function tests, perchlorate discharge tests. thyroid volume and pure-tone audiogram. Magnetic resonance imaging was used to determine the volume of the endolymphatic duct and sac of each patient. Results: A missense mutation, H723R, was identified in the homozygous state in three patients and in the heterozygous state in another three. Although none of the patients had goitre, increased serum thyroglobulin and an abnormal degree of iodide release were correlated with the number of mutant alleles identified. However, there was no relationship between the degree of hearing loss and the number of mutant alleles. Conclusion: The present study reveals that the number of mutant alleles correlates with the degree of subclinical thyroid abnormality, but not with the degree of hearing loss in Japanese patients with the PDS missense mutation H723R.

A 50-year-oid male presented with benign intracranial hypertension (BIH), He was admitted to our hospital for headache and papilledema. The diagnosis was BIH as continuous monitoring of lumbar cerebrospinal fluid pressure (CSFP) showed high basal pressure with intermittent plateau waves. Ten months after successful ventriculoperitoneal shunting, he presented with headache again due to shunt malfunction. CSFP monitoring showed the same findings as before, Regional cerebral blood flow (rCBF) was measured by positron emission tomography (PET) using the O-15-labeled water autoradiographic method with simultaneous recording of lumbar CSFP, The rCBF values of the cerebral cortex, white matter, thalamus, cerebellar cortex, and pens were evaluated during both the plateau waves and the intervals. In spite of severely reduced cerebral perfusion pressure, rCBF during the plateau waves was not reduced when compared with the rCBF of normal volunteers in all regions. This result might explain why patients with BIH show no impairment of consciousness or focal signs during the plateau waves.

Diagnostic accuracy of positron emission tomography (PET) using¹⁸F-fluorodeoxyglucose for lung cancer has been evaluated as a retrospective multi-center survey in Japan. A total of 600 studies were collected from the 15 institutions. For the differential diagnosis between benign and malignant tumors, sensitivity, specificity, and accuracy were 81.1 % (322/397), 63.5% (54/85), 78.9% (376/482), respectively. For the staging diagnosis of lung cancer patients, whole-body PET was superior to CT/MRI in 21.3% (35/164), equal to CT/MRI in 73.8% (121/164), inferior to CT/MRI in 4.9% (8/164) . It was assumed that sensitivity, specificity, and accuracy of whole-body FDDG-PET for the diagnosis of metastatic foci were 88.3%, each. Cost-effectiveness analysis of FDG-PET for the diagnosis of lung cancer in Japan was performed on the basis of these data. The strategy of whole-body FDG-PET for the staging diagnosis of lung cancer showed a saving of 43, 000 yen per patient as a result of improving staging of lung cancer and avoiding unnecessary surgery. The total saving in diagnosis and surgery of lung cancer in Japan will be 1.5 billion yen per year (1.9% of total cost in diagnosis and surgery) .

Purpose: The goal of this work was to determine a radiologist's ability to detect solitary pulmonary nodules on helical CT using both video (cine) viewing and film-based viewing. Methods Sixty-five chest helical CT studies were reviewed. Six radiologists searched for 40 lung nodules on CT images presented in three formats. Film-based viewing of images at 10 and 5 mm increments was performed with a light box. Video viewing of the same examinations was performed in 5 mm increments at 2 frames/s, The area under the receiver operating characteristic curve (A(z)) measured the observers ability to detect nodules. Results: The A(z) was 0.948 for the video viewing, 0.844 for 5 mm increment film-based viewing, and 0.879 for 10 mm increment film-based viewing, There were no statistically significant differences. Conclusion: Lung nodules can be detected with similar defection rates when viewing conventional film or videotaped helical CT images. Videotaped images incur a lower cost, an important consideration in mass screening for lung cancer.

This study was done by the PET working group under Japan Radioisotope Association. The usefulness of [¹⁸F] fluorodeoxyglucose (FDG) -PET in detecting local recurrence of colorectal carcinoma was investigated retrospectively, by the results of questionnaire. Six institutions participated in this study. One hundred and four cases were analyzed to calculate the diagnostic accuracy. The accuracy of FDG-PET in detecting local recurrence of colorectal carcinoma was 96.2%, with two false positive and two false negative cases. We also evaluated the cost-effectiveness of FDG-PET in staging recurrent colorectal carcinoma based on the results of questionnaire. FDG-PET reduced unnecessary radical surgery by 50% in comparison with that in the conventional protocol without PET, and the net savings were about 6.6 billion yen per year in Japan.

The aim of this study was to propose and validate a new method of making fused images from CT and FDG PET images for the upper abdominal area with no body surface marker. PET and CT were carried out in patients with pancreatic cancer (N=5) and mass-forming pancreatitis (N=2). First, we determined the midsagittal plane from PET and CT data. From the difference in location of the midsagittal planes, rotations of Y (from back to front) and Z axes (from foot to head) and X translation (from right to left) were calculated. An upper pole of the kidney was determined from PET and CT data. It showed Y and Z translations. The images of the three-dimensional data sets were fused on a workstation. Reproducibility was assessed with randomly misaligned PET and CT data sets. Pancreatic cancer and its lymph node metastases were identified easily on fused images. In reproducibility assessment, the average error of rotation was 0.77 degrees. The average errors of translation were 3.43, 4.70, and 9.23 mm on the X, Y, and Z axes, respectively. In conclusion, this PET/CT image registration technique is feasible and practical. It allows precise anatomical assessment of normal and abnormal FDG accumulation.

Objective: To evaluate interobserver agreement in the interpretation of breast ultrasonography. Methods: 55 breast masses (30 benign, 24 malignant) were interpreted by seven radiologists using a CRT viewing station. US criteria for differentiating between benign and malignant lesions included shape, border, boundary echoes, internal echoes, posterior echoes, and bilateral shadows. Each criterion and the observers' finial impression was scored using the 5-point rating scales. For analyzing interobserver agreement, the kappa (κ) values were employed. Results: The κ values of shape and posterior echoes were significantly higher than those of the other four criteria (P&lt 0.05). Agreement was intermediate in border and internal echoes, and was low in boundary echoes and bilateral shadows. Agreement in the senior group (four observers) was relatively higher than that in the junior group (three observers) for all criteria but for internal echoes. Easily-diagnosed cases showed significantly higher κ values compared with more ambiguous cases (P &lt 0.05). Conclusion: Interobserver agreement in shape and posterior echoes was significantly higher than those of the other four criteria. Agreement was significantly dependent on case difficulty.

Little is known about how ischemia affects hemodynamic responses to neural activation in the brain. We compare the effects of a motor activation task and a cerebral vasodilating agent, acetazolamide (ACZ), on regional cerebral blood flow (rCBF) in primary sensorimotor cortex (PSM) in six patients with major cerebral artery steno-occlusive lesions without paresis of the upper extremities. Quantitative rCBF was measured in all patients using (H2O)-O-15 autoradiographic method and positron emission tomography. The CBF was determined at rest, during a bimanual motor activation task, and 10 minutes after ACZ administration. With bimanual motor activation, rCBF increased significantly in both PSM compared with at rest (P < 0.01 on lesion side, and P < 0.02 on contralateral side). However, rCBF did not increase after ACZ injection in the PSM on the lesion side, whereas rCBF increased significantly in the contralateral PSM after ACZ injection compared with the level at rest. This result suggests that despite a decreased hemodynamic reserve, there is a nearly normal flow response to neural activation, indicating that the mechanism of vasodilation responsible for perfusion change is different for acetazolamide and neural activation. The relations among neural activation, hemodynamic status, and cerebral metabolism in the ischemic stroke patients are discussed.

Carbon dioxide (CO2) and acetazolamide are increasingly being used as vasodilators to detect cerebrovascular reserve capacity in patients of chronic cerebrovascular disease. The functional cerebrovascular reserve or ability of cerebral Vessels to lower their resistance in response to decrease in cerebral perfusion pressure is expressed as change in cerebral blood flow from baseline under a vasodilatory stimuli. Theoretically a vasodilator causing maximum vasodilation, and thereby expressing complete reserve capacity would be more suitable for such a purpose. We quantitatively compared the vasodilating effect of 5% CO2 inhalation and 1 g of intravenous acetazolamide by positron emission tomography. Cerebrovascular reserve was quantified in six patients with chronic cerebrovascular disease in is the same sitting using oxygen-15 labeled water ((H2O)-O-15) positron emission tomography at rest; during 5% CO2 inhalation and after 1 g intravenous acetazolamide. A significant linear correlation in both nonlesion hemisphere (r = 0.701, p < 0.001) and in lesion hemisphere (r = 0.626, p < 0.005) was found between CO2 and acetazolamide for cerebrovascular reserve capacity. This correlation improved by considering cerebrovascular reserve per unit change in arterial carbon dioxide (r = 0.744, p < 0.001 in nonlesion hemisphere and r = 0.721, p < 0.001 in lesion hemisphere). The quantitative value of global reserve capacity was different by CO2 stimuli (5.2%) and acetazolamide (49.7%). Though a similar vasodilatory response is elicited by both Vasodilators, acetazolamide seems to be more potent and therefore should be preferred to detect patients with exhausted cerebrovascular reserve capacity.

The specific accumulation of radiolabeled anti-carcinoembryonic antigen (CEA) monoclonal antibody (MoAb) CEA102 in colorectal cancers was investigated by autoradiography of surgical specimens using Fuji Computed Radiography (FCR). Five patients with colorectal cancer were injected intravenously with [I-131]-labeled intact CEA102 or its F(ab')(2). Primary tumor and liver metastases were successfully detected by external scanning with gamma camera in four cases. Autoradiographic study using FCR showed predominant localization of [I-131]-labeled CEA102 in primary tumors and liver metastases in all cases. Even the small-sized liver metastasis (0.5 cm) was clearly visualized. The pixel distribution curves showed the heterogeneity of the distribution of administered MoAb in the tumors. In the quantitative distribution analysis of CEA102, the uptake of the primary tumor was 10-fold greater than that of the normal colon mucosa. These results suggest that MoAb has great potential in radioimmunodetection as well as possible use in antibody-directed therapy.

Purpose: We examined the relation between cortical hypometabolism and delayed myelination in patients with West syndrome (WS). Methods: Serial positron emission tomography (PET) with [F-18]fluorodeoxyglucose ([F-18]FDG) and magnetic resonance imaging (MRI) were performed in 18 patients with WS, first at the onset of epileptic spasms and later at age 10 months. The age at onset of seizures ranged from 2 to 7 months. Ten patients were diagnosed as having cryptogenic WS and 8 as having symptomatic WS. Results: Cortical hypometabolism was detected in many patients at onset of epilepsy, but disappeared later, whereas delayed myelination tended to become evident with age. PET showed diffuse or focal cortical hypometabolism in 12 patients at onset, but in only 6 patients at age 10 months. MRT showed delayed myelination in only 2 patients at onset of epilepsy, but 12 at age 10 months. Delayed myelination was more often present in patients with cortical hypometabolism. Delayed myelination was noted in 11 (85%) of 13 patients with cortical hypometabolism on first or second PET scans, but in only 1 (20%) of 5 patients who did not show PET abnormalities. Hypometabolism on the first or second PET scan was positively correlated with delayed myelination at age 10 months. Conclusions: In patients with WS, assessing myelination with MRI again at age 8-10 months is important even when MRI at the onset of epilepsy appears normal. Serial MRI and PET scans disclose more detailed pathophysiology of WS.

A PET scanner with ring detectors has been modified to accomplish whole- body imaging with attenuation correction. To evaluate the performance of this system, phantom studies and clinical studies were performed in seven patients. The transaxial resolution (FWHM) at the center of the field was 8.6 mm, and the axial resolution was 12.3 mm. The counts on the images with attenuation correction were linearly related to accumulation of the radiopharmaceuticals, and attenuation correction was made accurately. The transmission scan from the top of the head to the thigh, about 110 cm in length, required 36 minutes, and one emission scan required 18 minutes. The total study time for one transmission scan and three sequential emission scans was 1.9 hours. In clinical studies, attenuation correction made the discrimination of organs clearer, and would facilitate the detection of tumors, especially those in the high attenuation organs or matter. The use of this system made it possible to obtain quantitative whole-body positron images with adequate diagnostic quality within a reasonable scanning time.

We selected 6 patients presenting with hemi-parkinsonism from a total of 20 patients with probable multiple system atrophy (MSA) and studied their nigrostriatal lesions using magnetic resonance (MR) imaging and positron emission tomography (PET) with F-18-labeled 2-deoxy-2-fluoro-D-glucose (FDG). T2 weighted MR images demonstrated a decreased signal intensity in the putamen of all patients. This decreased signal was more intense in the nucleus contralateral to the affected body side in 5 patients. A decreased signal in the substantia nigra was found, expanding more on the contralateral side in 3 patients. T1-weighted images showed that the contralateral putamen was smaller in size than the ipsilateral. These findings indicated that the iron deposit and the neuronal cell loss in the degenerative process were more remarkable in the contralateral nuclei. FDG uptake in 5 patients had likewise declined more in the contralateral than in the ipsilateral putamen. The study shows that these patients have the nigrostriatal lesions as described in previous reports on MSA and that an asymmetric lesion relating to clinical signs is present in the nigrostriatal system. When a patient presents with hemi-parkinsonism alone, MR imaging and PET/FDG are useful for the clinical diagnosis of MSA.

The effects of the operability of the prototype CRT workstation and room illumination upon observer's performance were studied. In the experiment of reading CT images as a routine daily work at the CRT workstation, the average time required to analyse one CT image under a room illuminance of 100 lux was longer than that on the film viewbox. Prolongation occurred due mainly to the longer time required to retrieve and to arrange images as observers desired, and the limitation to the number of images simultaneously displayed on two CRT monitors. In the ROC studies to detect small pulmonary nodules on CRT images of computed radiography with imaging plate, illuminance around 170 lux showed the best result and a statistically significant difference (P < 0.05) as compared with that of 480 lux. In addition to the radiologist's visual performance, room illumination must also be taken into consideration as it influences the observer's performance and diagnostic efficiency.

Anti-carcinoembryonic antigen monoclonal antibody (MAb) CEA102 was produced by immunization with purified CEA and the specific accumulation of radiolabeled CEA102 in colorectal cancers was investigated by autoradiography of surgical specimens using Fuji Computed Radiography (FCR). Five patients with colorectal cancer were injected intravenously with I-131-labeled intact CEA102 or its F(ab')2. Primary tumor and liver metastases were successfully detected by external scanning with a gamma camera in 4 cases. Autoradiographic study of the surgical specimens using FCR showed predominant localization of I-131-labeled CEA102 in primary tumors and liver metastases in all cases. Even a small liver metastasis (0.5 cm) was clearly visualized in the autoradiogram by FCR. The pixel distribution curves of the density of the respective tissues in the autoradiograms by FCR showed the heterogeneity of the distribution of administered radiolabeled MAb in individual tumors, but the density of the tumors was higher than that of the normal tissues. In the quantitative distribution analysis of CEA102, the uptake of the primary tumor (mean 1.10%ID/kg) was ten-fold greater than that of the normal colon mucosa (mean 0.10%ID/kg). These results revealed that the application of MAb has great potential in radioimmunodetection as well as in antibody-directed therapy.

The value of positron emission tomography (PET) and magnetic resonance (MR) imaging in differentiating recurrent rectal cancer and scar was investigated. PET with fluorine-18 2-fluoro-2-deoxy-D-glucose (FDG) and MR imaging were performed in 15 patients with suspected recurrence. FDG accumulation in the mass was measured by means of the differential absorption ratio (DAR). All 11 patients with confirmed recurrent rectal cancer had increased accumulation of FDG in the mass (DAR = 4.73 +/- 2.28). Low FDG accumulation in the mass (DAR = 0.97 +/- 0.15) was noted in the remaining four patients, in whom the presence of a scar was proved by means of follow-up observation with or without biopsy. On the MR images, the recurrent tumor could be differentiated from scar in all but one case. The lesion-muscle signal intensity ratios on the T2-weighted images for the recurrent tumor and scar were 2.18 +/- 0.55 and 0.89 +/- 0.30, respectively. PET and MR imaging complement each other in the differential diagnosis between recurrent rectal cancer and scar. PET may also permit the evaluation of the effect of therapy.

Iodine-131-labeled G-22 monoclonal antibody F(ab')2 fracgment reacting specifically with a glioma-associated surface glycoprotein was administered to 12 glioma patients to investigate its use in radioimag ing of intracranial gliomas. No immediate or delayed side effects were attributable to antibody injec tion. Nine patients received the radiolabeled complex intravenously. The images of low-grade gliomas were generally poor and disappeared within 4 days. High-contrast images were obtained beyond the 7th day in high-grade gliomas except one case in the pineal region. Three patients received intraven tricular or intratumoral administration. Clear images of all tumors were demonstrated from the 2nd until later than the 7th day. One patient with cerebrospinal fluid (CSF) dissemination of brainstem glioma demonstrated negative CSF cytology after intraventricular administration. © 1992, The Japan Neurosurgical Society. All rights reserved.