Significance of glomerular activation of the alternative pathway and lectin pathway in lupus nephritis

The objective of the present study was to elucidate the association between glomerular complement depositions belonging to the alternative (AP) and lectin (LP) pathways, and clinical findings of lupus nephritis (LN). Immunofluorescence (IF) was performed on 17 LN patients using antibodies against factor B, factor H, properdin, mannose-binding lectin (MBL) and L-ficolin. Compared with factor B/factor H negative patients (n = 9), positive patients (n = 8) showed longer duration of LN (p < 0.05) and more severe interstitial fibrosis (p < 0.05). Eleven patients had properdin deposition in glomeruli, and in three of them, with a duration of LN of less than 1 month, factor B was undetectable. Compared with properdin negative patients (n = 6), positive patients (n = 11) showed significantly higher urinary protein excretion (p < 0.01). MBL/L-ficolin positive patients (n = 11) also had significantly higher urinary protein excretion (p < 0.05) compared with negative patients (n = 6). An independent association was found between glomerular deposition of properdin and that of MBL/L-ficolin (p < 0.01) in addition to factor B/factor H. Traces of glomerular activation of AP and LP reflected the clinical status of LN. It appears that glomerular deposition of each complement component, especially properdin, may be an index of the histological activity of LN.

Parathyroid scintigraphy with 99mTc-MIBI and 123I subtraction: a comparison with magnetic resonance imaging and ultrasonography

The aim of this study was to evaluate the efficacy of 99mTc-MIBI and 123I subtraction scintigraphy for the detection of abnormal parathyroid glands to be referred for surgical treatment. Thirty-nine consecutive patients, including 35 primary and four secondary cases of hyperparathyroidism, were evaluated. 99mTc-MIBI/123I subtraction scintigraphy (MIBI/I) was performed on all patients, and the results were compared with delayed images of 99mTc-MIBI (D-MIBI), magnetic resonance imaging (MRI) and ultrasonography (US). The overall sensitivity of MIBI/I, MRI, US and D-MIBI was 55.9%, 43.4%, 50.8% and 39.0%, respectively. In cases of single-gland disease, the sensitivity of MIBI/I, MRI, US and D-MIBI was 62.1%, 48.3%, 55.2% and 44.8%, respectively. In cases of multi-gland disease, the sensitivity of MIBI/I, MRI, US and D-MIBI was 50.0%, 37.5%, 46.7% and 36.7%, respectively. In cases of parathyroid adenoma, the sensitivity of MIBI/I, MRI, US and D-MIBI was 71.4%, 50.0%, 71.4% and 50.0%, respectively. In cases of parathyroid hyperplasia, the sensitivity of MIBI/I, MRI, US and D-MIBI was 55.2%, 42.3%, 50.0% and 39.7%, respectively. It is concluded that 99mTc-MIBI/123I subtraction is more useful than the delayed imaging of 99mTc-MIBI, MRI and US.

A novel radiopharmaceutical for detection of malignant melanoma, based on melanin formation: 3-iodo-4-hydroxyphenyl-L-cysteine

The aim of this study was to develop a new artificial amino acid radiopharmaceutical labelled with radioiodine for detection of malignant melanoma, based on melanin formation. By considering the affinity for tyrosinase, a starting enzyme on the branching point to melanin biosynthesis, 3-[125I]iodo-4-hydroxyphenyl-L-cysteine (125I-L-PC) was synthesized and evaluated biologically. Labelling of 125I-L-PC using the chloramine-T method was carried out conveniently and efficiently in a short period of time, with high specific activity. In a biodistribution study, 125I-L-PC showed a low accumulation in normal tissue and relative retention in B16 melanoma. A high contrast image of peripheral tumour was obtained during autoradiography. During an in vitro accumulation study, inhibition of 125I-L-PC with a tyrosinase inhibitor suggested interaction of this tracer with tyrosinase. It indicates that the uptake mechanism of 125I-L-PC to melanoma tissue was dependent on high tyrosinase activity in melanoma cells. Thus, 125I-L-PC appears to be a promising radioiodinated amino acid radiopharmaceutical for imaging malignant melanoma in relation to melanin formation, namely specific metabolism with high tyrosinase activity.

The correlation between 99mTc-MIBI uptake and MIB-1 as a nuclear proliferation marker in glioma--a comparative study with 201Tl

Technetium-99m methoxy-isobutylisonitrile (MIBI), like thallium-201 (201Tl), is a highly efficient agent for the diagnosis and monitoring of glioma tumors. Although 201Tl uptake is known to be partly associated with proliferative activity, little is known about the correlation between MIBI uptake and proliferation activity in gliomas. The current study was performed to assess the correlation between MIBI uptake and proliferative activities in gliomas, estimated by the monoclonal antibody to Ki-67 antigen (MIB-1) staining method. By comparing the results with those of 201Tl, we determined which tracer would be suitable for estimating proliferative activities. Twenty-four presurgical glioma patients (six with low-grade gliomas, five with anaplastic astrocytomas, and 13 with glioblastomas) were given MIBI and 201Tl SPECT. Early (10 min after injection) and delayed images (3 h after injection) were obtained for both MIBI and 201Tl scintigraphy. SPECT parameters, early ratio (ER), delayed ratio (DR), and retention index (RI) were obtained in both radiopharmaceuticals. All patients underwent subsequent surgical excision, and the specimens were immunostained for MIB-1. The proliferative activity was measured as a percentage positive nuclear area for MIB-1 (MI; MIB-1 index). To evaluate the relationship between the proliferative activity and SPECT parameters, we performed a correlation analysis. MI correlated with the MIBI uptake ratio (r = 0.75 for ER, and r = 0.7 for DR). Both DR and RI of 201Tl also correlated with MI, but weakly (r = 0.6 for DR, and. r = 0.59 for RI). There was no significant correlation between the MIB-1 index and the other parameters. MIBI-uptake parameters demonstrated a stronger positive correlation with the MIB-1 index than that of 201Tl. With the use of MIBI SPECT, we can estimate the proliferative activity of glioma noninvasively.

Technetium-99m tetrofosmin for parathyroid scintigraphy: a direct comparison with (99m)Tc-MIBI, (201)Tl, MRI and US

The aim of this study was to evaluate the efficacy and role of technetium-99m tetrofosmin for the detection of abnormal parathyroid glands to be referred for surgical treatment. Twenty-eight consecutive patients, including 25 primary and 3 secondary cases of hyperparathyroidism, were evaluated. (99m)Tc-tetrofosmin/(99m)Tc-pertechnetate subtraction scintigraphy (TF/Tc) was performed on all patients, and the results were directly compared with those of (99m)Tc-methoxyisobutylisonitrile (MIBI)/(99m)Tc-pertechnetate subtraction scintigraphy (MIBI/Tc), (201)Tl/(99m)Tc-pertechnetate subtraction scintigraphy (Tl/Tc), magnetic resonance imaging (MRI) and ultrasonography (US). In cases of single-gland disease, the sensitivities of TF/Tc, MIBI/Tc, Tl/Tc, MRI and US were 63.2%, 68.4%, 57.9%, 55.6% and 63.2%, respectively. In cases of multi-gland disease, the sensitivities of TF/Tc, MIBI/Tc, Tl/Tc, MRI and US were 41.7%, 41.7%, 37.5%, 58.3% and 54.2%, respectively. In cases of parathyroid adenoma, the sensitivities of TF/Tc, MIBI/Tc, Tl/Tc, MRI and US were 68.8%, 75.0%, 68.8%, 62.5% and 75.0%, respectively. In cases of parathyroid hyperplasia, the sensitivities of TF/Tc, MIBI/Tc, Tl/Tc, MRI and US were 40.7%, 40.7%, 33.3%, 53.8% and 48.1%, respectively. It is concluded that, for the detection of abnormal parathyroid glands, (99m)Tc-tetrofosmin is as useful as (99m)Tc-MIBI and is more useful than (201)Tl.

[Reevaluation of 201Tl-SPECT for patients with solitary pulmonary nodule--comparison study with biopsy method and tumor marker measurement]

We compared the differential diagnostic capabilities of 201Tl-SPECT and biopsy methods and serum tumor marker in 125 patients with solitary pulmonary lesions composed of 87 lung cancer and 38 benign lesions. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of 201Tl-SPECT were 76%, 95%, 97%, 63%, and 82%, respectively. These parameters are similar in biopsy methods. Although sensitivity improved to be 85% by the combination with tumor marker methods, both specificity and accuracy deteriorated to be 55% and 76%. Using combination method with 201Tl-SPECT and biopsy, sensitivity, NPV and accuracy improved to be 84%, 70% and 85%. Based on its high PPV value, 201Tl-SPECT could be useful when biopsy method could not prove lung cancer or in case whose biopsy is considered to be invasive. Because of the lower NPV value owing to false negative cases in some adenocarcinoma, negative 201Tl-SPECT case should be followed up carefully.

[A new protocol of dual energy acquisition on stress 201Tl and rest 99mTc-tetrofosmin myocardial scintigraphy]

We carried out stress 201Tl (Tl) and rest 99mTc-tetrofosmin (TF) myocardial scintigraphy with dual energy acquisition in 24 patients with suspected ischemic heart disease performed coronary arteriography and elucidated the sensitivity of this method. One hour after light meal eating, TF (555 MBq) was injected intravenously at rest and after 3 minutes from injection of TF exercise or pharmacologic stress was performed. During stress Tl (111 MBq) was injected intravenously before end-point or at adequate point of pharmacologic stress. Dual energy acquisition using triple energy windows (TEW) was started after 5 minutes (early) and 4 hours (delayed) from stress. The sensitivity (Sn), specificity (Sp) and accuracy (Ac) in diagnosis of non-infarcted branches by using Tl (early)-TF (rest) and Tl (early)-Tl (delayed) were 79% vs. 53% (Sn), 78% vs. 96% (Sp) and 79% vs. 71% (Ac) respectively. Accordance of uptake score of infarcted region between TF (rest) and Tl (delayed) was 70%. In conclusion, this protocol is seemed to be useful as usual protocol for detection of myocardial ischemia and viability during about only 1 hour.

[Evaluation of technetium-99m-MIBI scintigraphy in metastatic differentiated thyroid cancer--comparison study with 131I and 201Tl]

Detectability of metastasis in differentiated thyroid cancer using technetium-99m-methoxyisobutyl isonitrile (99mTc-MIBI) was compared with that of 131I and 201Tl. Forty patients after total thyroidectomy were evaluated. The scan results were compared with those of 131I and 201Tl whole body scintigraphy per patient. The positive rate was 68% in 99mTc-MIBI, 84% in 131I, 60% in 201Tl respectively. As to the lymph node metastasis, the positive rates were 56% in 99mTc-MIBI, 78% in 131I, 39% in 201Tl. In lung metastasis, the positive rate was 46% in 99mTc-MIBI, 82% in 131I and 55% in 201Tl. Serum thyroglobulin (Tg) was significantly higher in 201Tl and/or 99mTc-MIBI positive group compared to that of negative group independent of 131I scan results. Although the detectability of both 99mTc-MIBI and 201Tl were inferior to that of 131I, 9 to 22% of metastasis were detected only by these radiopharmaceuticals. Both 99mTc-MIBI and 201Tl, therefore, should be used in cases with high serum Tg even with negative 131I uptake. Basing on the fact there was no prominent difference between 99mTc-MIBI and 201Tl in the detectability of metastasis, 99mTc-MIBI might be more suitable tracer because of better quality image.

rCBF in neurodegenerative diseases as estimated by the autoradiographic (ARG) method and delayed I-123-IMP studies

A total of 24 patients with a mean age of 45.8 +/- 20.8 were included in the study. The patients were grouped as Control (C), Degenerative Syndromes (DS), Degeneration Associated with External Factors (DEF), Degeneration Associated with Focal Neurologic Lesion (DFN) and Demyelinating Disease (DM). Imaging started 15 minutes for early and 4 hours for delayed scans after i.v. infusion of I-123 IMP. The rCBF was calculated by the IMP autoradiographic (ARG) method. The wash-out ratio (WR) was calculated as the ratio of the Delay/Early count. In the rCBF of the various areas of the brain, significant differences were noted between various disease groups. No correlation was noted between rCBF and WR (r = -0.50). The WR of patients grouped according to various disease processes did not show a significant difference between various areas of the brain. In conclusion, the rCBF was effective in separating both various areas of the brain and disease entities. WR from a delayed study is less useful in neurodegenerative diseases.

Retention of Tc-99m ECD in delayed SPECT of the brain

We determined the effect of retention on the changes in regional biodistribution of Tc-99m ECD in the brain. A total of 14 cases, 7 normal volunteers and 7 patients with various diagnoses but with very minimal radiologic findings or none were included in the study. SPECT images were taken at 30 min, 1, 2, 3, 4 and 6 hrs after an intravenous injection. Retention rates were calculated in various regions and were corrected according to the time decay of technetium. There was a tendency for the retention rate to increase up to three hours of imaging and then a decrease was noted in most regions of the brain. In the thalamus, increasing retention was noted. In conclusion, Tc-99m ECD retention in the different regions of the brain varies with time. These differences should always be considered when planning and interpreting SPECT quantitative studies.

123I-MIBG myocardial scintigraphy in diabetic patients: relationship with 201Tl uptake and cardiac autonomic function

PURPOSE

To investigate the influence of diabetic myocardial damage (suspected myocardial damage; SMD) diagnosed by 201Tl-SPECT and diabetic cardiac autonomic neuropathy (AN) on myocardial MIBG uptake in patients with non-insulin-dependent diabetes mellitus (NIDDM).

SUBJECTS AND METHODS

Eighty-seven diabetic patients divided into four subgroups: 23 with SMD (+) AN (+); 19 with SMD (+) AN (-); 27 with SMD (-) AN (+); 18 with SMD (-) AN (-), and 10 controls were studied. Both planar and SPECT images were taken at 30 minutes (early) and 3 hours (delayed) after 123I-MIBG injection. The heart to mediastinum uptake ratio (H/M) and washout ratio of 123I-MIBG (WR) were obtained from both planar images. On SPECT images, the total uptake score (TUS) was obtained by the 5 point score method by dividing the myocardium into 20 segments on visual analysis. Similarly, the difference between the 201Tl image and the 123I-MIBG image in TUS was taken as the difference in the total uptake score (delta TUS) representing cardiac sympathetic denervation without SMD.

RESULTS

On both early and delayed planar images, the mean H/M value in the subgroups of diabetic patients was significantly lower in the SMD (+) AN (+) group than in the control group, but among those subgroups, there was statistically significant difference between the SMD (+) AN (+) and SMD (-) AN (-) groups only on the delayed images. Regarding the WR value, there was no statistically significant difference among subjects. On SPECT image analysis, the diabetic subgroup with AN or SMD had statistically significant lower values for TUS than those of the control group. Among diabetics, there was a statistically significant differences between SMD [+] AN [+] and SMD [-] AN [-] on both early and delayed images. Similarly, the SMD [+] AN [-] group also had significantly lower values than those of SMD [-] AN [-] on early images. Regarding delta TUS, there was a statistically significant differences between AN [+] subgroups and controls. Similarly, the mean value for delta TUS was much higher in AN [+] subgroups than in AN [-] subgroups with or without SMD in diabetes mellitus.

CONCLUSION

123I-MIBG myocardial uptake is affected by both SMD and cardiac autonomic neuropathy. Based on the finding that delta TUS was much higher in AN [+] subgroups and there was no statistically significant difference between SMD [+] AN [+] and SMD [-] AN [+] subgroups, a decrease in myocardial 123I-MIBG uptake might progress independently of SMD.

Computer-Aided Diagnosis (CAD) for Mammography: Preliminary Results

PURPOSE: To evaluate the CAD system for screening mammograms. MATERIALS AND METHODS: Mammograms of patients with asymptomatic breast cancerwere examined retrospectively. A total of 260 screening mammograms from 65 patients (bilateral cranio-caudal and medio-lateral-oblique views from each) were tested by using the CAD system (ImageChecker M1000 system, R2 Technology, Los Altos, CA, USA). Results: With 0.58 microcalcifications marks/film and 0.20 mass marks/film set as the false positive rate, 100% of microcalcifications cases and 79% of mass cases were detected correctly. Conclusion: The CAD system has the potential to become a second reader. Further developments are expected to improve the accuracy of detection of mass lesions

Gallium-67 scintigraphy in the treatment and prognosis of acute adult T-cell lymphoma

The case of a 77-year-old male patient who complained of left upper quadrant pain and progressive vomiting. Laboratory examination showed extremely high lactic acid dehydrogenase (LDH) and adult T-cell leukemia antibody (ATLA). The anatomical studies CT, MRI, US and upper GI series substantiated an omental lymphadenopathy which was causing a circumferential compression of portions of the duodenum and jejunum. Gallium-67 citrate (Ga-67) scintigraphy showed high uptake at LUQ. Ultrasound guided biopsy failed to confirm the diagnosis. Irradiation was performed. Ga-67 scintigraphy had a contributory role in clinical subtyping of the disease, planning of treatment, posttreatment assessment and prognostication of adult T-cell lymphoma.

Relationship between extraosseous accumulation in bone scintigraphy with 99Tcm-HMDP and histopathology

We assessed the relationship between 99Tcm-HMDP extraosseous accumulation (EOA), the histopathology of primary lesions and various laboratory findings. In 155 of 4824 patients, 163 EOA were noted. Of these, 33.7% were in the abdomen, 27.6% in the chest, 22.7% in the extremities, 9.8% in the pelvic area and 6.1% in the head and neck area. We found that 72.4% of EOA were due to malignant processes and 27.6% to benign processes. In the abdomen, 36.6% of the EOA were due to hepatocellular carcinoma and intestinal carcinoma. In the chest, 46.7% of EOA were a result of breast carcinoma. In the extremities, 28.7% of the EOA were due to sarcoma. The mean white blood cell count was elevated (8.0 +/- 6.3 x 10(3)) in patients with malignant processes. The mean serum haemoglobin and haematocrit in benign and malignant processes, for both males and females, were below normal values. All other laboratory findings were within normal limits. Significant differences in serum haemoglobin and haematocrit were noted between male and female patients with benign processes (P = 0.04 and P = 0.04, respectively). No other significant differences between benign and malignant processes were noted. Therefore, EOA is more frequently associated with malignant processes of primary lesions and is often accompanied by leukocytosis and anaemia.

Application of SPET using technetium-99m sestamibi in brain tumours and comparison with expression of the MDR-1 gene: is it possible to predict the response to chemotherapy in patients with gliomas by means of 99mTc-sestamibi SPET?

Technetium-99m sestamibi (MIBI) is thought to be passively taken up by metabolically active tumour cells and effluxed from them by P-glycoprotein (Pgp). This 170-kDa membrane-bound protein, encoded by the MDR-1 gene, acts as an energy-dependent efflux pump for several antineoplastic agents, resulting in multidrug resistance. For this reason, it is of interest whether the tumour's response to chemotherapy can be predicted by MIBI single-photon emission tomography (SPET). In this study, MIBI SPET was compared with thallium-201 (Tl) SPET using magnetic resonance imaging as a guide in 16 patients with untreated brain tumours [ten glioblastomas (GBs), two anaplastic astrocytomas (AAs), two low-grade gliomas (LGASs) and two metastatic brain tumours) and in four patients who had received treatment for with brain tumours (two GBs, two AAs). In addition, we investigated the expression of the MDR-1 gene and its product Pgp in the same patients, and compared the results with MIBI SPET findings. MIBI, as well as Tl, was highly accumulated and retained in the enhanced region of malignant gliomas. In addition, MIBI SPET yielded sharp and well-contrasted images, and the margin of the tumour was more clearly defined than with Tl SPET due to a good signal-to-noise ratio. Follow-up MIBI SPET in patients who had received therapy showed marked uptake in a patient with malignant transformation, who deteriorated clinically. Patients with no uptake on MIBI SPET showed no sign of recurrence. Semiquantitative analysis of untreated patients showed a relationship between the early uptake index (UI, ratio of average count/pixel in the lesion to that in the contralateral area on early images) and the degree of malignancy (early UI = 1.08+/-0.06 in LGASs, 4.10+/-0.84 in AAs, 5.71+/-3.47 in GBs, and 7.52+/-1.52 in metastatic brain tumours). The retention index (RI, ratio of delayed to early UI) of MIBI was significantly lower than that of Tl in metastatic brain tumours (P<0.05), but not in malignant gliomas. Histological and biological investigation of gliomas showed that the MDR-1 gene and its product Pgp were expressed only in normal endothelial cells and not in tumour cells or proliferating endothelial cells; Pgp tended to decrease as the degree of malignancy rose. Hence, the presence of Pgp and the grade of malignancy were inversely related in gliomas. By contrast, immunohistochemical study showed strong accumulation of Pgp in metastatic brain tumour cells. These histopathological findings and MIBI SPET findings are compatible with experimental data; MIBI was washed out by Pgp. The main cause of chemoresistance is probably not an increasing drug efflux by Pgp in gliomas. Thus, MIBI SPET is useful for detecting the active lesions, but may not be useful for predicting the response to chemotherapy in gliomas.

[Evaluation of brain tumor by 99mTc-MIBI: comparison study with 201Tl and predictivity of therapeutic effect]

We compared the detectability of 99mTc-MIBI and 201Tl-chloride for brain tumor in relationship with histopathology. We also evaluated correlation between therapeutic effect using ACNU, Cisplatine and the degree of MIBI tumor uptake. The subjects were 31 brain tumor histologically confirmed by operation or biopsy. Dual-isotope SPECT technique was performed at both 20 min and 180 min after tracer injection. A tumor to normal lung ratio on both early (ER) and delayed image (DR) and retention index (RI) were calculated. The positive rates of 99mTc-MIBI (90.3% and 77.4%) were comparable to that of 201Tl (90.3% and 80.6%). In the relationship with histopathology, both MIBI and Tl accumulated in 100% of glioblastoma (GBM), metastasis (meta), anaplastic astrocytoma and 25% of low grade astrocytoma on both early and delayed images. On semiquantitative analysis, there were no statistical significance among GBM, meta and anaplastic astrocytoma of ER, DR, RI in the both radiopharmaceuticals. However, both ER and DR in GBM tended to be higher than those of anaplastic astrocytoma. In spite of intense MIBI uptake, GBM patients died within six months except one patient. We concluded that MIBI can be helpful in detecting brain tumor as Tl. MIBI also might be useful in estimating the degree of malignancy in glioma. However, intense MIBI uptake did not mean favorable therapeutic effect in patients with GBM treated with ACNU and Cisplatine.

[123I-MIBG lung uptake in patients with diabetes mellitus]

The purpose of this study is to clarify the relationship between 123I-MIBG lung uptake and silent myocardial ischemia (SMI), cardiac autonomic neuropathy (AN) or clinical characteristics. For the quantitative analysis, lung to upper mediastinum uptake ratio (L/M) and heart to upper mediastinum uptake ratio (H/M) were obtained from chest planar image. In addition, both lung washout ratio (%WR-L) and heart washout ratio (%WR-H) were calculated from early and delayed images. Each indices were compared in both diabetic and control groups. Mean values of H/M in diabetes with complication were significantly lower than those of control group. Particularly, AN(+)SMI(+) group showed lowest value. Similarly, mean values of %WR-H in diabetes with complication were significantly higher than those of control group and AN(+)SMI(+) group showed highest value. Although mean value of L/M in each diabetic group was significantly higher than that of control group, there was no statistical significance among each diabetes except AN(+)SMI(-) group on early image. Mean value of %WR-L in AN(+) or SMI(+) group was also significantly higher than that of control group, but there was no statistical significance among each diabetic group. The current study suggested that high pulmonary 123I-MIBG uptake in diabetes was independent of the complication of SMI or AN. Pulmonary endothelial dysfunction related with severity of diabetes mellitus was considered to be the most important factor.

Acetazolamide challenge and technetium-99m-ECD versus iodine-123-IMP SPECT in chronic occlusive cerebrovascular disease

We compared the acetazolamide challenge test using 99mTc-ECD SPECT and 123I-IMP SPECT images in patients with chronic occlusive cerebrovascular disease. We also evaluated the usefulness of linearization correction for acetazolamide challenge test of 99mTc-ECD SPECT.

METHODS

Twenty patients with unilateral chronic occlusive cerebrovascular disease (10 patients had middle cerebral arterial lesion and 10 had internal carotid lesion) were included in the study. Split-dose (a dose fractioning was 1:2), and sequential SPECT technique was used for 99mTc-ECD SPECT studies while only acetazolamide challenge test studies for 123I-IMP SPECT were performed. Permeability surface area product model (PS model) and back-diffusion model (Lassen's correction) were used for linearization correction of acetazolamide challenge with 99mTc-ECD SPECT.

RESULTS

Six of 16 patients with reduced vasodilatory capacity in 123I-IMP SPECT were underestimated by 99mTc-ECD SPECT acetazolamide challenge test. Relative ECD uptake normalized by cerebellar uptake compared with IMP uptake showed a nonlinear relationship, indicating relatively less uptake in high flow range. The underestimations of limited vasodilatory capacity observed in 99mTc-ECD SPECT without linearization correction was modified by linearization algorithm. However, the effect of correction based on PS model was superior than that of Lassen's correction. The corrected 99mTc-ECD uptake ratio, based on PS model, and IMP uptake ratio demonstrated a better linear relationship than that of Lassen's correction.

CONCLUSION

Technetium-99m ECD SPECT corrected based on the PS model is a better method of linearization for evaluating cerebrovascular reserve using acetazolamide challenge.

[Evaluation of primary lung cancer and mediastinal lymph node metastasis using 99mTc-MIBI: comparison with 201T1 and relation to chemotherapeutic effect]

We compared the detectability of 99mTc-MIBI and 201T1-chloride for primary lung cancer and mediastinal lymph node metastasis. We also analyzed the relationship between 99mTc-MIBI uptake and effectiveness of chemotherapy in patients with small cell lung cancer. The subjects were fourty-six primary lesions and 8 mediastinal metastatic lymph nodes confirmed by operation, and dual-isotope SPECT technique was performed at both 20 min and 180 min after tracer injection. A tumor to normal lung ratio on both early (ER) and delayed image (DR) and retention index (RI) were calculated. The positive rates of 99mTc-MIBI (early; 82.6%, delayed; 54.3%) were comparable to 201T1 in most primary tumor (87.0% and 84.8%). Whereas tumor smaller than 3 cm diameter was poorly visualized on both 99mTc-MIBI (25% and 0%) and 201T1 (37.5% and 37.5%). Detectabilities of metastatic mediastinal lymph nodes of 99mTc-MIBI (62.5% and 25.0%) was comparable to those of 201T1 (62.5% and 50.0%). Regarding effectiveness of chemotherapy, NC group showed lower uptake of 99mTc-MIBI and significant lower value of RI compared to PR group. We concluded that early image of 99mTc-MIBI SPECT can be helpful in detecting primary lung cancer and metastatic mediastinal lymph node. Additionary, it might be useful for predicting the effects of chemotherapy in small cell lung cancer.

Gadolinium-enhanced MR imaging of thyroid and parathyroid masses

PURPOSE

To evaluate spin-echo and contrast material-enhanced dynamic magnetic resonance (MR) imaging in characterization of thyroid and parathyroid masses.

MATERIALS AND METHODS

Conventional T1- and T2-weighted, gadolinium-enhanced dynamic, and gadolinium-enhanced T1-weighted spin-echo imaging sequences were performed in 85 patients with thyroid and parathyroid tumors. Findings from spin-echo imaging and dynamic curve patterns from mean signal intensity ratios were evaluated for each histologic tumor type.

RESULTS

T1- and T2-weighted imaging did not enable differentiation of benign from malignant tumors. Primary thyroid lymphoma enhanced less than other solid thyroid tumors, and parathyroid adenoma also enhanced less than other tumors (P < .05 compared with papillary carcinoma.

CONCLUSION

Gadolinium-enhanced MR imaging cannot enable prediction of histologic type in thyroid and parathyroid tumors. However, in cases of multiple tumors, the technique may improve the contrast between the different histologic types and sometimes suggest the diagnosis of primary thyroid lymphoma or parathyroid adenoma.

[Usefulness of rCBF SPECT in patients with encephalitis: comparison study with MRI]

Twenty-nine rCBF SPECT study was done in 17 patients with encephalitis. Five of 6 patients (83.3%) showed regional high uptake in acute phase within a week after onset and 16 of 23 studies (69.6%) showed regional low uptake in subacute and chronic phase. Six of 19 lesions (31.6%) with regional high uptake changed to low uptake and 11 lesions (57.9%) improved to normal uptake on follow up studies. Seventeen of 51 lesions with low uptake (33.3%) improved to normal uptake. On the comparative study with MRI, 8 of 18 (44.4%) high uptake area showed cortical thickness or high intensity on T2 weighted images. Thirty-six of 74 low uptake area (48.6%) showed cortical thickness, brain atrophy or high intensity on T2 weighted images. Forty-eight of 212 regions (22.6%) with normal MRI findings showed abnormal accumulation of cerebral tracer on rCBF SPECT studies. rCBF SPECT was useful tool for diagnosis and follow up management in patients with encephalitis.

[A case of transient tic disorder with abnormal findings on 99mTc-HMPAO SPECT]

We report a case of transient tic disorder with abnormal findings on 99mTc-HMPAO SPECT. The patient was 5-year-old girl with vocal and motor tic. There was no evidence of structural abnormality on magnetic resonance imaging (MRI). Electroencephalogram (EEG) showed spikes and sharp waves on both frontal lobes and parietal lobes (left-side dominant). 99mTc-HMPAO SPECT demonstrated focal regions of hyperperfusion in the both frontal lobes, both parietal lobes and right temporal lobe corresponding to the abnormal findings detected by EEG. It also demonstrated an area of hyperperfusion in the right basal ganglia. It is suggested that 99mTc-HMPAO SPECT is useful for the diagnosis and the understanding of the clinical state of tic disorder.

The use of 201Tl SPET to predict the response to radiotherapy in patients with head and neck cancer

Thallium-201 (201Tl) is widely used in the diagnosis of malignant tumours. However, its use in predicting the response to radiation therapy for head and neck cancer has not been established. Nineteen patients with histologically proven head and neck cancer were studied. 201Tl single photon emission tomographic (SPET) images were obtained 15 min (early) and 4 h (delayed) post-injection of the radionuclide. For a semi-quantitative assessment, regions of interest were drawn over the lesions and normal soft tissue. Lesion-to-normal tissue uptake ratios of 201Tl activity were measured from mean counts-per-voxel obtained on both the early and delayed scans, representing the early index (EI) and delayed index (DI) respectively. Subsequently, a retention index (RI) was calculated using the formula: RI = (DI - EI) x 100/(EI). The patients were classified into two groups according to the effect of radiotherapy: a partial response or complete response group (PR-CR group) and a no change group (NC group). In the analysis of primary lesions, both the delayed and retention indexes of the PR-CR group were significantly higher than those of the NC group. However, the early index was not significantly different between the two groups. In the metastatic lymph nodes, only the retention index was significantly different between the two groups. Our results demonstrate that 201Tl SPET and a 201Tl index can be used to predict the response to radiotherapy for primary head and neck cancer and lymph node metastases. The retention index is a useful parameter for estimating the effects of radiotherapy.

Reproducibility of measurements of regional resting and hyperemic myocardial blood flow assessed with PET

PET with 13N-ammonia permits the noninvasive quantification of myocardial blood flow (MBF) in humans. The present study was done to assess the reproducibility of quantitative blood flow measurements at rest and during pharmacologically induced hyperemia in healthy individuals.

METHODS

Thirty healthy volunteers (26 men, 4 women) were studied. Paired measurements of MBF at rest (n = 21), during adenosine (n = 15) and during dipyridamole (n = 7) were performed using a two-compartment model for 13N-ammonia PET. The mean difference between baseline and follow-up blood flow (% difference) was calculated to assess reproducibility.

RESULTS

No significant difference was observed between resting blood flow at baseline or follow-up (15.8% +/- 15.8%; p = ns). Baseline and follow-up resting blood flow were linearly correlated (r = 0.63, p < 0.005). Normalization of resting blood flow to the rate pressure product improved the reproducibility significantly (15.8% +/- 15.8% versus 10.1% +/- 10.5%, p < 0.05). Baseline and follow-up hyperemic myocardial blood flow did not differ (11.8% +/- 9.4%; p = ns) and were linearly correlated (r = 0.69, p < 0.0005).

CONCLUSION

MBF at rest can be measured reproducibly with 13N-ammonia PET. The individual response to pharmacologic stress appears to be relatively consistent. Thus, serial blood flow measurements with 13N-ammonia PET can be used to quantify the effect of various interventions on MBF and vasodilatory reserve.

Increased bone marrow uptake of Ga-67 in patients with fever of unknown origin

The relationships of clinical diagnosis, the effect of blood chemistry, and the clinical implication of increased Ga-67 citrate uptake in the bone marrow of patients with signs and symptoms of fever of unknown origin were studied. Based on intensity of Ga-67 citrate uptake in bone marrow, patients were classified as follows: type 1 when there was no evidence or very faint bone marrow uptake in the vertebrae, type 2 when mild to moderate, type 3 when uptake was severe. The relationships of WBC count, hemoglobin, hematocrit, serum iron, and unsaturated iron-binding capacity with the occurrence of increased bone marrow uptake in the different groups were noted. Analysis of variance with Fisher's protected least significant difference was used. A P value of less than 0.05 was considered significant. The results showed significant differences between types 1 and 2 and between types 1 and 3 for WBC counts, hemoglobin, and hematocrit levels. Serum iron concentration and unsaturated iron-binding capacity, however, did not show any significant differences. Significant changes in WBC count, hemoglobin and hematocrit in patients with fever of unknown origin were accompanied by a varying intensity of Ga-67 citrate uptake in the bone marrow.

[Normal distribution of CBF with advancing age measured by HMPAO SPECT]

SPECT with Tc-99m HMPAO was used to determine global and regional cerebral blood flow (CBF) in 52 healthy subjects ranging from 2 to 85 years old. These subjects were divided into six groups according to age. SPECT images were obtained using a three-headed gamma camera system equipped with low-energy ultra-high-resolution fan beam collimators (LEUHR-FAN). Absolute CBF values were estimated in 21 of 52 subjects using a Patlak plot technique. The SPECT images were obtained 5-10 minutes after the injection of 740MBq of Tc-99m HMPAO. A supercomputer system was used to reconstruct transverse section images at levels of 8, 32, 44 and 67 mm above the orbitomeatal line (2.7 mm thickness), and oblique transverse section images parallel to the temporal lobe (1.56 mm thickness). Lassen's linearization correction was applied. The average counts of four or five ROIs in eight regions were calculated. The cerebral to cerebellar activity ratio (C/C ratio) was estimated by dividing counts in the cerebral regions by those in the cerebellum. The interhemispheric differences in C/C ratios in the eight regions of all the groups were not significant. In elderly subjects there was a tendency for C/C ratios to decrease except in the thalamus and basal ganglia. Mean global CBF in 21 of 52 subjects was 49.3 +/- 10 ml/100g/min. A significant negative correlation was found between global CBF and advancing age (p < 0.05), particularly in males (p < 0.01).

[The quantitative regional cerebral blood flow measurement with autoradiography method using 123I-IMP SPECT: evaluation of arterialized venous blood sampling as a substitute for arterial blood sampling]

The purpose of this study is validation of calibrating a standard input function in autoradiography (ARG) method by one point venous blood sampling as a substitute for that by one point arterial blood sampling. Ten and 20 minutes after intravenous constant infusion of 123I-IMP, arterialized venous blood sampling from a dorsal vein were performed on 15 patients having ischemic cerebrovascular disease. And arterial blood sampling from radial artery was performed 10 min after 123I-IMP infusion. The mean difference rates of integrated input function between calibrated standard input function by arterial blood sampling at 10 min and that by venous blood sampling were 4.1 +/- 3% and 9.3 +/- 5.4% at 10 and 20 min after 123I-IMP infusion, respectively. The ratio of venous blood radioactivity to arterial blood radioactivity at 10 min after 123I-IMP infusion was 0.96 +/- 0.02. There was an excellent correlation between ARG method CBF values obtained by arterial blood sampling at 10 min and those obtained by arterialized venous blood sampling at 10 min. In conclusion, a substitution by arterialized venous blood sampling from dorsal hand vein for artery can be possible. The optimized time for arterialized venous blood sampling was 10 min after 123I-IMP infusion.

[Reye syndrome evaluated by 99mTc-ECD SPECT: a case report]

We report a three-year-old boy with Reye syndrome evaluated by 99mTc-ECD SPECT. On acute stage, 99mTc-ECD brain SPECT disclosed diffuse high uptake in the cerebral cortex in spite of normal findings on brain X-ray CT. These lesions changed to general low uptake on the chronic state and multiple high intensity areas were shown on T2 weighted MRI image. Such a change of cerebral tracer uptake was considered to reflect the neuropathological change of Reye syndrome. 99mTc-ECD SPECT was a useful modality to diagnose Reye syndrome complementary.

Nasal mucosal thickening simulating a tumor: potential for misdiagnosis in brain perfusion imaging

A 33-year-old, female presenting with dementia was admitted to our institution. Except for slight muscle atrophy noted on both lower extremities there were no other significant physical signs or laboratory findings. Since initial Tc-99m HMPAO SPECT showed hypoperfusion on both temporal, parietal and occipital lobes, follow up study with the same radiotracer was done. Increase in uptake was noted in the left side of the face. There was no abnormality noted on ENT examination. CT scan and MRI showed slight nasal mucosal wall thickening. T1-201 SPECT showed increased uptake in the nasal area. The increase in uptake could be due to nasal mucosal thickening. This could simulate nasal tumor and interfere in determining ROI for brain perfusion studies.

123I-MIBG myocardial scintigraphy in diabetic patients: relationship to autonomic neuropathy

The aim of this study was to investigate the relationship between autonomic nerve dysfunction and myocardial uptake of 123I-meta-iodobenzyl guanidine (MIBG) in patients with diabetes mellitus. Twenty-two non-insulin-dependent diabetic patients, 9 with autonomic neuropathy [ANP(+)] and 13 without autonomic neuropathy [ANP(-)], and 8 controls were included in the study. Both planar and single photon emission tomographic (SPET) images were obtained 30 min (early) and 3 h (delayed) after the 123I-MIBG injection. The heart-to-mediastinal uptake ratio (H/M) and the washout ratio of 123I-MIBG (%WR) were calculated from planar images. The uptake ratio of the inferior wall to the anterior wall (I/ A) and the %WR of both the inferior and anterior walls were calculated from the SPET images. On the early plantar images, the mean H/M ratio in the ANP(+) group was significantly lower than that of the control group. The mean %WR on the planar images in the ANP(-) group was significantly higher than that of the controls. The SPET images demonstrated a reduction in MIBG uptake and significantly increased clearance in the inferior wall of the ANP(-) patients. These findings extended to other areas of the heart in the ANP(+) patients. In the quantitative analysis of the SPET images, the ANP(+) group had significantly lower I/A values and significantly higher %WR values in the anterior wall. The ANP(+) group showed significantly increased clearance of 123I-MIBG in the inferior wall. We conclude that 123I-MIBG myocardial scintigraphy is a useful diagnostic tool both in the early detection and evaluation of the progression of myocardial sympathetic nerve dysfunction in patients with diabetes mellitus. Both the I/A and %WR calculated from SPET images are useful parameters.

The diagnostic role of 201T1 SPET imaging in patients with lung tumours: comparison with computed tomography

The aim of the study was to evaluate the use of 201Tl single photon emission tomography (SPET) in differentiating histological types and lymph node sized of lung tumours based on the early uptake ratio (EUR), delayed uptake ratio (DUR) and retention index (RI). We also wished to compare the effectiveness of 201Tl SPET and computed tomography (CT) in detecting lymphadenopathy. We examined 41 subjects using both 201Tl SPET and CT. Fifty-seven lymph nodes were detected and were grouped according to size. The EUR, DUR and RI were determined and analysed using Student's t-test and a P-value < 0.05 was considered significant. Lymphadenopathy detected by both 201Tl SPET and CT correlated with the operative findings. There were no statistically differences in the EUR, DUR and RI between the various histological types. Statistically significant differences in EUR were noted between lymph nodes > 5 cm in size and those 3-5 cm in size, as well as between those < 3 cm and > 5 cm in size No significant differences were seen for the RI. The specificity, sensitivity and accuracy of 201Tl SPET were 81.3, 90.2 and 87.7% respectively, whereas for CT they were 81.3, 100 and 94.74% respectively. In conclusion, quantitative analysis with 201Tl SPET was unable to differentiate with accuracy between histological types but it could differentiate between nodes of varying sizes. However, CT had a better specificity and accuracy.

Technetium-99m-sestamibi scintigraphy compared with thallium-201 in evaluation of thyroid tumors

Technetium-99m methoxyisobutylisonitrile (MIBI) is a myocardial perfusion imaging agent that has been reported to effectively localize in various tumors (e.g., lung and thyroid carcinomas and osteogenic sarcoma). To determine its usefulness in thyroid tumors, we compared 99mTc-MIBI with 201TI imaging.

METHOD

We evaluated 25 patients with thyroid tumors (papillary carcinoma in 11, follicular carcinoma in 2, follicular adenoma in 7, adenomatous goiter in 5). Fifteen metastatic lesions from differentiated thyroid carcinomas were also evaluated. Early (10 min after injection) and delayed images (120 min after injection) were obtained for both 99mTc-MIBI and 201TI scintigraphy.

RESULTS

The early images showed very similar findings for both 99mTc-MIBI and 201TI. However, the delayed images showed that malignant tumors tended to retain more tracer agent than benign nodules. Marked retention was in 61.5% (8 of 13) of 201TI images and 53.8% (7 of 13) of 99mTc-MIBI images. For metastatic lesions from thyroid carcinomas, the findings for 99mTc-MIBI imaging were nearly identical to those for 201TI imaging. A slight difference in clarity was seen that may have been due to the effect of the 99mTc.

CONCLUSION

Although 99mTc-MIBI scintigraphy does not have particularly good results in differentiating malignant from benign thyroid tumors, it may be useful in evaluating metastases or predicting recurrence because of its better imaging characteristics.

Susceptibility-weighted MR for evaluation of vasodilatory capacity with acetazolamide challenge

PURPOSE

To investigate cerebral vasodilatory capacity by acetazolamide challenge in healthy subjects and in patients with chronic occlusive cerebrovascular disease by using susceptibility-weighted gradient-echo MR imaging.

METHODS

Eight patients with chronic occlusive cerebrovascular disease and four healthy volunteers were studied with susceptibility-weighted MR imaging before and after intravenous administration of 1000 mg of acetazolamide. Signal intensities were measured as a function of time in several regions of interest defined on anatomic images. In all patients with chronic occlusive cerebrovascular disease, acetazolamide challenge and resting regional cerebral blood flow were also evaluated with single-photon emission CT (SPECT).

RESULTS

In healthy volunteers, signal intensities began to increase 3 to 4 minutes after acetazolamide administration, with a continuous increase during the subsequent 10 minutes. The effect lasted for approximately 45 minutes after administration. In patients with chronic occlusive cerebrovascular disease, signal changes on susceptibility-weighted MR images of occluded areas with normal vasodilatory capacity on SPECT images did not differ from signal changes of nonocclusive areas. In those patients with changes that reflected diminished vasodilatory capacity, the MR images showed a lower percentage of signal changes after acetazolamide administration than those in normally perfused areas.

CONCLUSION

Susceptibility-weighted MR imaging offers an alternative method for estimating vasodilatory capacity.

Tl-201 SPECT in Kimura's disease involving the parotid glands and cervical nodes

Kimura's disease is a chronic inflammatory condition producing subcutaneous tumor-like nodules, mainly in the head and neck region. Most patients have involvement of regional lymph nodes and major salivary glands. The authors present two cases of Kimura's disease with parotid gland and postauricular lymph node involvement. With Tl-201 SPECT, elevated uptake was noted on early and delayed images. Kimura's disease should be included in the differential diagnosis when increased Tl-201 uptake in head and neck mass lesions is noted.

201TL SPECT for evaluating head and neck cancer

BACKGROUND

Thallium-201 (201Tl) has come to be widely used in diagnosis of several kinds of malignant tumor, but its usefulness in diagnosing head and neck cancer has not been established.

PURPOSE

This study investigated the usefulness of 201Tl SPECT imaging in patients with head and neck cancer histologically confirmed.

METHODS

Eighteen patients with histologically proven head and neck cancer were studied. 201Tl SPECT images were obtained both 15 min and 4 hours after intravenous injection of 148 MBq of 201Tl-chloride. 201Tl-indices were calculated semiquantitatively to assess the tracer uptake in relation to tumor size and histological type.

RESULTS

High 201Tl uptake was noted in all primary tumors and metastatic lymph nodes on the both early and delayed images, but 201Tl-indices did not show any correlation with tumor size or histological type.

CONCLUSION

Primary had and neck cancer and lymph node metastasis can be effectively visualized with 201Tl SPECT. It may provide information in addition to morphological changes and may be supplemental method to use in the evaluation of head and neck cancer.

Scintigraphic evaluation of testicular torsion and acute epididymitis

PURPOSE OF THE STUDY

To evaluate the effectiveness of testicular scintigraphy in differentiating testicular torsion from acute epididymitis.

METHOD

14 out of 17 patients previously screened by urologist were referred for testicular scintigraphy. Preoperative diagnosis was made based on dynamic and static image findings. Close follow-up was done and final diagnosis was confirmed on the basis of operative findings or relief of symptoms after conservative management.

RESULTS

Eight of the nine patients with a photopenic area in the hemiscrotum were confirmed surgically as having testicular torsion. One patient was diagnosed as having an inflammatory process. Relief from symptoms after conservative management was noted in three patients with increased activity on the affected side and in two others whose uptake patterns were not different from the unaffected side.

CONCLUSION

Testicular scintigraphy is effective in differentiating testicular torsion from acute inflammation when all other scrotal anomalies have been eliminated.

Cerebral perfusion imaging evaluates pharmacologic treatment of unilateral moyamoya disease

Unilateral Moyamoya disease presents as unilateral stenosis or obstruction of the supraclinoid internal carotid artery, which causes cerebral hypoperfusion resulting in seizures or TIA-like attacks. In severe cases, surgical treatment is performed with superficial temporal artery-middle cerebral artery anastomosis. In mild cases, conservative management is the treatment of choice. Flunarizine is a calcium ion anti-blocking agent, whose primary effect is that the cerebral vessels have been used for the treatment of postcerebrovascular disorders. Recently, it has been suggested that flunarizine could be used to treat Moyamoya disease. This report documents the efficacy of flunarizine to improve regional cerebral perfusion in Moyamoya disease.

Graves ophthalmopathy: MR evaluation of 10-Gy versus 24-Gy irradiation combined with systemic corticosteroids

PURPOSE

To establish the most effective radiation dose for treatment of Graves ophthalmopathy (GO).

MATERIALS AND METHODS

A combination of 10 Gy (n = 15) or 24 Gy (n = 16) of radiation and corticosteroids was used to treat 31 patients with GO. Magnetic resonance (MR) images obtained before treatment showed swollen extraocular muscles with prolonged T2 relaxation times in all patients.

RESULTS

Before therapy, T2 relaxation time of extraocular muscle was 79.6 msec (95% confidence interval, 76.3, 82.9) in the 24-Gy group and 77.4 msec (95% confidence interval, 74.6, 80.1) in the 10-Gy group (P = .32). After therapy, T2 relaxation time was 62.8 msec (95% confidence interval, 61.2, 64.4) in the 24-Gy group and 68.9 msec (95% confidence interval, 66.8, 71.1) in the 10-Gy group. In the 24-Gy group, there was a significant decrease in T2 relaxation times (P = .001) and clinical response to initial treatment was better. At 1- and 3-month follow-up, the resistance rate was lower in the 24-Gy group.

CONCLUSION

In treatment of GO, 24 Gy of radiation is a more effective dose than 10 Gy when combined with systemic corticosteroids.

High-resolution SPECT to assess hippocampal perfusion in neuropsychiatric diseases

The purpose of this study is to clarify the changes of hippocampal perfusion in neuropsychiatric diseases, including dementia, compared with control subjects, and to correlate hippocampal perfusion with the dementia rating scale and the severity of memory disturbance in patients with these diseases.

METHODS

A total of 45 right-handed patients were investigated (13 with dementia of Alzheimer type, 6 with multi-infarct dementia, 4 with progressive dementia with motor neuron disease (MND), 3 with transient global amnesia, 5 with other diseases and 14 control subjects). Regional cerebral blood flow (rCBF) in the parietal cortex and hippocampus was evaluated by high-resolution SPECT technique with HMPAO in all subjects.

RESULTS

The rCBF measurements in the bilateral parietal cortices and hippocampus were lower in dementia of Alzheimer type and multi-infarct dementia patients than in controls. Hypoperfusion in the hippocampus was a more sensitive marker than hypoperfusion in the parietal cortex in diagnosing dementia of Alzheimer type. Hippocampal hypoperfusion was observed in demented patients regardless of etiology and in patients having memory disturbance without dementia, such as transient global amnesia. Finally, hippocampal hypoperfusion reflected the severity of dementia and memory disturbance regardless of etiology.

CONCLUSION

The rCBF image with high-resolution SPECT system may be useful in assessing the extent of dementia and memory disturbance in patients with neuropsychiatric diseases.

Crossed cerebellar diaschisis: analysis of iodine-123-IMP SPECT imaging

The aim of this study was to review the etiology of CCD and study factors that affect the development and manifestation of CCD.

METHODS

Three hundred and eleven patients with supratentorial lesions were evaluated for the presence of CCD with SPECT and 123I-IMP. In representative cases, continuous arterial blood sampling was done and rCBF was calculated using Kuhl's method.

RESULTS

IMP-SPECT detected an abnormality in 206 patients, of whom 30 had CCD. Of CCD patients, 27 had more than single lobe involvement, 17 had motor impairment, 8 of 11 had rCBF of less than 29.1 +/- 10.9 ml/100 g/min. There was also a significant difference in rCBF between non-CCD and CCD cases.

CONCLUSION

Although CCD can also occur with dementia (mixed or vascular type), it is more common with multilobar lesions. It is also associated with the presence of motor impairment but not related to its severity. It is more likely to develop, however, if rCBF is less than 29.1 +/- 10.9 ml/100 g/min regardless of etiology.

Thallium-201 uptake in eosinophilic granuloma of the frontal bone: comparison with technetium-99m-MDP imaging

An 11-yr-old female presented with a 6-wk history of left upper lid tenderness and left eye lacrimation. Left lateral supraorbital mass and left preauricular lymph node were the only significant physical examination findings. On skull x-ray, a left frontal bone defect was noted. CT and MRI showed a soft-tissue mass in the area of the bone defect. Bone scintigraphy exhibited peripheral uptake within the central photon deficient area. With 201TI SPECT, high uptake was noted on early and delayed images. Diagnosis of eosinophilic granuloma was performed by biopsy. Since thallium uptake was seen in the area where photon deficiency was exhibited by 99mTc-MDP scintigraphy, we speculate that thallium SPECT could detect eosinophilic granuloma when radiographic skeletal survey or radionuclide bone scan are equivocal. It could also rule out multiple bone involvement and recurrence or regrowth after therapy.

A comparative study of 123I-IMP SPET and CT in the investigation of chronic-stage head trauma patients

The aims of this study were (1) to compare N-isopropyl-p-[I-123]-iodoamphetamine (123I-IMP) SPET with computed tomography (CT) in chronic-stage head trauma patients with neurological abnormalities and (2) to quantify regional cerebral blood flow (rCBF) in patients with chronic-stage head trauma. 123I-IMP SPET and CT were performed in 23 patients with chronic-stage head trauma and 12 normal controls. Both types of imaging were evaluated visually. In addition for the SPET images, the rCBF in 12 regions (bilateral frontal cortex, temporal cortex, parietal cortex, occipital cortex, perilolandic area, cerebellum: total 276 regions) was analysed quantitatively using a reference sampling method. In total, 39 focal lesions related to neurological abnormalities were detected. Although 22 (56.4%) lesions were observed using both CT and SPET, another 17 (43.6%) were detected by SPET only. The mean rCBF in the localized lesions of each lobe, which correspond to low-density areas (LDAs), were lower on CT than those of each lobe seen only on SPET. These rCBF values were lower than the mean rCBF values in the lobes of the controls. The mean rCBF values in each lobe with visually normal tracer uptakes were also significantly lower in the 23 patients than in the controls. 123I-IMP SPET is useful for demonstrating brain dysfunction in morphologically intact brain regions and for providing objective evidence to account for the clinical presentation of patients presenting with chronic traumatic brain injury.

Bone scintigraphy as a prognostic factor in patients with adult T-cell leukemia-lymphoma

Bone scintigraphy in 26 patients with adult T-cell leukemia-lymphoma (ATLL) was evaluated. Abnormally high accumulations were observed in 7 of 26 patients (skull, 5; vertebra, 1; rib, 6; bony pelvis, 1; scapula, 2; lower extremities, 1). Serum calcium levels were significantly elevated in patients with abnormally high accumulations on bone scintigraphy. Survival rates of the patients with positive results on bone scintigraphy were significantly lower than were those with negative results on bone scintigraphy (P < 0.05). Survival rates of patients with high serum calcium levels, high WBC counts, and high serum lactate dehydrogenase (LDH) levels were also significantly lower than were those of the negative groups, in this order of significance. Bone scintigraphy was useful for detecting bone marrow involvement in ATLL and it can be one of the better indicators of the prognoses of patients with ATLL.