[Clinical significance of nuclear medicine in the presurgical diagnosis of epilepsy].
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Brain↗
Biomedical subjects
F Grünwald
Publications and source records attributed to F Grünwald.
[Incidence of lesions described by magnetic resonance imaging in the clarification of focal epilepsy of frontal and temporal origin].
AIM: Today, MRI is an integral part of the presurgical evaluation of patients suffering from partial epilepsy. These patients frequently show focal morphological abnormalities with potential epileptogenic character and surgical resection of these lesions is associated with superior postsurgical outcome as to seizure frequency. Apart from easily detectable defects, such as post-traumatic lesions or cerebral infarction, as wide variety of mainly small abnormalities can be detected using MRI. METHODS: In this study, 484 patients suffering from partial epilepsy of temporal or frontal onset were evaluated for the incidence of different lesions in this population. RESULTS: All lesions found were included without evaluating their potential epileptogenicity, which remains to be proven using other procedures (EEG, SPECT, PET, etc.). Involvement of the hippocampal formation was a major finding in temporal lobe epilepsy, which could be detected as sclerosis (T2w-images), atrophy (T2w-TSE or T1w-IR-images) or both (15%). In addition and in declining frequency various tumors (14%), post-traumatic lesion (-5%), and focal cortical dysplasia or other disturbances of cortical integrity (-4%) were found. These lesions are detectable with best contrast on different sequences. As a consequence it is suggested to acquire sequences in 3 dimensions including a T1w-SE, two (coronal and axial) double-echo-SE sequences and similarly two T1w-IR-sequences. The application of contrast media can be restricted to special questions, derived either from the first imaging results or from the patients history. CONCLUSION: Using qualitative data for interpretation, the sensitivity as to the detection of any focal pathology of a recent-generation MRI in this population was 75%, with 79% for temporal lobe epilepsies and 67% for frontal lobe epilepsies. Quantitative measurements of hippocampal volume or signal seem to be able to increase the sensitivity of the method.
Atrophy↗
[Determination of the count rate for quality control of combined lung ventilation and perfusion scintigraphy: case report].
We present the case of a 43-year-old male patient who suffered from a massive pulmonary embolism, induced by a peritoneovenous shunt of the Denver type. Calculation of the count rates of the ventilation and perfusion scintigraphy respectively showed a too low ventilation/perfusion ratio. After reinjection of additional 99mTc-MAA the second perfusion study showed further mismatch areals. Count rate ratio determination is essential as a clinical quality control.
Adult↗
Temporal lobe dysfunction and correlation of regional cerebral blood flow abnormalities with psychopathology in schizophrenia and major depression--a study with single photon emission computed tomography.
Studies of regional cerebral blood flow in both schizophrenic and depressed patients have yielded contradictory findings. Single photon emission computed tomography (SPECT) was used to compare brain-perfusion patterns in 17 patients with schizophrenia and 12 patients with major depression and to evaluate the relationship of the findings to psychopathology. The images were analyzed both visually and quantitatively. Twelve of the 17 schizophrenic patients and 8 of the 12 depressed patients showed a pathological blood flow pattern. Hypoperfusion of the left temporal lobe was observed in seven of the schizophrenic and five of the depressed patients. Five of the schizophrenic patients also had a hypoperfusion of the left frontal lobe. Separation of both diagnostic cohorts in two subgroups with pathological and normal cerebral blood flow patterns revealed significantly higher levels of symptomatology in the group with hypoperfusion in the SPECT image. The analysis of different cerebral regions revealed statistically significant temporal hypoperfusion was significantly related to positive symptoms in schizophrenia. Our data suggest that left-sided temporal lobe dysfunction is related both to schizophrenia and major depression. The localization of hypoperfusion seems to be associated with the type of psychopathology (positive vs. negative symptoms in schizophrenia). Thus, the results support the model of paralimbic and prefrontal dysfunction in both diseases.
Adolescent↗
Fluorine-18 fluorodeoxyglucose positron emission tomography in the follow-up of differentiated thyroid cancer.
Whole-body fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) imaging was performed during the follow-up of 33 patients suffering from differentiated thyroid cancer. Among them there were 26 patients with papillary and seven with follicular tumours. Primary tumour stage (pT) was pT1 in six cases, pT2 in eight cases, pT3 in three cases and pT4 in 14 cases. FDG PET was normal in 18 patients. In three patients a slightly increased metabolism was observed in the thyroid bed, assumed to be related to remnant tissue. In one case local recurrence, in ten cases lymph node metastases (one false-positive, caused by sarcoidosis) and in three cases distant metastases were found with FDG PET. In comparison with whole-body scintigraphy using iodine-131 (WBS) there were a lot of discrepancies in imaging results. Whereas three patients had distant metastases (proven with 131I) and a negative FDG PET, in four cases 131I-negative lymph node metastases were detectable with PET. Even in the patients with concordant "staging", differences between 131I and FDG were observed as to the exact lesion localization. Therefore, a coexistence of 131I-positive/FDG-negative, 131I-negative/FDG-positive and 131I-positive/FDG-positive malignant tissue can be assumed in these patients. A higher correlation of FDG PET was observed with hexakis (2-methoxyisobutylisonitrile) technetium-99m (I) (MIBI) scintigraphy (performed in 20 cases) than with WBS. In highly differentiated tumours 131I scintigraphy had a high sensitivity, whereas in poorly differentiated carcinomas FDG PET was superior. The clinical use of FDG PET can be recommended in all cases of suspected or proven recurrence and/or metastases of differentiated thyroid cancer and is particularly useful in cases with elevated serum thyroglobulin levels and negative WBS.
Adult↗
Scintimammography with technetium-99m methoxyisobutylisonitrile: comparison with mammography and magnetic resonance imaging.
The aim of the study was to compare the diagnostic accuracy of scintimammography with technetium-99m methoxyisobutylisonitrile (MIBI; SMM) in the detection of primary breast cancer with that of mammography (MM) and magnetic resonance imaging (MRI). Fifty-six patients with suspected lesions detected by palpation or MM were included in the study. Within the 4 weeks preceding excisional biopsy, MM and MRI were performed in all patients. Between 5 and 10 min after the injection of 740 MBq 99mTc-MIBI, SMM in the prone position was performed. In the total group of 56 patients, 43 lesions were palpable, while 13 were non-palpable but were detected by MM. Breast cancer was confirmed by histopathology in 27 of the patients (22 palpable and 5 non-palpable carcinomas). The tumour size ranged from 6 to 80 mm in diameter. For non-palpable lesions, the sensitivity of SMM, MM and MRI was 60%, 60% and 100%, respectively, while the specificity was 75%, 25% and 50%, respectively. For palpable breast lesions, all methods showed high sensitivity (SMM 91%, MM 95%, MRI 91%) but SMM demonstrated significantly higher specificity (SMM 62%, MM 10%, MRI 15%). In two mammographically negative tumours (dense tissue), SMM showed a positive result. In comparison to MRI, one additional carcinoma could be diagnosed by SMM. It may be concluded that for palpable breast lesions, the diagnostic accuracy of SMM is superior to that of MM and MRI. Through the complementary use of SMM it is possible to increase the sensitivity for the detection of breast cancer and multicentric disease. In patients in whom the status of a palpable breast mass remains unclear, SMM may help to reduce the amount of unnecessary biopsies.
Biopsy↗
Interventional brain SPECT--a review.
Brain SPECT with HMPAO or ECD has-due to its short accumulation period--a rather high time resolution of approx 60 sec. Compared to isopropyl amphetamine (I-123) and FDG-PET, shortlasting interventions may be evaluated by SPECT. Usually, a two-step approach is used, injecting one third of the dose under baseline conditions and two thirds during intervention. The first study is then subtracted from the second study, resulting in a "difference" image which allows to calculate the effect of the intervention. These interventional procedures may include drug, mechanical, and mental intervention as well as ictal, blood pressure and receptor intervention. Moreover, the difference of pCO2 after hyperventilation or hypoventilation may also be used as a stimulus. The above mentioned procedures are described in detail.
Brain↗
18F-fluorodeoxyglucose-PET and 99mTc-bicisate-SPECT in Creutzfeldt-Jakob disease.
In a patient with the occipitoparietal form of Creutzfeldt-Jakob disease (CJD) (Heidenhain type) positron emission tomography (PET) demonstrated decreased glucose utilization in the occipital lobes and adjacent cortical regions. Single photon emission computed tomography (SPECT) with 99mTc-bicisate showed a "coupled" decrease in blood flow in identical cortical areas in this patient. In contrast, magnetic resonance imaging (MRI) was normal. In the early stage of CJD, when still no major morphological abnormalities can be observed, functional imaging is useful for differential diagnosis, particularly to exclude other causes of dementia or pathological EEG patterns.
Aged↗
Scintimammography with Tc-99m MIBI in patients with suspicion of primary breast cancer.
The aim of the study was to evaluate the diagnostic accuracy of scintimammography with Tc-99m MIBI for the detection of breast cancer. Patients with a suspicious lesion detected by palpation or mammography were included in the study. Excisional biopsy was performed on all patients. Mammography was performed within 3 weeks prior to scintigraphy. All patients received 740 MBq Tc-99m MIBI intravenously in the arm contralateral to the suspicious breast and were subsequently examined in a prone position. At 5 to 10 min postinjection, planar images were obtained in lateral and anterior views, with an acquisition time of 10 min each. After planar imaging, a SPECT study was performed using a two-head camera. Breast cancer was confirmed in 29 out of 68 patients. The tumor size ranged from 6 to 90 mm in diameter. For scintigraphic studies, the overall sensitivity and specificity was 83% and 84%, respectively. However, sensitivity for palpable lesions was 100%. The smallest detectable tumor measured 9 mm in diameter and could be visualized only in the planar scintigram. Using Tc-99m MIBI, axillary lymph node metastases could be detected with a sensitivity of 82%. Scintigraphy with Tc-99m MIBI has a high diagnostic accuracy for the detection of primary breast cancer in patients with a palpable mass. Scintimammography may be used as a complementary method to mammography and help to decrease the number of unnecessary breast biopsies.
Adult↗
Are serum neopterin concentrations superior to other parameters in the differential diagnosis and prognostic assessment of Graves' disease?
There is a lack (1.) of a single criterion for the definitive differentiation between immunogenic (IH) and non-immunogenic hyperthyroidism (NIH), and (2.) also a lack of an unequivocal prognostic predictor for the individual course of patients with immunogenic hyperthyroidism. In 152 patients scheduled for iodine-131 therapy, serum neopterin concentrations were measured using a commercially available RIA, and the neopterin concentrations of IH (n = 84) and NIH (n = 42) patients were compared. Of these patients, 83 and 26 per cent respectively were treated with antithyroid drugs which did not have a significant impact on neopterin levels. In patients with IH and NIH, the concentrations [mean +/- SD] of neopterin were 1.89 +/- 0.79 milligrams and 1.98 +/- 0.9 milligrams, respectively (p = 0.4). After therapy with iodine-131, 28% of the IH-patients were euthyroid, 32% hyperthyroid, and 40% hypothyroid. In finally euthyroid patients, pretherapeutic neopterin concentrations were higher (3.1 +/- 2.8 milligrams) than in finally hyperthyroid (1.8 +/- 0.7 milligrams), or hypothyroid (1.6 +/- 0.7 milligrams) patients. These results argue against a relevant clinical role of neopterin concentrations for the differential diagnosis of IH versus NIH in these patients. However, a prognostic significance of neopterin concentrations in patients with IH is suggested.
Adult↗
[123I]IBZM SPECT for imaging of striatal D2 dopamine receptors in 56 schizophrenic patients taking various neuroleptics.
OBJECTIVE: The purpose of this study was to compare the binding of various typical and atypical neuroleptics to striatal D2 dopamine receptors in schizophrenic patients. METHOD: Fifty-six inpatients with schizophrenia, including 14 with schizoaffective disorder and one with schizophreniform disorder, were evaluated. Fourteen patients were neuroleptic free. Single photon emission computed tomography (SPECT) was performed 90 minutes after intravenous injection of [123I]benzamide ([123I]IBZM). Subsequent semiquantitative analysis of D2 receptor binding was done with the use of the basal ganglia (striatum)/frontal cortex (BG/FC) ratio of activity. Clinical symptoms were rated with the Positive and Negative Syndrome Scale and the Hamilton Depression Rating Scale. RESULTS: The BG/FC ratios in patients taking typical neuroleptics were significantly lower than those in the neuroleptic-free subjects but not lower than those in the patients taking atypical neuroleptics (clozapine, remoxipride). For atypical antipsychotics, a dose-dependent relationship with striatal D2 receptor binding could not be demonstrated. BG/FC ratios were not significantly correlated with clinical symptoms or with duration of illness. CONCLUSIONS: The results indicate that [123I]IBZM SPECT is useful for semiquantitative imaging of striatal D2 dopamine receptors and for estimating their blockade by neuroleptics. Thus, it may improve drug monitoring in psychiatric patients. Furthermore, the findings suggest a complex relationship between the antipsychotic effect of atypical neuroleptics and D2 receptor blockade.
Adult↗
Technetium-99m-MIBI scintimammography for suspicious breast lesions.
UNLABELLED: The aim of this study was to evaluate the diagnostic accuracy of scintimammography with 99mTc-MIBI in patients with suspected primary breast cancer as monitored by SPECT or planar imaging. METHODS: Patients with a suspect lesion detected by palpation or mammography were entered in the study. Excisional biopsy was performed on all patients and a mammography was performed within three weeks prior to scintigraphy. All patients received intravenously 740 MBq 99mTc-MIBI in the arm, contralateral to the suspicious breast, and were subsequently examined in a prone position. At 5-10 min postinjection, planar images were obtained in both the lateral and anterior views with an acquisition time of 10 min. After planar imaging, SPECT imaging was performed using a two-head high-resolution gamma camera. RESULTS: In the total patient group of 54 patients, 40 lesions were palpable and 14 were nonpalpable but were detected by mammography. Breast cancer was confirmed in 24 of the patients and 20 of the palpable masses were found to be carcinomas. The tumor size ranged from 6 to 90 mm in diameter. In scintigraphic studies, the overall sensitivity was 88% for planar imaging and 83% for SPECT. Specificity was 83% and 80%, respectively. Sensitivity for palpable lesions was 100%. The smallest detectable tumor measured was 9 mm in diameter and could only be visualized in the planar scintigram. CONCLUSION: Scintigraphy with 99mTc-MIBI is extremely sensitive for the detection of primary breast cancer in patients with a palpable mass. SPECT, however, did not improve the diagnostic accuracy over planar scintimammography.
Adenocarcinoma↗
[Pain therapy with rhenium-186 HEDP in multiple bone metastases].
AIM: Therapeutic means for patients with painful bony metastases are strongly limited. In these patients, a systemic therapy with isotopes can be helpful. The aim of this study was to evaluate the efficacy of rhenium-186 HEDP for pain palliation in patients with disseminated bone metastases. METHODS: 30 patients taking analgesics because of bone pain received one or more injection of 1295 MBq 186Re HEDP for pain palliation. RESULTS: In 70% of the patients, therapy resulted in a significant reduction of pain. The average duration of pain relief was 4 weeks (1 week-2.5 months). The main side effects of therapy were a decrease of platelets (aver. 30000/microliters) and an increase of pain for 1-2 days (flare-phenomenon). CONCLUSION: Therapy with rhenium-186 HEDP can be used complementarily to analgesic therapy in patients with painful, disseminated bone metastases.
Bone Neoplasms↗
"High-dose" radioiodine therapy in advanced differentiated thyroid carcinoma.
UNLABELLED: There is yet no consensus concerning the appropriate regimen of the application of [131I]sodium iodine (Nal) activities to patients suffering from advanced differentiated thyroid carcinoma. We report on a total of 167 applications of [131I]Nal, including 78 applications of 11.1 GBq. Response to high-activity radioiodine therapy (RIT) is correlated to the course of the disease as well as to the reaction of thyreoglobulin and acute/subacute side effects of radiation. METHODS: Following radioablation of thyroid remnants using 1.85 to 3.7 GBq[131I]Nal, 26 patients with advanced differentiated thyroid carcinoma (follicular, 11; papillary, 4;mixed-cell thyroid carcinoma, 11) were treated with repeated activities of 11.1 GBq[131I]Nal. Initial tumor staging according to UICC showed T4 in 54%, T3 in 19%, T2 in 19% and was not obtained in 8%. Differentiated thyroid carcinoma was multifocal in 23% of patients. Applied accumulated activities ranged from 14.8 to 99.9 GBq with a mean of 55.5 GBq per patient. RESULTS: Mean post-diagnostical follow-up was 73 mo, mean follow-up after diagnosis of metastatic spread was 48 mo. Follicular thyroid carcinoma remained as stable disease in 7 of 11 patients, 6 of whom showed metastatic disease after a mean of 20 mo, and only 1 complete remission was achieved using high-dose therapies, with progressive disease in the remaining patients. Overall, 73% of follicular thyroid carcinoma had progressive disease without major response to high-activity RIT. In contrast, only 20% of papillary thyroid carcinoma/mixed-cell thyroid carcinoma showed progressive disease, and complete remission was achieved in 47% of patients. Pulmonary and lymph node metastases in the majority of patients showed good response to therapy, whereas local recurrences and bone metastases showed minor reactions to RIT. After low-activity therapies 8% of patients showed WHO grade I hematotoxic reactions. After high-activity therapies, 38% of patients had WHO I, 8% WHO II and one patient had WHO III toxicity (4%). CONCLUSION: Use repetitive high-activity RIT with a maximum of 44.4 GBq applied during 1 yr and a maximum of 99.9 GBq accumulated activity resulted in a significant increase of hematotoxicity. However, during the follow-up period (mean, 4 yr), no clinical symptoms possibly related to low blood counts were seen in patients with advanced differentiated thyroid carcinoma. Initiation of high-activity RIT in reaction to metastatic tumor outspread to achieve complete remission was found to be useful in treating papillary thyroid carcinoma and mixed-cell thyroid carcinoma, but only in a minority of follicular thyroid carcinoma patients.
Adenocarcinoma, Follicular↗
Evaluation of technetium-99m-ECD in childhood epilepsy.
UNLABELLED: In childhood epilepsy, it is difficult, but of critical importance, to determine whether surgical intervention might be beneficial for an individual patient. Because both established procedures-MRI and electroencephalography (EEG)-have limitations, interictal and ictal regional cerebral blood flow (rCBF) SPECT has proven to be a valuable adjunctive method in the presurgical evaluation of children. METHODS: We evaluated the usefulness of the new rCBF tracer 99mTc-ECD in 14 children with focal epilepsy (mean age 9.7 yr). Eleven interictal and 8 ictal studies were performed. Results were correlated with ictal and interictal surface EEG, MRI and histological findings and the postsurgical outcome. RESULTS: On the basis of the presurgical evaluation, nine patients underwent surgery. MRI studies demonstrated pathological features with possible relation to epilepsy in 50%. Overall, interictal 99mTc-ECD SPECT showed areas of hypoperfusion in 80% of patients. Ictal rCBF SPECT was informative in all patients, including one who showed bifrontal hyperperfusion in accordance with EEG results. CONCLUSION: Technetium-99m-ECD has proven to be of value for interictal and ictal rCBF SPECT in childhood epilepsy. No side effects during or after tracer administration were noticed. Ictal and interictal rCBF SPECT showed good correlation with MRI and EEG results in patients in whom correlation with the postoperative situation was possible and presented additional significant information in those patients with normal MRI and uninterpretable EEG results. No false lateralizations occurred. In children with focal epilepsy, interictal rCBF SPECT may accelerate the application of long-term electrocorticography (ECoG) in patients with normal MRI results. Ictal rCBF SPECT may also help to avoid ECoG, if a focal hyperperfusion correlates with a focal MRI abnormality, and the surface EEG gives no contradictory information.
Brain↗
Prognostic value of thyroglobulin after thyroidectomy before ablative radioiodine therapy in thyroid cancer.
UNLABELLED: Serum thyroglobulin (Tg) is a suitable marker for differentiated thyroid carcinoma after total thyroid ablation by surgery and 131I therapy. Before the first 131I treatment, Tg is not a reliable tumor marker since it can also originate from remnant tissue. It was hypothesized that the ratio of serum Tg to 131I uptake in the thyroid bed could be used to correct Tg values for variations in remnant tissue. METHODS: The hypothesis was evaluated in 111 patients with differentiated thyroid cancer (38 follicular/73 papillary). Tg and 131I uptake in the thyroid bed were measured before the first 131I therapy. The ratio of Tg to 131I uptake was determined in four groups: Group A, tumor free (n = 81); Group B, lymph node metastases (n = 11); Group C, distant metastases (n = 11); Group D, later recurrence [during a mean follow-up of 56 mo; (n = 8)]. Wilcoxon two-sample test was performed to determine statistical significance between Group A and Groups B-D. RESULTS: Significant differences in the Tg/131I uptake ratios (median) between Group A (1.0 ng/ml/%) and Groups B (3.3 ng/ml/%) and D (3.3 ng/ml/%) were observed (p < 0.01). In tumor-free patients (Group A), there was no value higher than 5.7 ng/ml/%. Therefore, a higher ratio, observed in 14 of the 30 remaining patients, was indicative of metastases or later recurrence. CONCLUSION: The ratio of serum Tg to 131I uptake in the thyroid bed might be used as a prognostic marker for thyroid cancer before implementing ablation with 131I.
Adenocarcinoma, Follicular↗
[Scintigraphy of the parathyroid glands with 99mTc-MIBI].
AIM: Since about 3 years 99mTc-MIBI is used instead of 201Tl/99mTc subtraction scintigraphy for the localization of parathyroid involvement in hyperparathyroidism (HPT). The sensitivity of the new method was evaluated. PATIENTS AND METHODS: 24 patients aged between 28 and 83 years with surgically confirmed primary HPT were studied. Planar images were acquired 15 minutes and 3 hours after tracer injection. Additionally, in 9 patients dynamic images were obtained for 2 hours to study tracer kinetics. RESULTS: 19 out of 24 adenomas (79%) were identified correctly with 99mTc-MIBI. CONCLUSION: The sensitivity of the scintigraphy using 99mTc-MIBI is in the range of the 201Tl/99mTc subtraction scintigraphy. Because of the superior logistic and the lower radiation exposure, 99mTc-MIBI can replace the 201Tl/99mTc scintigraphy in the preoperative diagnostic assessment.
Adenoma↗