摘要:

The preferred treatment for patients with multifocal thyroid carcinoma or a single focus of malignancy larger than 1.5 cm is near-total thyroidectomy followed by radioiodine ablation therapy of the remaining thyroid tissue. The authors describe a patient who had a 2.6-cm papillary thyroid carcinoma but no evidence of metastatic disease. This malignancy was not diagnosed during intraoperative frozen section examination, but rather at the final pathologic analysis. The unilateral thyroid lobectomy resulted in a recurrent laryngeal nerve palsy. During subsequent I-131 therapy of the remaining lobe, features of acute radiation thyroiditis, including thyrotoxicosis, developed.

ISSN:0363-9762    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

The authors report the use of lymphoscintigraphy and gamma probe–guided resection of the sentinel lymph node in a 65-year-old woman with clinically and cytologically indicated metastasizing papillary thyroid carcinoma. The results of the preoperative lymphoscintigraphy corresponded well with FDG PET and histologic findings, which gives promise of its validity in thyroid carcinoma. With experience in ultrasound-guided fine-needle aspiration biopsy, this method can be performed without any serious side effects for the patient. The validity of the sentinel lymph node concept in thyroid carcinoma and a possible improvement of nodal staging and local recurrence rate must still be proved.

ISSN:0363-9762    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

PurposeThe aim of this study was to correlate regional ventilation and perfusion images and perfusion SPECT with images made using a newly developed magnetic resonance ventilation (MRV) method.Materials and MethodsThe investigation included a single patient with chronic obstructive pulmonary disease and a healthy control participant. Ventilation and perfusion images using Xe-133 and Tc-99m MAA, including perfusion SPECT, were compared with single-breath MRV with hyperpolarized He-3.ResultsVentilation and perfusion defects correspond to areas of poor ventilation on MRV. High-resolution MRV images show preservation of bronchi and acinus units in areas of the “stripe sign” on the V/Q study.ConclusionsMRV imaging confirms that the stripe sign seen on nuclear perfusion imaging correlates with subsegmental preserved lung. MRV imaging has the potential for high-resolution innovative studies of subsegmental lung function, using either He-3 or Xe-129 hyperpolarized gases.

ISSN:0363-9762    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

The authors evaluated the ability of dual SPECT with Tc-99m MIBI and Tl-201 chloride to differentiate malignant and benign solitary pulmonary nodules smaller than 3 cm in diameter. Forty-three patients had solitary pulmonary nodules smaller than 3 cm in diameter based on the findings of chest CT. All patients underwent dual-isotope SPECT with Tc-99m MIBI and Tl-201 chloride. Regions of interest were placed over the tumors (T) and contralateral normal lung tissue (N) on one coronal SPECT view, and T:N ratios and retention indices were calculated. The sensitivities of early and delayed Tc-99m MIBI SPECT and early and delayed Tl-201 chloride SPECT for differentiating malignant and benign lesions were 44%, 48%, 56%, and 52%, respectively. The corresponding specificity rates were 44%, 56%, 25%, and 31%, respectively, and corresponding accuracy rates were 44%, 51%, 44%, and 44%, respectively. There were no statistically significant differences between malignant and benign lesions in the early and delayed T:N ratios for Tc-99m MIBI and Tl-201 chloride and the retention index for Tc-99m MIBI. However, the retention index using Tl-201 chloride in malignant lesions was significantly higher (P< 0.01) than that in benign lesions. Analysis of semiquantitative parameters of the T:N ratio and retention index from Tc-99m MIBI SPECT appears to have little or no value for differentiating malignant from benign solitary pulmonary nodules smaller than 3 cm in diameter. However, the retention index using Tl-201 chloride seems to be a better parameter for differentiating between these malignant and benign lesions.

ISSN:0363-9762    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Increased bone activity in the sacroiliac joints has been shown to be a sensitive method for detecting sacroiliitis in brucellosis. Because symmetrically increased uptake usually is difficult to detect, this study was performed to improve the sensitivity by quantifying sacroiliac joint uptake. Quantification was accomplished by normalizing sacroiliac joint activity to activity in the lumbar spine and sacrum. From rectangular regions of interest over a standardized posterior pelvic view, the ratios of the sacroiliac:lumbar spine and sacroiliac:sacrum were calculated. Abnormal sacroiliac joint uptake was defined as uptake greater than the mean +2 SD of normal. This was applied to 79 patients with brucella sacroiliitis. The quantitative approach was compared with visual interpretation. Of the 16 patients in the age group of 5 to 19 years, 7 patients had visual evidence of sacroiliitis and 9 patients had positive evidence by sacroiliac–sacrum and 12 by sacroiliac–lumbar spine quantification. Of 21 patients who were 20 to 30 years old, 10 patients had positive visual evidence, whereas 17 and 20 patients had positive evidence of sacroiliitis by sacroiliac–sacrum and sacroiliac–lumbar spine, respectively. Of 42 patients who were 31 to 85 years old, 24, 32, and 36 patients had positive evidence of sacroiliitis by visual inspection, sacroiliac–sacrum, and sacroiliac–lumbar spine, respectively. Thus, the quantitative approach increased the sensitivity in diagnosingBrucellasacroiliitis in all age groups by 31.3%, 47.6%, and 28.6%, respectively, for sacroiliac–lumbar spine and by 12.5%, 33.3%, and 19%, respectively, for sacroiliac–sacrum.

ISSN:0363-9762    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

PurposeExercise-induced myocardial perfusion abnormalities have been reported in patients with myocardial bridging, possibly by tachycardia-induced shortening of diastole. Dipyridamole Tl-201 SPECT findings were evaluated in patients with myocardial bridging to assess perfusion abnormalities during dipyridamole stress.Materials and MethodsDipyridamole Tl-201 SPECT images of 12 patients with myocardial bridging (≥50% systolic narrowing) were evaluated. The peak heart rate during dipyridamole stress was less than 110 beats/min in all patients. The control group was 118 patients with fixed left anterior descending artery (LAD) disease.ResultsFourteen sites of systolic arterial narrowing were present in LAD: two in mid-LAD, seven in distal LAD, and five in septal branches. Dipyridamole Tl-201 SPECT showed reversible perfusion defects in three of six sites with 50% to 70% systolic narrowing and seven of eight sites with more than 80% systolic narrowing. Overall, 71% (10 of 14) had a reversible perfusion defect. Five patients with septal branch compression had a perfusion defect in the midanteroseptal wall without an apical abnormality. In the control group, no patient had an isolated perfusion defect in the midanteroseptal wall or septal branch disease (5 of 12 compared with 0 of 118;P< 0.001).ConclusionsPerfusion abnormalities on dipyridamole Tl-201 SPECT are observed in LAD or its branches in patients with high-grade myocardial bridging. Myocardial bridging may decrease coronary flow reserve but not necessarily via tachycardia. Isolated perfusion defects in the midanteroseptal wall may be a characteristic finding of septal branch compression, because a fixed lesion involving a septal branch only is rare.

ISSN:0363-9762    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

PurposeThis study was undertaken to determine the usefulness of Tc-99m methoxyisobutylisonitrile (MIBI) in brain tumors compared with Tl-201 imaging. The authors evaluated the correlation between MIBI uptake and the presence of P-glycoprotein, and also the relation between MIBI uptake in response to combined radiotherapy and chemotherapy in glioblastoma.Materials and MethodsThirty-four brain tumors composed of 15 glioblastoma multiforme (GBM), 5 anaplastic astrocytomas, 5 low-grade astrocytomas, and 9 metastases were evaluated. Early and delayed images were obtained for MIBI and Tl-201 scintigraphy. P-glycoprotein status in all GBM, 2 anaplastic astrocytomas, 2 low-grade astrocytomas, and 2 metastases were evaluated immunohistochemically. Patients with GBM were divided into an effective and a noneffective group according to the change in tumor size. MIBI uptake indices were compared for these two groups.ResultsBoth radiopharmaceuticals accumulated in all GBM and anaplastic astrocytomas. In low-grade astrocytomas, only one case showed tracer uptake. In metastasis, two cases showed high uptake on early images and marked washout on delayed images. Uptake ratio values (early uptake ratio and delayed uptake ratio) in all tumors were significantly higher in MIBI than in Tl-201. Immunohistochemical studies showed that the metastases were positive for P-glycoprotein but the GBM were not. In low-grade astrocytomas, a few cells were positively stained. In relation to the therapeutic outcome of GBM, both the early and delayed uptake ratios of MIBI were significantly greater in the noneffective group.ConclusionsAlthough diagnostic ability was comparable in MIBI and Tl-201, the imaging quality was better in MIBI. Both radiopharmaceuticals are useful in differentiating low-grade glioma from high-grade glioma. MIBI delayed imaging could also reflect the presence of P-glycoprotein. Intense MIBI uptake was also predictive of a poor clinical outcome in GBM.

ISSN:0363-9762    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

PurposeTo monitor progression of cerebral blood flow deterioration, this study used consecutive surface SPECT to evaluate the feasibility of brain surface displays (BSD) to follow Alzheimer’s disease (AD) to determine whether overtime is a consistent feature of the disease.MethodsEighteen men (mean age, 75.7 years) with probable Alzheimer’s disease (AD), with moderate to profound dementia indicated by the Mini-Mental State Examination (MMSE; median score, 10; range, 0 to 19), underwent brain Tc-99m ethyl cysteinate dimer SPECT. Brain SPECTs were obtained using a three-head gamma camera. Brain surface displays (BSD) were reconstructed from transaxial data using a threshold of 55% of the maximum pixel count. A second series of SPECTs were obtained after 5 to 23 months (except for one, which was done after 60 months). Each BSD was graded semiquantitatively, by visual interpretation, from zero to 8 (normal = 0, mild = 2, moderate = 4, severe = 6, and profound = 8) depending on the extent of the perfusion defects in the frontal, temporal, or parietal (or all of these) pattern of AD. MMSE scores were used to calculate “time index” values for estimating severity at the time of the SPECTs.ResultsThe initial BSD scores correlated significantly with dementia severity (r = 0.71,P< 0.001). All 18 patients had decreased blood flow on consecutive SPECTs. Scores for BSD progressed at a rate of 2.5 ± 1.7 points per year and correlated significantly with the time interval between the scans (r = 0.71;P< 0.001).ConclusionsThe BSDs of SPECT scan data have considerable objective discriminatory power for assessing the severity and progression of AD-related hypoperfusion, particularly in the moderate to profound dementia ranges, and is potentially more reliable than the MMSE. Consecutive BSDs simplify SPECT image interpretation for measuring loss of brain function over time and could be useful for assessing the efficacy of therapeutic interventions for AD patients such as vitamin E and cholinesterase inhibitors.

ISSN:0363-9762    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Two cases of pancreatitis induced by autoimmunity with PET images using F-18 fluoro-2-deoxy-D-glucose (FDG) are reported. The patients had abdominal pain and were thought to have possible pancreatic neoplasms. In one patient, PET showed intense uptake of the entire pancreas, but a Ga-67 scan yielded a negative result. Because the serum immunoglobulin G level was high, autoimmune pancreatitis was diagnosed in this patient. He underwent steroid therapy and fully recovered. In another patient with positive antinuclear antibodies and hyperglobulinemia, focal intense uptake was found in the head of the pancreas on the FDG PET. She also recovered with steroid therapy. Autoimmune pancreatitis is a relatively new form of chronic pancreatitis and should be kept in mind when making a differential diagnosis of pancreatic cancer with the assistance of FDG PET.

ISSN:0363-9762    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

PurposeTo assess the use of a Tc-99m erythrocyte-labeled SPECT scan to characterize a giant splenic hemangioma.MethodsA patient clinically mistaken to have a myelodysplastic disorder underwent a contrast-enhanced CT followed by a Tc-99m erythrocyte-labeled SPECT scan.ResultsCT showed a heterogeneous vascular lesion arising in the spleen. Percutaneous biopsy was nondiagnostic. A Tc-99m erythrocyte-labeled SPECT study revealed findings consistent with a giant splenic hemangioma, which was subsequently confirmed at surgery.ConclusionA Tc-99m erythrocyte-labeled SPECT scan may be very useful in confirming the diagnosis of a large or giant splenic hemangioma.

ISSN:0363-9762    

出版商:OVID    

年代:1999

数据来源: OVID