摘要:

This study attempts to find the cause of differences observed between measurements of the thyroid uptake using a thyroid uptake probe and a gamma camera. The thyroid uptakes of 65 patients were measured using the gamma camera with a pinhole collimator and two commercially available thyroid uptake systems. Moreover, simulated thyroid uptake measurements using 0.111 to 7.4 MBq (3 to 200 µCi) of 1-123 were also taken using the same probe systems and gamma cameras. Results of the patient and phantom studies were evaluated by regression analyses. The gamma cameras recorded counts in direct proportion to the amount of 1-123 in the phantom, but the probe systems exhibited a non-linear relationship. A 20% loss of counts was observed with 1.48 Mq (40 µCI), and up to 50% at the dose relating to a clinically administered dose of 7.4 MBq (200 µCi) in the neck phantom. Because of severe dead-time losses at high count rates associated with counting the capsule standard, the uptake ratios were artifactually higher. The 65 patient study showed a similar trend with the probe technique yielding uptake ratios higher than the gamma camera. Users of thyroid uptake systems should calibrate their instrument's counting efficiency in.the dose range of the 1-123 activity to be used clinically. To obtain an accurate uptake ratio, the counts must be corrected by calibration factors corresponding to the efficiency of the probe at multiple counting rates including that from counting the Intended dose before therapy.

ISSN:0363-9762    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

Hyperfunctioning thyroid adenomas causing thyrotoxicosis (Plummer's disease) is not an uncommon cause of hyperthyroidism in the elderly. Most commonly, the adenoma appears as a so-called "hot" nodule on thyroid scintlgraphy causing suppression (i.e., nonvlsualization) of the remainder of the gland. This report describes a case of Plummer's disease in an elderly patient in whom the toxic nodule primarily responsible for causing the hyperthyroidism became sclntigraphically apparent at 96 hours after 1-131 therapeutic ablation.

ISSN:0363-9762    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

The aim of this study was to define the use of the triple radiopharmaceutical renal study (TRRS) for renal scintigraphy as a physiological tool for renal evaluation, and to determine If the sensitivity and/or specificity of a renal study for the diagnosis of renovascular hypertension (RVH) could be improved by the combination of three radiopharmaceuticals (i.e., 1-131 OIH, Tc-99m DTPA, and Tc-99m glucoheptonate). One hundred ninety-five patients with suspected RVH underwent TRRS, standard Tc-99m DTPA renal studies, and renal angiography. One hundred eighty-nine patients were hypertensive and ischemlc nephropathy was suspected in six. Ninety-one, including three patients with ischemic nephropathy, had a renal artery stenosis of 70% or more (66 unilateral, 25 bilateral). Effective renal plasma flow (ERPF), glomerular filtration rate (GFR) (from plasma clearance of 1-131 OIH and Tc-99m DTPA), and geometric renal masses (from Tc-99m glucoheptonate study) were compared to normal values corrected for body surface, to determine the severity of renal dysfunction. For the TRSS, RVH criteria included: 1) differential Tc-99m DTPA function minus differential Tc-99m glucoheptonate function of affected kidney ( < - 5% or > 5%); and 2) functional parameters: ERPF = 1.6-2.0 ml/g/minute, GFR = 0.25-0.4 ml/g/ minute, and filtration fraction (i.e., GFR/ERPF = 0.15- 0.20) on the affected side. For the standard Tc-99m DTPA renogram, two of the following criteria were used for diagnosis of RVH: time to peak (>5 minutes or a difference of more than 1 minute between kidneys), differential uptake (<40%), and cortical excretion rate (T½ > 25 minutes or a difference of more than 5 minutes). The sensitivities of TRRS and standard Tc-99m DTPA were 77% and 68%`, respectively, and the specificities were 83.5% and 68%. Sensitivity was only slightly improved (chl-square test, P < 0.2). However, specificity was significantly higher with TRRS than with standard Tc-99m DTPA (chl-square test, P < 0.01). The combination of the renographic curves and the functional parameters, as done in TRRS, improves sensitivity and mostly specificity, for the detection of renovascular disease. Higher specificity is particularly important in a population with a low prevalence of the disease. As exemplified by this study, TRRS can be a noninvasive test to assess renal physiological parameters, for clinical and research purposes.

ISSN:0363-9762    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

A total of 282 renal scintigrams with Tc-99m DMSA in 238 children ranging in age from 10 days to 13 years performed during a 3-year period were reviewed. The authors present 94 kidneys in 85 children in whom no sign of pathology was demonstrated clinically, either by ultrasound or intravenous urography, or by micturating urethrocystography. By exploring homogeneity or heterogeneity of tracer distribution, kidney length, and background level, the authors were able to identify a "normal" pattern of tracer distribution according to age. They found that the average kidney length was 56 mm at birth, growing 1 mm per month during the first year of life, and 4 mm per year thereafter, until puberty. Average background activity was 14% of the average kidney activity at birth which decreased to approximately 6% during the first year of life, with no further decrease thereafter.

ISSN:0363-9762    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

The authors present a patient with Fanconi syndrome who demonstrated poor renal uptake of Tc-99m DMSA and high urinary concentration of the tracer. Tc-99m DTPA imaging was normal and the creatinine clearance was only minimally decreased. These findings suggest that Tc-99m DMSA may be accumulated in the kidney by glomerular filtration and subsequent tubular reabsorption. A Tc-99m MDP bone scan showed faint renal uptake, as well as diffuse high skeletal uptake, particularly in the spine, demonstrating that the metabolic bone disease associated with Fanconi syndrome can be one of the causes of poor renal visualization on a bone scan.

ISSN:0363-9762    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

Single and dual radionucllde techniques have been described in localization of parathyroid adenomas. Although single radionucllde Imaging with Tc-99m sestamibi has many advantages, it can fail to demonstrate a parathyroid adenoma, which, In the case presented, is well demonstrated with dual radionucllde imaging. The authors recommend dual tracer imaging when searching for parathyroid adenoma.

ISSN:0363-9762    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

The authors describe a case In which Tc-99m sestamibi demonstrated increased vascularlty and uptake in a hyperfunctioning autograft in a patient with recurrent hyperparathyroidism and multiple endocrine neoplasia type 1. Findings were confirmed by differential parathyroid hormone levels in antecubital venous blood samples, ultrasound with color Doppler, MRI, and surgery.

ISSN:0363-9762    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

Gastric accumulation of Ga-67 greater than that seen in the liver was observed in 16 of 162 (9.8%) patients with lymphoma. Endoscopic biopsies in six patients showed one instance each of histiocytic lymphoma, mixed cellularity Hodgkin's disease, adenocarcinoma, and hiatal hernia with mucosal deformity, as well as two instances of benign gastric ulcer. All six patients had chronic gastric symptoms, as well as persistent radiogallium accumulation on sequential examinations of 2 years duration. The remaining 10 patients exhibited transient radiotracer gastric uptake and only two had gastric symptoms. Persistent gastric Ga-67 accumulation is not common in lymphoma and warrants endoscopy when accompanied by prolonged symptoms.

ISSN:0363-9762    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

lndlum-111 satumomab pendetide (ln-111 OncoScint) planar and SPECT imaging and F-18 FDG positron emission tomography (PET) have been found individually to be helpful in the detection of recurrent colorectal and ovarian cancer, but have not been compared. Twelve patients who were examined for recurrent colorectal or ovarian carcinoma underwent both ln-111 OncoScint imaging and F-18 FDG PET imaging. All had normal or equivocal results of CT or MR studies. Tumor detection abilities were similar in most cases. However, Oncoscint demonstrated an advantage in the detection of carcinomatosls. PET demonstrated an advantage in detecting focal tumor recurrence in one case and, not unexpectedly, In detecting liver metastases. All positive nuclear studies for tumor were found to be true-positives at pathology (7 patients), or by diagnostic new CT changes (1 patient). Finally, unreported, bone marrow, bowel, and colostomy sites appear to be normal sites of localization of F-18 FDG 1 hour after injection.

ISSN:0363-9762    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

ln-111 pentetreotide has been recommended for the detection of somatostatin receptor (SSR) positive tumors. Sites with increased numbers of activated lymphocytes may also show ln-111 pentetreotide with Graves' cphthalmopathy (GO) compared to various other orbital disorders. Five patients with GO, three patients with necrotizing scleritis, and two patients with orbital pseudotumor were imaged at 4 hours, 24 hours, and 48 hours after injection of ln-111 pentetreotide. Although planar images did not show considerable uptake, SPECT slices showed marked and persistent uptake in the orbits unilaterally in one patient, and bilaterally in three patients with GO. There was no significant correlation between the ln-111 pentetreotide activity and the degree of ophthalmopathy determined by Werner's classification. Pseudotumors also showed positive uptake. Early uptake was present in one patient with necrotizing scleritis because of Wegener's granulomatosis, and was completely diminished at 24 hours. Octreotide treatment in three patients with GO did not cause any clinical improvement. Although the presence of SSR, either on the infiltrated lymphocytes or on fibroblasts, implies that octreotide treatment for GO can be considered, the results are not encouraging. Nonspecific binding might be present when uptake patterns of orbits and persistence of activity during octreotide treatment are considered.

ISSN:0363-9762    

出版商:OVID    

年代:1995

数据来源: OVID