摘要:

PurposeTc-99m bone scintigraphy is widely used for evaluation of osseous spread of malignant tumors.PatientA 60-year-old man had multiple areas of increased uptake on a bone scan in a pattern considered characteristic for extensive metastatic disease. However, a primary neoplasm could not be identified. Finally, acute myelofibrosis-a rare, fatal myeloproliferative syndrome-was diagnosed.ConclusionTo avoid delays and extensive diagnostic procedures, acute myelofibrosis should be considered in the differential diagnosis of bone scans showing multiple hot spots. In such cases, a diagnosis can be made on an a tissue sample.

ISSN:0363-9762    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

BackgroundPositron emission tomography (PET) with fluorine-18 labeled deoxyglucose (FDG) can detect tumor recurrences in surgical patients that are otherwise difficult to assess by CT, as well as distant metastases and small malignant nodes that are not identified by other imaging modalities. However, the evaluation of such malignancy is complicated by urinary and colonic concentrations of FDG. Methods and examples of the elimination of artifactual accumulation of FDG in PET imaging of the abdomen and pelvis are presented.MethodsElimination of artifactual accumulation requires patient preparation that begins with cleansing of the colon using an isosmotic solution taken the evening prior to examination. Approximately 500 MBq of F-18 FDG is intravenously administered upon arrival at the PET facility and then the patient is hydrated. After administration of furosemide, a Foley catheter with a drainage bag is placed and the patient is then scanned. Just prior to scanning over the pelvis, normal saline is delivered retrogradely into the urinary bladder. At the end of scanning, the patient voids and repeated pelvic images are obtained.ResultsThese routines yield a clean scanning field. Lesions that will generally be missed because they are obscured by FDG accumulations along the colon or in the kidneys, ureters, or bladder are better visualized and identified with greater confidence. Artifacts that lead to misinterpretation also are reduced.ConclusionElimination of artifactual accumulation of FDG in the colon and urinary system is essential if primary cancer, associated adenopathy, or subtle recurrences are to be evaluated in FDG PET imaging of the abdomen and pelvis.

ISSN:0363-9762    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

A radiocolloid study was carried out, after splenectomy, in a 75-year-old man who had idiopathic thrombocytopenic purpura. The patient, who did not have an increase in platelet counts after spleen removal or after platelet infusions, showed radiocolloid accumulation in the lungs and in the bone marrow. This suggested some"activation" of reticuloendothelial cells, perhaps by circulating immune complexes. The left femur (site of an episode of poliomyelitis many years previously) had less radiocolloid uptake than the right.

ISSN:0363-9762    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

A case of nonfunctional struma ovarii preoperatively diagnosed by scintigraphy of the pelvis using I-123 Nal is reported. US, CT, and MRI revealed a multilobulated mass composed of cystic and solid components. CT showed cystic components with slightly high density and MRI showed various signal intensities on T1- and T2-weighted images. I-123-scintigraphy of the pelvis showed uptake in the pelvic mass. Microscopic examination revealed the histologic appearance of thyroid tissue accompanied by follicular adenoma. I-123 scintigraphy of the pelvis was useful for reaching the correct preoperative diagnosis in this patient with nonfunctional struma ovarii.

ISSN:0363-9762    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

A 16-year-old boy had a swollen neck that was a result of multiple endocrine neoplasia Type 2B (MEN 2B). CT revealed bilateral thyroid tumors, swelling of right cervical lymph nodes, and slight enlargement of the right adrenal gland. I-131 metaiodobenzylguanidine (MIBG) scintigraphy demonstrated increased uptake in the right adrenal gland and the left thyroid tumor, but no abnormal uptake in the right thyroid tumor and the right cervical lymph nodes. Postoperative pathologic findings were consistent with the diagnosis of right adrenal medullary hyperplasia, which is a precursor of pheochromocytoma. In patients with MEN 2B, I-131 MIBG scintigraphy in conjunction with CT of the adrenal glands should be performed to determine the disease stage of the adrenal medullae. In the cervical region, the diagnosis was medullary thyroid carcinoma (MTC) in both thyroid tumors and metastases in the right cervical lymph nodes. The right MTC was more aggressive than the left MTC. It is interesting that not all sites of known MTC take up I-131 MIBG to the same degree.

ISSN:0363-9762    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

A 44-year-old man had an intractable right-sided pleural effusion due to cirrhosis, despite the absence of abdominal ascites. Instillation of Tc-99m macroaggregated serum albumin under CT guidance into the peritoneal space demonstrated transdiaphragmatic communication. This finding indicated the necessity for decompressing the portal system to treat the hydrothorax. The diagnostic radionuclide ascites scan may play an important role in the treatment approach to such patients.

ISSN:0363-9762    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

ObjectiveFibrosing alveolitis is a prominent feature of systemic sclerosis (SSc), and accounts for much of the morbidity and mortality of this disease. Sensitive techniques for the detection and monitoring of fibrosing alveolitis could target patients for early therapeutic intervention. The objective of this small pilot study was to assess the frequency and clinical significance of abnormal lung uptake of Tc-99m MIBI, a novel radionuclide imaging agent that selectively accumulates in cells rich in mitochondria.MethodsSixteen patients with SSc and evidence of pulmonary involvement were studied. The uptake of radionuclide in the lungs, and the ratio of pulmonary to cardiac uptake were evaluated after intravenous injection of Tc-99m MIBI. Results were correlated with clinical and laboratory parameters.ResultsLung uptake of Tc-99m MIBI was increased in all 16 SSc patients compared to control patients with coronary heart disease but no evidence of pulmonary abnormality. The degree of isotope uptake in the lungs was correlated with the extent of maximal skin induration and with radiologic evidence of interstitial lung disease, but not with other clinical or laboratory parameters of disease activity or extent of pulmonary involvement. The ratio of pulmonary to cardiac uptake of isotope was also increased in patients with SSc compared to controls.ConclusionAccumulation of Tc-99m MIBI is abnormally elevated in the lungs of SSc patients with pulmonary involvement. Isotope accumulation in the lungs may be related to activation of fibroblasts or endothelial cells. The specificity and sensitivity of Tc-99m MIBI scanning in the detection and monitoring of pulmonary involvement, and its potential role in the management of SSc, deserve further investigation.

ISSN:0363-9762    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Abdominal and, specifically, hepatic abscesses have always been difficult to diagnose clinically. The In-111 leukocyte scan has proven to be a valuable modality assisting in the diagnosis of an abscess. The authors present the case of a 64-year-old man who presented with vague clinical symptoms and inconclusive laboratory data for a hepatic abscess. Both the ultrasound and CT scan were nondiagnostic; however, a distinct cold defect within the liver on an In-111 leukocyte scan resulted in a liver biopsy, confirming the presence of an abscess. The potential causes of cold defects on In-111 WBC scanning and the limitations of this modality are discussed.

ISSN:0363-9762    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

PurposeDifferentiation of recurrent nasopharyngeal carcinoma (NPC) from radiation fibrosis using conventional diagnostic methods can be difficult. The authors prospectively studied patients with NPC to determine the efficacy of Tc-99m MIBI scintigraphy in detecting the primary, residual, and recurrent tumors.Materials and MethodsThe authors performed Tc-99m MIBI SPECT studies of the head and neck and whole-body scans on 21 healthy adult volunteers and 43 patients with NPC before (n = 26) or after (n = 17) radiotherapy. The images were qualitatively assessed by comparing the nasopharyngeal uptake to scalp radioactivity. MIBI uptake index was calculated as a ratio of mean counts per pixel in the normal nasopharynx or tumor to mean counts per pixel in the scalp.ResultsThere was significantly higher uptake of Tc-99m MIBI by NPC than normal nasopharynx and radiation fibrosis (P<.05). The authors determined the optimum cutoff MIBI uptake index value of 1.3 with a sensitivity of 97%, a specificity of 100%, a positive predictive value of 100%, a negative predictive value of 96%, and an accuracy of 98% for diagnosing NPC.ConclusionThis study suggests that Tc-99m MIBI SPECT is useful for detecting primary NPC and for differentiating residual or recurrent tumor from radiation fibrosis. The authors propose the cutoff MIBI uptake index value of 1.3 for diagnosing NPC.

ISSN:0363-9762    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Although hepatic cysts occur in 34-75% of patients with polycystic kidney disease (PKD), infection of hepatic cysts is rare. The detection of infected hepatic cysts in PKD presents diagnostic and therapeutic difficulties, especially when a focus of infected cysts exists with innumerable uncomplicated cysts. The authors describe a 44-year-old woman with PKD who had recurrent infected hepatic cysts that were previously treated with percutaneous drainage and antibiotics. CT revealed innumerable hepatic cysts, but no discrete focus of hepatic infection. An In-111 WBC scan, however, demonstrated intense uptake in the right superior posterior hepatic lobe, consistent with infected hepatic cysts. The patient underwent partial resection of the right hepatic lobe. The patient had no evidence of hepatic infection since resection. A postoperative In-111 WBC scan demonstrated normal uptake in the liver. The In-111 WBC scan not only identified the precise location of the infected hepatic cysts, but also confirmed their complete resection.

ISSN:0363-9762    

出版商:OVID    

年代:1998

数据来源: OVID