ABSTRACT
PURPOSE: This study aimed to determine the diagnostic value of the relative filtration fraction (RFF) assessed by dynamic ⁹⁹mTc-diethylenetriaminepentaacetic acid (⁹⁹mTc-DTPA) renal scintigraphy after angiotensin-converting enzyme (ACE) inhibition for renovascular hypertension (RVHT) diagnosis.METHODS: ⁹⁹mTc-DTPA captopril renal scintigraphy performed in adolescents or adults (≥ 10 years) with suspected RVHT was retrospectively reviewed. The RFF of the affected kidney was qualitatively assessed as the relative glomerular filtration rate during the 2 to 3-min period compared with the relative perfusion during the first 60 s (qualitative RFF) and scored from 1 (definitely same) to 5 (definitely decreased). The quantitative RFF of the affected kidney was obtained by dividing the percentage of glomerular filtration rate by the percentage of renal perfusion.RESULTS: Overall, 173 patients (high probability, n = 15; and low probability, n = 158) were included based on conventional captopril renal scintigraphic criteria. An abnormal qualitative RFF was observed in 12 patients with high probability, and the diagnostic sensitivity was 80.0% (95% CI, 51.9–95.7). The RFF was normal in 152 patients with low probability, and the diagnostic specificity was 96.2% (95% CI, 91.9–98.6). The RFF was lower in patients with high probability than in those with low probability (0.79 ± 0.15 vs. 1.02 ± 0.11, P < 0.0001).CONCLUSIONS: The RFF assessed by dynamic ⁹⁹mTc-DTPA renal scintigraphy after ACE inhibition can detect patients with high probability for RVHT. The RFF after ACE inhibition might be a useful diagnostic criterion especially when baseline scintigraphy is not available for evaluating ACE inhibition-induced changes.
Subject(s)
Adolescent , Adult , Humans , Captopril , Diagnosis , Filtration , Glomerular Filtration Rate , Hypertension, Renovascular , Kidney , Perfusion , Radionuclide Imaging , Retrospective Studies , Sensitivity and SpecificityABSTRACT
PURPOSE@#This study aimed to determine the diagnostic value of the relative filtration fraction (RFF) assessed by dynamic â¹â¹mTc-diethylenetriaminepentaacetic acid (â¹â¹mTc-DTPA) renal scintigraphy after angiotensin-converting enzyme (ACE) inhibition for renovascular hypertension (RVHT) diagnosis.@*METHODS@#â¹â¹mTc-DTPA captopril renal scintigraphy performed in adolescents or adults (≥ 10 years) with suspected RVHT was retrospectively reviewed. The RFF of the affected kidney was qualitatively assessed as the relative glomerular filtration rate during the 2 to 3-min period compared with the relative perfusion during the first 60 s (qualitative RFF) and scored from 1 (definitely same) to 5 (definitely decreased). The quantitative RFF of the affected kidney was obtained by dividing the percentage of glomerular filtration rate by the percentage of renal perfusion.@*RESULTS@#Overall, 173 patients (high probability, n = 15; and low probability, n = 158) were included based on conventional captopril renal scintigraphic criteria. An abnormal qualitative RFF was observed in 12 patients with high probability, and the diagnostic sensitivity was 80.0% (95% CI, 51.9–95.7). The RFF was normal in 152 patients with low probability, and the diagnostic specificity was 96.2% (95% CI, 91.9–98.6). The RFF was lower in patients with high probability than in those with low probability (0.79 ± 0.15 vs. 1.02 ± 0.11, P < 0.0001).@*CONCLUSIONS@#The RFF assessed by dynamic â¹â¹mTc-DTPA renal scintigraphy after ACE inhibition can detect patients with high probability for RVHT. The RFF after ACE inhibition might be a useful diagnostic criterion especially when baseline scintigraphy is not available for evaluating ACE inhibition-induced changes.
ABSTRACT
Brown tumor is the benign bone lesion consists of woven bone and fibrous tissue without matrix, which develop due to chronic excessive osteoclastic activity such as hyperparathyroidism. Usually they appear with normal uptake or occasionally focally increased uptake on bone scan. We present a case with brown tumor shown more increased uptake and more number of lesions on bone scan after parathyroidectomy, and lesser increased uptake on serial bone scans without any other treatment through several months. This finding is thought to be similar to 'flare phenomenon' which is occasionally seen after treatment of metastatic bone lesions of malignant cancer, and may represent curative process of brown tumor with rapid normal bone formation.
Subject(s)
Hyperparathyroidism , Osteoclasts , Osteogenesis , ParathyroidectomyABSTRACT
PURPOSE: This study was performed to know whether [(18)F]Fluorothymidine (FLT) positron emission tomography (PET) can be used to monitor early response to radiotherapy in comparison with [(18)F]Fluorodeoxyglucose (FDG) PET, and to establish the optimal imaging time for prediction of therapy response. MATERIALS AND METHODS: Two patients with nasopharyngeal cancer underwent serial FLT PET and FDG PET before and during radiotherapy. Three on-treatment FLT and FDG PET scans were performed on 1 week, 2 weeks and 3 weeks (at each time of 10 Gy, 20 Gy and 30 Gy delivered). The peak standardized uptake values (SUV(peak)) of primary tumors were measured on FLT and FDG PET. Then, percent changes of SUV(peak) after therapy were calculated. RESULTS: In two patients, baseline values of SUV(peak) on FDT PET were higher than those on FLT PET (FLT vs FDG; 3.7 vs 5.0, and 5.7 vs 15.0). In patient 1, FLT SUV(peak) showed 78%, 78% and 84% of decrease on 1 week, 2 and 3 weeks after treatment, whereas FDG SUV(peak) showed 18%, 52% and 66% of decrease, respectively. In patient 2, FLT SUV(peak) showed 75%, 75% and 68% of decrease, whereas FDG SUV(peak) showed 51%, 49% and 58% of decrease, respectively. Both patients reached to complete remission after radiotherapy. CONCLUSION: After radiotherapy, the decrease of FLT tumor uptake preceded the decrease of FDG tumor uptake in patients with nasopharyngeal cancer, and 1 week after therapy may be appropriate time for the assessment of early response. FLT PET might be more useful than FDG PET for monitoring early response to radiotherapy.
Subject(s)
Humans , Nasopharyngeal Neoplasms , Organothiophosphorus Compounds , Pilot Projects , Positron-Emission TomographyABSTRACT
PURPOSE: The aim of this study was to determine the incidence and malignant rate of incidental asymmetric palatine tonsillar uptake (ATU) on (18)F-FDG PET/CT in various clinical indications and to evaluate the clinical and PET/CT findings suggesting malignancy. MATERIALS AND METHODS: We retrospectively reviewed a total of 2,901 patients (58.4+/-12.3 yrs, range 20~88 yrs, M:F=1,841:1,060) who underwent (18)F-FDG PET/CT during an 1-year period with various indications except primary tonsillar cancer and lymphoma evaluation. On (18)F-FDG PET/CT, metabolic abnormality of the palatine tonsil and cervical lymph node were visually assessed. ATU was defined as increased palatine tonsillar uptake with diffuse, focal, or irregular pattern compared to contralateral side. The incidence and malignant ratio of ATU were evaluated according to clinical and PET/CT findings. RESULTS: Of 2,901 cases, 290 (10.0%) showed ATU. The incidence of ATU showed seasonal variation and was high in the winter (12.1%). Of 209 cases with ATU confirmed pathologically and/or clinically, five (2.4%) were malignant lesions. ATU with irregular uptake pattern (2/2) and in cases referred for cervical lymph node metastasis of unknown origin (3/5) were frequently associated with malignant lesion (p<0.05). CONCLUSION: ATU was not infrequently observed on (18)F-FDG PET/CT, and the malignant risk of ATU was low. However, ATU with cervical lymph node metastasis or with irregular pattern on PET/CT would be further evaluated by the histopathologic examination.