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INTRODUCTION: To perform a head-to-head comparison of the uptake pattern of F-18 fluorodeoxyglucose in positron emission computed tomography (FDG PET/CT) in radioiodine refractory thyroid carcinomas (RAIR) in the same patient under elevated TSH levels (eTSH) and suppressed TSH levels (sTSH). METHODS: FDG PET/CT studies were performed under two conditions: levothyroxine intake (sTSH) and 30 days after hormonal withdrawal (eTSH). SUVmax values and the number of lesions detected (local recurrence and metastases in cervical and distant lymph nodes, lungs and bone) where blindly evaluated. Blood serum TSH and Tg levels were obtained prior to both studies. FDG PET/CT imaging, neck ultrasound, biopsy and follow-up were considered the reference standard. RESULTS: Fifteen patients performed both eTSH and sTSH FDG PET/CT studies. Both were positive for metastases in 80% of the patients. eTSH FDG PET/CT studies did not reveal increased uptake (p = 0.0640) and did not demonstrate a higher number of lesions (p = 0.320) when compared to sTSH FDG PET/CT studies. There was no change in the clinical management of these patients. CONCLUSIONS: eTSH FDG PET/CT in patients with RAIR did not show more metastases in comparison to sTSH FDG PET/CT and there was no impact in clinical management of patients. Elevating TSH levels (whether by hormonal withdrawal or recombinant TSH) in patients being submitted to FDG PET/CT may not be necessary.

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ABSTRACT Objective: To investigate, in a large prospective multicenter study, whether 2-[18F]-fluoro-2-deoxy-D-glucose-positron emission tomography is sufficiently accurate to identify clinically important bone marrow involvement by Hodgkin's lymphoma to replace routine bone marrow biopsy in a developing tropical country. Methods: Patients newly diagnosed with Hodgkin's lymphoma were recruited from six cancer centers in Brazil. All were staged by the results of positron emission tomography/computed tomography that were centrally reviewed and by iliac crest bone marrow biopsy. Patients were classified as having marrow disease if they had lymphoma identified by marrow biopsy histology or had focal 2-[18F]-fluoro-2-deoxy-D-glucose marrow uptake that resolved following chemotherapy. Results: A total of 246 participants were recruited from six different centers and 62 (25.2%) were judged to have Hodgkin's lymphoma in the bone marrow. Positron emission tomography and biopsies were concordant in 206 patients (83%). Positron emission tomography correctly identified marrow disease in 59/62 patients (95.1%) and marrow biopsy in 25/62 patients (40.3%). In 22/62 (35.4%) patients, the two techniques were concordant in the diagnosis of marrow involvement. Of the forty discordant results, positron emission tomography found bone marrow involvement in 37 patients, upstaging 22 to stage IV and having an impact on therapeutic decision in nine cases given their reallocation from early to advanced stage. Three false negative positron emission tomography results were obtained with bone marrow biopsy giving positive findings. All three cases were classified as stage IV regardless of bone marrow findings implying no modification in the clinical management. The sensitivity, specificity and accuracy of positron emission tomography for detecting bone marrow disease were 95%, 100% and 98% and for bone marrow biopsy they were 40%, 100% and 84%, respectively. Conclusion: We conclude that positron emission tomography can replace marrow biopsy in Brazilian patients with Hodgkin's lymphoma without compromising clinical management.

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OBJECTIVE: To investigate, in a large prospective multicenter study, whether 2-[18F]-fluoro-2-deoxy-d-glucose-positron emission tomography is sufficiently accurate to identify clinically important bone marrow involvement by Hodgkin's lymphoma to replace routine bone marrow biopsy in a developing tropical country. METHODS: Patients newly diagnosed with Hodgkin's lymphoma were recruited from six cancer centers in Brazil. All were staged by the results of positron emission tomography/computed tomography that were centrally reviewed and by iliac crest bone marrow biopsy. Patients were classified as having marrow disease if they had lymphoma identified by marrow biopsy histology or had focal 2-[18F]-fluoro-2-deoxy-d-glucose marrow uptake that resolved following chemotherapy. RESULTS: A total of 246 participants were recruited from six different centers and 62 (25.2%) were judged to have Hodgkin's lymphoma in the bone marrow. Positron emission tomography and biopsies were concordant in 206 patients (83%). Positron emission tomography correctly identified marrow disease in 59/62 patients (95.1%) and marrow biopsy in 25/62 patients (40.3%). In 22/62 (35.4%) patients, the two techniques were concordant in the diagnosis of marrow involvement. Of the forty discordant results, positron emission tomography found bone marrow involvement in 37 patients, upstaging 22 to stage IV and having an impact on therapeutic decision in nine cases given their reallocation from early to advanced stage. Three false negative positron emission tomography results were obtained with bone marrow biopsy giving positive findings. All three cases were classified as stage IV regardless of bone marrow findings implying no modification in the clinical management. The sensitivity, specificity and accuracy of positron emission tomography for detecting bone marrow disease were 95%, 100% and 98% and for bone marrow biopsy they were 40%, 100% and 84%, respectively. CONCLUSION: We conclude that positron emission tomography can replace marrow biopsy in Brazilian patients with Hodgkin's lymphoma without compromising clinical management.

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OBJECTIVE: To evaluate suspicious amorphous calcifications diagnosed on full-field digital mammography (FFDM) and establish correlations with histopathology findings. MATERIALS AND METHODS: This was a retrospective study of 78 suspicious amorphous calcifications (all classified as BI-RADS® 4) detected on FFDM. Vacuum-assisted breast biopsy (VABB) was performed. The histopathological classification of VABB core samples was as follows: pB2 (benign); pB3 (uncertain malignant potential); pB4 (suspicion of malignancy); and pB5 (malignant). Treatment was recommended for pB5 lesions. To rule out malignancy, surgical excision was recommended for pB3 and pB4 lesions. Patients not submitted to surgery were followed for at least 6 months. RESULTS: Among the 78 amorphous calcifications evaluated, the histopathological analysis indicated that 8 (10.3%) were malignant/suspicious (6 classified as pB5 and 2 classified as pB4) and 36 (46.2%) were benign (classified as pB2). The remaining 34 lesions (43.6%) were classified as pB3: 33.3% were precursor lesions (atypical ductal hyperplasia, lobular neoplasia, or flat epithelial atypia) and 10.3% were high-risk lesions. For the pB3 lesions, the underestimation rate was zero. CONCLUSION: The diagnosis of precursor lesions (excluding atypical ductal hyperplasia, which can be pB4 depending on the severity and extent of the lesion) should not necessarily be considered indicative of underestimation of malignancy. Suspicious amorphous calcifications correlated more often with precursor lesions than with malignant lesions, at a ratio of 3:1.

OBJETIVO: Correlacionar o achado mamográfico de calcificações amorfas suspeitas diagnosticadas na mamografia digital com seus diagnósticos anatomopatológicos. MATERIAIS E MÉTODOS: Setenta e oito casos de calcificações amorfas suspeitas (todas classificadas como BI-RADS® 4) detectadas na mamografia digital e submetidas a biópsia percutânea assistida à vácuo foram retrospectivamente avaliados. A classificação anatomopatológica utilizada na biópsia foi: pB2 para lesão benigna, pB3 para lesão com potencial incerto de malignidade, pB4 para lesão suspeita, e pB5 para lesão considerada maligna. O tratamento foi recomendado para as lesões pB5, a exérese cirúrgica foi indicada para lesões pB3 e pB4, para descartar malignidade, e o seguimento evolutivo foi adotado para as demais pacientes. RESULTADOS: A histologia demonstrou 8 (10,3%) casos malignos (6 lesões pB5 e 2 lesões pB4) e 36 (46,2%) casos benignos (pB2). As demais 34 (43,6%) lesões foram classificadas como pB3 (33,3% foram lesões precursoras - hiperplasia ductal atípica, neoplasia lobular ou atipia epitelial plana - e 10,3% foram lesões de alto risco). A taxa de subestimação das lesões pB3 foi zero. CONCLUSÃO: O diagnóstico de lesões precursoras (excluindo hiperplasia ductal atípica, que pode corresponder a lesão pB4 dependendo da severidade e extensão dos achados) na biópsia percutânea assistida à vácuo por calcificações amorfas suspeitas não necessariamente representa lesão subestimada. Calcificações amorfas suspeitas se associaram a lesões precursoras numa proporção de 3:1 em relação às lesões malignas.

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Abstract Objective: To evaluate suspicious amorphous calcifications diagnosed on full-field digital mammography (FFDM) and establish correlations with histopathology findings. Materials and Methods: This was a retrospective study of 78 suspicious amorphous calcifications (all classified as BI-RADS® 4) detected on FFDM. Vacuum-assisted breast biopsy (VABB) was performed. The histopathological classification of VABB core samples was as follows: pB2 (benign); pB3 (uncertain malignant potential); pB4 (suspicion of malignancy); and pB5 (malignant). Treatment was recommended for pB5 lesions. To rule out malignancy, surgical excision was recommended for pB3 and pB4 lesions. Patients not submitted to surgery were followed for at least 6 months. Results: Among the 78 amorphous calcifications evaluated, the histopathological analysis indicated that 8 (10.3%) were malignant/suspicious (6 classified as pB5 and 2 classified as pB4) and 36 (46.2%) were benign (classified as pB2). The remaining 34 lesions (43.6%) were classified as pB3: 33.3% were precursor lesions (atypical ductal hyperplasia, lobular neoplasia, or flat epithelial atypia) and 10.3% were high-risk lesions. For the pB3 lesions, the underestimation rate was zero. Conclusion: The diagnosis of precursor lesions (excluding atypical ductal hyperplasia, which can be pB4 depending on the severity and extent of the lesion) should not necessarily be considered indicative of underestimation of malignancy. Suspicious amorphous calcifications correlated more often with precursor lesions than with malignant lesions, at a ratio of 3:1.

Resumo Objetivo: Correlacionar o achado mamográfico de calcificações amorfas suspeitas diagnosticadas na mamografia digital com seus diagnósticos anatomopatológicos. Materiais e Métodos: Setenta e oito casos de calcificações amorfas suspeitas (todas classificadas como BI-RADS® 4) detectadas na mamografia digital e submetidas a biópsia percutânea assistida à vácuo foram retrospectivamente avaliados. A classificação anatomopatológica utilizada na biópsia foi: pB2 para lesão benigna, pB3 para lesão com potencial incerto de malignidade, pB4 para lesão suspeita, e pB5 para lesão considerada maligna. O tratamento foi recomendado para as lesões pB5, a exérese cirúrgica foi indicada para lesões pB3 e pB4, para descartar malignidade, e o seguimento evolutivo foi adotado para as demais pacientes. Resultados: A histologia demonstrou 8 (10,3%) casos malignos (6 lesões pB5 e 2 lesões pB4) e 36 (46,2%) casos benignos (pB2). As demais 34 (43,6%) lesões foram classificadas como pB3 (33,3% foram lesões precursoras - hiperplasia ductal atípica, neoplasia lobular ou atipia epitelial plana - e 10,3% foram lesões de alto risco). A taxa de subestimação das lesões pB3 foi zero. Conclusão: O diagnóstico de lesões precursoras (excluindo hiperplasia ductal atípica, que pode corresponder a lesão pB4 dependendo da severidade e extensão dos achados) na biópsia percutânea assistida à vácuo por calcificações amorfas suspeitas não necessariamente representa lesão subestimada. Calcificações amorfas suspeitas se associaram a lesões precursoras numa proporção de 3:1 em relação às lesões malignas.

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A 32-year-old woman presented with progressive myalgia, bone pain, fatigue, insufficiency hip fractures, high urine phosphate, and low serum phosphate and vitamin D levels. These findings were suggestive of oncogenic osteomalacia. A whole-body Tc-octreotide scintigraphy with SPECT/CT showed uptake on a sclerotic intramedullary lesion in the left medial tibia plateau. MRI depicted a solid lesion. The lesion was surgically removed; the patient became asymptomatic, and follow-up laboratory results normalized. Histopathologic examination revealed a vascular hemangiopericytoma-like tumor, positive for somatostatin receptor (SSR-2). Whole-body Tc-octreotide scintigraphy with SPECT/CT may detect occult oncogenic osteomalacia tumors.

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UNLABELLED: There are different metabolic imaging methods, various tracers, and emerging anatomic modalities to stage neuroendocrine tumor (NET). We aimed to compare NET lesion detectability among (99m)Tc-hydrazinonicotinamide (HYNIC)-octreotide (somatostatin receptor scintigraphy [SSRS]) SPECT/CT, (68)Ga-DOTATATE PET/CT, and whole-body diffusion-weighted MR imaging (WB DWI). METHODS: Nineteen consecutive patients (34-77 y old; mean, 54.3 ± 10.4 y old; 10 men and 9 women) underwent SSRS SPECT/CT, (68)Ga-DOTATATE PET/CT, and WB DWI. Images were acquired with a maximum interval of 3 mo between them and were analyzed with masking by separate teams. Planar whole-body imaging and SPECT/CT were performed from thorax to pelvis using a double-head 16-slice SPECT/CT scanner 4 h after injection of 111-185 MBq of (99m)Tc-HYNIC-octreotide. (68)Ga-DOTATATE PET/CT was performed from head to feet using a 16-slice PET/CT scanner 45 min after injection of 185 MBq of tracer. WB DWI was performed in the coronal plane using a 1.5-T scanner and a body coil. The standard method of reference for evaluation of image performance was undertaken: consensus among investigators at the end of the study, clinical and imaging follow-up, and biopsy of suggestive lesions. RESULTS: McNemar testing was applied to evaluate the detectability of lesions using (68)Ga-DOTATATE PET/CT in comparison to SSRS SPECT/CT and WB DWI: a significant difference in detectability was noted for pancreas (P = 0.0455 and P = 0.0455, respectively), gastrointestinal tract (P = 0.0455 and P = 0.0455), and bones (P = 0.0082 and P = 0.0082). Two unknown primary lesions were identified solely by (68)Ga-DOTATATE PET/CT. (68)Ga-DOTATATE PET/CT, SSRS SPECT/CT, and WB DWI demonstrated, respectively, sensitivities of 0.96, 0.60, and 0.72; specificities of 0.97, 0.99, and 1.00; positive predictive values of 0.94, 0.96, and 1.00; negative predictive values of 0.98, 0.83, and 0.88; and accuracies of 0.97, 0.86, and 0.91. CONCLUSION: (68)Ga PET/CT seems to be more sensitive for detection of well-differentiated NET lesions, especially for bone and unknown primary lesions. NET can be staged with (68)Ga-DOTATATE PET/CT. WB DWI is an efficient new method with high accuracy and without ionizing radiation exposure. SSRS SPECT/CT should be used only when (68)Ga-DOTATATE PET/CT and WB DWI are not available.

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Cervical uptake detected by 131I whole body scintigraphy (131I-WBS) may be due to thyroid remnants or loco-regional metastases. We describe a patient with follicular carcinoma submitted to total thyroidectomy. 131I-WBS showed left cervical linear uptake and focal areas of uptake in the abdomen and pelvis. SPECT/CT images demonstrated a potential thrombus in the left jugular vein (confirmed by doppler neck ultrasound and MRI) as well as bone metastases. The patient was submitted to thrombectomy and histopathology confirmed metastasis of follicular carcinoma.

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A 43-year-old man, previously submitted to right hepatectomy, right hepatic artery chemoembolization, and surgical resection of liver lesions, with well-differentiated and moderately differentiated hepatocellular carcinoma (HCC) confirmed by histopathology, underwent cholescintigraphy with Tc diisopropyliminodiacetic acid (Tc-DISIDA) due to recurrent cholangitis. The scintigraphic images and the coregistered CT images showed radiotracer uptake in an area of biliary ectasia near the hepatic surface (which may be associated with recurrent cholangitis), in a hepatic nodule, and in multiple pulmonary metastases.

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OBJECTIVE: This study was aimed to evaluate myocardial perfusion in asymptomatic patients with type 1 (DM1) and type 2 diabetes mellitus (DM2) without previous diagnoses of coronary artery disease (CAD) or cerebral infarction. MATERIALS AND METHODS: Fifty-nine consecutive asymptomatic patients (16 DM1, 43 DM2) underwent myocardial perfusion scintigraphy with 99mTc-sestamibi (MPS). They were evaluated for body mass index, metabolic control of DM, type of therapy, systemic arterial hypertension, dyslipidemia, nephropathy, retinopathy, peripheral neuropathy, smoking, and familial history of CAD. RESULTS: MPS was abnormal in 15 patients (25.4%): 12 (20.3%) with perfusion abnormalities, and 3 with isolated left ventricular dysfunction. The strongest predictors for abnormal myocardial perfusion were: age 60 years and above (p = 0.017; odds ratio [OR] = 6.0), peripheral neuropathy (p = 0.028; OR = 6.1), nephropathy (p = 0.031; OR = 5.6), and stress ECG positive for ischemia (p = 0.049; OR = 4.08). CONCLUSION: Silent myocardial ischemia occurs in more than one in five asymptomatic diabetic patients. The strongest predictors of ischemia in this study were: patient age, peripheral neuropathy, nephropathy, retinopathy and a stress ECG positive for ischemia.

OBJETIVO: Este estudo teve por finalidade avaliar a perfusão miocárdica de pacientes com diabetes mellitus tipo 1 (DM1) e tipo 2 (DM2) assintomáticos, sem diagnóstico prévio de doença arterial coronariana (DAC) ou acidente vascular cerebral. MATERIAIS E MÉTODOS: Cinquenta e nove pacientes consecutivos (16 DM1, 43 DM2) foram submetidos a cintilografia de perfusão miocárdica com sestamibi-99mTc (CPM). Foram avaliados quanto ao índice de massa corpórea, controle metabólico do diabetes, dislipidemia, terapia para o diabetes, hipertensão arterial sistêmica, nefropatia, retinopatia, neuropatia periférica, tabagismo e história familiar de DAC. RESULTADOS: CPM foi anormal em 25,4%: 12 (20,3%) com alterações de perfusão e 3 com disfunção ventricular esquerda isolada. Os mais fortes preditores de perfusão miocárdica anormal foram: idade igual ou maior a 60 anos (p = 0,017, odds ratio [OR] = 6,0), neuropatia periférica (p = 0,028, OR = 6,1), nefropatia (p = 0,031, OR = 5,6) e ECG de esforço positivo para isquemia (p = 0,049, OR = 4,08). CONCLUSÃO: A isquemia miocárdica silenciosa ocorre em mais de um em cada cinco diabéticos assintomáticos. Os mais fortes preditores de isquemia foram: idade avançada, neuropatia periférica, nefropatia, retinopatia e ECG de esforço positivo para isquemia.

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BACKGROUND: This study aimed to compare the clinical target volumes (CTV) delineated by computed tomography (CT) and positron emission tomography (PET)/CT using fluoro-deoxy-glucose to assess the impact of using PET information for radiotherapy (RT) planning. METHODS: We retrospectively reviewed data on patients with tumors from different sites who had indications for RT and had undergone RT treatment planning with PET/CT at our institution between July 2003 and July 2009. Statistical analysis included the comparison of CTV planned for treatment only by CT (CTV(CT)) with that by PET/CT (CTV(PET)) using the Wilcoxon test for paired samples. RESULTS: Of 105 patients eligible for analysis, 56.2% were men. The most common diagnoses were head and neck cancer (28.6%), lung cancer (21.9%), lymphoma (11.4%), upper gastrointestinal (10.5%), and others (14.3%). Comparison of CTV(CT) and CTV(PET) revealed that RT planning has changed in 77% of cases because of PET/CT additional information, with impact on treatment volume varying according to diagnosis. Despite the absolute difference observed between median CTVs, there was no significant difference between CTV(CT) and CTV(PET) (114 vs. 90.4 ml, respectively; P=0.1266), considering all patients. Nonetheless, a significant difference between CTVs delineated by CT and PET/CT was found when only head and neck, lung and lymphoma cases--representing more than 60% of the sample--were examined (112.5 and 80.7 ml, respectively; P=0.0053). CONCLUSION: We have shown that PET/CT use promotes significant changes in the CTV delineated for treatment of different tumors, modifying RT planning. Our data suggest that PET/CT has a good potential for optimizing RT treatment planning, especially in head and neck, lung, and lymphoma tumors.

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OBJECTIVE: Demonstrate brain perfusion changes due to neuronal activation after functional electrical stimulation (FES). METHOD: It was studied 14 patients with hemiplegia who were submitted to a program with FES during fourteen weeks. Brain perfusion SPECT was performed before and after FES therapy. These patients were further separated into 2 groups according to the hemiplegia cause: cranial trauma and major vascular insults. All SPECT images were analyzed using SPM. RESULTS: There was a significant statistical difference between the two groups related to patient's ages and extent of hypoperfusion in the SPECT. Patients with cranial trauma had a reduction in the hypoperfused area and patients with major vascular insult had an increase in the hypoperfused area after FES therapy. CONCLUSION: FES therapy can result in brain perfusion improvement in patients with brain lesions due to cranial trauma but probably not in patients with major vascular insults with large infarct area.

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OBJECTIVE: Demonstrate brain perfusion changes due to neuronal activation after functional electrical stimulation (FES). METHOD: It was studied 14 patients with hemiplegia who were submitted to a program with FES during fourteen weeks. Brain perfusion SPECT was performed before and after FES therapy. These patients were further separated into 2 groups according to the hemiplegia cause: cranial trauma and major vascular insults. All SPECT images were analyzed using SPM. RESULTS: There was a significant statistical difference between the two groups related to patient's ages and extent of hypoperfusion in the SPECT. Patients with cranial trauma had a reduction in the hypoperfused area and patients with major vascular insult had an increase in the hypoperfused area after FES therapy. CONCLUSION: FES therapy can result in brain perfusion improvement in patients with brain lesions due to cranial trauma but probably not in patients with major vascular insults with large infarct area.

OBJETIVO: Demonstrar mudanças na perfusão cerebral devido à ativação neuronal depois de estimulação elétrica funcional (EEF). MÉTODO: Foram estudados 14 pacientes com hemiplegia submetidos a quatorze semanas de um programa com EEF. O SPECT de perfusão cerebral foi realizado antes e depois da terapia com EEF. Estes pacientes foram separados em 2 grupos com relação à causa da hemiplegia: trauma craniano e acidente vascular cerebral (AVC). As imagens de SPECT foram analisadas usando SPM. RESULTADOS: Houve diferença estatisticamente significativa entre os dois grupos relacionada a idade dos pacientes e extensão da hipoperfusão. Os pacientes com trauma craniano tiveram redução na área de hipoperfusão e pacientes com AVC tiveram aumento na área de hipoperfusão após terapia com EEF. CONCLUSÃO: A terapia com EEF pode levar a melhora na perfusão cerebral em pacientes com lesões cerebrais secundárias a trauma craniano; entretanto, provavelmente não em pacientes com extensas áreas de infarto secundárias a AVC.

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OBJECTIVE: To compare the accuracy of SPM and visual analysis of brain SPECT in patients with mesial temporal lobe epilepsy (MTLE). METHOD: Interictal and ictal SPECTs of 22 patients with MTLE were performed. Visual analysis were performed in interictal (VISUAL(inter)) and ictal (VISUAL(ictal/inter)) studies. SPM analysis consisted of comparing interictal (SPM(inter)) and ictal SPECTs (SPM(ictal)) of each patient to control group and by comparing perfusion of temporal lobes in ictal and interictal studies among themselves (SPM(ictal/inter)). RESULTS: For detection of the epileptogenic focus, the sensitivities were as follows: VISUAL(inter)=68%; VISUAL(ictal/inter)=100%; SPM(inter)=45%; SPM(ictal)=64% and SPM(ictal/inter)=77%. SPM was able to detect more areas of hyperperfusion and hypoperfusion. CONCLUSION: SPM did not improve the sensitivity to detect epileptogenic focus. However, SPM detected different regions of hypoperfusion and hyperperfusion and is therefore a helpful tool for better understand pathophysiology of seizures in MTLE.

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UNLABELLED: Brain SPECT imaging (BSI) with statistical parametric mapping (SPM) offers a clear and accurate vision of perfusion changes. OBJECTIVE: To study brain perfusion abnormalities in adolescents' dependent of multiple drugs. METHOD: Sixteen male patients (15.1 + or - 2.1 years) were submitted to (99m)Tc-HMPAO BSI with SPM. RESULTS: Cortical hypoperfusion occurred in 7/16 patients (44%). There was a significant inverse correlation between the number of hypoperfused regions and the patient's age (p= -0.6737; p=0.004) and with the age when the drug dependence began (p= -0.5616; p=0.023). There was also a tendency towards an inverse correlation between regions of hypoperfusion and the duration of the drug dependence. CONCLUSION: BSI with SPM can help detect hypoperfusion in adolescents dependent on multiple drugs. The younger the patients, the more regions of hypoperfusion are noted. Probably, the neuronal plasticity has an important role in this phenomenon because the highest neural activity occurs in childhood.

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Brain SPECT imaging (BSI) with statistical parametric mapping (SPM) offers a clear and accurate vision of perfusion changes. OBJECTIVE: To study brain perfusion abnormalities in adolescents' dependent of multiple drugs. METHOD: Sixteen male patients (15.1±2.1 years) were submitted to 99mTc-HMPAO BSI with SPM. RESULTS: Cortical hypoperfusion occurred in 7/16 patients (44 percent). There was a significant inverse correlation between the number of hypoperfused regions and the patient's age (p= -0.6737; p=0.004) and with the age when the drug dependence began (p= -0.5616; p=0.023). There was also a tendency towards an inverse correlation between regions of hypoperfusion and the duration of the drug dependence. CONCLUSION: BSI with SPM can help detect hypoperfusion in adolescents dependent on multiple drugs. The younger the patients, the more regions of hypoperfusion are noted. Probably, the neuronal plasticity has an important role in this phenomenon because the highest neural activity occurs in childhood.

SPECT cerebral (SC) com statistical parametric mapping (SPM) oferece uma visão clara e acurada de alterações perfusionais. OBJETIVO: Avaliar anormalidades perfusionais cerebrais em adolescentes usuários de múltiplas drogas. MÉTODO: Dezesseis pacientes masculinos (15,1±2,1 anos) foram submetidos a SC com SPM utilizando-se HMPAO-99mTc. RESULTADOS: Hipoperfusão cortical ocorreu em 7/16 pacientes (44 por cento). Houve uma significativa correlação inversa entre o número de áreas hipoperfundidas e a idade dos pacientes (p= -0,6737; p=0,004) e com a idade quando iniciaram o abuso das drogas (p= -0,5616; p=0,023). Também houve uma tendência para uma correlação inversa entre as áreas de hipoperfusão e a duração do abuso de drogas. CONCLUSÃO: SC com SPM pode auxiliar na detecção de hipoperfusão cortical em adolescentes dependentes de múltiplas drogas. Quanto menor a idade, mais áreas de hipoperfusão são identificadas. Provavelmente a plasticidade neuronal tem importante papel neste fenômeno, pois a maior atividade neuronal ocorre na infância.

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OBJECTIVE: To compare the accuracy of SPM and visual analysis of brain SPECT in patients with mesial temporal lobe epilepsy (MTLE). METHOD: Interictal and ictal SPECTs of 22 patients with MTLE were performed. Visual analysis were performed in interictal (VISUAL(inter)) and ictal (VISUAL(ictal/inter)) studies. SPM analysis consisted of comparing interictal (SPM(inter)) and ictal SPECTs (SPM(ictal)) of each patient to control group and by comparing perfusion of temporal lobes in ictal and interictal studies among themselves (SPM(ictal/inter)). RESULTS: For detection of the epileptogenic focus, the sensitivities were as follows: VISUAL(inter)=68 percent; VISUAL(ictal/inter)=100 percent; SPM(inter)=45 percent; SPM(ictal)=64 percent and SPM(ictal/inter)=77 percent. SPM was able to detect more areas of hyperperfusion and hypoperfusion. CONCLUSION: SPM did not improve the sensitivity to detect epileptogenic focus. However, SPM detected different regions of hypoperfusion and hyperperfusion and is therefore a helpful tool for better understand pathophysiology of seizures in MTLE.

OBJETIVO: Comparar a acurácia do SPM com a análise visual na detecção do foco epileptogênico e alterações perfusionais à distância no SPECT cerebral. MÉTODO: Foram realizados os SPECTs ictal e interictal de 22 pacientes com epilepsia de lobo temporal mesial (ELTM). A análise visual foi realizada nos estudos interictal (VISUAL(inter)) e ictal (VISUAL(ictal/inter)). Na análise com SPM foi comparado o estudo interictal (SPM(inter)) e ictal (SPM(ictal)) de cada paciente com o grupo controle e comparou-se a perfusão dos lobos temporais entre os estudos ictal e interictal (SPM(ictal/inter)). RESULTADOS: Para a detecção do foco epileptogênico, as sensibilidades foram as seguintes: VISUAL(inter)=68 por cento; VISUAL(ictal/inter)=100 por cento; SPM(inter)=45 por cento; SPM(ictal)=64 por cento and SPM(ictal/inter)=77 por cento. O SPM foi capaz de detectar mais áreas de hiperperfusão e hipoperfusão. CONCLUSÃO: O SPM não aumentou a sensibilidade na detecção do foco epileptogênico. Entretanto, o SPM detectou diferentes regiões de hipoperfusão e hiperperfusão e portanto, ele pode ser uma ferramenta de ajuda para se melhor entender a patofisiologia das crises na ELTM.

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PURPOSE OF THE REPORT: To compare thyroid imaging using Tc-99m sestamibi with the standard Tc-99m pertechnetate scintigraphy in patients on chronic use of amiodarone. MATERIALS AND METHODS: A total of 23 patients on oral amiodarone for at least 4 months had thyroid scintigraphy and uptake measurement using Tc-99m pertechnetate and Tc-99m sestamibi. Thyroid function was evaluated by measuring serum concentrations of thyrotropin, free thyroxine, and free triiodothyronine, and antithyroglobulin and antithyroperoxidase antibodies. RESULTS: Ten of the 23 patients were euthyroid, 9 hypothyroid, and 4 hyperthyroid, with normal, increased, and decreased serum thyrotropin, respectively. All euthyroid patients had markedly decreased thyroid Tc-99m pertechnetate uptake and normal or slightly increased Tc-99m sestamibi uptake, except for one patient who had increased uptake of both radiotracers. One of the 4 hyperthyroid patients had Graves' disease and markedly increased thyroid uptake of both tracers. The other 3 hyperthyroid patients had normal or decreased Tc-99m pertechnetate uptake and increased Tc-99m sestamibi uptake. Differently than expected, all 9 hypothyroid patients had normal or increased uptake of both radiopharmaceuticals. CONCLUSIONS: This study suggests that Tc-99m sestamibi may be an alternative tracer for thyroid scintigraphy and uptake measurement of patients on chronic use of amiodarone. Tc-99m sestamibi seems to be better than Tc-99m pertechnetate for the scintigraphic evaluation of the thyroid of euthyroid and hyperthyroid patients.

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CONTEXT AND OBJECTIVE: Studies using radionuclides are the most appropriate method for estimating renal function. Dimercaptosuccinic acid chelate labeled with technetium-99m (99mTc-DMSA) is the radiopharmaceutical of choice for high-resolution imaging of the renal cortex and estimation of the functional renal mass. The aim of this study was to evaluate a simplified method for determining the absolute renal uptake (ARU) of 99mTc-DMSA prior to nephrectomy, using the radioactivity counts of nephrectomy specimens as the gold standard. DESIGN AND SETTING: Prospective study at the Division of Nuclear Medicine, Department of Radiology, Universidade Estadual de Campinas. METHODS: Seventeen patients (12 females; range 22-82 years old; mean age 50.8 years old) underwent nephrectomy for various reasons. Renal scintigraphy was performed three to four hours after intravenous administration of a mean dose of 188.7 MBq (5.1 mCi) of 99mTc-DMSA, which was done six to 24 hours before surgery. The in vivo renal uptake of 99mTc-DMSA was determined using the radioactivity of the syringe before the injection (measured using a dose calibrator) and the images of the syringe and kidneys, obtained from a scintillation camera. After surgery, the reference value for renal uptake of 99mTc-DMSA was determined by measuring the radioactivity of the nephrectomy specimen using the same dose calibrator. RESULTS: The ARU measurements were very similar to those obtained using the reference method, as determined by linear regression (r-squared = 0.96). CONCLUSION: ARU estimation using the proposed method before nephrectomy seems to be accurate and feasible for routine use.

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RESUMO

CONTEXT AND OBJECTIVE: Studies using radionuclides are the most appropriate method for estimating renal function. Dimercaptosuccinic acid chelate labeled with technetium-99m (99mTc-DMSA) is the radiopharmaceutical of choice for high-resolution imaging of the renal cortex and estimation of the functional renal mass. The aim of this study was to evaluate a simplified method for determining the absolute renal uptake (ARU) of 99mTc-DMSA prior to nephrectomy, using the radioactivity counts of nephrectomy specimens as the gold standard. DESIGN AND SETTING: Prospective study at the Division of Nuclear Medicine, Department of Radiology, Universidade Estadual de Campinas. METHODS: Seventeen patients (12 females; range 22-82 years old; mean age 50.8 years old) underwent nephrectomy for various reasons. Renal scintigraphy was performed three to four hours after intravenous administration of a mean dose of 188.7 MBq (5.1 mCi) of 99mTc-DMSA, which was done six to 24 hours before surgery. The in vivo renal uptake of 99mTc-DMSA was determined using the radioactivity of the syringe before the injection (measured using a dose calibrator) and the images of the syringe and kidneys, obtained from a scintillation camera. After surgery, the reference value for renal uptake of 99mTc-DMSA was determined by measuring the radioactivity of the nephrectomy specimen using the same dose calibrator. RESULTS: The ARU measurements were very similar to those obtained using the reference method, as determined by linear regression (r-squared = 0.96). CONCLUSION: ARU estimation using the proposed method before nephrectomy seems to be accurate and feasible for routine use.

CONTEXTO E OBJETIVO: Os estudos com radionuclídeos são os mais adequados para se estimar a função renal. O ácido dimercaptosuccínico marcado com tecnécio-99m (DMSA-99mTc) é o radiofármaco de escolha para imagens de alta resolução dos rins, permitindo, também, estimar massa de parênquima renal funcionante. O objetivo deste estudo foi avaliar um método mais simples para determinar-se a captação renal absoluta (CRA) de DMSA-99mTc antes de nefrectomias e validá-lo utilizando-se as contagens radioativas das próprias peças de nefrectomia como padrão-ouro. TIPO DE ESTUDO E LOCAL: Estudo prospectivo, desenvolvido no Serviço de Medicina Nuclear do Departamento de Radiologia da Universidade Estadual de Campinas. MÉTODOS: Foram estudados 17 pacientes (12 pacientes do sexo feminino, média de idade de 50,8 anos), selecionados para a realização de nefrectomia. A cintilografia renal foi realizada três a quatro horas após a administração venosa de 188,7 MBq de DMSA-99mTc, seis a 24 horas antes da cirurgia. A CRA in vivo foi determinada utilizando-se a radioatividade da seringa antes da injeção (medida com um calibrador de dose) e as imagens da seringa e dos rins, obtidas em uma câmara de cintilação. Após a cirurgia, o valor de referência para a CRA foi determinado medindo-se a radioatividade da peça de nefrectomia com o mesmo calibrador de dose. RESULTADOS: Os valores de CRA foram muito semelhantes àqueles obtidos com o método de referência, conforme foi demonstrado pela análise de regressão linear (r-quadrado = 0,96). CONCLUSÃO: A estimativa da CRA com o método proposto antes de nefrectomiasparece ser acurado e aplicável ao uso rotineiro.

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