Semiología de la PET/TAC con 18F-FDG / No disponible

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[Utility of myocardial perfusion SPECT for evaluation of patients from Chest Pain Unit]. / Análisis y utilidad de la tomografía de emisión de fotón único de perfusión miocárdica en la evaluación de pacientes de la Unidad de dolor torácico.

UNLABELLED: The Chest Pain Units (CPU) are currently the best solution to improve management of patients with acute chest pain in the Emergency Room thanks to the use of reliable ischemia diagnostic detection tests and early treatment. OBJECTIVE: To assess the value of myocardial perfusion SPECT (MPS) in the CPU in order to treat acute coronary syndromes (ACS) early and discharge patients with low risk of coronary artery disease (CAD) who can be treated as outpatients. MATERIAL AND METHODS: We studied 629 patients from January 2003 to September 2005 with acute chest pain suggestive of angina, normal cardiac enzymes and normal or non-diagnostic ECG who had been referred to Nuclear Medicine for evaluation with a stress test for ischemia: 32 p treadmill stress testing and 597 p MPS (525 p exercise-rest and 72 p pharmacologic stress test). We compared the results with catheterization and clinical follow up for a 6-months period, evaluating new coronary events. RESULTS: 76 % of MPS were normal and 24 % pathological. Only 1.5 % of the patients with normal MPS had CAD or coronary events in the follow-up, increasing to 35.2 % in patients with ischemia. A total of 45 catheterizations were performed, showing CAD 27 (24 with pathological MPS). A total of 2.6 % of the patients had coronary events during follow-up, 75 % of whom had pathological MPS. CONCLUSION: The MPS improves diagnosis of ACS in the CPU, with a very low number of new coronary events at 6 months of the follow-up and permits safe discharge of these patients.

[Iatrogenic lung microembolism detected by 18FDG PET/CT]. / Microembolia pulmonar iatrogénica detectada mediante 18F-FDG PET/TC.

We present the cases of two oncology patients: a male with Hodgkin's disease after completion of chemotherapy, and a woman recently diagnosed of melanoma, who underwent positron emission tomography/computed tomography (PET/CT) with 18F-FDG for therapeutic monitoring and initial staging, respectively. In both cases, hypermetabolic foci of 18F-FDG in lung parenchyma were found, without morphologic abnormalities in CT. These findings would have been consistent with lung pathology in the absence of any anatomic correlation. Combined PET/CT interpretation was of lung microembolisms probably originated at the injection site.

Microembolia pulmonar iatrogénica detectada mediante 18F-FDG PET/TC / Iatrogenic lung microembolism detected by 18FDG PET/CT

Presentamos los casos de dos pacientes oncológicos: varón con enfermedad de Hodgkin tras finalizar tratamiento quimioterápico y mujer recién diagnosticada de melanoma coroideo, a los que se realiza tomografía por emisión de positrones/tomografía computarizada (PET/TC) con 18F-fluorodesoxiglucosa ( 18F-FDG) para monitorización terapéutica y estudio de extensión inicial, respectivamente. En ambos casos se encuentran focos hipermetabólicos de 18F-FDG en parénquima pulmonar, sin concordancia morfológica en la TC. Estos hallazgos hubieran sugerido patología pulmonar en caso de no disponer de estudio anatómico conjunto. La interpretación de la PET/TC fue de microembolismos pulmonares probablemente originados en el punto de inyección

We present the cases of two oncology patients: a male with Hodgkin's disease after completion of chemotherapy, and a woman recently diagnosed of melanoma, who underwent positron emission tomography/computed tomography (PET/CT) with 18F-FDG for therapeutic monitoring and initial staging, respectively. In both cases, hypermetabolic foci of 18F-FDG in lung parenchyma were found, without morphologic abnormalities in CT. These findings would have been consistent with lung pathology in the absence of any anatomic correlation. Combined PET/CT interpretation was of lung microembolisms probably originated at the injection site

Quiste del colédoco: diagnóstico mediante gammagrafía hepatobiliar / Choledochal cyst: diagnosis by hepatobiliary scintigraphy

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[Renal angiomyolipoma and fever: assessment with isotopic renogram and 67Ga scintigraphy]. / Angiomiolipoma renal y fiebre: valoración mediante renograma isotópico y gammagrafía con 67Ga.

A 26 year-old woman with tuberous sclerosis who came to the Emergency Department with high fever, bilious vomit, right hemiabdomen pain and syncope during 2 weeks. Laboratory analyses show hemoglobin 6.7 g/dl, creatinine 1.5 mg/dl and leukocytes 30,000. Abdominal CT is performed because of suspicion of active bleeding in right hemiabdomen, following rupture of right angiomyolipoma, treated by selective arterial embolization. She was referred to the Nuclear Medicine Department to perform a 67Gallium scintigraphy for the detection of infection, and static and dynamic renal scintigraphy for evaluation of the renal morphology and function.

Angiomiolipoma renal y fiebre: valoración mediante renograma isotópico y gammagrafía con 67Ga / Renal angiomyolipoma and fever: assessment with isotopic renogram and 67Ga scintigraphy

Mujer de 26 años con esclerosis tuberosa, que acude a urgencias por cuadro de dos semanas de evolución de fiebre, vómitos biliosos, dolor en flanco derecho y síncope de segundos de duración. En analítica se refleja hemoglobina de 6,7 g/dl, creatinina de 1,5 mg/dl y leucocitosis (30.000/μl). Se realiza TC abdominal por sospecha de sangrado activo, llegándose al diágnostico de rotura de angiomiolipoma renal derecho, que se trata mediante embolización arterial selectiva. Se remite al servicio de Medicina Nuclear para determinar mediante Gammagrafía con 67Ga posible origen de foco infeccioso no puesto en evidencia por otras técnicas diagnósticas, así como Gammagrafía renal y Renograma isotópico para evaluar la morfología renal y el grado de funcionalidad

A 26 year-old woman with tuberous sclerosis who came to the Emergency Department with high fever, bilious vomit, right hemiabdomen pain and syncope during 2 weeks. Laboratory analyses show hemoglobin 6.7 g/dl, creatinine 1.5 mg/dl and leukocytes 30,000. Abdominal CT is performed because of suspicion of active bleeding in right hemiabdomen, following rupture of right angiomyolipoma, treated by selective arterial embolization. She was referred to the Nuclear Medicine Department to perform a 67Gallium scintigraphy for the detection of infection, and static and dynamic renal scintigraphy for evaluation of the renal morphology and function

[Follow-up of children and young adults with differentiated thyroid cancer treated with radioiodine]. / Seguimiento de niños y jóvenes adultos con cáncer diferenciado de tiroides (CDT) tratados con radioyodo.

This is a retrospective study carried out in a group of 30 patients with differentiated thyroid cancer (age at diagnosis equal to or less than twenty years old). The aim of the study is to evaluate outcome after 131I therapy. Patients were classified into three groups on the basis of initial surgery, pathology and scintigraphic results: group I (thyroid extent), group II (locoregional extent), and group III (distant metastatic disease). Clinical parameters, 131I scans, serum thyroglobulin determinations and 131I therapeutic administered doses were evaluated in the follow-up. Some other complementary techniques such as chest X-ray and pulmonary function tests are also described. Scintigraphic absence of thyroid tissue has been observed in 83% of the cases; high thyroglobulin level is still detectable in 34% of the patients as a single evidence of disease, and 21% remain without any abnormal clinical, scintigraphic or analytical findings. Total doses administered have increased in groups I, II and III respectively, and have also been inversely proportional to the extension of lymph node surgery. At present, all the patients are alive and in good general condition. According to the results obtained, we conclude that children and young adults with DTC should undergo periodical 131I therapeutic doses in case of positive scans (once total thyroidectomy has been realized, with or without lymph node resection depending on the extension of disease). In our experience, the use of radioiodine is effective and safe in the follow-up of children and youngs with DTC.

Seguimiento de niños y jóvenes adultos con cáncer diferenciadode tiroides (CDT) tratados con radioyodo / Follow-up of children and young adults with differentiated thyroid cancer treated with radioiodine

Este es un estudio retrospectivo realizado en un grupo de treinta pacientes con carcinoma diferenciado de tiroides (edad al dignóstico igual o menor a veinte años), que tiene como objetivo valorar la respuesta al tratamiento con radioyodo. Los pacientes fueron clasificados en tres grupos según los resultados quirúrgicos, anatomopatológicos y gammagráficos iniciales: grupo I (enfermedad limitada al tiroides), grupo II (enfermedad locorregional), grupo III (afectación metastásica a distancia). En el seguimiento se evaluaron parámetros clínicos, resultados de rastreos gammagráficos con Iodo-131, determinaciones de tiroglobulina sérica y dosis terapeúticas de radioyodo administradas. También se describen otras técnicas complementarias como la radiología de tórax y las pruebas de función respiratoria. Hemos observado una negativización gammagráfica en el 83 por ciento de los casos; un 34 por ciento presenta niveles de tiroglobulina elevados como único hallazgo sugestivo de existencia de enfermedad y un 21 por ciento no presenta hallazgos clínicos, analíticos o gammagráficos patológicos. Las dosis totales de radioyodo administradas han sido crecientes en los grupos I, II y III respectivamente, e inversamente proporcionales a la extensión de la limpieza ganglionar efectuada. En la actualidad todos los pacientes están vivos y presentan un buen estado general.De acuerdo con los resultados obtenidos, concluímos que el manejo adecuado del CDT en este grupo de edad debe incluir rastreos gammagráficos periódicos con 131I y dosis terapeúticas de 131I en caso de rastreos positivos (una vez realizada la tiroidectomía total, con o sin limpieza ganglionar dependiendo de la extensión de la enfermedad). Según nuestra experiencia, el empleo de radioiodo es eficaz y seguro en el seguimiento de niños y jóvenes con CDT. (AU)

The diagnostic value of Tc-99m human polyclonal immunoglobulin imaging compared to Tc-99m HMPAO labeled leukocytes in inflammatory bowel disease.

The aim of this study was to establish the usefulness of Tc-99m human polyclonal immunoglobulin (HIG) imaging in a group of patients who were suspected of having inflammatory bowel disease (IBD). The authors performed 30 scans (15 with Tc-99m HMPAO leukocytes and 15 with Tc-99m HIG) on 15 patients with IBD. Ten patients had Crohn's disease and five had ulcerative colitis. The sensitivity of Tc-99m HIG scintigraphy for detecting IBD was 33%, while the sensitivity of Tc-99m HMPAO leukocyte imaging was 100%. The Tc-99m HMPAO leukocyte imaging also detected a larger number of affected segments and provided better image quality of the extent of disease than Tc-99m HIG. On the basis of these results, the authors believe that Tc-99m HIG imaging is not a useful technique in the evaluation of patients with IBD, in the identification of location, or the extension or degree of disease activity.

MCA serum determination in breast carcinoma patients for the diagnosis of bone metastases.

Serum MCA levels were determined in 173 consecutive patients with breast cancer in order to assess the clinical utility of MCA for the detection of bone metastases. Bone pathology was diagnosed by scintigraphy, radiology and clinical follow-up. Metastases were found in 37 patients, benign lesions in 25, and in 111 no bone lesions were found. Eighteen of the 173 bone scans were considered indeterminate for metastases. Based on the receiver-operating characteristic curves (ROC) analysis, the cut-off level for MCA was set at 20 U/ml. Only in 4 of the 37 patients with bone metastases MCA was below 20 U/ml. All 4 patients had completed their chemotherapy course within six months before MCA determination. Only in 6 patients of the 136 without bone metastases MCA levels were above 20 U/ml. Of the 18 patients with indeterminate bone scans, 15 had benign lesions and all of them had MCA levels below 20 U/ml. MCA determination is a sensitive method for the detection of bone metastases in breast carcinoma. We encourage the use of this procedure for the selection of high-risk groups or as a complementary method for the interpretation of bone scintigraphy.

Diabetic foot infections: scintigraphic evaluation with 99Tcm-labelled anti-granulocyte antibodies.

Thirty-eight lesions found by physical and/or radiological examination in 25 patients with long-term diabetes mellitus were studied in order to evaluate the clinical utility of immunoscintigraphy using 99Tcm-labelled anti-granulocyte monoclonal antibodies (MAb BW 250/183) for the diagnosis of infectious pathology in diabetic foot. All the patients underwent three-phase bone scintigraphy with 740 MBq 99Tcm-methylene disphosphonate. Immunoscintigraphy was performed 4 and 24 h after administration of 500 MBq of the labelled antibody by planar selective views. Uptake intensity was scored 0 to 4 (0 = normal, 1 = mildly increased, 2 = moderately increased, 3 = intense, 4 = very intense) when compared with adjacent or contralateral uninvolved bone marrow and soft tissue. Several projections were performed and anatomical references of bone scan were used to determine whether the lesion involved the bone or soft tissue. Definitive diagnoses were 15 osteomyelitis, 14 soft tissue lesions (nine cellulitis and five noninfected ischaemic or trophic wounds), and nine degenerative bone disease. 99Tcm-granulocyte scintigraphy showed increased uptake in seven soft tissue lesions, in four of which exclusively soft tissue involvement was demonstrated by scintigraphy. Only one false negative scintigraphic finding was observed (chronic osteomyelitis). No abnormal anti-granulocyte antibody uptake was observed in degenerative lesions. Based on our observations, immunoscintigraphy with 99Tcm-MAb BW250/183 has a sensitivity of 93% in the diagnosis of osteomyelitis involving diabetic patients' feet. Although it is feasible to distinguish exclusive soft tissue involvement, this is still the main cause of misdiagnosis in current clinical practice.