Detection of inflammation/infection with human polyclonal immunoglobulin G labelled with 99Tcm.

Radiolabelled human polyclonal immunoglobulin G (IgG) has been successful in identifying inflammatory/infectious processes in human and animal models. We studied 71 patients with suspicion of inflammation of varied origin and location (44 of musculoskeletal location and 27 other) using 99Tcm. IgG images correctly identified 21/22 inflammatory sites of musculoskeletal origin and only 4/14 sites of soft-tissue location. Five false negative studies corresponded to granulomatous processes, three of them tuberculosis. Four false positive studies were obtained in the musculoskeletal group corresponding to three synovial tumours and a Charcot joint. No false positive results were seen in the soft tissue group. 99Tcm-IgG performs well in the identification of bone-joint lesions and rules out non-inflammatory conditions (with the important exception of tumours). The role of 99Tcm-IgG in soft-tissue inflammatory sites, especially in highly vascular organs is inferior, with a high yield of false negative studies. Granulomatous lesions probably represent situations of low or absent IgG uptake.

[Renal hypertrophy studied by techniques of nuclear medicine in post-nephrectomy patients]. / Estudio de la hipertrofia renal compensadora con técnicas de medicina nuclear en pacientes sometidos a nefrectomía.

Study of group of 61 patients, nephrectomized as a result of various diseases and who before and three months after surgery underwent blood pressure, effective renal plasma flow (EPFF) and unilateral renal function determinations in order to verify the compensating ability of the remaining kidney. Effective renal plasma flow was determined by a single injection and removal of six serial blood samples with 125-I-Hippuran. Unilateral renal function was determined from the relative uptake of 99mTc-DMSA 24 hours after injection. The patients were divided into four groups according to their overall and unilateral renal function as well as the presence or absence of hypertension. Patients with normal EPFF and symmetrical renal function showed a significantly increase in the function of the remaining kidney after surgery (p < 0.001). Patients with normal or slightly reduced EPFF (< 10%) and highly asymmetrical unilateral function as well as those with decreased EPFF (> 10%) and symmetrical or asymmetrical unilateral renal function did not increased the function of the remaining kidney after nephrectomy, and hypertensive patients whose blood pressure returned to normal values after nephrectomy had a decreased function of the remaining kidney after surgery (< 0.001). It is concluded that it is possible to predict the functional behaviour of the remaining kidney after nephrectomy, and that the compensating ability will basically depend on the previously existing (overall and unilateral) renal function as well as the presence or absence of hypertension.

[Fibrous bone dysplasia in the context of a McCune-Albright Syndrome]. / Displasia ósea fibrosa en el contexto de un síndrome de McCune-Albright.

Young male patient clinically and radiologically diagnosed of a tumour in IX right rib. A subsequent study with bone scintigraphy showed other areas of focal uptake in the skull, ribs and left trochanterian region. The biopsy of the costal lesion showed a fibrous dysplasia in the clinical context of a McCune-Albright syndrome. The convenience of using complementary imaging techniques is discussed to establish adequate therapeutic behavior.

[Diagnosis of renovascular hypertension by pre- and post-captopril renal scintigraphy with 99mTc-DMSA]. / Diagnóstico de hipertensión vasculorrenal mediante gammagrafía renal con 99mTe-DMSA pre y postcaptopril.

AIM: Value the utility of studies with 99mTc-DMSA with captopril (scintigraphy imaging and unilateral renal function) in identifying renovascular disease or renal disease in hypertension patients with high probability of renovascular hypertension. METHODS: We studied 27 hypertension patients (12 males, 15 females) mean age 49 years, SD: 9.46, with high probability of renovascular disease. General analysis and radiology was made to all of them including renal arteriography as gold standard. Two renal scintigraphies with 99mTc-DMSA were made to all of them, baseline study and one hour after administration of 50 mg of captopril, a week between both studies. Renal scintigraphy (anterior and posterior images) was obtained 4 hours after the administration of 111 MBq (3 mCi) of 99mTc-DMSA and results were evaluated quantitatively and qualitatively calculating unilateral renal function. We considered positive for renovascular hypertension studies with decrease of more than five percentual points in unilateral renal function or a new defect absent in baseline study. Scintigraphic results were compared with arteriography to determine sensitivity, specificity and predictive values. RESULTS: Arteriography demonstrated significant renal artery stenosis in 18.5% of patients. Renal scintigraphy with captopril using 99mTc-DMSA demonstrated sensitivity of 60%, specificity of 91%, positive predictive value of 60% and negative predictive value of 91%. We identified 3 patients with segmental defects of uptake consistent with chronic pyelonephritis scarring. CONCLUSIONS: Studies with 99mTc-DMSA using captopril present high specificity and are useful in patients with high probability for renovascular hypertension, identifying high number of patients with significant renal artery stenosis. The utility of DMSA in identify renal abnormalities, as specially pyelonephritis scarring, add value to renal studies with captopril using others tracers. DMSA could identify renal etiologies of renovascular hypertension different to renal artery stenosis.

[Diuretic isotopic urography. A method for its diagnostic use in nephro-urologic pathology in children]. / Urografía isotópico diurética (UID). Un método de aplicación diagnóstica en patología nefrourológica infantil.

In clinical pediatric urology distinction between obstructive and non obstructive dilatation of the upper urinary tract represents a difficult task for which usual procedures, both radioisotopes and conventional radiologic methods, have not discriminatory value. The aim of this investigation in to suggest a method of study that contributes to establish, in children, true diagnosis in clinical situations of hydronephrosis and to study evolution of renal function in surgical patients. Suggested technique, known an isotopic diuretic urography (UID), consists in intravenous administration of a diuretic (Furosemide, 0.4 mg/kg body weight) thirty minutes after injection of a radiotracer (I-123 Hippuran and or Tc-99-DTPA) into the vascular space and recording and analysis of variations of activity in parenchyma and renal pelvis during, at least, the following 60 m. Method described has been used in a series of 24 patients suffering from uni or bilateral hydronephrosis, with ages ranging from 2 months to 12 years. Results obtained, have shown that UID is notably superior to actually existing non-invasive methods of study of obstructive uropathy.

Diagnóstico de hipertensión vasculorrenal mediante gammagrafía renal con 99mTc-DMSA pre y postcaptopril / Diagnosis of vasculorenal hypertension by pre- and post-captopril renal scintigraphy with 99mtc-dmsa

Objetivo: Valorar la utilidad de los estudios con 99mTc-DMSA pre y postcaptopril (imagen gammagráfica y función renal unilateral) para identificar el origen vasculorrenal o renal de la enfermedad en pacientes hipertensos con alta sospecha clínica de hipertensión vasculorrenal. Pacientes y Métodos: Se han estudiado 27 pacientes hipertensos (12 varones, 15 mujeres) de edades comprendidas entre 23 y 65 años (edad media 49 años, DE: 9,46) con alta sospecha clínica de hipertensión vasculorrenal, a los que se les realizó protocolo general analítico, ecográfico y radiológico incluyendo arteriografía renal que se utilizó como gold standard. A todos se les practicaron dos estudios gammagráficos con 99mTc-DMSA, uno basal y otro una hora después de la administración de 50 mg de captopril, con una semana de intervalo entre ambos. Los estudios gammagráficos se obtuvieron a las 4 horas de la administración de 3 mCi (111MBq) de 99mTc-DMSA, obteniéndose imágenes en anterior y posterior, y evaluándose los resultados cualitativamente y cuantitativamente mediante el cálculo de la función renal unilateral porcentual. Se consideraron positivos para hipertensión vasculorrenal los estudios con disminución de 5 puntos porcentuales de la función renal unilateral porcentual o la aparición de un defecto nuevo no existente en el estudio basal. Los resultados gammagráficos fueron comparados con el estudio arteriográfico para determinar la sensibilidad y valores predictivos. Resultados: El estudio arteriográfico demostró la existencia de un 18,5 por ciento de pacientes con estenosis de la arteria renal angiográficamente significativa ( > 50 por ciento de la luz).Los estudios gammagráficos pre y postcaptopril con 99mTcDMSA mostraron una sensibilidad del 60 por ciento, especificidad del 91 por ciento, valor predictivo positivo del 60 por ciento y valor predictivo negativo del 91 por ciento. Se identificaron 3 pacientes con defectos de captación segmentarios compatibles con cicatrices pielonefríticas crónicas. Conclusiones: Los estudios con 99mTc-DMSA basal y tras captopril presentan una alta especificidad y son útiles en pacientes con alta sospecha clínica de hipertensión vasculorrenal, identificando adecuadamente un alto porcentaje de pacientes con estenosis arterial renal significativa. La capacidad del DMSA para identificar la presencia o ausencia de anomalías renales, sobre todo cicatrices pielonefríticas, aporta un valor añadido a los estudios de renograma tras IECAs con otros trazadores pudiendo identificar causas renales de hipertensión diferentes a la estenosis de la arteria renal (AU)