[Effect of attenuation correction and scatter compensation on the 99mTc-MIBI myocardial perfusion spect in patients without coronary artery disease]. / Efecto de la corrección de la atenuación y de la radiación dispersa en la SPET de perfusión miocárdica con 99mTc-MIBI de pacientes sin cardiopatía isquémica.

OBJECTIVE: Attenuation correction (AC) and scatter compensation (SC) techniques are recent developments of myocardial perfusion SPECT. Our aim was to evaluate the effect of AC + SC on the myocardial distribution of 99mTc-MIBI in a population without coronary artery disease. MATERIAL AND METHODS: A multiarray of Gd-153 linear sources was used for simultaneous transmission/emission 99mTc-MIBI myocardial perfusion SPECT in 27 patients without coronary artery disease. A visual analysis and polar map quantification was performed. Changes between non-corrected (NC) and corrected (AC + SC) studies were compared. RESULTS: AC + SC produced an increase in liver activity and better visualization of the right ventricle. Intestinal activity increased in six patients. Myocardial homogeneity was increased by AC + SC. No differences by gender were observed after AC + SC. In females AC + SC led to a decrease of uptake in the anterior wall, apex and apical segments of the lateral wall and septum, and an increase in the inferior wall. In males AC + SC caused an increase of uptake in the inferior wall and in the basal segments of septum and a decrease of uptake in apex and apical segments of anterior and lateral walls. AC + SC generated false defects in the anterior wall of five patients. CONCLUSIONS: Our results show the usefulness of AC + SC for compensating the interferences produced by attenuation on the myocardial distribution of 99mTc-MIBI. Because AC + SC may introduce false defects, it must not be applied to normal perfused myocardium.

Efecto de la corrección de la atenuación y de la radiación dispersa en la SPET de perfusión miocárdica con 99mTc-MIBI de pacientes sin cardiopatía isquémica / Effect of attenuation correction and scatter compensation on the 99mTc-MIBI myocardial perfusion spect in patients without coronary artery disease

FUNDAMENTO Y OBJETIVOS: Este trabajo pretende conocer la prevalencia de infección por Francisella tularensis en la población de Castilla y León previa al brote de tularemia humana de finales de 1997. SUJETOS Y MÉTODO: Se obtuvieron 4.825 sueros (entre abril de 1996 y abril de 1997) de residentes en Castilla y León. Se realizó una prueba de microaglutinación en placa para detectar anticuerpos anti-F. tularensis. En los sueros positivos se llevaron a cabo seroaglutinaciones en tubo frente a Brucella, Yersinia enterocolitica y Proteus. RESULTADOS: Se detectaron anticuerpos anti-F.tularensis en 9 (0,19 per cent) de los 4.825 sueros.De esos 9 sueros, uno fue positivo en la seroaglutinación frente a Brucella, siendo todos negativos frente a las otras bacterias. CONCLUSIONES: Antes de 1997 la seroprevalencia de anticuerpos anti-F. tularensis en la población de Castilla y León era baja (0,19 per cent).... (AU)

Assessment of cerebral perfusion and cerebrovascular reserve in insulin-dependent diabetic patients without central neurological symptoms by means of 99mTc-HMPAO SPET with acetazolamide.

The detection of subclinical abnormalities in cerebral blood flow could be of great value in identifying diabetic patients at risk of stroke. The aim of this study was to assess the contribution of semiquantified post-acetazolamide technetium-99m hexamethylpropylene amine oxime single-photon emission tomography (99mTc-HMPAO SPET) in 15 diabetic patients with no clinical history of central neurological disease. After baseline 99mTc-HMPAO SPET, a second SPET scan was acquired after activation of the cerebrovascular reserve (CVR) with an injection of 1 g of acetazolamide (post-ACZ SPET). Semiquantitative analysis was made in 16 regions of interest (ROIs) drawn for each of the three supratentorial slices selected, and in two ROIs in the infratentorial slice. The CVR was calculated in each ROI by subtracting the decay-corrected baseline images from those obtained in the post-ACZ SPET and expressed as the percent increase in the average counts between the two scans. Baseline perfusion and CVR values in the study group were compared with the corresponding values in a control group. Of 750 cortical ROIs studied, 332 showed a decreased CVR (44.3%). The baseline perfusion SPET study showed hypoperfusion in 65 ROIs (8.6%) and hyperperfusion in 56 (7.4%). Of the 65 hypoperfused regions, 66.2% had a normal CVR and 33.8% had a decreased CVR, whereas of the 56 hyperperfused regions, 51.8% had a CVR within normal limits and 48.2% showed a decreased CVR. In conclusion, in comparison with baseline 99mTc-HMPAO SPET, the ACZ activation test provided additional information in the study of cerebrovascular impairment, and allowed characterisation of the subclinical abnormalities in the population studied. The technique may therefore prove useful in evaluating future preventive strategies for stroke in diabetic patients.

Significado clínico de la hipercaptación costal única en la gammagrafía ósea. A propósito de un osteoblastoma / Clinical significance of the increased uptake of a solitary rib lesion in the bone scintigraphy. based on an osteoblastoma

Se presenta un tumor óseo localizado en el 6º arco costal derecho cuya imagen en la gammagrafía ósea fue de una lesión hipercaptadora única. Aunque la radiografía de tórax y la TAC fueron normales, en la RMN se observó una lesión hipointensa en secuencias T1 e hipertensa en T2.El diagnóstico histológico postcirugía fue de osteoblastoma. Se realiza una revisión sobre el significado clínico de las lesiones costales únicas que aparecen hipercaptadoras en la gammagrafía ósea. El osteoblastoma debe de ser considerado cuando se realiza un diagnóstico diferencial de las lesiones costales únicas que aparecen en la gammagrafía ósea (AU)

[Clinical significance of the increased uptake of a solitary rib lesion in the bone scintigraphy. Based on an osteoblastoma]. / Significado clínico de la hipercaptación costal única en la gammagrafía ósea. A propósito de un osteoblastoma.

A case of a bone tumor located in the right sixth rib detected by means of the bone scan as a solitary lesion is presented. Although the chest X-ray and CT were normal, a low signal intensity on T1 images and high-intensity on T2 images were seen in the MRI. The post-surgical histological diagnosis was osteoblastoma. A review of the clinical significance of solitary rib lesions which appear with increased uptake on bone scan was performed. When a differential diagnosis is made of a solitary rib lesion that appears on a bone scan, osteoblastoma should be considered.

[Localization by bone SPET of osteoid osteoma in the vertebral lamina]. / Localización mediante SPET óseo de un osteoma osteoide en la lámina vertebral.

The combined use of bone SPET and CT was a good approach for diagnosing an osteoid osteoma of spine in a 16-year-old young woman with a history of several months of back pain. Pain was increased at night and relieved by aspirin intake. Plain films of the spine only revealed a scoliosis. Bone SPET demonstrated a focal increased activity in the left posterior elements of T12 vertebra. CT of this vertebra discovered a lytic lesion in the left lamina. An osteoid osteoma was removed by laminectomy.

Coronary artery occlusion and myocardial infarction: a seldom encountered complication of blunt chest trauma.

Myocardial infarction is a rare complication that can occur after blunt chest trauma. The authors describe a 30-year-old man who experienced a fatal anterolateral myocardial infarction after chest trauma in a motorcycle accident. The electrocardiogram and creatine phosphokinase-MB isoenzymes levels suggested myocardial necrosis. Tc-99m phosphate myocardial scintigraphy identified an extensive doughnut-shaped uptake over the cardiac area. An echocardiogram revealed severe left ventricular impairment. Coronary angiography confirmed complete occlusion of the proximal left anterior descending coronary artery.