[Assessment of cerebral blood flow in patients with eating disorders in the acute clinical phase using Tc99m-HMPAO spect]. / Valoración del flujo sanguíneo cerebral en pacientes con trastornos de la conducta alimentaria en fase aguda mediante SPECT con HMPAO-Tc99m.

OBJECTIVE: To assess the status of cerebral perfusion in patients with eating disorders (ED) in the acute phase of the disease. MATERIALS AND METHODS: Seventeen patients, with a mean age of 22 years, diagnosed with ED according to DSM-III-R (Diagnostic and Statistical Manual of Mental Disorders) criteria and under close clinical monitoring were studied in the initial acute phase of their disease. Brain SPECT with 15 mCi of Tc99m HMPAO was performed on all patients and assessed using visual and semi-quantitative analysis. The latter was carried out by obtaining left/right indices in sixteen symmetrical 5 x 5 pixel regions of interest (ROI) in three transverse slices, one below the cantho-meatal line and two above, at 2 and 5 cm, respectively. RESULTS; Visual analysis showed hypoperfusion of the anteroinferior region of the left temporal lobe in 7/17 patients, and in the homonymous region of the right temporal lobe in 1/17. Semi-quantitative analysis did not show statistically significant differences in the slices above the cantho-meatal line when the means of the asymmetry indices were compared between the anterior (frontal), middle (temporal and parietal) and posterior (occipital) regions of each slice, obtaining values ranging between 0.99 +/- 0.05 and 1.02 +/- 0.03. However, in the lowest slice, the anterior (temporal) region showed a mean asymmetry value of 0.89 +/- 0.15, and on comparing it with the mean of the asymmetry indices of the posterior region (cerebellum), it showed a statistically significant difference (p < 0.05). CONCLUSION: Patients with ED frequently show hypoperfusion of the anteroinferior region of the temporal lobe, predominantly in the left hemisphere, in the acute phase of the illness.

[Potential sources of diagnostic pitfall and variants in FDG-PET/CT]. / Potenciales fuentes de error diagnóstico y variantes de la FDG-PET/TAC.

UNLABELLED: Oncological FDG PET show variants and findings that may lead to a diagnostic error and that may be clarified by the morfofunctional imaging from PET/CT. In this article we show the experience acquired since a Siemens PET/CT Biograph LSO Pico3D was applied in our centre. We describe some representative examples of FDG distribution patterns which may lead to erroneous interpretations of the clinical studies when they refer to specific clinical situations. The examples included are classified into two main groups according to the cause: Technical and biological, and the latter into physiological and non-physiological (pathophysiological). Patterns are described within the biological group showing changes of the FDG biodistribution that may reduce the uptake in tumoural lesions, the physiological variants that may be interpreted as pathology, the effects of previous treatment and uptakes related to benign diseases. CONCLUSION: We consider that knowledge of these variants and findings to be crucial in order to obtain optimal performance of PET/CT and to overcome the PET limitations.

[Bone scintigraphy in Erdheim-Chester disease]. / Gammagrafía ósea en la enfermedad de Erdheim-Chester.

Erdheim-Chester disease (ECD) is a rare disorder with fewer than 80 cases reported in the world. It consists of a non-Langerhans' cell histiocytosis that usually presents as pain due to bone involvement; however, the prognosis is marked by extraskeletal involvement. Although the final diagnosis needs an anatomophatologic study (normally through a bone biopsy), radiologic and scintigraphic findings are quasi pathognomonic. In this work, we report 2 ECD cases and their respective bone scans showing typical findings described in the literature. We found bilateral and symmetrical increased uptake of diaphyses and metaphyses of long bones, mainly in lower limbs. The mid-diaphyses and the epiphyses (partially in the first case) as well as the axial skeleton are spared.