Gioconda Taddei

Hippocampal perfusion in mild Alzheimer's disease

Perfusion and metabolic studies in patients with Alzheimers disease (AD) have so far yielded conflicting results on the functional status of the hippocampal region, whose deep location in the brain makes it critical to optimize the image-reconstruction technique employed in emission tomography. We used a brain-dedicated device (CERASPECT) to perform single photon emission computed tomography (SPECT) studies with 99mTc-hexamethylpropylene-amine-oxime in 22 consecutive patients (mean age: 74+/-6.5 years) with mild [mini-mental status examination (MMSE) score > or =15, mean 20.8+/-3.2], probable AD. The control subjects were 11 healthy elderly people (mean age: 70.5+/-6.5 years). In patients, the total score on the selective reminding test (SRT) was used as an index of memory function. Counts from a hippocampal and a temporoparietal region of interest in each hemisphere were referred to the average thalamic counts. To optimize SPECT images, we used conventional filtered back-projection (FBP) reconstruction and a new iterative method of conjugate gradients (CG), which takes into account the geometrical and physical characteristics of the gamma-camera. Hippocampal perfusion in the two hemispheres was significantly lower in patients than in control subjects, regardless of which reconstruction method was used, and correlated with the MMSE score. The correlation between hippocampal perfusion and the SRT score was significantly (bootstrap procedure) higher with the CG method than with the FBP method (CG: r=0.52 and 0.54; FBP: r=0.39 and 0.47, for the right and left hemisphere, respectively). These results show hippocampal hypoperfusion in patients with mild AD, a correlation between hippocampal perfusion and the severity of cognitive impairment, and enhanced identification of these subtle perfusional changes with the use of an alternative image-reconstruction method that improves the spatial resolution of SPECT images.

Lymphatic Dysplasias in Newborns and Children: The Role of Lymphoscintigraphy

We performed lymphoscintigraphy in 15 patients (newborns and children) affected by congenital lymphatic dysplasia. We suggest that lymphoscintigraphy is mandatory in all patients with signs of lymphatic dysplasia, including those with minimal and initial signs of lymphatic impairment, to obtain very early diagnosis and begin treatment.

Hennekam syndrome presenting as nonimmune hydrops fetalis, congenital chylothorax, and congenital pulmonary lymphangiectasia

We report a female infant with congenital lymphedema, facial anomalies, intestinal lymphangiectasia consistent with a diagnosis of Hennekam syndrome. At birth the patient presented with severe respiratory distress due to nonimmune hydrops fetalis, a congenital chylothorax (CC), and pulmonary lymphangiectasia. Hydrops fetalis may be present in newborns with the Hennekam syndrome. Lymphoscintigraphy can be useful in explaining pleural‐pulmonary involvement of this generalized lymph vessel malformation syndrome.

Lymphoscintigraphic evaluation of congenital lymphedema of the newborn

The authors present a case of the Hennekam syndrome diagnosed in a newborn. Lymphedema is usually present in this syndrome, and the lymphoscintigraphic imaging findings for its detection are discussed. This case confirms the utility of lymphoscintigraphy in providing important physiologic and anatomic information for presurgical planning. An etiologic diagnosis could possibly be obtained. The procedure is relatively easy to perform, safe, reliable, minimally invasive, and not uncomfortable for the patient. It should be considered a valuable diagnostic tool, especially in newborns, in whom conventional contrast lymphoangiography is difficult to perform.