The patient scores very low results in short time memory when tested by a professional.
The primary modality to check ischemic areas of the brain in my practice is contrast-enhanced MRI. If additional data really is needed the gut feeling is that H20-015 PET provides more information that HMPAO Spect, but it might be worth while to check the current literature. The setting is different for clinical needs and for research purposes.
Of the commonly available techniques, FDG PET-CT will detect areas of glucose hypometabolism and hence is indicative of hypoxia/ischaemia. ECD or HMPAO SPECT-CT detects areas of hypoperfusion and is an alternative.
Tracers used in PET and SPECT are different. Image resolution is better with PET.
If you suspect dementia, FDG PET-CT scores better than SPECT-CT. If Alzheimer's disease is a differential diagnosis and if available, PIB and Florbetapir PET-CT help in identifying areas of amyloid plaques.
Hi Cristiana
If you are suspecting ischemia as the source of the neurological disfunction, probably Magnetic Ressonance (MR) will be better than any Nuclear Medicine technique.
MR can also detect other abnormalities and evaluate for dementia that is already settled.
Nevertheless, if you are looking for early congnitive disorders, FDG PET pattern can be a better predictor of pathology and outcome.
[11C]CN PET will tell you if RBCs (and functional hemoglobin) are making it to the area and [15O]water PET will tell you if even passive diffusion is going on in the vicinity of the suspected lesion.
FDG PET is problematic in the brain because normal tissue has so much uptake that small regions of hypometabolic tissue can be swamped out by adjacent healthy tissue.
In this case, maybe MRS looking for NAA and Glu + Gln might be helpful but acquiring good voxels takes a very long time in a patient who may not remember to lie still. If this method is chosen and your patient needs sedation, be very careful what is used as agents like ketamine would ruin your results and may harm your patient.
PET-F-MISO for anoxia can be used. Alternatively, you can do MRI-CSI to look at lactate