99mTc-HMPAO SPECT in the diagnosis of brain death.
OBJECTIVE
To evaluate the effectiveness of single proton emission tomography (SPECT) with 99mTc-HMPAO in the diagnosis of brain death (BD).


METHODS
Prospective study in comatose and brain-dead patients.


METHODS
Neurologic ICU.


METHODS
Fifty comatose patients (age range: 10 days-75 years) were submitted to SPECT study. In 21 of them (42%) reversible factors (e.g., influence of drugs affecting the central nervous system) were present. Thirty-eight patients were clinically brain-dead, while the remaining 12 were tested both in pre-terminal conditions and after the clinical onset of BD.


METHODS
Brain SPECT following i.v. injection of 99mTc-HMPAO (300-1100 MBq), using a 4-headed gamma-camera (20 min, 360 degrees, 88 images).


RESULTS
All patients tested in pre-terminal conditions showed preserved brain perfusion. Two of them had flat EEGs despite the absence of any reversible cause of coma; three patients survived, but remained in persistent vegetative states. SPECT confirmed the diagnosis of BD in 45 out of 47 patients (95.7%), clearly showing the arrest of brain perfusion (picture of "empty skull"); in two clinically brain-dead children (aged 10 days and 12 months, respectively) weak perfusion of the basal ganglia, thalamus and/or brain stem was still present, precluding the diagnosis of BD; both of them died a few days later.


CONCLUSIONS
Our results confirm the reliability of SPECT in the diagnosis of BD. A problem arises about its effectiveness in brain-dead children, but this seems to be a matter of definition of BD and cerebral viability, rather than a limit of SPECT.
Facco
E
E
Dept. of Anesthesiology and Intensive Care, University of Padua, Italy. efacco@uxl.unipd.it
Zucchetta
P
P
Munari
M
M
Baratto
F
F
Behr
A U
AU
Gregianin
M
M
Gerunda
A
A
Bui
F
F
Saladini
M
M
Giron
G
G
D000293:Adolescent; D000328:Adult; D000368:Aged; D001926:Brain Death / Q000175:diagnosis* / Q000000981:diagnostic imaging; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D019275:Radiopharmaceuticals; D019690:Technetium Tc 99m Exametazime; D015899:Tomography, Emission-Computed, Single-Photon
D019275:Radiopharmaceuticals; D019690:Technetium Tc 99m Exametazime