Spectral analysis of99mTc-HMPAO for estimating cerebral blood flow: A comparison with H2 15O PET

Abstract

Cerebral blood flow (CBF) can be quantified non-invasively using the brain perfusion index (BPI), which is determined using radionuclide angiographic data obtained through the use of technetium-99m hexamethylpropylene amine oxime (99mTc-HMPAO). The BPI is generally calculated using graphical analysis (GA). In this study, BPI was measured using spectral analysis (SA), and the usefulness of SA was compared with that of GA. Thirteen patients with various brain diseases and four healthy male volunteers were examined using radionuclide angiography with 99mTc-HMPAO. The BPI was measured for each subject using both SA and GA. In the four healthy volunteers, the BPI was examined at rest and after the intravenous administration of 1 g of acetazolamide (ACZ). An H2(15)O PET examination was also performed in the 13 patients; the BPIS and BPIG values were compared with the CBF measurements obtained using H2(15)O PET (CBFPET). The BPI values obtained by SA (BPIS) (x) and by GA (BPIG) (y) were correlated (y = 0.568x + 0.055, r = 0.901) in the 13 patients and four healthy volunteers at rest, although the BPIG values were underestimated by 36.1 +/- 7.5% (mean +/- SD) compared with the BPIS values. The degree of underestimation tended to increase with increasing BPIS values. The increase in the BPIS was 32.1 +/- 8.0% after the intravenous administration of ACZ, while the increase in BPIG was only 8.1 +/- 2.8%. This discrepancy was considered to be the result of the BPIG values being affected by the first-pass extraction fraction of the tracer. Although both BPIS and BPIG values were significantly correlated with the CBFPET values, the correlation coefficient for BPIS was higher than that for BPIG (BPIS: r = 0.881; BPIG: r = 0.832). These results suggest that SA produces a more reliable BPI for quantifying CBF using 99mTc-HMPAO than the conventional method using GA. The SA method should be especially useful for activation studies involving pharmacological intervention and/or clinical cases with an increased CBF.

Neuropsychological disturbances and cerebral blood flow in bipolar disorder

“…That is, a reduction of left temporal activity accompanied by a loss of semantic knowledge and increased visual revivifying of early life experiences may have occurred in the childhood enactment [1].Nevertheless, neuroscientists and practitioners blithely attribute symptoms of DID to antecedent traumatic events, albeit this connection has never been corroborated; they also accept the patient's self-report of child abuse without any type of corroborating evidence and fail to confirm the existence of DID symptoms prior to psychotherapy, an important consideration given possible iatrogenic aetiology of DID. In short, the patient in this case study may have displayed iatrogenic symptoms or may simply have been a very good actress [2]. In addition, the current findings are consonant with a number of competing explanations that involve temporal lobe functioning: seizures, transcendental beliefs, false memory, and other forms of suggestibility.References 1.…”

“…One of the problems with the use of 99m Tc HMPAO in assessment of cerebral blood flow is that the rate of first-pass extraction falls with increases in cerebral blood flow [2]. This may have been an issue in patients who were anxious or agitated, particularly if injected without eyes patched and ears plugged.…”

Neuropsychological Disturbances and Cerebral Blood Flow in Bipolar Disorder

“…Nevertheless, neuroscientists and practitioners blithely attribute symptoms of DID to antecedent traumatic events, albeit this connection has never been corroborated; they also accept the patient's self-report of child abuse without any type of corroborating evidence and fail to confirm the existence of DID symptoms prior to psychotherapy, an important consideration given possible iatrogenic aetiology of DID. In short, the patient in this case study may have displayed iatrogenic symptoms or may simply have been a very good actress [2]. In addition, the current findings are consonant with a number of competing explanations that involve temporal lobe functioning: seizures, transcendental beliefs, false memory, and other forms of suggestibility.…”

Alzheimer ́s Disease – The New Actors of an Old Drama

“…We explored also a possible association between gCBF and cognitive function, after controlling for age, gender, level of education and global brain atrophy (quantified on 3D T1-weighted MRI images). gCBF was measured by spectral analysis of radionuclide angiography, which is a simple and non-invasive method for the quantification of gCBF (Murase et al, 1999;Van et al, 2001) and linearly correlated with gCBF measured by using PET (Takasawa et al, 2004). Our results show a significant decrease of gCBF in the MCI group as compared with controls (p < 0.05, Mann-Whitney U Test, figure 5).…”