Tc-99m HMPAO Cerebral Scintigraphy A Reliable, Noninvaslve Method for Determination of Brain Death

Clinical Utility of Arterial Spin-Labeling as a Confirmatory Test for Suspected Brain Death

“…According to the criteria we used, ASL revealed the absence of CBF in brain death by both visual and quantitative analysis. Because the absence of CBF is generally accepted as a definite sign of brain death, 3,5,11,12,16 ASL has the potential to be a noninvasive and reliable confirmatory test for diagnosing brain death. However, the assessment of criteria should be performed carefully and strictly.…”

“…The ASL findings for diagnosing the absence of CBF were made on the basis of the findings from previous studies by using reference standard tests, radionuclide scans, and cerebral angiography. 3,[9][10][11][12][13][14][15][16] The ASL findings used to assess the absence of intracranial blood flow were the following: 1) extremely decreased perfusion in the whole brain, 2) bright vessel signal intensity around the entry of the carotid artery to the skull suggesting flow stagnation, and 3) patent external carotid circulation corresponding to the findings of brain death on conventional angiography. 3 In addition, we reviewed the "hollow skull sign," which was defined as a finding of extremely impaired cerebral perfusion with preserved perfusion in the distribution of the external carotid artery on ASL images.…”

Severe brain injury to neurological determination of death: Canadian forum recommendations

“…Currently validated imaging techniques are cerebral angiography 16 and radionuclide angiography. 17 We recognize that additional cerebral blood flow imaging technologies may further develop or evolve, but they cannot be recommended at this time. Electroencephalograms are no longer recommended as an ancillary test, in view of limitations, as discussed below.…”

“…In the last decade, radiopharmaceuticals, especially Tc99m hexamethylpropylene-amine oxime (Tc99m HMPAO), have been studied extensively and provide enhanced detection of intracerebral, posterior fossa and brainstem blood flow. 17,18 Tc99m HMPAO is lipid-soluble, crossing the blood-brain barrier, providing information on arterial cerebral blood flow and uptake of tracer within perfused brain tissue. The traditional gamma cameras used in this technique are immobile, necessitating patient transfer for study; but newer technologies are portable, allowing for studies to be performed at the bedside.…”

Infrequently Performed Studies in Nuclear Medicine: Part 2

“…6) and a posterior view if possible. SPECT has been recommended to improve the assessment of perfusion in the posterior fossa or brain stem (8) and to help with study interpretation if significant scalp activity is present (9). However, SPECT may be difficult to perform with an unstable patient condition and the patient's associated medical equipment, and in practice this procedure is rarely used.…”