Diagnostic Utility of Amyloid PET in Cerebral Amyloid Angiopathy-Related Symptomatic Intracerebral Hemorrhage

Abstract

By detecting β-amyloid ( Aβ) in the wall of cortical arterioles, amyloid positron emission tomography (PET) imaging might help diagnose cerebral amyloid angiopathy (CAA) in patients with lobar intracerebral hemorrhage (I-ICH). No previous study has directly assessed the diagnostic value of 11-Pittsburgh compound B (PiB) PET in probable CAA-related I-ICH against healthy controls (HCs). 11C-PiB-PET and magnetic resonance imaging (MRI) including T2* were obtained in 11 nondemented patients fulfilling the Boston criteria for probable CAA-related symptomatic I-ICH (sl-ICH) and 20 HCs without cognitive complaints or impairment. After optimal spatial normalization, cerebral spinal fluid (CSF)-corrected PiB distribution volume ratios (DVRs) were obtained. There was no significant difference in whole cortex or regional DVRs between CAA patients and age-matched HCs. The whole cortex DVR was above the 95% confidence limit in 4/9 HCs and 10/11 CAA patients (sensitivity = 91%, specificity = 55%). Region/frontal or occipital ratios did not have better discriminative value. Similar but less accurate results were found using visual analysis. In patients with sl-ICH, 11C-PiB-PET has low specificity for CAA due to the frequent occurrence of high 11C-PiB uptake in the healthy elderly reflecting incipient Alzheimer's disease (AD), which might also be present in suspected CAA. However, a negative PiB scan rules out CAA with excellent sensitivity, which has clinical implications for prognostication and selection of candidates for drug trials.

Florbetapir-PET to diagnose cerebral amyloid angiopathy

“…21 One previous study found that 4 out of 9 cognitively healthy older controls had high PiB retention, the highest reported rate of false positivity in amyloid imaging field but the sensitivity to detect CAA was still excellent (91%) in this particular study. 38 It is plausible that the high specificity that we found might suffer in patients 80 and older due to increased incidence of asymptomatic amyloid positivity. Our data nevertheless suggest that a negative florbetapir scan might be used to exclude a diagnosis of severe CAA, providing valuable guidance to the management of patients with isolated lobar ICH, mixed location ICH, and cerebellar ICH, and patients who cannot undergo MRI.…”

Clinico-Radiological Characteristics and Pathological Diagnosis of Cerebral Amyloid Angiopathy-Related Intracerebral Hemorrhage

“…1,3,29 On the other hand, several attempts using amyloid imaging, such as 11 C-Pittsburgh compound B positron emission tomography ( 11 C-PiB PET), have been made to detect CAA as an underlying disease in several pathological conditions such as dementia, cortical SAH, and cerebral angitis. [30][31][32][33][34] A positive relationship between local amyloid burden and a future risk for hemorrhage has been suggested based on the result of a longitudinal cohort study with 11 C-PiB PET and MRI. 31 However, the presence of vascular amyloid in the tissue sample is not perfectly specific for CAA-ICH because elderly people may incidentally present with asymptomatic vascular amyloid deposition.…”

White Matter Perivascular Spaces on Magnetic Resonance Imaging

“…4 The protocol was approved by the Cambridgeshire Ethics Committee, and all subjects gave informed consent.…”

“…4 On the same day as the PiB-PET, each subject underwent 3T MRI (slice thickness, 4 mm; slice gap, 5 mm), including T2-weighted, T1-weighted magnetization-prepared rapid gradient-echo, fluid-attenuated inversion recovery, and gradient-recalled echo, using standard T2* sequences. MRIs were reviewed blinded to clinical and PET data.…”