Abnormal perfusion fluctuation and perfusion connectivity in bipolar disorder measured by dynamic arterial spin labeling

Abstract

Objectives:We sought to evaluate whether dynamic Arterial Spin Labeling (dASL), a novel quantitative technique robust to artifacts and noise that especially arise in inferior brain regions, could characterize neural substrates of BD pathology and symptoms.Methods: Forty-five subjects (19 BD patients, 26 controls) were imaged using a dASL sequence. Maps of average perfusion, perfusion fluctuation, and perfusion connectivity with anterior cingulate cortex (ACC) were derived. Patient symptoms were quantified along four symptom dimensions determined using factor analysis of the subjects from the Bipolar and Schizophrenia Network on Intermediate Phenotypes (BSNIP) study. Maps of the perfusion measures were compared between BD patients and controls and correlated with the symptom dimensions in the BD patients only by voxel-level and region-level analyses. Results: BD patients exhibited (i) significantly increased perfusion fluctuations in the left fusiform and inferior temporal regions (P = .020, voxel-level corrected) and marginally increased perfusion fluctuations in the right temporal pole and inferior temporal regions (P = .063, cluster-level corrected), (ii) significantly increased perfusion connectivity between ACC and the occipitoparietal cortex (P = .050, clusterlevel corrected). In BD patients, positive symptoms were negatively associated with ACC perfusion connectivity to the right orbitofrontal and superior frontal regions (P = .002, cluster-level corrected) and right orbitofrontal and inferior frontal regions (P = .023, cluster-level corrected). Conclusion: The abnormal perfusion fluctuations and connectivity alterations may underlie the mood fluctuations and cognitive and emotional dysregulation that characterize BD. K E Y W O R D S arterial spin labeling, bipolar disorder, functional connectivity, perfusion fluctuation, symptom dimension S U PP O RTI N G I N FO R M ATI O N Additional supporting information may be found online in the Supporting Information section. How to cite this article: Dai W, Chen M, Duan W, et al Abnormal perfusion fluctuation and perfusion connectivity in bipolar disorder measured by dynamic arterial spin labeling.

Recent Technical Developments in ASL: A Review of the State of the Art

“…Early on, it was shown that connectivity of the sensorimotor network could be detected with ASL by evaluating fluctuations in the CBF signal. 139 Since then, several studies performed to identify resting state networks, applying different analysis methods, such as seed-based connectivity, [140][141][142] independent component analysis [143][144][145][146][147] and whole-brain voxel level connectivity, 143,148 have found similar brain networks as those observed in resting state BOLD studies. As in the case of task activation studies, resting-state functional connectivity measured with ASL can potentially provide better localization of resting state networks than BOLD, despite the lower spatial resolution of the ASL images.…”

Rotated spiral RARE for high spatial and temporal resolution volumetric arterial spin labeling acquisition

“…This would enable study of the blood flow modulations at rest, potentially both from vasoregulatory changes and from correlated neural activity. In some pathologies, fluctuations may be more diagnostic than mean blood flow values ( Dai et al, 2020 ). Of course, modulations of blood flow may also be stimulated for diagnostic and research purposes, such as by CO 2 ( Last et al, 2007 ) or acetazolamide ( Detre et al, 1999 ; Dai et al, 2020 ), blood pressure cuffs ( Panerai et al, 2001 ), respiratory protocols ( Detre et al, 1999 ; Puig et al, 2019 ), and electrical ( Zheng et al, 2011 ) or task based ( Kim, 1995 ) brain activity stimulations.…”

Altered cerebral perfusion in bipolar disorder: A pCASL MRI study

“…MRI data were acquired on 3T scanners: GE Signa HDxt (Boston) and Philips Achieva (Dallas). The GE scanner pCASL sequence 24 used a 3D stack of spiral RARE readout with a labeling duration (LD)=2000msec, post‐labeling decay (PLD)=1800msec, background suppression to less than 0.3% of background tissue signals and scan time (ST)=9:00min 24‐26 . The reference volume was collected for the purpose of CBF quantification.…”

“…CBF‐weighted images were corrected for head motion and a mean head‐motion corrected image was generated. No subjects were dropped due to motion 26,27 . The GE CBF map for each subject was quantified using the standard kinetic model 28‐30 along with the mean of the head‐motion corrected ASL images and the reference image.…”