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Sudipto Dolui

Possible papers associated with this exact author name in Arrow. This page groups case-insensitive exact name matches and is not a full identity disambiguation profile.

5 papers

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YNICL Journal 2025 Journal Article

Spatial and signal features of white matter integrity and associations with clinical factors: A CARDIA brain MRI study

Faezeh Vedaei
Dhivya Srinivasan
Drew Parker
Guray Erus
Sudipto Dolui
Farzaneh A. Sorond
David R. Jacobs
Lenore J. Launer

White matter hyperintensities (WMH) may be indicative of age-related cerebrovascular diseases and contribute to cognitive and functional decline. Normal appearing WM (NAWM) adjacent to WMH, termed "penumbra," is known to be vulnerable to future WMH pathology. WM integrity can be evaluated using multiple magnetic resonance imaging (MRI) modalities. We aimed to identify MRI features predictive of WMH growth and to compare the implications of these features based on spatial proximity to existing WMH versus signal features in baseline NAWM. We used baseline and 5-year follow-up MRI scans in 485 middle-aged participants form the Coronary Artery Risk Development in Young Adults (CARDIA). Multimodal MRI at baseline, including fluid attenuated inversion recovery (FLAIR), diffusion tensor imaging (DTI), and cerebral blood flow (CBF), was measured within WM ROIs including baseline WMH and regions that later developed into new WMH, within and external to the baseline penumbra. Overall, we found that 80% of new WMH appeared within the baseline penumbra. We also found lower fractional anisotropy (FA) and CBF and higher FLAIR and median diffusivity (MD) in NAWM at baseline in regions with subsequent WMH growth compared to those without WMH growth. For NAWM regions defined by signal features, subthreshold FA and suprathreshold MD and FLAIR abnormality at baseline were the most robust predictors of WMH growth. Baseline systolic blood pressure had significant associations with baseline abnormalities in NAWM and subsequently with cognitive decline, particularly for FA and MD measures. The findings support the use of DTI as the predictor of WMH growth, which is correlated with subtle, adverse WM alterations and cognitive function years before developing to WMH. The results may contribute to future clinical trials aimed at preserving WM integrity.

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YNICL Journal 2023 Journal Article

Temporal dynamics of cerebral blood flow during the first year after moderate-severe traumatic brain injury: A longitudinal perfusion MRI study

Naomi L. Gaggi
Jeffrey B. Ware
Sudipto Dolui
Daniel Brennan
Julia Torrellas
Ze Wang
John Whyte
Ramon Diaz-Arrastia

Traumatic brain injury (TBI) is associated with alterations in cerebral blood flow (CBF), which may underlie functional disability and precipitate TBI-induced neurodegeneration. Although it is known that chronic moderate-severe TBI (msTBI) causes decreases in CBF, the temporal dynamics during the early chronic phase of TBI remain unknown. Using arterial spin labeled (ASL) perfusion magnetic resonance imaging (MRI), we examined longitudinal CBF changes in 29 patients with msTBI at 3, 6, and 12 months post-injury in comparison to 35 demographically-matched healthy controls (HC). We investigated the difference between the two groups and the within-subject time effect in the TBI patients using whole-brain voxel-wise analysis. Mean CBF in gray matter (GM) was lower in the TBI group compared to HC at 6 and 12 months post-injury. Within the TBI group, we identified widespread regional decreases in CBF from 3 to 6 months post-injury. In contrast, there were no regions with decreasing CBF from 6 to 12 months post-injury, indicating stabilization of hypoperfusion. There was instead a small area of increase in CBF observed in the right precuneus. These CBF changes were not accompanied by cortical atrophy. The change in CBF was correlated with change in executive function from 3 to 6 months post-injury in TBI patients, suggesting functional relevance of CBF measures. Understanding the time course of TBI-induced hypoperfusion and its relationship with cognitive improvement could provide an optimal treatment window to benefit long-term outcome.

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YNICL Journal 2020 Journal Article

Arterial spin labeling versus 18F-FDG-PET to identify mild cognitive impairment

Sudipto Dolui
Zhengjun Li
Ilya M. Nasrallah
John A. Detre
David A. Wolk

Neurodegenerative biomarkers support diagnosis and measurement of disease progression in the Alzheimer's disease (AD) continuum. 18F-Fluorodeoxyglucose Positron Emission Tomography (18F-FDG-PET), which measures glucose metabolism, is one of the most commonly used biomarkers of neurodegeneration, but is expensive and requires exposure to ionizing radiation. Arterial Spin Labeled (ASL) perfusion Magnetic Resonance Imaging (MRI) provides non invasive quantification of cerebral blood flow (CBF), which is believed to be tightly coupled to glucose metabolism. Here we aimed to compare the performances of ASL derived CBF and 18F-FDG-PET derived standardized uptake value ratio (SUVR) in discriminating patients with mild cognitive impairment (MCI) from older Controls. 2D pseudo continuous ASL and 18F-FDG-PET data with adequate scan quality from 50 MCI study participants (age=73. 0 ± 7. 0 years, 16 female) and 35 older controls (age=70. 2 ± 6. 9 years, 20 female), acquired in close temporal proximity, usually on the same day, were considered for this study. We assessed Control-patient group differences both at voxel level and within a priori regions of interest (ROIs). We also compared their area under receiver operating characteristic curves (AUC) with mean CBF or SUVR in a priori selected posterior cingulate cortex (PCC). CBF and 18F-FDG-PET showed abnormalities in similar areas, particularly in medial temporoparietal regions, consistent with the typically observed pattern of prodromal AD. The hypoperfusion pattern with relative CBF (obtained by normalizing voxel CBF values with mean CBF in putamen) was more localized than with absolute CBF. Pearson's correlation coefficients between the T-scores corresponding to the group-differences obtained with 18F-FDG-PET SUVR and absolute and relative ASL CBF were 0. 46 and 0. 43 (p<0. 001), respectively. ROI analyses were also consistent, with the strongest differences observed in PCC (p<0. 01). 18F-FDG-PET SUVR, absolute and relative CBF in the PCC ROI demonstrated moderate and similar discriminatory power in predicting MCI status with AUC of 0. 71 ± 0. 12, 0. 77 ± 0. 12 and 0. 74 ± 0. 13, respectively. In conclusion, ASL CBF may be a reasonable, less expensive and safer substitute for 18F-FDG-PET in clinical research.

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YNICL Journal 2019 Journal Article

Characterizing a perfusion-based periventricular small vessel region of interest

Sudipto Dolui
Dylan Tisdall
Marta Vidorreta
David R. Jacobs
Ilya M. Nasrallah
R. Nick Bryan
David A. Wolk
John A. Detre

The periventricular white matter (PVWM) is supplied by terminal distributions of small vessels and is particularly susceptible to developing white matter lesions (WML) associated with cerebral small vessel disease (CSVD). We obtained group-averaged cerebral blood flow (CBF) maps from Arterial Spin Labeled (ASL) perfusion MRI data obtained in 436 middle-aged (50.4 ± 3.5 years) subjects in the NHLBI CARDIA study and in 61 elderly (73.3 ± 6.9 years) cognitively normal subjects recruited from the Penn Alzheimer's Disease Center (ADC) and found that the lowest perfused brain voxels are located within the PVWM. We constructed a white matter periventricular small vessel (PSV) region of interest (ROI) by empirically thresholding the group averaged CARDIA CBF map at CBF < 15 ml/100 g/min. Thereafter we compared CBF in the PSV ROI and in the remaining white matter (RWM) with the location and volume of WML measured with Fluid Attenuated Inversion Recovery (FLAIR) MRI. WM CBF was lower within WML than outside WML voxels (p < <0.0001) in both the PSV and RWM ROIs, however this difference was much smaller (p < <0.0001) in the PSV ROI than in the RWM suggesting a more homogenous reduction of CBF in the PSV region. Normalized WML volumes were significantly higher in the PSV ROI than in the RWM and in the elderly cohort as compared to the middle-aged cohort (p < <0.0001). Additionally, the PSV ROI showed a significantly (p = .001) greater increase in lesion volume than the RWM in the elderly ADC cohort than the younger CARDIA cohort. Considerable intersubject variability in PSV CBF observed in both study cohorts likely represents biological variability that may be predictive of future WML and/or cognitive decline. In conclusion, a data-driven PSV ROI defined by voxels with low perfusion in middle age defines a region with homogeneously reduced CBF that is particularly susceptible to progressive ischemic injury in elderly controls. PSV CBF may provide a mechanistically specific biomarker of CSVD.

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YNICL Journal 2016 Journal Article

A brain stress test: Cerebral perfusion during memory encoding in mild cognitive impairment

Long Xie
Sudipto Dolui
Sandhitsu R. Das
Grace E. Stockbower
Molly Daffner
Hengyi Rao
Paul A. Yushkevich
John A. Detre

Arterial spin labeled perfusion magnetic resonance imaging (ASL MRI) provides non-invasive quantification of cerebral blood flow, which can be used as a biomarker of brain function due to the tight coupling between cerebral blood flow (CBF) and brain metabolism. A growing body of literature suggests that regional CBF is altered in neurodegenerative diseases. Here we examined ASL MRI CBF in subjects with amnestic mild cognitive impairment (n = 65) and cognitively normal healthy controls (n = 62), both at rest and during performance of a memory-encoding task. As compared to rest, task-enhanced ASL MRI improved group discrimination, which supports the notion that physiologic measures during a cognitive challenge, or "stress test", may increase the ability to detect subtle functional changes in early disease stages. Further, logistic regression analysis demonstrated that ASL MRI and concomitantly acquired structural MRI provide complementary information of disease status. The current findings support the potential utility of task-enhanced ASL MRI as a biomarker in early Alzheimer's disease.

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