About

Derrick Wang, DMD, is an Adjunct Assistant Professor in the Department of Endodontics at Penn Dental Medicine. His role involves contributing to the academic and clinical education within the department, supporting the training of dental students and residents. The page indicates his association with Penn Dental Medicine, located at the University of Pennsylvania, and his involvement in the faculty team dedicated to advancing dental education and research.

Research topics

• Medicine
• Pathology
• Neuroscience
• Radiology
• Internal medicine
• Cardiology
• Psychology
• Psychiatry

Selected publications

• Reduced cortical brain perfusion following COVID-19 infection: impact of COVID-19 severity and relation to memory performance

  Frontiers in Human Neuroscience · 2026-04-10

  articleOpen access

  Introduction: Changes to brain perfusion may be contributing to long-term cognitive dysfunction following COVID-19 infection. Lower brain perfusion beyond the acute phase of infection, as measured by perfusion MRI, has been observed in both hospitalized and non-hospitalized cases. Additionally, the hippocampus has been previously shown to be particularly sensitive to changes in blood flow. Therefore, the hippocampus may be vulnerable to perfusion changes associated with COVID-19, leading to long-term cognitive sequalae. The literature suggest that this may be particularly true among those with severe respiratory symptoms. However, the relationship between COVID-19 respiratory severity, perfusion, and cognitive dysfunction has yet to be thoroughly explored, especially after longer recovery times. Methods: Seventy-eight participants completed a neuroimaging session and two memory tests, the Mnemonic Similarity Task (MST) and Face-Name Associative Memory Exam (FNAME), tasks known to be mediated by the hippocampus. Participants were divided into four groups based on the severity of self-reported respiratory symptoms experienced during the acute infection: controls without a reported diagnosis of COVID-19, those with COVID-19 and without respiratory symptoms, those with COVID-19 and respiratory symptoms, and hospitalized participants with respiratory symptoms from COVID-19. On average, participants were 13 months from initial infection. Perfusion was measured with pseudo-continuous arterial spin labeled (pCASL) MRI. Total cortical gray and white matter perfusion, as well as gray matter perfusion in the territories of the anterior, middle, and posterior cerebral arteries were obtained using a mask adapted from previous studies. Results: < 0.01, even after controlling for age and education. Discussion: Results provide evidence for global perfusion dysfunction among hospitalized participants with severe respiratory symptoms that persists for more than a year after COVID-19 infection. Additionally, there was a relationship between perfusion and pattern separation performance among all participants, suggesting that poorer perfusion may underlie some of the long-term COVID-19 cognitive symptoms.

  PublisherOA PDFDOI

• Imaging BBB for treating brain disorders

  Elsevier eBooks · 2025-11-29

  book-chapter1st authorCorresponding
  PublisherDOI

• Age differences in spontaneous cerebrovascular reactivity at rest

  GeroScience · 2025-10-30

  articleOpen access

  Deficits in cerebral blood flow (CBF) and cerebrovascular reactivity (CVR) may indicate vulnerability to vascular dysfunction and cognitive impairment. Prior findings on age-related change in CVR are mixed, and no studies to date have investigated age group differences in spontaneous CVR (sCVR) at rest. The present study compared whole brain and regional sCVR at rest between 24 healthy younger adults (ages 18-34) and 163 cognitively unimpaired older adults (ages 55-87). Relative to younger adults, older adults had deficits in both whole brain and regional sCVR at rest. Among the regions examined, medial temporal lobe areas showed the largest age differences in sCVR at rest. Age differences in sCVR and CBF variability were larger than age differences in mean CBF. Results show age-related deficits in sCVR are present even in cognitively unimpaired older adults, suggesting sCVR may be indicative of cerebrovascular aging. Further research should investigate sCVR as a means for early detection of age-related vascular dysfunction that may predate irreversible vascular brain injury.

  PublisherOA PDFDOI

• Cerebral Perfusion and Blood−Brain Barrier Changes After Cranioplasty: A Diffusion‐Prepared Arterial Spin Labeling Study

  Journal of Neuroimaging · 2025-11-01

  articleOpen accessSenior authorCorresponding

  BACKGROUND AND PURPOSE: Cranioplasty reconstruction after hemicraniectomy restores skull integrity and has been associated with neurological improvement, but the physiological mechanisms underlying recovery remain incompletely understood. This study investigated cerebral blood flow (CBF), arterial transit time (ATT), and blood-brain barrier (BBB) water exchange rate (Kw) as imaging metrics of hemodynamic recovery following cranioplasty. METHODS: Fourteen patients (mean age: 33.4 ± 8.53 years; 2 females, 12 males) who previously underwent hemicraniectomy for traumatic brain injury, ruptured aneurysm, or hemorrhagic stroke were included. All participants underwent diffusion-prepared pseudo-continuous arterial spin labeling (DP-pCASL) Magnetic Resonance Imaging (MRI) at 3 Tesla before and after cranioplasty. Hemodynamic parameters were quantified globally and regionally, with particular focus on the middle cerebral artery perforator (MCA Perf) territory. RESULTS: Post-surgical imaging revealed significant increases in CBF within the ipsilateral MCA Perf territory compared to pre-surgical values. BBB Kw asymmetry between MCA Perf territories also improved, indicating enhanced perfusion and BBB function in the impacted hemisphere. ATT changes were region-specific, with significant increases in asymmetry observed in the leptomeningeal anterior cerebral artery and posterior cerebral artery territories, but not in the MCA Perf region. CONCLUSIONS: These findings underscore the mechanobiological role of cranioplasty reconstruction in neurological recovery. Advanced hemodynamic imaging with DP-pCASL MRI provides quantitative insight into cerebral perfusion, BBB function, and regional perfusion timing. This approach may guide future research on post-cranioplasty recovery and inform personalized rehabilitation strategies.

  PublisherOA PDFDOI

• Imaging natural variations of BBB function

  Elsevier eBooks · 2025-11-29

  book-chapter1st authorCorresponding
  PublisherDOI

• Reliability of Pseudocontinuous Arterial Spin-Labeling in Ischemic Stroke and Comparison with Other Perfusion Techniques: Systematic Review and Meta-Analysis

  American Journal of Neuroradiology · 2025-10-09

  articleOpen access

  <h3>ABSTRACT</h3> <h3>BACKGROUND:</h3> Pseudocontinuous arterial spin labeling (pCASL) is a non-invasive, gadolinium-free MRI technique for assessing brain perfusion. <h3>PURPOSE:</h3> To evaluate the test-retest reliability of pCASL-CBF measurements in ischemic stroke (IS) and compare pCASL metrics with those from DSC, CTP, and PET. <h3>DATA SOURCES:</h3> Systematic searches were conducted in MEDLINE, EMBASE, and LILACS. Risk of bias and methodological quality were evaluated using QUADAS-2 and QAREL tools. <h3>STUDY SELECTION:</h3> 11 studies, encompassing 383 participants with IS were included. <h3>DATA ANALYSIS:</h3> Random-effects meta-analysis with inverse variance method and heterogeneity assessed using I² statistics. <h3>DATA SYNTHESIS:</h3> No PET studies were identified. Only one low-quality, high-risk-of-bias study assessed test-retest reliability, finding no significant differences in repeated absolute CBF measurements over time and excellent reliability across regions. Most studies comparing pCASL with DSC, and all comparing pCASL with CTP, had a low risk of bias. In the hyperacute phase of IS, pCASL and DSC showed no significant differences in infarct core relative CBF (95% CI: -0.11 to 0.13; I² = 0%) or hypoperfusion volumes (95% CI: -0.28 to 0.68; I² = 69%). Evidence on the comparability of pCASL with other DSC or CTP metrics was limited. <h3>LIMITATIONS:</h3> The small number of included studies prevented a meta-analysis for the primary outcome and limited conclusions for secondary outcomes. <h3>CONCLUSIONS:</h3> Robust conclusions about the test-retest reliability of pCASL or the comparability of metrics obtained with this technique and DSC, CTP, or PET in different phases following ischemic stroke could not be drawn. ABBREVIATIONS: pCASL＝pseudocontinuous arterial spin labeling; IS: ischemic stroke; QUADAS-2＝Quality Assessment of Diagnostic Accuracy Studies-2; QAREL＝ Quality Appraisal for Reliability Studies.

  PublisherDOI

• Biology of the blood–brain barrier (BBB)

  Elsevier eBooks · 2025-11-29

  book-chapter1st authorCorresponding
  PublisherDOI

• Blurring-free 3D perfusion and arterial blood T2 mapping using partition encoding reordered GRASE (PER-GRASE) ASL at 5T

  Proceedings on CD-ROM - International Society for Magnetic Resonance in Medicine. Scientific Meeting and Exhibition/Proceedings of the International Society for Magnetic Resonance in Medicine, Scientific Meeting and Exhibition · 2025-09-16

  article

  Motivation: The blurring along the slice direction using traditional 3D GRASE ASL acquisition and its reduced SNR efficiency for measuring arterial blood T2 presents notable challenges. Goal(s): To simultaneously acquire blurring-free ASL maps and arterial blood T2 mapping at 5T. Approach: In our method, we reordered k-space partition acquisition across TRs, achieving fully sampled k-space at each echo time after recombination. Mono/bi-exponential models were used for calculating the T2 values of blood, gray matter, and white matter. Results: The proposed technique provides full-brain blurring-free perfusion and T2 mapping. Arterial blood increased at longer PLD, suggesting a potential peri-capillary compartment between capillary and tissue space. Impact: We proposed a PER-GRASE ASL technique for blurring-free perfusion and arterial blood T2 mapping with full-brain coverage at 5T, which has the potential to be adapted for measuring neurovascular function such as brain oxygenation and BBB function in clinical studies.

  PublisherDOI

• Multi-modal MRI and plasma biomarker factors distinguish neurovascular dysfunction, fluid stagnation and neurodegenerative pathology

  Proceedings on CD-ROM - International Society for Magnetic Resonance in Medicine. Scientific Meeting and Exhibition/Proceedings of the International Society for Magnetic Resonance in Medicine, Scientific Meeting and Exhibition · 2025-09-16

  article

  Motivation: Neurovascular dysfunction and fluid stagnation are observed in aging and Alzheimer's disease pathology, but the mechanisms underlying these changes remain unclear. Goal(s): We aimed to use advanced MRI and plasma biomarkers to identify biologically meaningful latent factors that elucidate neurovascular and pathological processes of aging and Alzheimer's disease. Approach: We performed exploratory factor analysis on multi-modal biomarkers in healthy older adults and investigated factor associations with age and cognitive performance. Results: Analysis revealed factors distinguishing neurovascular dysfunction, fluid stagnation and Alzheimer's disease pathology. These factors did not correlate with cognition, suggesting relevance to aging or early pathology before cognitive symptoms arise. Impact: This multi-modal study uncovered distinct neurovascular and pathological constructs in aging, offering a framework for investigating early markers of neurodegenerative processes before cognitive symptoms arise. Our findings provide a foundation for future studies investigating complex mechanisms underlying Alzheimer's disease progression.

  PublisherDOI

• Changes in Cerebral Small Vessel Density and Hemodynamics in CADASIL Patients Revealed by high-resolution Black-Blood MRI and Multi-Delay pCASL

  Proceedings on CD-ROM - International Society for Magnetic Resonance in Medicine. Scientific Meeting and Exhibition/Proceedings of the International Society for Magnetic Resonance in Medicine, Scientific Meeting and Exhibition · 2025-09-16

  articleSenior author

  Motivation: CADASIL causes reduction in small vessels, disrupted cerebral hemodynamics, and cognitive impairments. Their interrelations remain unclear. Goal(s): To evaluate changes in cerebral small vessel density and cerebral hemodynamics including CBF, ATT, and their contribution to cognitive impairments in CADASIL patients. Approach: 29 CADASIL patients and 33 healthy controls underwent 5-PLD pCASL and high-resolution black blood MRI. Alterations in ATT, CBF, and small vessel density, and their relationships with cognitive performance were assessed. Results: significant reductions in small vessel density and CBF, along with prolonged ATT, were observed across multiple brain regions in CADASIL patients. Similar changes are also associated with poor cognitive ability. Impact: This study employed a high-resolution black blood MRI alongside 5-PLD pCASL to offer comprehensive assessments of the alterations of cerebral small vessel density and hemodynamics and their relationships with cognitive impairments in CADASIL patients.

  PublisherDOI

Recent grants

• Multiband ASL for Neurodevelopment Study

  NIH · $2.2M · 2019–2025

• NIH Grant R21HD049893

  NIH · $294k · 2008

• NIH Grant R21MH072576

  NIH · $313k · 2007

• Perturbation of the treatment resistant depression connectome by fast-acting therapies

  NIH · $5.5M · 2016–2022

• Imaging-guided tDCS therapy in major depression

  NIH · $2.2M · 2017–2022

Frequent coauthors

• John A. Detre

  University of Pennsylvania

  148 shared

• Xingfeng Shao

  University of Southern California

  120 shared

• Kay Jann

  University of Southern California

  76 shared

• Lirong Yan

  70 shared

• Yan Zhuo

  52 shared

• Patricia A. Blissitt

  Harborview Medical Center

  50 shared

• W. Andrew Kofke

  50 shared

• David S. Liebeskind

  46 shared

Education

• Master of Science in Clinical Epidemiology (MSCE)

  University of Pennsylvania

  2010

• PhD

  University of Science and Technology of China (USTC)

  1998

• BS

  Fudan University

  1993

Awards & honors

• Leonard Davis Institute Summer Research Fellowship