Peter Chiarelli, DPhil, MD
Associate professor, attending neurosurgeon, Barrow Neurological Institute at Phoenix Children’s Hospital
Date: Friday, March 27
Time: 9–9:50 a.m.
Location: SCOB 228
Faculty host: Ding Ding Zheng
Abstract
Disorders of abnormal cerebrospinal fluid, or CSF, flow are common conditions treated by neurosurgeons, yet many questions still exist pertaining to clinical management and operative decision-making that lack tools to guide therapy. Hydrocephalus, for instance, is a serious condition of inappropriate imbalance between CSF production and reabsorption, and ventricular shunts are used for life-saving cerebrospinal fluid diversion. Existing methods for shunt evaluation provide correlative/qualitative information, leading to commonplace clinical diagnostic challenges.
Our group has focused on non-invasive MRI-based sequence development, protocol manipulation and direct clinical investigation to address answers to neurosurgical questions with an active clinical need. For ventricular shunts, we conducted a single-center, prospective observational cohort study at an urban, quaternary-care center, obtaining data from 207 patients with ages ranging from eight days to 27 years. Both phase-contrast MRI methods and spin-labeled inversion-recovery methods (TimeSTAMP) were used to provide measurement of CSF flow within ventricular shunts during the study period. We were able to investigate shunt flow rate/physiology in human patients, including a first-of kind assessment for mean cerebrospinal fluid flow rate (9.9 ± 8 ml/hr with a range of 0.5-54 ml/hr). Among patients who obtained repeat scans, no significant difference was seen in flow measurements between initial and follow-up imaging, illustrating a new role for routine baseline shunt flow that could contribute to improved patient-centered care. Among examples of symptomatic patients, shunt flow measurement accurately demonstrated failure in three patients, and avoided unnecessary surgery in a fourth, and led to early detection of failure avoiding future emergent symptomatic presentation.
There is a wide landscape and a research need for the development of non-invasive biomarker strategies that can be specifically designed to address common questions within standard surgical workflow. The mission of our multi-institutional CSF Flow Dynamics Group, or CFDG, is to bridge MRI physics with patient care, and address real problems among conditions pertaining to CSF flow in the human brain, for the benefit of kids and their families.
Biosketch
Dr. Peter A. Chiarelli is a pediatric neurosurgeon and associate professor of neurological surgery at the Barrow Neurological Institute at Phoenix Children’s. Dr. Chiarelli is director of the Phoenix Children’s Hydrocephalus Program and the Advanced Research in Neurosurgical Illness Program. He specializes in treating children with tumors of the brain and spine, as well as spina bifida, hydrocephalus, neurotrauma and Chiari malformation.
Dr. Chiarelli studied as a Rhodes Scholar and earned a research doctorate in neuroscience from Oxford University in Oxford, England, before continuing to his medical degree from Harvard Medical School and the Massachusetts Institute of Technology. He completed residency training in neurological surgery and a fellowship in pediatric neurosurgery in Seattle at the University of Washington and Seattle Children’s. As a pediatric neurosurgeon focused on neuroimaging research and applied physics/chemistry, Dr. Chiarelli’s goal is to combine a clinical knowledge base, access to the surgical suite and a background in benchtop science for investigation of neurological illness, as well as the application of this multi-disciplinary perspective to the improved treatment of patients.
Developments in the field of human brain imaging have contributed toward many significant advances in neurosurgical practice and outcomes over the past century. Multiple neurological diseases, including hydrocephalus, all stand to benefit from further investigation and implementation of advanced imaging, including magnetic resonance imaging. Dr. Chiarelli works to develop MRI methods, not currently available, that can be used for straightforward application to the clinical neurosciences. For instance, his lab has developed new tools to analyze CSF flow in shunted patients to improve our understanding of overall hydrocephalus physiology. Dr. Chiarelli’s research has received funding from the National Institutes of Health, the U.S. Department of Defense, the Southern California Clinical and Translational Science Institute, the Hydrocephalus Association, the Rudi Schulte Research Institute, as well as multiple other foundations. Dr. Chiarelli received the Hydrocephalus Association Innovator Award and has been recognized throughout his academic career as a Top Doc by Los Angeles magazine and Pasadena Magazine.
