Changes in Apparent Diffusion Coefficient (ADC) during Cardiac Cycle of the Brain in Idiopathic Normal Pressure Hydrocephalus Before and After Cerebrospinal Fluid Drainage. Issue 4 (28th October 2020)

• Record Type: Journal Article
• Authors: Osawa, Tomoshi; Ohno, Naoki; Mase, Mitsuhito; Miyati, Tosiaki; Omasa, Ryoko; Ishida, Shota; Kan, Hirohito; Arai, Nobuyuki; Kasai, Harumasa; Shibamoto, Yuta; Kobayashi, Satoshi; Gabata, Toshifumi
• Is Part Of: Journal of magnetic resonance imaging. Volume 53:Issue 4(2021)
• Page Start: 1200
• Page End: 1207
• Publication Date: 2020-10-28
• Subjects: idiopathic normal‐pressure hydrocephalus -- lumbar tap -- shunt surgery -- diffusion‐weighted imaging -- apparent diffusion coefficient; Magnetic resonance imaging -- Periodicals; 616
• DOI: 10.1002/jmri.27412
• Languages: English
• ISSNs: 1053-1807

Abstract

Abstract : Background: The causative mechanisms of idiopathic normal‐pressure hydrocephalus (iNPH) symptoms are currently unknown. Purpose: To assess the dynamic changes in the apparent diffusion coefficient (ADC) during the cardiac cycle (ΔADC) of the brain before and after the lumbar tap and shunt surgery for the purpose of determining changes in hydrodynamic and biomechanical properties in the brain after cerebrospinal fluid (CSF) drainage for iNPH. Study Type: Retrospective. Subjects: Overall, 22 patients suspected to have iNPH were examined before and after the lumbar tap and were divided into patients who showed symptomatic improvements (positive group, n = 17) and those without improvement (negative group, n = 5) after the lumbar tap. Seven patients in the positive group were examined after the shunt surgery. Field Strength/Sequence: 1.5T, electrocardiographically synchronized single‐shot diffusion echo‐planar imaging. Assessment: The frontal white matter ΔADC and mean ADC (ADCmean ) were compared between before and 24 hours after lumbar tap and from 1 week to 1 month after the shunt surgery. Statistical Tests: Wilcoxon signed‐rank test was used. P < 0.05 was considered statistically significant. Results: The ΔADC after the lumbar tap in the positive group was significantly lower than that before ( P < 0.05), whereas no significant difference was found in the negative group ( P = 0.23). After the lumbar tap, ΔADC decreased in 16 of 17 patients in the positive group, whereas ADCmean did not significantly change ( P = 0.96). After the shunt surgery, ΔADC decreased in all seven patients ( P < 0.05), whereas ADCmean did not significantly change ( P = 0.87). Data Conclusion: The frontal white matter ΔADC in iNPH decreased after the lumbar tap and shunt surgery. ΔADC analysis may provide detailed information regarding changes in the hydrodynamic and biomechanical properties through CSF drainage. Level of Evidence: 4. Technical Efficacy Stage: 4.