Differential diagnosis of normal pressure hydrocephalus by MRI mean diffusivity histogram analysis

AJNR Am J Neuroradiol. 2013 Jun-Jul;34(6):1168-74. doi: 10.3174/ajnr.A3368. Epub 2012 Dec 20.

Abstract

Background and purpose: Accurate diagnosis of normal pressure hydrocephalus is challenging because the clinical symptoms and radiographic appearance of NPH often overlap those of other conditions, including age-related neurodegenerative disorders such as Alzheimer and Parkinson diseases. We hypothesized that radiologic differences between NPH and AD/PD can be characterized by a robust and objective MR imaging DTI technique that does not require intersubject image registration or operator-defined regions of interest, thus avoiding many pitfalls common in DTI methods.

Materials and methods: We collected 3T DTI data from 15 patients with probable NPH and 25 controls with AD, PD, or dementia with Lewy bodies. We developed a parametric model for the shape of intracranial mean diffusivity histograms that separates brain and ventricular components from a third component composed mostly of partial volume voxels. To accurately fit the shape of the third component, we constructed a parametric function named the generalized Voss-Dyke function. We then examined the use of the fitting parameters for the differential diagnosis of NPH from AD, PD, and DLB.

Results: Using parameters for the MD histogram shape, we distinguished clinically probable NPH from the 3 other disorders with 86% sensitivity and 96% specificity. The technique yielded 86% sensitivity and 88% specificity when differentiating NPH from AD only.

Conclusions: An adequate parametric model for the shape of intracranial MD histograms can distinguish NPH from AD, PD, or DLB with high sensitivity and specificity.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Alzheimer Disease / diagnosis
  • Alzheimer Disease / pathology
  • Alzheimer Disease / physiopathology
  • Brain / pathology*
  • Diagnosis, Differential
  • Female
  • Humans
  • Hydrocephalus, Normal Pressure / diagnosis*
  • Hydrocephalus, Normal Pressure / pathology
  • Hydrocephalus, Normal Pressure / physiopathology
  • Image Processing, Computer-Assisted / methods
  • Image Processing, Computer-Assisted / standards
  • Lewy Body Disease / diagnosis
  • Lewy Body Disease / pathology
  • Lewy Body Disease / physiopathology
  • Magnetic Resonance Imaging / methods*
  • Magnetic Resonance Imaging / standards
  • Male
  • Middle Aged
  • Models, Theoretical*
  • Neurodegenerative Diseases / diagnosis*
  • Neurodegenerative Diseases / pathology
  • Neurodegenerative Diseases / physiopathology
  • Parkinson Disease / diagnosis
  • Parkinson Disease / pathology
  • Parkinson Disease / physiopathology
  • Reproducibility of Results
  • Sensitivity and Specificity