Value of Three-Dimensional Maximum Intensity Projection Display to Assist in Magnetic Resonance Imaging (MRI)-Based Grading in a Mouse Model of Subarachnoid Hemorrhage.

Medical science monitor : international medical journal of experimental and clinical research

PubMedID: 27307024

Mutoh T, Mutoh T, Sasaki K, Nakamura K, Taki Y, Ishikawa T. Value of Three-Dimensional Maximum Intensity Projection Display to Assist in Magnetic Resonance Imaging (MRI)-Based Grading in a Mouse Model of Subarachnoid Hemorrhage. Med Sci Monit. 2016;222050-5.
BACKGROUND
Subarachnoid hemorrhage (SAH) is one of the most devastating cerebrovascular disorders.We report on the diagnostic value of three-dimensional (3-D) maximum intensity projection (MIP) reconstruction of T2*-weighted magnetic resonance images (MRI), processed using graphical user interface-based software, to aid in the accurate grading of endovascular-perforation-induced SAH in a mouse model.

MATERIAL AND METHODS
A total of 30 mice were subjected to SAH by endovascular perforation; three (10%) were scored as grade 0, six (20%) as grade 1, six (20%) as grade 2, eight (27%) as grade 3, and seven (23%) as grade 4 according to T2*-weighted coronal slices.In comparison, none of mice were scored as grade 0, eight (27%) as grade 1, five (17%) as grade 2, nine (30%) as grade 3, and eight (27%) as grade 4 based on subsequent evaluation using reconstructed 3-D MIP images.

RESULTS
Mice scored as grade 0 (10%; no visible SAH) on T2*-coronal images were categorized as grades 1 (thin/localized SAH) and 3 (thick/diffuse SAH) according to 3-D MIP images.Grades based on T2* 3-D MIP images were more closely correlated with conventional SAH score (r2=0. 59; P<0. 0001) and neurological score (r2=0. 25; P=0. 005) than those based on T2*-coronal slices (r2=0. 46; P<0. 0001 for conventional score and r2=0. 15; P=0. 035 for neurological score).

CONCLUSIONS
These results suggest that 3-D MIP images generated from T2*-weighted MRI data may be useful for the simple and precise grading of SAH severity in mice to overcome the weakness of the current MRI-based SAH grading system.