Proximal femur bone marrow blood perfusion indices are reduced in hypertensive rats: a dynamic contrast-enhanced MRI study.
OBJECTIVE
To investigate the differences in proximal femoral bone marrow blood perfusion indices between hypertensive and normotensive rats using perfusion magnetic resonance imaging (MRI).


METHODS
Six-month-old male spontaneously hypertensive rats (SHR) and Wistar Kyoto rats (WKY) were used (12 of each). Dynamic contrast-enhanced MRI of the right hip was performed after bolus injection of Gd-DOTA administered through a tail vein cannula. In all, 800 images were acquired at 0.6 sec/image. Regions of interest (ROIs) were drawn comprising the medullary component of proximal femoral shaft and femoral head. MRI maximum enhancement (E(max)) and enhancement slope (E(slope)) were analyzed.


RESULTS
The E(max) and E(slope) of proximal femoral shaft and femoral head of SHR were significantly lower than those of WKY (E(max): 107.4 +/- 18.2% vs. 130.6 +/- 21.5%, P = 0.009, and 76.0 +/- 12.5% vs. 97.9 +/- 6.9%, P < 0.001, respectively; E(slope): 3.01 +/- 0.63%/sec vs. 3.75 +/- 0.74%/sec, P = 0.016, and 1.95 +/- 0.33%/sec vs. 2.28 +/- 0.28%/sec, P = 0.012, respectively). The E(max) and E(slope) of femoral head were significantly lower than those of proximal femoral shaft in both SHR and WKY (P < 0.001). In both SHR and WKY, proximal femoral shaft and femoral head had a rather different contrast enhancement pattern.


CONCLUSIONS
Proximal femoral shaft and femoral head bone marrow blood perfusion indices were significantly lower in hypertensive rats than in normotensive rats. Femoral head bone marrow was less perfused than proximal femoral shaft in both rats.
Zhang
Ya-Feng
YF
Department of Medicine and Therapeutics, Prince of Wales Hospital, Chinese University of Hong Kong, Shatin, NT, Hong Kong, China.
Wang
Yi-Xiang J
YX
Griffith
James F
JF
Kwong
William K M
WK
Ma
Heather T
HT
Qin
Ling
L
Kwok
Timothy C Y
TC
D000818:Animals; D001794:Blood Pressure; D015519:Bone Density; D001853:Bone Marrow / Q000473:pathology; D001854:Bone Marrow Cells / Q000166:cytology*; D003287:Contrast Media / Q000494:pharmacology*; D005269:Femur / Q000473:pathology*; D006973:Hypertension / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D010477:Perfusion; D011312:Pressure; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY
D003287:Contrast Media