Micro-MRI methods to detect renal cysts in mice.
BACKGROUND
Mouse models of disease, especially using transgenic and knockout technologies, are powerful tools to analyze the molecular basis of disease. We recently reported that a new dynamic micro-MRI method with dendrimer-based contrast agents can visualize renal structure and function in normal living mice and mice with acute renal failure. While MRI contrast enhancement is useful for detecting functional impairment of the kidneys, this technology has limitations in assessing morphologic changes, particularly cystic disease, because contrast-enhanced micro-MRI depicts cysts as low-intensity areas that cannot be distinguished from fibrotic foci.


METHODS
In the current study, we evaluated if micro-MRI employing a new three-dimensional MR hydrography signal sequence [three-dimensional fast imaging employing steady-state acquisition (3D-FIESTA)] can visualize chronic cystic changes without any contrast agents.


RESULTS
We were able to positively depict multiple renal cortical cysts of approximately 0.2 mm diameter in a mouse model of sickle cell disease and observe serial changes of renal cysts (>0.2 mm diameter) in cyclooxygenase-2 (COX-2) knockout mice during a 21/2-month period. Some cysts decreased in size over time.


CONCLUSIONS
Micro-MRI with 3D-FIESTA can depict cyst formation in the diseased kidneys of living mice without injection of contrast agents.
Kobayashi
Hisataka
H
Metabolism Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA. Kobayash@mail.nih.gov
Kawamoto
Satomi
S
Brechbiel
Martin W
MW
Jo
Sang-Kyung
SK
Hu
Xuzhen
X
Yang
Tianxin
T
Diwan
Bhalchandra A
BA
Waldmann
Thomas A
TA
Schnermann
Jurgen
J
Choyke
Peter L
PL
Star
Robert A
RA
D000755:Anemia, Sickle Cell / Q000150:complications; D000818:Animals; D002908:Chronic Disease; D003287:Contrast Media; D051546:Cyclooxygenase 2; D021621:Imaging, Three-Dimensional; D007527:Isoenzymes / Q000172:deficiency; D007672:Kidney Cortex / Q000473:pathology; D052177:Kidney Diseases, Cystic / Q000175:diagnosis* / Q000209:etiology / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods; D051379:Mice; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D011451:Prostaglandin-Endoperoxide Synthases / Q000172:deficiency; D012680:Sensitivity and Specificity
D003287:Contrast Media; D007527:Isoenzymes; D051546:Cyclooxygenase 2; D011451:Prostaglandin-Endoperoxide Synthases