MR FINDINGS IN DIFFUSE RENAL PARENCHYMAL DISEASE

This study evaluates the MR appearance of the kidney in diffuse renal parenchymal diseases, using precontrast, and immediate and delayed pos tgadolinium chelate (Gd), spoiled gradient echo (SGE), and pre- and po st-Gd, T1-weighted, fat-suppressed spin-echo MR images to determine if characteristic findings exist for various types of renal disease, One hundred twenty-one patients with renal disease underwent MRI, Underly ing diagnoses included: (a) glomerular disease (GD), (b) tubulointerst itial disease (TID), (c) microvascular disease (MVD), (d) ischemic nep hropathy (INP), (e) obstructive nephropathy (ON), Cf) infectious renal disease (IRD), (g) sickle cell disease (SCD), (h) renal cortical necr osis (CN), and (i) renal insufficiency of unknown etiology (UE), MR ex aminations of 22 patients with normal kidneys (NK) were evaluated as a control group. The presence of corticomedullary differentiation (CMD) demonstrated strong inverse correlation with serum creatinine concent ration (SCr) (r = - .568, P < .001). Mean thickness of the renal corte x was 8.4 and 7.8 mm in patients with NK and Gd, respectively. The mea n cortical thickness in patients with MVD, TID/Chemo, INP, and ON was 5.2, 5.6, 5.5, and 4.3 mm, respectively, significantly thinner than th e renal cortex in the NK and GD groups (P < .01). Irregularity of the renal cortex was more frequent in MVD (60.9%), IRD (62.5%), ON (55.6%) , and TID/other (53.8%) than in GD (3.8%) and NK (0%) (P < .01). Diffu se high SI of the entire medulla on delayed postcontrast images was ob served in 25 (20.7%) of the patients with renal disease and none of th e NK group, Although no pathognomonic features were found, certain fin dings were observed that may correlate with the etiology of the kidney disease and, therefore, assist in the differential diagnosis of renal parenchymal disease.