Abstract |
Ga-67 citrate scan has been requested for detection or
follow-up of inflammatory or neoplastic disease.
Visualization of Ga-67 citrate in the kidneys at 48 and
72 hr post injection is usually interpreted as evidence
of renal pathology. But precise mechanisms of abnormal
Ga-67 uptake in kidneys were unknown. We undertook a
study to determine the clinical value of Ga-67 citrate
imaging of the kidneys in 68 patients with primary or
secondary nephropathy confirmed by renal biopsy and 66
control patients without renal disease. Renal uptake in
48 to 72 hr images was graded as follows: Grade
0=background activity;1=faint uptake greater than
background; 2= definite uptake, but less than lumbar
vertebrae;3 same uptake as lumbar vertebrae, but less
than liver; 4=same or higher uptake than liver. The
results were as follows. 1) 42 of 68(62%) patients with
noninfectious nephritis showed grade 2 or higher Ga-67
renal uptake but only 10 percent of control patients
showed similar uptake. 2) In 14 patients with systemic
lupus erythematosus, 8 of 9 (89%) patients with lupus
nephritis exhibited marked renal uptake. 3) 36 of 41
patients (88%) with combined nephrotic syndrome showed
Grade 2 or higher renal uptake. 4) Renal Ga-67 uptake
was correlated with clinical severity of nephrotic
syndrome determined by serum albumin level, 24 hr urine
protein excretion and serum lipid levels. 5) After
complete remission of nephrotic syndrome, renal uptake
in all 8 patients who were initially Grade 3 or 4,
decreased to Grade 1 or 0. In conclusion, we think that
the mechanism of renal Ga-67 uptake in nephrotic
syndrome might be related to the pathogenesis of
nephrotic syndrome. In systemic lupus erythematosus,
Ga-67 citrate scan is useful in predicting renal
involvement. |