Obstructive Uropathy
A bone scan performed with 99mTc MDP in a 43 year old male, with history of low back pain was referred to assess Paget disease. Slight increase is observed, diffuse and irregular osteoblastic activity in the spine, higher in middle and lumbar, mild activity also was increased in the upper third of left sacroiliac joint, slightly increased in knees, ankles and tarsal. It was observed right pyelocalyceal urine retention and marked tortuosity of the right ureter explained by hydroureteronephrosis. Left kidney within normal limits. In conclusion, mild joint inflammatory degenerative disease. Evidence of right hydroureteronephrosis, incidentally detected and to be correlated with clinical history and ancillary studies.
In the past decades bone imaging has become a routine diagnostic tool in the clinical practice. The urinary excretion, and skeletal uptake of 99mTc-Diphosphonate are pharmacokinetic parameters that can be helpful to diagnose of several extraosseous conditions such as the one of clinical case presented.
References:
1 Castronovo FP.Normal pharmacokinetics of 99mTc-diphosphonate after intravenous administration. Biopharm Drug Dispos. 1981 Jul-Sep;2(3):283-9.