Diuretic Renal Scintigraphy in Normal Cats

Abstract

The purpose of this study was to develop a protocol for diuretic renal scintigraphy (renography) in cats and describe normal findings. 99mTc-DTPA renal scintigraphy was performed twice in 10 healthy cats. Furosemide or saline were injected 4.5 min after radiopharmaceutical administration for the diuretic or control scan, respectively. A dynamic acquisition was performed for 8 min. The following parameters were evaluated: (1) global and individual glomerular filtration rate (GFR); (2) shape of the time-activity curve (TAC); (3) time of peak (TOP); (4) individual kidney excretion half-time (T1/2) of the radiopharmaceutical; (5) percentage of maximum activity measured at the end of the study. Global GFR in the control studies (2.79 +/- 0.83 ml/min/kg, mean +/- SD) did not differ significantly from the diuretic scans (2.34 +/- 0.51 ml/min/kg). The shape of most (16/ 20) TAC of diuretic renograms was similar to those of control renograms. The TOP of the diuretic renogram curves was 3.06 +/- 0.58 min, and did not differ from that of the control scans (3.01 +/- 0.61 min). T1/2 of the diuretic renograms was significantly shorter (5.15 +/- 0.83 min) than that of the control renograms (6.31 +/- 1.50 min). A significantly lower percentage of maximum activity was present at the end of the study in diuretic renograms (median: 47.25%; range: 33.60-59.60%) compared with control renograms (63.40%; 30.00-69.40%). Diuretic renal scintigraphy is a noninvasive and fast procedure to perform in cats. The applicability of this technique needs to be investigated in patients with significantly impaired renal function and obstructive uropathies.

99mTc-DTPA diuretic renal scintigraphy in cats with nephroureterolithiasis

“…Renal excretion scintigraphy was performed as described previously. 30 An intravenous catheter was placed in the cephalic vein. If necessary, animals were sedated.…”

“…34 Evaluation included visual inspection of TAC, determination of individual kidney GFR, TOP of the TAC and individual excretion half-time of radiopharmaceutical (T ½ ). Shape of the curve was described as either 'classic non-obstructive drainage pattern' with a steep drop after onset of diuretic action starting after or at the point of peak maximum activity, 24,25 non-obstructive pattern with gradual and continuous down slope of the curve following administration of furosemide, 30,34 or obstructed pattern with continuous rise or initial rise to a plateau of the renal TAC. 24 A flat TAC was considered non-diagnostic.…”

“…28,29 A diuretic renal scintigraphy protocol and findings in normal cats have been described. 30 TAC were characterized by either a steep drop or gradual downward slope of the curve after injection of furosemide. T ½ was 4.93 (4.16e6.95) min (median (range)), and time of peak (TOP) of TAC was 3.06 AE 0.58 min.…”

Determination of effect of aspirin and captopril on cat glomerular filtration rate using renovascular hypertension scintigraphy

“…This is in agreement with the results for cat in the present study. The present study revealed that 99m Tc pharmaceutical can be used in cats as well as humans [3] and the other animals [11,12]. In addition, renal scintigraphy of cats can be performed easily and their GFR can be measured [10,16].…”

“…It is also used in animal studies. For instance, this technique has been exploited for studying the kidneys and its diseases in dogs [11] and in cats [12].…”