^99mTc-MAEC Complexes: New Renal Radiopharmaceuticals Combining Characteristics of ^99mTc-MAG3 and ^99mTc-EC

Data were acquired in 1 volunteer after simultaneous injection of 69.93 MBq (1.89 mCi) syn-^99mTc-d-MAEC and 11.47 MBq (0.31 mCi) ¹³¹I-OIH; postvoid images were acquired ∼30 min after injection. The 2-min syn-^99mTc-d-MAEC images (A) and renogram curves (B) can be compared with simultaneously acquired ¹³¹I-OIH images (C) and renogram curves (D). (A) Sequential 2-min images after injection of 69.93 MBq (1.89 mCi) syn-^99mTc-d-MAEC; differential (relative) uptake is 51.3% in left kidney and 48.7% in right kidney. Final image is postvoid image obtained ∼30 min after injection. (B) Renogram curves and curve parameters based on whole kidney ROIs assigned over kidneys in A. Whole kidney and background ROIs are superimposed over the 2- to 3- and 19- to 20-min images at top. TTP refers to time-to-peak height of renogram curve and values are expressed in minutes; 20/max expression refers to ratio of counts at 20 min divided by maximum counts; 20/2–3 expression refers to ratio of counts at 19–20 min divided by counts at 2–3 min; TT1/2P refers to time (minutes) for counts in renogram curve to fall to half of peak value. RT = right; LT = left. (C) Sequential 2-min images after injection of 11.47 MBq (0.31 mCi) ¹³¹I-OIH. ¹³¹I-OIH images were acquired simultaneously as syn-^99mTc-d-MAEC images in A. Differential (relative) uptake is 54.3% in left kidney and 45.7% in right kidney. Final image is postvoid image obtained ∼30 min after injection. (D) Renogram curves and curve parameters based on whole kidney ROIs assigned over kidneys in A and applied to ¹³¹I-OIH image data (C). Whole kidney and background ROIs are superimposed over 2- to 3- and 19- to 20-min images at top. TTP, 20/max expression, 20/2–3 expression, and TT1/2P are as described in B.