Technetium-99m-L,L-ethylenedicysteine renal scan as a single-modality investigation for the evaluation of renal morphology and function: a comparative study with technetium-99m-dimercaptosuccinic acid.
OBJECTIVE
To evaluate whether cortical scars can be detected using the summed images of technetium-99m-L,L-ethylenedicysteine (99mTc-L,L-EC) renal dynamic scan, and to compare the results with technetium-99m-dimercaptosuccinic acid (99mTc-DMSA) scan. To evaluate the inter-observer variability for 99mTc-L,L-EC and 99mTc-DMSA scan reporting.


METHODS
One hundred and three patients were initially included in the study; 21 were excluded, five due to a single functioning kidney and 16 due to impaired renal function (serum creatinine>2.5 mg.dl(-1)). Eighty-two patients (39 females, 43 males), including 31 children, with a mean age of 33.4+/-11.3 years (range, 4 months to 74 years), underwent both 99mTc-DMSA and 99mTc-L,L-EC scintigraphy within a period of 14 days. 99mTc-L,L-EC images were regrouped into 2 min image sets, and the initial 2 min summed image (cortical phase) was used for the evaluation of scars. Three independent observers analysed both images separately on different days without being aware of the identity and clinical details of the patients. Their 99mTc-L,L-EC findings were compared with the consensus 99mTc-DMSA scan findings taken as reference.


RESULTS
The overall sensitivity of 99mTc-L,L-EC scans was 93% and the specificity was 96%. The inter-observer variability was 0.91 for 99mTc-L,L-EC and 0.94 for 99mTc-DMSA scan reporting, using the weighted kappa analysis at P<0.05.


CONCLUSIONS
99mTc-L,L-EC is an excellent single-modality comprehensive investigational agent for renal morphology, function and outflow tract evaluation with the added advantages of lower cost, convenience and low radiation exposure to the patient.
Narayana
Chandrashekar
C
Department of Nuclear Medicine, All India Institute of Medical Sciences, New Delhi, India.
Tripathi
Madhavi
M
Kumar
Ajay
A
Gowda
Naveen Krishne
NK
Phom
Hentok
H
Chandra
Prem
P
Bandopadhyaya
Gurupad
G
Bal
Chandrasekhar
C
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D002921:Cicatrix / Q000000981:diagnostic imaging*; D003545:Cysteine / Q000031:analogs & derivatives*; D005260:Female; D006801:Humans; D007223:Infant; D007674:Kidney Diseases / Q000000981:diagnostic imaging*; D007677:Kidney Function Tests / Q000379:methods; D008297:Male; D008875:Middle Aged; D015609:Organotechnetium Compounds; D011866:Radioisotope Renography / Q000379:methods*; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016037:Single-Blind Method; D019783:Technetium Tc 99m Dimercaptosuccinic Acid
D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; C073806:technetium Tc 99m-ethylenedicysteine; D019783:Technetium Tc 99m Dimercaptosuccinic Acid; D003545:Cysteine