Download PDF
Nuklearmedizin 1994; 33(06): 244-247
DOI: 10.1055/s-0038-1629712
Original Article
Schattauer GmbH

Evaluation of Obstructed Kidneys by Discriminant Analysis of 99mTc-MAG3 Renograms

A. González
1   From the Laboratory of Biophysics and Bio-engineering, Faculty of Medicine, University of Barcelona, the Spain
,
L. Jover
2   From the Department of Public Health, University of Barcelona, and the Spain
,
LI. Mairal
3   From the Department of Nuclear Medicine, Hospital of Bellvitge, Spain
,
J. Martin-Comin
3   From the Department of Nuclear Medicine, Hospital of Bellvitge, Spain
,
R. Puchal
3   From the Department of Nuclear Medicine, Hospital of Bellvitge, Spain
› Author Affiliations
Further Information

Publication History

Received: 10 May 1994

in revised form: 11 June 1994

Publication Date:
04 February 2018 (online)

    Permissions and Reprints

Summary

This study sought to develop a method of improving the differential diagnostic between healthy and obstructed kidneys using only parameters derived from the 99mTc-MAG3 renogram. The analysis included data from 46 healthy and 36 obstructed kidney units. The parameters calculated were: mean transit time (MTT), time at 20% of the initial height of the renal retention function (T20) and time to peak of the renogram (TP). A discriminant analysis was carried out to obtain a discriminant function in order to differentiate between the two groups. The best results were obtained using the function: (2.5629 lnT20) +(2.1280 In TP) -27.1224 which correctly classified 97.56% of the cases, giving a sensitivity of 94.44% and a specificity of 99.99%.

Zusammenfassung

Zweck dieser Arbeit war die Differentialdiagnose von gesunden (46) und abflußbehinderten Nieren (36) aus verschiedenen Werten des 99mTc-MAG3 Radio-isotopennephrogramms (RIN) und seiner Dekonvolution. Es wurden folgende Parameter berücksichtigt: mittlere Transitzeit (MTT), Zeit bis zum Abfall der maximalen Aktivität der Impulsreaktionsfunktion auf 20% (T20) und Zeit bis zum Erreichen des Kulminationspunktes (sog. Sekretionsmaximum) des RIN (TP). Mittels der Diskriminanzanalyse wurde folgende Funktion als die beste gefunden: (2,5629 lnT20) + (2,1280 In TP) - 27,1224 mit 94,44% Sensitivität, 99,99% Spezifität und 97,56% Genauigkeit.

Key words

Discriminant analysis - obstructed kidneys - renographic parameters - deconvolution - isotope renography

Schlüsselwörter

Diskriminanzanalyse - abflußbehinderte Nieren - renographische Parameter - Dekonvolution - Isotopen-Renographie
 

  • REFERENCES

  • 1 Blaufox MD, Britton KE, Nimmon C. et al. The radionculide renogram. In: Evaluation of renal function and disease with radionuclides. The upper urinary tract. Blaufox MD. (ed). Basel: Karger; 1989: 98-129.
    Google Scholar
  • 2 Britton KE, Nawaz MK, Whitfield HN. et al. Obstructive nephropathy: Comparison of the parenchymal transit time index with furosemide diuresis. Br J Urol 1987; 127-32.
    Google Scholar
  • 3 Fatti LP, Hawkins DM, Raath EL. Discriminant analysis. In: Topics in applied multivariate analysis. Hawkins DM. (ed). Cambridge University Press; 1982: 1-71.
    CrossrefGoogle Scholar
  • 4 González A, Ros D, Pavía J. Determination of the relative renal function and the mean transit time by deconvolution of the isotopic renogram. Proceedings IV Internat Symp Biomed Engin 1991; 264-5.
    Google Scholar
  • 5 González A. Study of renal function from dynamic sequences of gammagraphic images. Ph D. Thesis 1991
    Google Scholar
  • 6 González A, Puchal R, Mairal L. et al. Utilidad de un índice de retardo para la clasificación de ríñones obstructivos. Rev Esp Med Nuclear 1993; 12: 350-3.
    Google Scholar
  • 7 Lachenbruch PA. Discriminant analysis. Hafner Press; 1975
    Google Scholar
  • 8 O’Reilly PH, Lupton EW. Obstructive urop-athy. In: Nuclear medicine in urology and nephrology. O’Reilly PH, Shields RA, Testa HJ. (eds). London: Butterworths; 1986: 91-108.
    CrossrefGoogle Scholar
  • 9 Piepsz A, Ham H, Erbsman F. et al. A cooperative study on the clinical value of dynamic renal scanning with deconvolution analysis. Br J Radiol 1982; 55: 419-33.
    CrossrefGoogle Scholar
  • 10 Puchal R, Pavia J, González A. et al. Optimal filtering values in renogram deconvolution. Phys Med Biol, 1988; 33: 831-45.
    CrossrefGoogle Scholar
  • 11 Report of working group 3 software quality assurance of renal radionuclide studies.. Clinical validatio protocols for the selection of patient studies for inclusion in a software phantom database. COST B2 project. EUCO-B2/02/90.1990
    Google Scholar
  • 12 Valentinuzzi ME, Montaldo Volachec EM. Discrete deconvolution. Med Biol Eng, 1975; 13: 123-5.
    CrossrefGoogle Scholar