Abstract | UNLABELLED: This study was performed to evaluate a quantitative method based on (99m)Tc-DMSA renal planar scintigraphy performed during acute pyelonephritis (APN) to detect kidneys at risk of scarring. METHODS: A total of 43 children (5.8 +/- 3.6 y old [mean +/- SD]) were examined by (99m)Tc-DMSA scintigraphy during ( DMSA 1) and 8 +/- 2 mo after ( DMSA 2) APN. Two levels of interpretation were performed independently: first, a semiquantitative analysis to classify the kidneys by considering the evolution between DMSA 1 and DMSA 2 (i.e., to determine which kidneys had developed scarring), and second, an automatic quantitative analysis of DMSA 1 to define and to evaluate a predictive index for kidney evolution from DMSA 1 to DMAS 2. The method consisted of determining an automatic threshold for the kidney and then calculating ratios of the count density in a given isocount n% (region of interest containing all the pixels with a value > or = n% of the value of the pixel with the maximal activity value) to the count density in a 20% isocount (C(n%)) and the number of pixels in a given isocount to the number of pixels in a 20% isocount (S(n%)). RESULTS: All kidneys normal at DMSA 1 remained normal at DMSA 2. For the automatic index, the C(70%) ratio was considered the best index for the prediction of scarring. When this C(70%) ratio was used, a cutoff value of 0.45 was able to predict scarring with a sensitivity of 0.83, a specificity of 0.78, a positive predictive value of 0.85, and a negative predictive value of 0.77. CONCLUSION: A cutoff value of 0.45 for the C(70%) ratio calculated for (99m)Tc-DMSA scintigraphy performed during APN may be useful for detecting kidneys at risk of scarring.
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Authors | Anne Hitzel, Agnès Liard, Jean-Nicolas Dacher, Isabelle Gardin, Jean-François Ménard, Alain Manrique, Pierre Véra |
Journal | Journal of nuclear medicine : official publication, Society of Nuclear Medicine
(J Nucl Med)
Vol. 45
Issue 2
Pg. 285-9
(Feb 2004)
ISSN: 0161-5505 [Print] United States |
PMID | 14960649
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- Radiopharmaceuticals
- Technetium Tc 99m Dimercaptosuccinic Acid
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Topics |
- Acute Disease
- Child, Preschool
- Female
- Follow-Up Studies
- Humans
- Image Processing, Computer-Assisted
- Kidney
(diagnostic imaging)
- Male
- Observer Variation
- Predictive Value of Tests
- Prognosis
- Prospective Studies
- Pyelonephritis
(diagnostic imaging)
- Radioisotope Renography
- Radiopharmaceuticals
- Reproducibility of Results
- Sensitivity and Specificity
- Technetium Tc 99m Dimercaptosuccinic Acid
- Time Factors
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