Diagnostic efficacy of parametric clearance images in detection of renal scars in children with recurrent urinary tract infections.

Abstract

OBJECTIVE:

Static renal scintigraphy with Tc-99m dimercaptosuccinic acid (DMSA) is considered a scintigraphic gold standard in detection of post-inflammatory renal scars. Reports on usefulness of conventional summed (SUM) Tc-99 m mercaptoacetyltriglycine (MAG3) or Tc-99m ethylene dicysteine (EC) dynamic scintigraphic images in detection of renal scarring are ambiguous and some authors emphasize low sensitivity of this method. The work aimed at assessment of a diagnostic efficacy of parametric clearance images (PAR) generated from a dynamic renal scintigraphy in detection of renal scars.

METHODS:

A study group consisting of 80 children (56 girls, 24 boys, age 5-18 years) with recurrent urinary tract infections (UTI) and documented one to five incidents of APN-28 children, and with recurrent UTI of the lower part of the urinary tract only-52 children. Altogether 160 kidneys were evaluated. Static renal Tc-99m DMSA SPECT scintigraphy and after 2-4 days Tc-99m EC dynamic renal scintigraphy were performed in every patient not earlier than 6 months after the last documented incident of UTI. PAR images generated from a dynamic renal scintigraphy acquired between 40 and 140 s. generated by in-house developed software and SUM images obtained in the same time period were compared with a reference Tc-99m DMSA SPECT study.

RESULTS:

For all kinds of images (SPECT, PAR and SUM), high indices of reproducibility were obtained-89 % (κ = 0.80), 88 % (κ = 0.78) and 89 % (κ = 0.73). Agreement in a Howard scale of a reference method (SPECT) with PAR and SUM methods amounted to 83 and 64 %, respectively (p = 0.004). Sensitivity and accuracy of PAR method as compared with SUM method were significantly higher: 89 vs. 49 % (p < 0.0001) and 88 vs. 73 % (p = 0.002), and specificity was slightly lower: 88 vs. 93 % (p = 0.043). SPECT and PAR methods revealed higher incidence of renal scars than a SUM method in patients with documented incident(s) of APN-64, 68 and 39 %, p = 0.009 and 0.008, respectively.

CONCLUSION:

PAR images generated from a dynamic renal scintigraphy improved sensitivity of detection of renal scars as compared with SUM images, providing a high reproducibility and diagnostic efficacy, similar to that of Tc-99m DMSA, in detection of post-inflammatory renal scarring.

• Authors: Jacek Kuśmierek, Ewa Pietrzak-Stelmasiak, Małgorzata Bieńkiewicz, Wojciech Woźnicki, Marian Surma, Izabela Frieske, Anna Płachcińska
• Journal: Annals of nuclear medicine (Ann Nucl Med) Vol. 29 Issue 3 Pg. 313-8 (Apr 2015) ISSN: 1864-6433 [Electronic] Japan
• PMID: 25563578 (Publication Type: Comparative Study, Journal Article)

Chemical References

• Organotechnetium Compounds
• Radiopharmaceuticals
• technetium Tc 99m-ethylenedicysteine
• N-(mercaptoacetyl)glycine
• Technetium Tc 99m Dimercaptosuccinic Acid
• Cysteine
• Glycine

Topics

• Adolescent
• Child
• Child, Preschool
• Cysteine (analogs & derivatives)
• Female
• Glycine (analogs & derivatives)
• Humans
• Image Processing, Computer-Assisted
• Kidney (diagnostic imaging)
• Male
• Organotechnetium Compounds
• Prospective Studies
• Radiopharmaceuticals
• Recurrence
• Reproducibility of Results
• Sensitivity and Specificity
• Software
• Technetium Tc 99m Dimercaptosuccinic Acid
• Tomography, Emission-Computed, Single-Photon (methods)
• Urinary Tract Infections (diagnosis, diagnostic imaging)