Tc-99m dimercaptosuccinic acid(DMSA) renal scintigraphy in patients with acute pyelonephritis

Ultrasound for acute pyelonephritis: a systematic review and meta-analysis

BACKGROUND

There is little consensus regarding the indications and utility of urinary tract imaging and type of imaging to perform in patients presenting with acute pyelonephritis (APN).

AIMS

The aims of this systematic review were to, among patients with APN, (i) identify the proportion of patients investigated with ultrasound (US), (ii) identify the proportion of abnormal US and (iii) identify the proportion of patients with a change in management resulting from abnormal US.

METHODS

A comprehensive search covered two electronic databases (Medline and EMBASE), with selection of studies performed independently by two investigators. Inclusion criteria were English language APN diagnosis and quantification of patients assessed with US or abnormal US results. Quality appraisal used the Newcastle-Ottawa instrument.

RESULTS

There were 35 studies included. The proportion of patients assessed with US was reported in 16 manuscripts and ranged from 20% to 94%, with significant heterogeneity and publication bias. The proportion of abnormal US was reported in 31 manuscripts and ranged from 7% to 79%. The proportion of abnormal US leading to change in management was reported in five studies and ranged from 7% to 59%. There was marked heterogeneity among studies included in all three subgroups.

CONCLUSIONS

Patients with APN are commonly investigated with US, but only a small proportion have abnormalities and appear to be associated with changes in clinical management. The use of routine US for APN is therefore questioned. The identification of clinical variables for appropriate selection of patients to investigate with US requires further research.

Urine bacterial culture growth and association with urine sedimentation and clinical findings in cats with acute kidney injury

OBJECTIVES

A urine culture is often pursued in cats with acute kidney injury (AKI) to screen for bacterial growth in the urine, but it can be cost prohibitive. The aim of the study was to determine the ability of a urinalysis and lower urinary tract signs (LUTS) to predict urine culture results in cats with AKI.

METHODS

Ninety-seven cats with AKI were included in this study. This was a retrospective, observational study. Medical records from 2008 to 2018 were reviewed to identify cats with AKI that had a paired urinalysis and urine bacterial culture. The sensitivity, specificity, positive predictive value and negative predictive values of microscopic bacteriuria, pyuria, hematuria and the presence of LUTS for predicting urine culture results was calculated.

RESULTS

Thirty-two percent of cats (n = 31) had a positive urine culture. Of these, 28 (90%) had bacteriuria, 21 (68%) had pyuria, 13 (42%) had hematuria and 10 (32%) had LUTS. Of the 42 cats without hematuria or pyuria, seven had a positive urine culture (17%). Bacteriuria had a high sensitivity (90%) and specificity (92%) for predicting urine culture bacterial growth. The absence of bacteriuria had a high negative predictive value for no bacterial growth (95%). The odds of a positive urine culture were increased with bacteriuria (odds ratio [OR] 114, 95% confidence interval [CI] 29-621; P <0.001), pyuria (OR 21, 95% CI 7-70; P <0.001) and LUTS (OR 5, 95% CI 1.7-16; P = 0.004). Hematuria was not associated with a positive culture (sensitivity 42%, specificity 52%).

CONCLUSIONS AND RELEVANCE

Microscopic bacteriuria and pyuria on urine sediment evaluation and LUTS can be helpful for predicting bacterial culture results in cats with AKI and in settings where submitting a urine culture may not be financially feasible.

[Power Doppler sonography and acute pyelonephritis in children: comparison with Tc-DMSA scintigraphy]

Acute pyelonephritis is a common infection in children. The clinical and biological diagnosis is still sometimes difficult. For most authors, Technecium 99m dimercaptosuccinic acid scintigraphy is considered as the gold standard tool for diagnosis but it is invasive and expensive. The aim of our study was to compare the sensitivity and the specificity of B-mode sonography and power doppler to DMSA-Tc scintigraphy in acute pyelonephritis.

PATIENTS AND METHODS

Forty-nine children were enrolled in this study with suspicion of pyelonephritis. All infants underwent doppler sonography and scintigraphy within 48 hours after their hospitalization. Doppler sonography criteria were increased kidney size, thickness of sinus wall, vascular defect, and various echogenicity of the kidneys (focal or diffuse hyperechogenicity or focal hypoechogenicity).

RESULTS

Among 28 children with a positive scintigraphy, 15 had a positive doppler sonography (sensitivity 54%) and 13 had a negative doppler sonography. Among 21 children with a negative scintigraphy, 20 had a negative doppler sonography (specificity 95%) and one had a positive doppler sonography.

CONCLUSION

In clinically suspected acute pyelonephritis, doppler sonography has a high specificity. A positive doppler sonography should avoid the use of scintigraphy.