Value of TC-99M DMSA scintigraphy in urinary tract infection: comparative study with other imaging modalities

Urinary tract infection [UTI] is a common medical problem. It causes considerable morbidity specially if complicated, can cause severe renal damage. The aim of this study is to evaluate value of Tc-99m DMSA in UTI comparing with ultrasound and CT scan. We analyzed a random sample of 63 patients approved to have urinary tract infection. Abdominal ultrasound, CT, and [99m] Tc-DMSA scintigraphy of the kidneys were performed in all patients. Tc-99m DMSA scan showed scintigraphic changes consistent with pyelonephritis in all patients. The involvement was either unilateral in 53 patients [84%] or bilateral in 10 patients [16%]. The number of diseased kidneys were 73/126 [58%], 16/73 kidneys had abnormal unifocal defects [22%], 27/73 kidneys had multifocal defects [37%], while 30/73 kidneys had diffuse hypoactivity [41%]. The sensitivity of CT scan in detecting pyelonephritis was 82.8% while the sensitivity of ultrasound was poor [23.8%] and there was a statistically significant difference between the sensitivity of ultrasound and that of Tc-99m DMSA. Tc-99m DMSA is reliable diagnostic, cost-effective, simple, safe and noninvasive modality and may be taken as a routine procedure for the patients with clinical suspicion of upper UTI whenever the facilities are available

[Diagnostic value of kidney length and volume in sonography for determining kidney scar among infants with urinary infection]

Diagnosis of kidney scar could prevent vesico urethral reflax and its complications such as hypertension and renal failure. This study was conducted to determine average kidney length and volume in infants by sonography to accurate diagnosis of scars. This study was conducted on infants with the history of UTI who referred to Imam Reza Hospital, Kermanshah Iran, for DMSA scan. They underwent kidney sonography before DMSA scan. Difference in kidney length and volume were calculated and data was recorded and were analyzed using statistical tests. Right kidney length was less than left in 60% of right kidney scars this rate was 77.8% in nonscar patients [P=0.657]. Left kidney length was less than right in 50% of left kidney scar and that was 22% in nonscar patients [P=0.241]. Kidney volume was smaller than other side in 55.6% of right kidney scar and 62.5% of left kidney scar. Higher length detected in 100% and 47% of right and left kidney inflammation respectively. Higher volume detected in 40% and 76.5% of right and left kidney inflammation. In comparison with other studies suggesting kidney length as a valuable predictor for diagnosis of scar we did not find any relationship between scar and kidney length or volume

[Diagnostic value of power doppler sonography in acute pyelonephritis in children]

Urinary tract infection is common in pediatric age group and can result in serious complications such as chronic renal failure and hypertension if renal parenchyma is involved. Thus, definitive diagnosis of pyelonephritis in equivocal cases is of great importance. Comparing the diagnostic value of power color Doppler sonography and DMSA scan in acute pyelonephritis in children. This was a descriptive study carried out on 80 pediatric patients [160 renal units] suspected of having pyelonephritis. Two diagnostic methods [DMSA scan and power color Doppler sonography] were performed for all patients. Assuming DMSA scan as the gold standard method in diagnosis of acute pyelonephritis, the sensitivity, specificity, positive and negative predictive values and also the accuracy of power color Doppler sonography were calculated and analyzed, statistically. Power color Doppler sonography showed a sensitivity of 66.3%, specificity of 77.5%, positive predictive value of 78.7%, and negative predictive value of 64.7% with an accuracy of 71.3% in diagnosis of acute pyelonephritis in children. The agreement between the two diagnostic tests was shown to be around 43%. Based on our data, the power color Doppler sonography of kidneys has lower sensitivity and specificity compared to those obtained by DMSA scan in diagnosing acute pyelonephritis in children and is not considered as an ideal diagnostic technique for this particular clinical condition

Technetium Tc 99m dimercaptosuccinic acid renal scintigraphy in diagnosis of urinary tract infection in children with negative culture

The aim of this study was to evaluate the accuracy of Technetium Tc 99m dimercaptosuccinic acid [99mTc-DMSA] renal scintigraphy in the diagnosis of urinary tract infection [UTI] in children with suspected infection but with a negative urine culture. The records of all children with suspected or definite diagnosis of UTI presented during a 2-year period were reviewed in this study. Abnormal findings on renal scintigraphy, voiding cystourethrography [VCUG], and ultrasonography were evaluated and compared between the patients with the definite diagnosis of UTI and those with suspected UTI and negative urine cultures. Of 210 patients, 86 had a definite diagnosis of UTI [group 1] and 124 had suspected UTI without a positive culture [group 2]. Abnormal findings on DMSA scans were seen in 76 patients [88.4%] in group 1 and 84 [67.7%] in group 2. Vesicoureteral reflux was detected by VCUG in 50% and 32.3% of the patients in groups 1 and 2, respectively. In group 2, vesicoureteral reflux was seen in 40.5% of the patients with abnormal DMSA scan. Ultrasonography findings were abnormal in 51.3% and 39.8% of the patients with abnormal DMSA scan findings in groups 1 and 2, respectively. According to our findings, in children with a negative urine culture and abnormal urinalysis, 99mTc-DMSA renal scintigraphy is helpful in diagnosing UTI and vesicoureteral reflux; we recommend VCUG when DMSA scan supports UTI despite a negative urine culture and a normal ultrasongraphy

Urinary tract infections in children

Urinary tract infections [UTI] are common in children and should always be confirmed by quantitative urine culture. Children with symptomatic UTI should be started on antibiotics without delay and continued for 10 days. Every child with UTI, especially younger children, should be investigated radiologically to reveal obstructive lesions, vesico-ureteric reflux and other anatomical and functional abnormalities. Local facilities and experience are of major importance when selecting imaging techniques and the timing of the investigations. All children with UTI especially if associated with scars should be followed up, to monitor their growth, renal functions and blood pressure