Quantitative analysis of 99mTc-DMSA during acute pyelonephritis for prediction of long-term renal scarring.

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.     

Renal cortical scintigraphy in the diagnosis of acute pyelonephritis

Comparative clinical studies have shown renal cortical scintigraphy, using technetium-99m (99mTc)-labeled glucoheptonate or dimercaptosuccinic acid (DMSA), to be significantly more sensitive than either intravenous pyelography or renal sonography in the diagnosis of acute pyelonephritis. However, due to uncertainties about the diagnostic accuracy of the clinical and laboratory parameters used in these studies, true sensitivity of renal cortical scintigraphy was unknown. Therefore, we evaluated the accuracy of [99mTc]DMSA scintigraphy in the diagnosis of experimentally induced acute pyelonephritis in piglets using strict histopathologic criteria as the standard of reference. The sensitivity and specificity of the DMSA scan for the diagnosis of acute pyelonephritis were 91% and 99%, respectively, with an overall 97% agreement between the scintigraphic and histopathologic findings. Based on the results of this experimental study, we used the [99mTc]DMSA scan as the standard of reference for the diagnosis of acute pyelonephritis, and conducted a prospective clinical study of 94 children hospitalized with the diagnosis of acute febrile urinary tract infection (UTI). The aims of this study were (1) to determine the relationship among vesicoureteral reflux, P-fimbriated Escherichia coli, acute pyelonephritis, and renal scarring, and (2) to evaluate the diagnostic reliability of the clinical and laboratory parameters commonly used in the diagnosis of acute pyelonephritis. We documented acute pyelonephritis in 62 (66%) of 94 patients. Vesicoureteral reflux was demonstrated in 29 (31%) of the total group and in only 23 (37%) of 62 patients with acute pyelonephritis. The prevalence of P-fimbriae in the E coli isolates was 64% in the patients with acute pyelonephritis and 78% in those with a normal DMSA scan. Even in patients without reflux, P-fimbriae were found in 71% of isolates from the patients with acute pyelonephritis and in 75% of those with a normal renal scan. Follow-up DMSA scans were obtained in 33 patients with acute pyelonephritis in 38 kidneys. We found complete resolution of the acute inflammatory changes in 58% of the involved kidneys and renal scarring in the remaining 42%, including 40% of the kidneys associated with reflux and 43% of those without reflux.(ABSTRACT TRUNCATED AT 400 WORDS)     

Accurate diagnosis of acute pyelonephritis: How helpful is procalcitonin?

AIM: This prospective study aimed to investigate the diagnostic value of serum procalcitonin levels in children with acute pyelonephritis documented by Tc-dimercaptosuccinic acid (DMSA) scintigraphy. METHODS: We compared the symptoms and laboratory findings of fever, vomiting, abdominal/flank pain, leukocyte count, serum C-reactive protein and procalcitonin levels with the results of the DMSA scan obtained within the first 72 h after referral in children who were diagnosed as having acute pyelonephritis. Thirty-three children (31 female and two male) aged 1-11 years (mean 4.42 years) were enrolled in this prospective study. RESULTS: Twenty-one of 33 patients (64%) had positive DMSA scans. On the scans obtained after 6 months, five of 21 patients (23.8%) had renal scars. No correlation was found between clinical and laboratory parameters, alone or combined with each other, and positive DMSA scans. Serum procalcitonin levels were 0.767+/-0.64 and 1.23+/-1.17 ng . ml in children with normal and positive DMSA scans, respectively. The cut-off value for procalcitonin using receiver operating characteristic analysis was 0.9605 ng . ml, while sensitivity and specificity were 86.4% and 36.4%, respectively. However, if the cut-off value was chosen as 2 ng . ml, the sensitivity increased to 100% while specificity did not change markedly. CONCLUSION: The serum procalcitonin test, like other commonly used laboratory parameters, e.g. serum C-reactive protein and white blood cell count, was inadequate in distinguishing renal parenchymal involvement in acute febrile urinary tract infections.     

Power Doppler sonography versus Tc-99m DMSA scintigraphy for diagnosing acute pyelonephritis in children: are these two methods comparable?

PURPOSE This study assessed the role of renal power Doppler ultrasonography (PDU) to identify acute pyelonephritis (APN) and to determine whether PDU can replace Tc-99m DMSA renal scintigraphy in the diagnosis of APN in children.METHODS A prospective study was conducted in 40 infants and young children (78 kidneys were evaluated) with a mean age of 25.9 months (range, 1 to 68 months) who were hospitalized with a first episode of high fever and bacteruria, possibly APN. All children were examined by PDU and Tc-99m DMSA within the first 3 days after admission. Patients with congenital abnormalities, hydronephrosis, and urinary reflux were excluded.RESULTS Twenty-seven of the 78 kidneys appeared abnormal on Tc-99m DMSA, and 20 of them were abnormal on PDU. Fifty-one of 78 kidneys were normal on Tc-99m DMSA, and 3 of 51 appeared diseased on PDU. The accuracy of PDU was 87%, sensitivity was 74%, and specificity was 94%. The positive predictive and negative predictive values were both 87%. When considering the numbers of lesions in 27 kidneys with positive Tc-99m DMSA studies (38 lesions), PDU did not disclose 16 lesions (false-negative results). Thus, the sensitivity of PDU for diagnosing lesions of APN decreased to 58%.CONCLUSIONS A positive PDU finding should obviate the use of Tc-99m DMSA in patients thought to have possible APN. However, because of a large number of false-negative results (26%) and underestimation of the number of pyelonephritic lesions (low sensitivity of 58%), PDU cannot replace Tc-99m DMSA in the diagnosis of APN in children.     

How accurate is dimercaptosuccinic acid scintigraphy for the diagnosis of acute pyelonephritis? A meta-analysis of experimental studies.

The purpose of this study was to evaluate the performance of dimercaptosuccinic acid (DMSA) scintigraphy in the diagnosis of acute pyelonephritis and to compare the test performance of the standard technique, planar DMSA, with the newly introduced technique, SPECT DMSA. METHODS: All published animal studies in which DMSA scintigraphy was compared with histopathology, the reference standard for acute pyelonephritis, were identified using a comprehensive search strategy with the MEDLINE and EMBASE databases. Test performances of all DMSA methods and SPECT versus planar DMSA were analyzed using summary receiver operating characteristic (sROC) curves. RESULTS: Seven studies were identified, including 2 of SPECT DMSA. Problems in study design or reporting were common, with numerical errors in 4 studies. Overall, at a sensitivity of 86%, specificity was estimated to be 91%. Detection of acute pyelonephritis was at a lower threshold for SPECT than for planar DMSA (sensitivity/specificity values of 97%0/66% compared with 82%/ 97%), and the overall test performance of SPECT was not demonstrably better than that of planar DMSA. When applied to a group of children with a prevalence of renal damage of 40%, this means that 98% of children with abnormal planar DMSA scans will have renal damage, whereas only 65% of those with abnormal SPECT scans will have renal damage. Planar and SPECT DMSA will miss 11% and 3% of children with renal damage, respectively. Out of 100 children in the hypothetical group with 40% experiencing renal damage, SPECT will identify 6 extra true cases of renal damage at the expense of 19 extra false positives, when compared with planar DMSA. CONCLUSION: Published studies of DMSA test performance are few in number and have significant methodologic problems that should be avoided in future studies. DMSA, particularly the planar technique, performs well for the diagnosis of acute pyelonephritis. Using test performance criteria, SPECT DMSA alone has not been shown to be preferable to the established planar method and will result in a small number of true-positives at the expense of a larger number of false-positives.     

Interobserver reproducibility in reporting on 99mTc-DMSA scintigraphy for detection of late renal sequelae.

This study was designed to evaluate the interobserver variability in reporting on 99mTc-dimercaptosuccinic acid (DMSA) scanning performed 6 mo after an acute episode of pyelonephritis for the detection of late renal sequelae. METHODS: Forty-six children were selected, who had early and late DMSA studies for evaluation of acute pyelonephritic lesions as well as sequelae. Three observers reported independently and separately on the early and late DMSA scans and, in a second step, on the late scan in the presence of the early scan. Interobserver reproducibility was evaluated for the early DMSA scan, the late DMSA scan alone, and the late DMSA scan with the early scan for comparison. RESULTS: Complete agreement between the three observers was reached in 75%, 78%, and 77% for the early DMSA scan, the late DMSA scan alone, and the late DMSA scan with the early scan for comparison, respectively. CONCLUSION: Interobserver reproducibility was high and was comparable for both early and late DMSA scintigraphy.     

Evolution of differential renal function after acute pyelonephritis

(99m)Tc dimercaptosuccinic acid (DMSA) renal scans can provide accurate diagnosis of acute pyelonephritis, its sequelae (renal scars) and differential renal function (DRF). The purposes of this retrospective study were (1) to assess the relationship between DRF obtained during acute pyelonephritis and at follow-up, and (2) to elucidate the value of initial DRF in predicting subsequent renal scars. A total of 47 children were enrolled. All had both unilateral acute pyelonephritis diagnosed by initial DMSA renal scans, and follow-up DMSA renal scans. We found the correlation between initial and follow-up DRF poor (adjusted R2 = 0.396). Whether or not renal scars developed determined the follow-up DRF. Vesicoureteral reflux was significantly more common in children who developed renal scars. In addition, the higher the grade of vesicoureteral reflux, the lower the follow-up DRF and the improvement in DRF. When using a DRF of 46% as the cut-off value to predict subsequent renal scars, the sensitivity and specificity were 47.8% and 83.3%, respectively. Owing to the low sensitivity, initial DRF is not suitable for predicting the occurrence of renal scars.     

Preoperative risk stratification using gated myocardial perfusion studies in patients with cancer.

Cancer patients frequently have anemia or an altered coagulation state that may affect their risk stratification for perioperative cardiac events. We performed this study to investigate the incidence of perioperative cardiac events in cancer patients who had abnormal stress myocardial perfusion imaging (MPI) results versus cancer patients with normal MPI results. METHODS: We included 394 consecutive cancer patients with normal (n = 201) or abnormal (n = 193) results on MPI studies performed for preoperative risk stratification. MPI was performed within 6 mo before each patient's scheduled operation. All the patients had surgical procedures requiring general anesthesia, except for 18 who had endoscopic or colonoscopic procedures. We retrospectively reviewed their data for the incidence of major cardiac events intraoperatively and for 1 mo postoperatively. We collected data on their cancer type, risk factors for coronary artery disease, MPI findings, risk of operation, and intraoperative or postoperative major cardiac events, which included death, myocardial infarction (MI), and congestive heart failure (CHF). RESULTS: The patients with abnormal MPI results included 97 with ischemia, 80 with scarring, and 16 with mixed scarring and ischemia. The mean left ventricular ejection fraction and end-diastolic volume were 63.8% +/- 9.8% and 82.0 +/- 53.5 mL in the normal MPI group versus 52.1% +/- 13.1% and 118.1 +/- 53.4 mL in the abnormal-MPI group (P < 0.001). There were 9 major intraoperative or postoperative cardiac events (4.7%) in the patients with abnormal MPI results and none in the patients with normal MPI results (P = 0.001). These major events consisted of 3 deaths, 2 acute MIs, 1 non-Q-wave MI, and 3 cases of CHF. Four of these patients had only scarring on their MPI studies, 3 had ischemia, and 2 had scarring and ischemia. CONCLUSION: Normal MPI results have a high negative predictive value for perioperative cardiac events in cancer patients. Abnormal MPI results, whether demonstrating scarring or ischemia, should prompt appropriate perioperative management in patients with cancer to minimize major cardiac events.     

Renal fibrosis: prediction from acute pyelonephritis focus volume measured at 99mTc dimercaptosuccinic acid SPECT.

PURPOSE: To evaluate whether acute pyelonephritis lesion volume derived from acute technetium 99m ((99m)Tc) dimercaptosuccinic acid (DMSA) renal single photon emission computed tomographic (SPECT) images is predictive of the development of subsequent renal fibrosis. MATERIALS AND METHODS: Children with acute pyelonephritis underwent (99m)Tc DMSA renal SPECT during acute infection and 6-10 months later. At quantitative analysis, the volume of photopenic lesions and the ratio of radioactivity in the photopenic lesion to that in normal renal tissue were calculated. Sensitivity, specificity, and positive and negative predictive values were determined. RESULTS: Sixty-nine acute pyelonephritis foci in 44 children were analyzed. Thirty-seven (54%) of these lesions were normal on follow-up renal scans, while 32 (46%) developed scars. Significant differences in the photopenic lesion volume were found between the two groups (P < .001). When photopenic lesion volume indicated a positive diagnosis (>or=4.6-cm(3) lesion volume), sensitivity, specificity, positive predictive, and negative predictive values were 96.7%, 92.3%, 90.6%, and 97.3%, respectively. CONCLUSION: Quantitative analysis of acute DMSA renal SPECT findings is valuable in predicting renal fibrosis. The volume of an acute pyelonephritis lesion is useful in predicting the development of fibrosis.     

The value of Ga-67 renal SPECT in diagnosing and monitoring complete and incomplete treatment in children with acute pyelonephritis.

PURPOSE: This study evaluated the utility of Ga-67 renal SPECT for diagnosing acute pyelonephritis (APN) in children and monitoring them. METHODS: Seventy-one children (ages 1 week to 12 years) who were thought clinically to have APN were included in the study. The disease was considered present if the patients had all of the following: fever (38.5 degrees C), pyuria (leukocyte counts/per high-power field > or = 10), and a positive result of a urinary culture or blood culture. Tc-99m DMSA, Ga-67 renal SPECT, and voiding cystourethrography were performed, with informed consent from the patients' parents, within 3 days after hospitalization. Three months after treatment, Tc-99m DMSA and Ga-67 renal SPECT were repeated in those patients who had abnormal results of the initial Ga-67 renal SPECT. RESULTS: In the diagnostic study, Ga-67 renal SPECT was superior to DMSA renal SPECT in detecting lesions (97% vs. 79%). Three children had false-negative results with Ga-67 renal SPECT. Seventeen kidneys were negative with Tc-99m DMSA but positive with Ga-67 renal SPECT. No patients had any Ga-67 uptake on post-therapy imaging. However, 32 of 107 kidneys (30%) had permanent renal scars. In these 107 kidneys, 78 (73%) were associated with high-grade vesicoureteral reflux (VUR; VUR grade > or = 3) and 29 (27%) with low-grade or no VUR. CONCLUSIONS: High-grade VUR tends to be associated more with APN than has been reported by others, probably because of an underestimation of APN by ultrasonography or DMSA. Ga-67 renal SPECT is sensitive and useful not only in diagnosis but also for monitoring and follow-up of children with clinical suspicion of APN, especially in those with equivocal results after DMSA renal SPECT studies.     

99Tcm-DMSA肾皮质显像和肾超声检查在小儿急性肾盂肾炎中的对比研究

目的 比较肾超声检查和99Tcm-二巯基丁二酸（DMSA）肾皮质显像在诊断小儿急性肾盂肾炎（APN）中的作用.方法 对临床拟诊为APN的165例患儿均行肾超声检查及99Tcm-DMSA肾皮质显像.其中男79例,女86例,年龄1.5个月11岁,平均20个月.以肾皮质显像为诊断参考标准,确定肾超声检测APN的灵敏度及特异性.结果 165例患儿330个肾,其中99Tcm-DMSA肾皮质显像发现99个肾存在APN阳性表现,而肾超声仅发现31个肾表现阳性.在余231个99Tcm-DMSA肾皮质显像无异常的肾中,超声检查发现4个肾有异常表现.肾超声探测APN的灵敏度为31.3%（31/99）,特异性为98.3%（227/231）.结论 肾超声对小儿APN的诊断特异性较高,但灵敏度较低.对于肾超声检查阴性的APN,临床仍需采用99Tcm-DMSA肾皮质显像以帮助确诊.     

99Tcm-DMSA肾皮质显像和肾超声检查在小儿急性肾盂肾炎中的对比研究

目的 比较肾超声检查和99Tcm-二巯基丁二酸(DMSA)肾皮质显像在诊断小儿急性肾盂肾炎(APN)中的作用.方法 对临床拟诊为APN的165例患儿均行肾超声检查及99Tcm-DMSA肾皮质显像.其中男79例,女86例,年龄1.5个月11岁,平均20个月.以肾皮质显像为诊断参考标准,确定肾超声检测APN的灵敏度及特异性.结果 165例患儿330个肾,其中99Tcm-DMSA肾皮质显像发现99个肾存在APN阳性表现,而肾超声仅发现31个肾表现阳性.在余231个99Tcm-DMSA肾皮质显像无异常的肾中,超声检查发现4个肾有异常表现.肾超声探测APN的灵敏度为31.3%(31/99),特异性为98.3%(227/231).结论 肾超声对小儿APN的诊断特异性较高,但灵敏度较低.对于肾超声检查阴性的APN,临床仍需采用99Tcm-DMSA肾皮质显像以帮助确诊.     

DMSA study performed during febrile urinary tract infection: a predictor of patient outcome?

Technetium-99m dimercaptosuccinic acid (DMSA) study has been advocated as a method for the assessment of renal sequelae after acute febrile urinary tract infection (UTI). However, it is not known whether DMSA scintigraphy performed during acute UTI has any prognostic value for outcome assessment. The objective of this study was to evaluate the usefulness of DMSA scintigraphy performed during UTI as a predictor of patient outcome, to identify children at risk of events [vesico-ureteral reflux (VUR) or recurrent UTI] that may lead to the development of progressive renal damage. One hundred and fifty-two children (including 78 girls) with a mean age of 20 months (range 1 month to 12 years) with first febrile UTI were evaluated by DMSA scintigraphy during acute UTI. After acute UTI, children were explored by voiding cysto-urethrography. Children who presented an abnormal DMSA study, or a normal DMSA study but VUR or recurrent UTI, underwent a DMSA control study 6 months after UTI. Children with VUR were followed up by direct radionuclide cystography. DMSA scintigraphy performed during acute UTI was normal in 112 children (74%). In 95 of these children, follow-up DMSA scintigraphy was not performed owing to a good clinical outcome. In the remaining 17 children, follow-up scintigraphy was normal. Forty children (26%) presented abnormal DMSA study during acute UTI. Twenty-five of them presented a normal follow-up DMSA, and 15 presented cortical lesions. Children with abnormal DMSA had a higher frequency of VUR than children with normal DMSA (48% vs 12%). It is concluded that children with normal DMSA during acute UTI have a low risk of renal damage. Children with normal follow-up DMSA and low-grade VUR have more frequent spontaneous resolution of VUR.     

Diagnosis of acute pyelonephritis in children: comparison of sonography and 99mTc-DMSA scintigraphy.

Ninety-one children 1 week to 10 years old with culture-documented febrile urinary tract infection were evaluated with renal sonography and renal cortical scintigraphy by using 99mTc-labeled dimercaptosuccinic acid (DMSA). On the basis of previous experimental studies, DMSA scintigraphy was used as the standard of reference for the diagnosis of acute pyelonephritis. The DMSA scans showed changes consistent with acute pyelonephritis in 63% (57/91) of the patients. Sonograms showed changes consistent with acute pyelonephritis in 24% (22/91) of the whole group and in only 39% (22/57) of the patients with scintigraphically documented acute pyelonephritis. Pertinent sonographic findings were areas of increased cortical echogenicity in 14 patients and decreased echogenicity in eight, including three patients with renal abscesses. Dilatation of the renal collecting system was noted in nine patients and renal enlargement was noted in three. We conclude that renal sonography is a relatively insensitive test for the detection of acute inflammatory changes of renal cortex. Therefore, it should not be used as the primary imaging technique for the diagnosis of acute pyelonephritis. However, sonography is a useful technique in evaluating the nature of the defects seen on the DMSA scan and in detecting obstructive uropathies that may be associated with urinary tract infections.     

123I-hippuran renal scintigraphy with evaluation of single-kidney clearance for predicting renal scarring after acute urinary tract infection: comparison with (99m)Tc-DMSA scanning.

The value of (123)I-hippuran (OIH) renal sequential scintigraphy (RSS) in predicting the evolution of defects detected by (99m)Tc-dimercaptosuccinic acid (DMSA) scanning during a first episode of acute pyelonephritis (APN) was assessed. METHODS: Fifty-eight children with APN underwent (99m)Tc-DMSA planar scanning and (123)I-OIH RSS during acute infection and at least 5 mo later. Renal lesions found by (99m)Tc-DMSA scanning were classified according to the following (99m)Tc-DMSA grading system: 0 = normal, 1 = 1 lesion, 2 = 2 lesions, and 3 = diffuse damage with renal parenchymal subversion. Renal scarring was diagnosed whenever a renal cortical defect detected at the first (99m)Tc-DMSA examination persisted on the follow-up (99m)Tc-DMSA examination. Single-kidney clearance rate (Cl) was evaluated by a method that was previously validated at our institution and is based on time-activity curves measured on the heart and kidney areas by the region-of-interest technique. RESULTS: (99m)Tc-DMSA scanning showed renal damage in 76 kidneys and had negative findings for the remaining 40 kidneys (2 patients had bilaterally negative findings). (99m)Tc-DMSA scanning determined 40 kidneys to be grade 0, 49 to be grade 1, 21 to be grade 2, and 6 to be grade 3. For (99m)Tc-DMSA grades of 0-3, the corresponding Cl mean values (in mL/min/1.73 m(2) of body surface area [BSA]) were 292 +/- 33, 237 +/- 39, 210 +/- 54, and 140 +/- 53, respectively. The Spearman regression coefficient (R) demonstrated a significant correlation between (99m)Tc-DMSA grade and Cl (R = 0.69, P < 0.0001). Thirty-six of the lesions detected by staging (99m)Tc-DMSA were shown to have recovered on follow-up renal scans, whereas 40 developed scars. A significant difference in Cl was found between the 2 groups (P < 0.0002). The Cl cutoff value was determined by univariate discriminant analysis; a Cl value of 232 mL/min/1.73 m(2) of BSA discriminated best between scarred and nonscarred kidneys, with a specificity, sensitivity, positive predictive value, negative predictive value, and overall accuracy of 95%, 95%, 90%, 97%, and 95%, respectively. CONCLUSION: Cl evaluation, in the course of acute urinary tract infection, is highly valuable in predicting the fibrotic evolution of renal damage detected on acute (99m)Tc-DMSA scanning. Also, our data show close agreement between Cl and the grade determined by staging (99m)Tc-DMSA.     

Follow-up of acute pyelonephritis in children by Tc-99m DMSA scintigraphy: quantitative and qualitative assessment

PURPOSE: The author's goal was to create a system to identify children at risk for development of progressive renal damage. METHODS: Thirty-four children were examined with Tc-99m DMSA scintigraphy in the acute stage of an initial episode of pyelonephritis, after 6 months, and again after 1 year. The scintigraphic findings were correlated with clinical and laboratory data. RESULTS: All children had parenchymal defects in the acute stage: 93% of the kidneys and 85% bilaterally. After 6 months, the defects had diminished or disappeared in 66% of the kidneys. New defects appeared in 22%. At 1 year, no further improvement was seen in the kidneys, with an improved or unchanged pattern at 6 months. New defects appeared in 34%. Mean kidney activity uptake expressed as the percentage of administered dose (KU/AD), was low in the acute stage, increased at 6 months, with no further significant increase at 1 year. Eighty-three percent of children with urine cultures growing > or = 104 bacteria/ml at follow-up had decreased KU/AD values, whereas all children with urine cultures growing < 104 bacteria/ml had increased KU/AD values. CONCLUSIONS: Quantitative assessment increases the sensitivity of Tc-99m DMSA scintigraphy. Follow-up with this method makes it possible to identify the children with decreasing renal tubular function who may be at risk for progressive renal damage. Moderate bacteruria of 104 bacteria/ml urine is associated with deterioration of renal tubular function.     

Diuretic MAG3 scintigraphy (F0) in acute pyelonephritis: regional parenchymal dysfunction and comparison with DMSA.

99mTc-DMSA late static planar imaging or SPECT is being used for the investigation of focal acute pyelonephritis (APN), especially in children with urinary tract infection (UTI). Diuretic 99mTc-mercaptoacetyltriglycine (MAG3) dynamic scintirenography has been applied in the evaluation of kidney function and structure, frequently to exclude obstruction. However, in children and adults with a clinical picture of APN, diuretic MAG3 scintigraphy with zero time injection of furosemide (MAG3-F0) was observed to display focal parenchymal abnormalities; regional dysfunction (focal parenchymal decrease in early uptake; slow filling in and prolonged late retention of activity); or, less frequently, fixed defects. This observation was further studied both retrospectively and prospectively, and its sensitivity and specificity for APN were compared with those of dimercaptosuccinic acid (DMSA). METHODS: In the retrospective study, for 36 children with UTI and regional parenchymal findings on MAG3-F(0), data were reviewed, analyzed, and compared with the results of concurrent DMSA studies. In the prospective study, for 57 children with clinical and laboratory findings suggestive of APN, the 2 radiopharmaceuticals were used for imaging sequentially and the results of the 2 studies were compared. The criteria for abnormal findings compatible with the diagnosis of APN were, for MAG3-F(0), regional parenchymal dysfunction and fixed focal defects and, for DMSA, focal defects without parenchymal loss. RESULTS: In all groups of patients, most abnormal MAG3-F(0) studies (80%) showed regional parenchymal dysfunction, but in some (20%) a fixed defect was found. Compared with DMSA and when both regional dysfunction and focal defects were considered, MAG3-F(0) was as sensitive as DMSA. Some patients had only MAG3-F(0) abnormalities, suggesting a slightly lower specificity for MAG3-F(0) compared with DMSA (86%); this finding needs further study, because it also raises questions about the sensitivity of DMSA, considering that only a small percentage of patients with clinically suggestive findings had abnormal study findings. In most patients with fixed defects on both DMSA and MAG3-F(0), follow-up studies showed no resolution, suggesting that a fixed defect on MAG3-F(0) may indicate either more severe APN or preexistent scars and that regional dysfunction may be a sign more specific for APN and prognostic of potential recovery. In addition, a pattern more specific for a scar--a fixed defect with a dilated regional calyx--was seen on follow-up MAG3-F(0). CONCLUSION: A fast (25-min) planar dynamic MAG3-F(0) study was found to be as sensitive at depicting focal parenchymal abnormalities in APN as was the 3- to 4-h DMSA routine procedure. The sensitivity and specificity of both studies need further evaluation.     

99Tcm-DMSA肾显像诊断肾盂肾炎和 肾脏瘢痕的动物模型实验研究

目的　制作猪肾盂肾炎和肾脏瘢痕动物模型 ,评价99Tcm 二巯基丁二酸 (DMSA)肾脏平面显像和SPECT断层显像诊断肾盂肾炎和肾脏瘢痕的灵敏度和特异性 ,并探讨SPECT的诊断价值。方法　中国实验动物小型猪 13只 ,先制成膀胱输尿管返流动物模型 ,然后引入大肠埃稀杆菌导致上尿路感染 ,感染前后用ADACVertex型双探头SPECT仪 ,配低能高分辨率准直器进行肾脏前后位平面和断层显像 ,将显像结果同组织病理学检查进行对比研究。结果　平面显像诊断肾盂肾炎和肾脏瘢痕的灵敏度为 71 2 % ,特异性为 10 0 % ,准确性为 87 5 % ;平面加断层显像诊断肾盂肾炎和肾脏瘢痕的灵敏度为 78 3% ,特异性为 10 0 % ,准确性为 90 5 %。以病理检查为标准 ,平面显像和平面加断层显像对病灶的检出率差异无显著性。结论　99Tcm DMSA肾脏显像是诊断肾盂肾炎和肾脏瘢痕的灵敏可靠方法。平面加断层显像可能有助于提高检测的灵敏度 ,并对病变范围作更准确的估价     

The role of DMSA renal scintigraphy in the first episode of urinary tract infection in childhood

Objective

The role of dimercaptosuccinic acid (DMSA) renal scintigraphy in the first episode of urinary tract infection (UTI) has been the subject of debate for many years. The aim of this study was to evaluate the relationship of voiding cystourethrography (VCUG), renal ultrasonography and DMSA renal scintigraphy and to detect renal parenchymal changes by performing DMSA renal scintigraphy at 6 months after the first episode of UTI.

Methods

A prospective study was conducted in 67 hospitalized children (46 boys, 21 girls). Mean age of the patients was 0.97 ± 1.57 years (0.02–7.26 years). All children received VCUG, renal ultrasonography and DMSA renal scintigraphy. DMSA renal scintigraphy was performed at 1 and 6 months after UTI.

Results

Of 67 children, 17 (25.4 %), 23 (34.3 %) and 20 (29.9 %) had vesicoureteral reflux (VUR), abnormal renal ultrasonography and abnormal DMSA renal scintigraphy, respectively. Unilateral hydronephrosis had a significant correlation with VUR at p value 0.024. In renal units, abnormal renal ultrasonography and hydronephrosis had significant correlations with VUR at p values 0.039 and 0.021, respectively. In patients and renal units, hydronephrosis had no significant correlation with abnormal DMSA renal scintigraphy at 1 month after UTI. However, abnormal renal ultrasonography and VUR had significant correlations with abnormal DMSA renal scintigraphy at p values 0.022 and <0.001 in patients and at p values 0.024 and <0.001 in renal units, respectively. Both in patients and renal units, VUR (Grade I–III) had no significant correlation with abnormal DMSA renal scintigraphy. However, severe VUR (Grade IV–V) had significant correlations with abnormal DMSA renal scintigraphy at p values <0.001 and <0.001, respectively. Seventeen patients underwent DMSA renal scintigraphy at 6 months after UTI. In addition, 15 (88.2 %) developed persistent renal scarring.

Conclusion

Abnormal renal ultrasonography and severe VUR identify renal parenchymal changes. DMSA renal scintigraphy in the first episode of UTI should be carried out in those patients. Abnormal DMSA renal scintigraphy at 1 month after UTI has a tendency to persist.     

^99Tc^m-DMSA肾皮质显像预测急性肾盂肾炎患儿肾瘢痕危险性的价值

目的应用^99Tc^m-二巯基丁二酸（DMSA）肾皮质显像预测急性肾盂肾炎（APN）患儿肾瘢痕危险性及分析相关危险因素。方法研究对象为118例临床首次诊断为APN的患儿,男44例,女74例,年龄1个月至14岁。所有患儿急性期行^99Tc^m-DMSA肾皮质显像,根据肾受累范围将肾损害程度分为5级,0级为肾功能正常,肾损害自轻度到重度依次分为Ⅰ至Ⅳ级,治疗至少6个月再次显像判断是否形成肾瘢痕。72例患儿进行直接法核素膀胱显像（DRC）评价膀胱输尿管反流（VUR）,反流程度分为轻、中、重度。应用SPSS 11．5软件,分别对相应数据进行Spearman等级相关分析。结果118例患儿以单肾为单位共236个肾,急性期（发病2周内）肾显像结果,正常肾组79个,Ⅰ级肾损害组64个,Ⅱ级肾损害组51个,Ⅲ级肾损害组19个,Ⅳ级肾损害组23个。6个月后再次显像显示肾功能正常组无一个肾形成肾瘢痕;肾损害形成肾瘢痕的发生率分别为Ⅰ级7．81％（5／64）,Ⅱ级49．02％（25／51）,Ⅲ级68．42％（13／19）,Ⅳ级100．00％（23／23）。肾瘢痕发生率与首次肾显像肾损害程度呈明显正相关（r=0．877,P〈0．01）。另外,72例进行DRC患儿中,以单肾为单位共144个肾,VUR发生率54．17％（78／144）,其中轻、中、重度反流。肾分别为4,43和31个。66个无VUR肾瘢痕发生率仅为4．55％（3／66）,肾瘢痕发生率在轻度VUR为1／4,在中度VUR为46．51％（20／43）,在重度VUR为87．10％（27／31）。VUR与肾瘢痕形成呈明显正相关（r=0．624,P〈0．01）。结论APN患儿急性期^99Tc^m-DMSA。肾皮质显像肾损害程度分级对预测肾瘢痕危险性有重要价值,肾损害程度越重,VUR程度越重,肾瘢痕形成危险性越大。对于急性期有肾损害,尤其是Ⅱ级以上肾损害、伴有输尿管反流的APN患儿应重视,积极治疗,以预防或减少永?