Dynamic Renal Scan Research Articles

Dynamic renal scans as a modality for follow-up of flexible ureteroscopy.

To determine whether dynamic renal scans - DTPA or MAG3 - routinely performed after flexible ureteroscopies (f-URS) could detect the development of an obstruction and thus promote prompt early intervention for kidney preservation. In this retrospective study, with all the data recorded prospectively between April 2010 and October 2023, 250 renal units in 242 patients with upper urinary tract stones (UUTS) who underwent ureterorenoscopy by one surgeon in the same medical center were evaluated. Stone-free rate (SFR) was defined as no residual fragments at all using an intraoperative "triple test". The following characteristics were examined: gender, BMI, age, Hounsfield unit, stone diameter, laterality, renal/ureteral stones, stone-free rate, and auxiliary procedures per renal unit. The Clavien-Dindo classification was used to report complications. Renal units with residual stones were scheduled for a 2nd f-URS. Post- flexible ureteroscopy ureteral obstruction and renal function were detected using renal scan DTPA or MAG-3. The primary outcome was renal/ ureteral obstruction. The mean patient age was 53 years. The mean stone size was 12.3 mm. Stones in renal pelvis, upper, middle and lower calyces were treated in 9.2% (23), 27.6% (69), and 30.8% (77) of cases, respectively; 44% (110) ureteral stones were also treated. The single- and second-session SFRs were 94.8% and 99.7%, respectively. A third auxiliary procedure was needed in one renal unit (0.4%). The mean number of procedures per renal unit was 1.06 (264/250). Ureteral double-J stents were inserted in 53.6% (134) of the cases. In 37 (14.8%) cases, a stent was placed before surgery. Post-operative complications were minor, with readmission and pain control needed in only two patients (0.8%). No avulsion or perforation of the ureters was observed. In six patients with t1/2 between 10-20 minutes, a second renal scan revealed spontaneous improvement and no obstruction in five patients. One patient with large stones and a history of prior ureteroscopy developed a ureteral stricture (0.4%) and needed treatment with laser endoureterotomy. Post-flexible ureteroscopy obstruction due to ureteral stricture is very rare. A routine renal scan post-operatively may be used in potentially high-risk patients.

Analysis of the Efficacy of Elastography in Comparison with Dynamic Renal Nuclear Scintigraphy in the Evaluation of Unilateral Pelvi–Ureteric Junction Obstruction

IntroductionIn hydronephrosis due to pelviureteric junction obstruction (PUJO), an obstruction to urine flow may lead to increased pelvic pressure, which may cause interstitial fibrosis and renal impairment. Recently, there have been reports on renal pelvic assessment using ultrasound elastography (USE). This study was conducted to see if USE can evaluate PUJO and if it can be correlated to the findings of the dynamic renal nuclear scan. Material and methodsIn this observational study, only patients with unilateral PUJO underwent acoustic radiation force impulse (ARFI) elastography. A rectangular region of interest (ROI) measuring 5 × 10 mm was positioned on the cortex region of the upper, mid, and lower poles of the affected kidney. Three valid measurements were obtained, from which a mean value was calculated. A dynamic renal nuclear scan using Technetium-99m ethylene dicysteine (EC or TC99 m EC) was obtained and split renal function (SRF) was used for comparison. ResultsIn the group of 20 patients, the mean age was 3.37 years. The mean SRF of the affected kidney was 26.65 %, and the corresponding USE value was 0.45 kpa. The Spearman's rho correlation coefficient for SRF and USE was 1 and 0.672, respectively (p = 0.001). Elastography was not feasible if SRF was less than 20 %. ConclusionUSE may be able to comment on the renal functional status of hydronephrosis. If USE is reported as non-feasible, it may suggest that renal function is grossly compromised. It may serve as an alternative diagnostic modality for renal functional evaluation. Level of evidenceLevel II, Prospective Cohort Study.

Correlation between ADC Values and Split Renal Function by Renal Isotope Scan in Assessment of Nephropathy

Background Early assessment of renal structure and function is crucial for the proper management and treatment of renal disease. DW-MRI show the Brownian motion of water molecules using the ADC values yielding information on water diffusion in the extracellular and extravascular space and capillary perfusion. Aim of the Work to study the ability of DWI in assessing and evaluating the individual renal function by correlating the ADC values calculated with split GFR obtained from dynamic renal scan among cases and healthy control group. Patients and Methods This prospective study was conducted on 30 patients and 30 control healthy group. Both MR examination and dynamic renal scan were performed on 30-case group, only MR examination was done on 30-healthy control group. DWI (b = 0, 200, 800 s/mm2) was done on 1.5T MRI unit. ADC map was calculated for every kidney. Split GFRs were measured from 99-Tcm DTPA scintigraphy. Results our study revealed that ADC values of normal control group is lower than that of case group. Cut off value of ADC, that discriminate between case and control group (using average ADC value of both kidneys), was ≤2.1 x10-3 mm2/s with Sensitivity = 87% and Specificity = 47%. We classified renal dysfunction, according to the total GFR measured from the dynamic renal scan and comparing it with the standard normalized GFR ranges according to age and sex in to 3 groups : suboptimal, decompensated and deteriorated renal dysfunction, the mean ADC values were 2.07 ± 0.21, 2.01 ± 0.13 and 1.45 ± 0.19 x10-3 mm2/s respectively. Conclusion There is a positive relationship between the ADC values and split GFR. DWI has a potential value for evaluating individual renal function, and may provide functional and morphological information at the same time.

Predictors of mortality and nephrectomy in emphysematous pyelonephritis: a tertiary care centre study.

Emphysematous pyelonephritis (EPN) is a deadly disease due to its associated morbidity and mortality. Attempts have been made to identify predictors of severity, mortality and need for nephrectomy in EPN with little success. We conducted an ambispective study of EPN patients between March 2014 and September 2019. Retrospective data were collected which included age, sex, comorbidities, symptoms, signs, laboratory investigations including imaging, need for dialysis, management and any complications. All patients were then followed prospectively for renal dynamic scan, stone surgery or nephrectomy. Univariate analysis was performed to identify factors affecting mortality and need for elective nephrectomy. In total, 112 patients were included. Mean patient age was 50.01 years, 55% were female and 5% had bilateral involvement. Fever and flank pain were the most common symptoms. Diabetes was seen in 75% of cases and 30% of cases required haemodialysis at initial presentation. About 60% of patients improved with pigtail drainage. Need for nephrectomy was greater in Huang-Tseng stage 3a (14.8%). Huang-Tseng stages 3b and 4 had higher mortality rates (25%) than the other stages (2.2%). Twelve of 99 patients had non functional kidney on follow-up and underwent elective nephrectomy. Low platelet counts, high body mass index, septic shock, dialysis and higher Huang-Tseng stage were found to be predictive of mortality and renal parenchymal thickness on computed tomography scan was predictive of follow-up nephrectomy. Thrombocytopaenia, high body mass index, septic shock, haemodialysis and higher Huang-Tseng stage are predictors of mortality and renal parenchymal thickness <5mm is a predictor of poor salvage of affected kidney on follow-up.

Clinical Comparison of the Glomerular Filtration Rate Calculated from Different Renal Depths and Formulae

A camera-based method using Technetium-99m diethylenetriaminepentaacetic acid (Tc-99m DTPA) is commonly used to calculate glomerular filtration rate (GFR), especially, as it can easily calculate split renal function. Renal depth is the main factor affecting the measurement of GFR accuracy. This study aimed to compare the difference of renal depths between three formulae and a CT scan, and, additionally, to calculate the GFRs by four methods. We retrospectively reviewed the medical records of patients receiving a renal dynamic scan. All patients underwent a laboratory test within one month, and a computed tomography (CT) scan within two months, before or after the renal dynamic scan. The GFRs were calculated by employing a renal dynamic scan using renal depth measured in three formulae (Tonnesen’s, Itoh K’s, and Taylor’s), and a CT scan. The renal depths measured by the above four methods were compared, and the GFRs were compared to the modified estimated GFR (eGFR). Fifty-one patients were enrolled in the study. The mean modified eGFR was 60.5 ± 42.7 mL/min. The mean GFRs calculated by three formulae and CT were 45.3 ± 23.3, 54.7 ± 27.5, 56.5 ± 26.3, and 63.7 ± 30.0, respectively. All of them correlated well with the modified eGFR (r = 0.87, 0.87, 0.87, and 0.84, respectively). The Bland–Altman plot revealed good consistency between the calculated GFR by Tonnesen’s and the modified eGFR. The renal depths measured using the three formulae were smaller than those measured using the CT scan, and the right renal depth was always larger than the left. In patients with modified eGFR &gt; 60 mL/min, the GFR calculated by CT was the closest to the modified eGFR. The Renal depth measured by CT scan is deeper than that using formula, and it influences the GFR calculated by Gate’s method. The GFR calculated by CT is more closely related to modified eGFR when modified eGFR &gt; 60 mL/min.

Correlation of Plasma Renin Activity Values and Resistive Index on Ultrasound Doppler with Findings of Renal Dynamic Scan in Patients with the Society of Fetal Ultrasound grades 3 and 4 Unilateral Hydronephrosis.

Renal dynamic scans (RDS) despite being considered the gold standard for the diagnosis of pelvic ureteric junction obstruction (PUJO), fail to help resolve the dilemma about management issues in many patients. Multiple invasive and noninvasive methods are being studied to help the decision-making in these patients. We did this study to find correlation of plasma renin activity (PRA) values and resistive index (RI) on Doppler ultrasound with findings of RDS in patients with the Society for Fetal Urology (SFU) Grades 3 and 4 unilateral hydronephrosis (HDN) and also to determine the cut-off values of PRA and RI that could categorically acknowledge the success of pyeloplasty. Twenty patients with SFU Grades 3 and 4 unilateral HDN due to PUJO were enrolled. Demographic details were recorded. All underwent Anderson-Hynes dismembered pyeloplasty. Based on the follow-up RDS scans, these patients could fall into one of three categories- improved (successful), status quo, or deteriorated (unsuccessful). Outcomes were compared based on RDS (split renal function [SRF]), ultrasonography, and Doppler findings were done at 3 months of postoperative period. Follow up period was 3 months after Pyeloplasty. Seventeen patients had successful outcomes based on RDS findings, 12 had improvement in SRF (>5%), and 6 had normal drainage curves (t-t1/2<10 min). Three patients had indeterminate curves (t-t1/2between 10 to 20 min). Four had improvement on both the criteria, i.e., SRF and drainage curves. Among the three patients who showed no improvement in RDS, two were in "status quo" category and one patient showed deterioration. Seventeen patients also showed improvement in PRA and RI. No significant correlation between PRA and RI with SRF could be established. However, PRA was found to have good concordance with RDS (90%). No significant correlation could be demonstrated between SRF and the respective values of PRA and RI. However, PRA could act as an adjunct to predict the early success of pyeloplasty in view of good concordance with RDS. A larger trial with bigger cohort of patients is required to confirm our contention.

Prediction of renal function improvement in azotemic patients using glomerular filtration rate from 99mTc-DTPA renal scan: An observational study.

This study aimed to evaluate the ratio of glomerular filtration rate (GFR) from 99mTc-diethylenetriamine-pentaacetic acid dynamic renal scan (GFRSCAN) to estimated GFR (eGFR) as a predictor of renal function improvement in patients with azotemia.A retrospective review of medical records was conducted to identify consecutive patients with newly discovered or aggravated azotemia who underwent 99mTc-diethylenetriamine-pentaacetic acid renal scan. Significant renal function improvement was defined as ≥100% and ≥10 mL/min improvement of eGFR at 12 weeks compared to eGFR on the day of renal scan (eGFR0). The GFRSCAN/eGFR0 ratio was evaluated as a predictor of significant renal function improvement using logistic regression and receiver operating characteristic (ROC) curve analyses. Added value of the GFRSCAN/eGFR0 ratio in the prediction of significant renal function improvement were demonstrated by adjusting for best clinical predictor variables.The eligibility criteria were met by 224 patients, among whom 22 patients (9.8%) showed significant renal function improvement. The odds ratios of the GFRSCAN/eGFR0 ratio for predicting significant renal function improvement were 1.76 (95% confidence interval [CI]: 1.26–2.45, P < .001) in the univariable analysis and 1.70 (95% CI: 1.19–2.42, P = .003) after adjusting for clinical variables. The area under the ROC curve of the GFRSCAN/eGFR0 ratio for predicting significant renal function improvement was 0.762 (95% CI: 0.648–0.871). The addition of the GFRSCAN/eGFR0 ratio to the best clinical prediction model raised the area under the ROC curve from 0.726 to 0.794, and this increment was statistically significant (P = .02).The GFRSCAN/eGFR ratio can predict renal function improvement in patients with azotemia. Future prospective studies are necessary to validate its potential clinical utilities.

Postablation and α-1 blocker therapy in children with congenital obstructing posterior urethral membrane

Background: Congenital obstructing posterior urethral membrane (COPUM) or posterior urethral valve (PUV) is the most common cause of lower urinary tract obstruction in boys. Approximately one-third of boys with PUV develop end-stage renal disease. Various prognostic factors have been recognized which determines the long-term outcome of these cases. Materials and Methods: This was a retrospective case–control analysis of data from January 1998 to May 2014. All patients of COPUM with radiological evidence of bladder neck hypertrophy with follow-up of 7 years were included in the study. Patients with urethral strictures, neurogenic bladder, and incomplete records were excluded. Group I (n = 57) received selective α-1 blocker (prazosin), after valve ablation. Group II (n = 36) who had not received the α-1 blocker was treated as a control group. Investigations include renal function test, ultrasonography, micturating cystourethrography renal dynamic scan, and glomerular filtration rate. Statistical analysis was done using the paired t-test, multiple serial analyses using ANOVA. P &lt;0.05 was considered as significant. Results: A total of 113 patients of COPUM were treated from January 1998 to May 2014. Out of these 113, 93 patients (82.3%) were included in the study. Fifty-seven (61.2%) received α-1 blocker, while 36 patients (38.8%) acted as control. Significant decrease in bladder neck hypertrophy noted in Group I as compared to Group II (P&lt;0.001). Conclusion: Uses of alpha-1 blocker hastens the recovery in terms of clinical improvement, resolution of bladder neck hypertrophy, and improved peak urine flow rate.

Retrocaval Ureter: a Rare Cause of Abdominal Colic

Retrocaval ureter is an uncommon cause of ureteric obstruction, and presentation as abdominal colic is even rarer. It usually manifest in the 3 rd decade of life and presents with flank pain and hematuria or incidentally detected. Most common is type 1 deformity in which classical reversed J or fish hook deformity is seen on imaging. Contrast study is essential for diagnosis. Renal dynamic scan is helpful to confirm obstructed drainage and function. Surgical intervention mandates excision of atretic segment and end-to-end ureteroureterostomy. We present a 28-year-old male presenting with acute abdominal colic diagnosed with right retrocaval ureter.

Current Sudan protective practice in diagnostic nuclear medicine and patient dose

Reflecting upon the influence of current diagnostic imaging radiation protection practices in Sudan, a sampling evaluation is made of administered activity across all five of the nuclear medicine departments in the country. Data were collected in respect of 423 patients, administered nuclide activities showing accord with international levels. For administered activity, four of the five departments use International Atomic Energy Agency (IAEA) Basic Safety Standard protocols, the other adopting UK Administration of Radioactive Substances Advisory Committee (ARSAC) practice. For national nuclear medicine diagnostic purposes overwhelming use is made of 99mTc. Thyroid and parathyroid scans account for 43% of the 423 investigations, while whole body bone and renal scans provide for the imaging needs of the respective 34% and 23% remaining patients. Of the acquired images, in excess of 80% of these were planar. The mean and standard deviation effective dose values were 2.26 ± 0.61, 4.70 ± 0.77 and 1.03 ± 0.29 mSv, for thyroid, bone and dynamic renal scans respectively, comparable with that of previous studies. While department designs are observed to comply with radiation protection regulations, the personal monitoring service is much less satisfactory, data frequently being found to be absent in all five departments. Moreover, only 60% of the medical physicists have been in receipt of regular radiation protection training, while other medical staff within the departments have not benefited from the relevant training at all, including physicians, nurses and nuclear medicine technologists. None have received regular specific medical checks. Accordingly, the Sudanese Nuclear & Radiological Regulatory Authority are now playing a major role in development of nuclear medicine practice and associated safety requirements, seeking accord with the principle of ALARA. Physician/medical physicist cooperation is needed in addressing optimization of radiation dose and image quality, also radiation protection awareness and training, as well as in medical surveillance.

Effects of Changes in Analytic Variables and Contrast Material on Measurement of Computed Tomography Glomerular Filtration Rates in Healthy Candidates.

This study aimed to prospectively assess the effects of changes in analytic variables and contrast material (CM) osmolality when measuring glomerular filtration rate using computed tomography (CT-GFR). One hundred healthy participants were included in this analysis. Glomerular filtration rate was measured by technetium-99m diethylene-triamine-penta-acetic acid (Tc-DTPA), and each participant underwent CT-GFR with iodinated CM (iohexol 240 or iobitridol 400) following a crossover study design. Dynamic renal CT scanning was performed. Patlak plot analysis was used to calculate GFR, selecting either the renal cortex or the whole kidney as the region of interest. The renal cortex was analyzed just before time of the second cortical attenuation peak. The whole kidney was analyzed 60, 80, 100, and 120 seconds after the appearance of CM. Automated GFR calculations were performed using perfusion software at 2 noise reduction levels (medium and strong). The CT-GFRs were compared with GFR measured by Tc-DTPA. There was no significant difference in CT-GFR with iohexol 240 versus iobitridol 400. The CT-GFR at the renal cortex, for the whole kidney 60 seconds after appearance of CM and calculated by perfusion software with medium noise reduction, did not differ significantly from GFR measured by Tc-DTPA. Whole-kidney CT-GFR at ≥80 seconds after CM appearance and CT-GFR calculated using perfusion CT software with strong noise reduction were lower when compared with GFR measured by Tc-DTPA. Results from CT-GFR were most accurate when the kidney cortex was selected as the region of interest or when using 60-second time point for whole-kidney assessment, regardless of CM osmolarity.

Experience of management of bilateral pelvi-ureteric junction obstruction (PUJO) in children – Can surgery be avoided on one side?

Management of children with bilateral PUJO involves complex issues. The aim was to highlight clinical presentation, management and outcomes in children with bilateral PUJO and if pyeloplasty could be avoided on one side. Children with bilateral PUJO managed from January 2006 to December 2017 were retrospectively reviewed. Diagnosis was by ultrasonography and Technetium-99m-L,L-ethylenedicysteine (LLEC) renal dynamic scan. Nineteen children with a median (IQR) age of 20 months (range 3-60) were included in the study. Bilateral hydronephrosis was diagnosed antenatally in 10/19 cases (53%). While 7/19 (37%) were asymptomatic, 6/19 (32%) had an abdominal distension and 3/19 (16%) presented with pain abdomen. Palpable flank mass was appreciable in 10/19 (53%), of whom in 4 it was bilateral, 3-left and 3-right. Only 1/19 (5%) had hypertension at presentation. The median (IQR) Glomerular filtration rate (GFR) at presentation was 77 (50-93) ml/min/1.73m2. Percutaneous nephrostomy was done in 8/38 (21%) renal units (4-unilateral, 2-bilateral). Seventeen patients had undergone operative repair (2 were lost to follow up). Eleven (65%) underwent surgical treatment on both sides while six (35%) had undergone pyeloplasty only on the poorer functioning or symptomatic side. Seven (64%) underwent concurrent bilateral pyeloplasty, three (27%) successive pyeloplasty and one (9%)- pyeloplasty on one side and nephrectomy on the other. Complications after surgery included UTI, persistent lump and excessive flank drain soakage in one case each. The child with excessive soakage was managed with DJ stenting. Persistent PUJO was seen in one renal unit which underwent redo-pyeloplasty. The median (IQR) follow-up duration was 49 months (12-71). GFR on follow up showed improvement with median (IQR) value of 86 (61-111) ml/min/1.73m2. Bilateral PUJO can be managed by bilateral pyeloplasty or close observation of the contralateral kidney after pyeloplasty of the worse/symptomatic side remains with no deterioration. Pyeloplasty could be avoided in 35% of the renal units, therefore a policy of successive pyeloplasty is better than concurrent pyeloplasty.

Is it safe to use a ureteral access sheath in an unstented ureter?

BackgroundThe aim of this study was to examine ureteral stricture rate after the use of UAS in an unstented ureter and compare complications of smaller vs. larger-caliber UAS.MethodsWe conducted a retrospective analysis of consecutive RIRS for renal stones, with the use of UAS in unstented ureters. We excluded cases with previous ureteroscopies, who carried ureteral stent or nephrostomy, had impacted stones, underwent radiation treatment, or had urinary tract malignancies. The primary outcome was formation of ureteral strictures diagnosed by hydronephrosis in ultrasound test and late secretion in dynamic renal scan. Secondary outcome was stone-free-rate (SFR) and complications. In addition, we compared safety and efficacy of smaller (9.5/11.5Fr) vs. larger-caliber (12/14Fr) UAS.ResultsThe cohort included 165 patients with a median follow-up time of 115 days. There was no case of ureteral stricture formation after the use us UAS, despite using a larger-caliber UAS in nearly half the cases. Larger-caliber UAS was not associated with more complications compared to the smaller-caliber one (p = 0.780). SFR was non-significantly higher in the larger-caliber UAS group (p = 0.056), despite having a larger stone burden, and only stone number was associated with SFR (p = 0.003).ConclusionsThese data suggest that the use of UAS during RIRS in an unstented ureter is safe and does not involve ureteral stricture formation after one procedure. Furthermore, the use of wider sheaths was not found to be associated with higher complications rate.

Investigation of the relation between administered dose and image quality for pediatric 99mTc-DMSA renal scintigraphy: clinical study applying the JSNM (Japanese Society of Nuclear Medicine) pediatric dosage card : The Japanese Society of Nuclear Medicine Technology (JSNMT), the Optimization of Imaging Technique Committee for Pediatric Nuclear Medicine Studies.

In 2013, the Japanese Society of Nuclear Medicine (JSNM) announced consensus guidelines for pediatric nuclear medicine. These JSNM guidelines proposed use of lower administered doses compared with traditionally determined doses, which were estimated from age, weight or body surface area (BSA) based on the administered dose for adults in Japan. When the JSNM guidelines are used, the relationship between this recommended administered dose and image quality remains unclear. In this study, we clarified the relationship between administered dose and image quality for pediatric 99mTc-DMSA renal scan retrospectively, and verified the diagnosable image quality with the recommended administered dose of the JSNM guidelines. Data from 7 pediatric patients who underwent 99mTc-DMSA dynamic renal scans according to the guidelines' recommended doses were collected. Scan frame rate was 1 frame/min, and scan time was up to 8min. Eight images, which had different acquired time periods from 1min to 8min were prepared by adding each frame. Nine nuclear medicine specialists determined 8 images with different acquired times as diagnosable or undiagnosable. A region of interest (ROI) with 50% thresholds was placed on each kidney of every image. Coefficient of variation (CV) was calculated by dividing the standard deviation (σ) by the mean counts (µ) of each ROI (CV = σ/µ × 100). 99mTc-DMSA renal scans (total of 2821 cases) that were performed previously in collaboration with 6 hospitals were collected, and CVs of these images were calculated in all cases. These 2821 cases were separated into 5 groups for every 10kg weight; i.e., (1) less than 10kg, (2) 10-19.9kg, (3) 20-29.9kg, (4) 30-39.9kg, and (5) above 40kg. Regression line of each group was analyzed in relation to the CV and administered dose. The CV at the point of intersection with the recommended dose range from the guideline was determined for each group. This CV value was considered as the estimated CV of the image obtained when the recommended dose of the guideline was used. Thus, if the CV was equal to or less than the estimated CV value, then the diagnostic image quality was deemed satisfactory. Average CV of the lower limit of diagnosable images in 7 cases as determined by 9 nuclear medicine specialists was 19.9%. Estimated CV was 21.2-24.2% in the group weighing < 10kg (group 1), 19.9-20.6% in the group weighing > 10kg and < 20kg (group 2), 19.6% in group weighing > 20kg and < 30kg (group 3), 19.4-19.5% in the group weighing > 30kg and < 40kg (group 4), and 19.8% in the group weighing > 40kg (group 5). The estimated CVs from groups 1 and 2 with weight < 20kg exceeded 19.9%. Although 99mTc-DMSA renal scan can be carried out using the guidelines' recommended dose with conventional image acquisition time in patients weighing 20kg or more, those < 20kg need consideration for a longer image acquisition time to obtain diagnosable images.

Assessment of iterative image reconstruction on kidney and liver donors: Potential role of adaptive iterative dose reduction 3D (AIDR 3D) technology

ObjectiveThe aim of this study was to evaluate the radiation exposure levels in two different types of subjects including liver and kidney donors in diagnostic assessment of transplant operation and also the significance of dose reduction on total effective dose. Materials and methodsA number of Sixty subjects (40 males and 20 females, average age of 35 ± 10 years) were randomly prospectively recruited and equally divided into two distinct groups namely kidney donors (KD, 24 M and 6 F) and liver donors (LD, 21 M and 9 female). Kidney donors were divided into full dose (KFD, n = 20) group and low dose (KLD, n = 10) group. They had undergone dynamic renal scan using Tc99 m-DTPA, CT renal angiography and x-ray plain radiograph. Liver donors were divided into full dose (LFD, n = 20) and low dose (LLD, n = 10) groups and performed CT liver volumetry. The CT dose index (CTDIvol), dose length product (DLP), total milli-ampere product time mAs, effective dose and image noise index were measured in all subjects of kidney and liver donors comparing full dose and low dose protocols. ResultsIn comparison of all subjects of kidney donor groups (KFD vs KLD), the parameters (mAs = 16386.8 ± 3140.7 vs 2830.286 ± 831.676), (CTDIvol = 183.19 ± 32.58 mGy vs. 45.5 ± 13.3 mGy), DLP = 2884 ± 859.0 mGy.cm vs. 1437.5 ± 399 mGy.cm) and (effective dose = 49.0 ± 9.0 mSv vs. 18.9 mSv±5.7 mSv) were significant, p < 0.0005. Statistical evaluation of liver donors groups (LFD vs LLD) showed that (mAs = 14348.8 ± 4571.8 vs 3123.357 ± 794.5), (CTDIvol = 333.6 ± 59.5 mGy vs. 51.4 ± 13 mGy), (DLP = 3268.3 ± 604.3 mGy.cm vs 1260.5 ± 404.6 mGy.cm) and (effective dose = 43.3 mSv±12.9 mSv vs. 21.6 ± 5.9 mSv) are statistically significant, p < 0.0005. Nevertheless, the comparative evaluation of the image quality noise index of KFD vs KLD groups and LFD vs LLD showed a no statistical significance p > 0.05. ConclusionRenal and liver donors bear a relatively significant radiation dose due to diagnostic evaluation and patient management. The CT iterative reconstruction using AIDR3D proved very valuable tool in dose reduction such that it can reduce 37% in kidney donors and 48% in liver donors while able to maintain an acceptable image quality. Monitoring of those subjects on the clinical and radiobiological levels are recommended.

Evaluation of the Efficiency of 99mTc-DMSA as a Radiopharmaceutical in Dynamic Renal Scans

Evaluation of the Efficiency of 99mTc-DMSA as a Radiopharmaceutical in Dynamic Renal Scans

Pelviureteric Junction Obstruction with Crossing Lower Polar Vessel: Indicators of Preoperative Diagnosis.

Introduction:A crossing lower polar vessel (CLPV) is found in 11%–20% of children of pelviureteric junction obstruction (PUJO). Preoperative imaging (Doppler or magnetic resonance angiography (MRA)) may help but does not form a part of routine diagnostic workup. An attempt has been made here to evaluate clinical and imaging features (ultrasound and renal dynamic scan [RDS]) in children of PUJO with CLPV and define variables that could provide a diagnostic clue to its presence.Materials and Methods:Records of children having PUJO with CLPV over 10 years (2006–2015) were reviewed retrospectively. Their demographic profile, clinical presentation, imaging features, management, and outcomes were evaluated.Results:Of 372 children with PUJO, 21 (5.6%) had a CLPV. Median age at presentation was 7 years (range 4 months–11 years). Presenting features included pain (66.6%), urinary tract infection (14.3%), antenatally diagnosed fetal hydronephrosis (14.3%) and lump (4.8%). All had an obstructive drainage on RDS and mean split renal function (SRF) of the affected kidney was 32.5% ± 15.65%. The majority had mild-moderate hydronephrosis with intrarenal pelvis. None of the ultrasound images suggested the presence of a CLPV. Diagnosis of a CLPV was made intraoperatively in all. Dismembered pyeloplasty anterior to the vessel was done in the majority (80.9%). Mean SRF on postoperative RDS improved to 36.6% ±17.76% with nonobstructive drainage. All were asymptomatic at a mean follow-up of 34.5 ± 17.5 months (range 2–56 months).Conclusions:Pain is the predominant presenting feature in these patients who present at an older age. Despite older age at presentation, these patients have well-preserved renal function and mild hydronephrosis. No specific RDS or ultrasound findings can predict the presence of a CLPV. As the incidence of CLPV is <10% and management is essentially same as PUJO with intrinsic obstruction, preoperative Doppler or MRA are extraneous.

Effects of changes in analytic variables and contrast medium on estimation of glomerular filtration rates by computed tomography in healthy dogs.

OBJECTIVE To investigate effects of changes in analytic variables and contrast medium osmolality on glomerular filtration rate estimated by CT (CT-GFR) in dogs. ANIMALS 4 healthy anesthetized Beagles. PROCEDURES GFR was estimated by inulin clearance, and dogs underwent CT-GFR with iodinated contrast medium (iohexol or iodixanol) in a crossover-design study. Dynamic renal CT scanning was performed. Patlak plot analysis was used to calculate GFR with the renal cortex or whole kidney selected as the region of interest. The renal cortex was analyzed just prior to time of the second cortical attenuation peak. The whole kidney was analyzed 60, 80, 100, and 120 seconds after the appearance of contrast medium. Automated GFR calculations were performed with preinstalled perfusion software including 2 noise reduction levels (medium and strong). The CT-GFRs were compared with GFR estimated by inulin clearance. RESULTS There was no significant difference in CT-GFR with iohexol versus iodixanol in any analyses. The CT-GFR at the renal cortex, CT-GFR for the whole kidney 60 seconds after appearance of contrast medium, and CT-GFR calculated by perfusion software with medium noise reduction did not differ significantly from GFR estimated by inulin clearance. The CT-GFR was underestimated at ≥ 80 seconds after contrast medium appearance (whole kidney) and when strong noise reduction was used with perfusion CT software. CONCLUSIONS AND CLINICAL RELEVANCE Selection of the renal cortex as region of interest or use of the 60-second time point for whole-kidney evaluation yielded the best CT-GFR results. The perfusion software used produced good results with appropriate noise reduction. IMPACT FOR HUMAN MEDICINE The finding that excessive noise reduction caused underestimation of CT-GFR suggests that this factor should also be considered in CT-GFR examination of human patients.

ULTRASOUND MASS SCREENING OF NEONATES WITH CONGENITAL ANOMALIES OF THE KIDNEY AND URINARY TRACT (CAKUT)

Background: Congenital anomalies of kidney and urinary tract represent the most common cause of end stage kidney disease in infant and children. Early detection of these changes allows timely initiation of more specific diagnostic studies, and of therapeutic interventions. Objective: This study was done to detect the incidence and risk factors of (CAKUT) in neonate. Patients and methods: This study was carried out on 390 neonates in the incubator of Al-Matariya Teaching Hospital and Al-Hussein University Hospital during the period from July 2014 to July 2015.All neonates were included except those with apparent congenital anomalies, surgical emergency orinborn errors of metabolism. All neonates after parent consents were subjected to full history, clinical examination and investigated by pelvi-abdominal ultrasound, serum creatinine level, and some cases subjected to more investigations in the form of computed tomography scan with intravenous urographin contrast medium, ascending cystourethrography and TC 99m DTPA dynamic renal scan. Results: The overall incidence of congenital anomalies of kidney and urinary tract was 3.3%. Positive family history of renal anomalies together with maternal history of diabetes mellitus and maternal age above 35 years were considered predictors for renal anomalies by binary logistic regression. Conclusion: Congenital anomalies of kidney and urinary tract (CAKUT) were major health issues and were the leading cause of ESRD in pediatric population.

Objective improvement in renal function post-Dietl's crisis: Documented on renal dynamic scintigraphy.

Dietl's crisis is one of the treatable causes of intermittent abdominal pain. The pain is due to acute hydronephrosis that leads to stretching of the pelvis. The most common cause of this intermittent hydronephrosis is aberrant renal vessel at lower pole that causes pelvi-ureteric junction obstruction.(PUJO). High insertion of the ureter is one of the other rare causes. We present a case of 5-year-old boy with intermittent abdominal pain and distension with ultrasonography features of gross left hydronephrosis. Renal dynamic scan.(RDS) with ethylene dicysteine showed negligible functioning left kidney. On third follow-up day, the patient passed a lot of urine with decrease in abdominal pain and distension. Then, again the patient was sent to us 8.days after the first study for repeat RDS, which showed significant improvement in function and decreased in the size of left kidney though with persistent PUJO. On exploration high insertion of the ureter at pelvis was found to be the cause and was treated.