Quantification and longitudinal trends of kidney, renal cyst, and renal parenchyma volumes in autosomal dominant polycystic kidney disease

ABSTRACT.: The aims of this study were to assess the accuracy and reproducibility of volumetric determinations of total kidney, renal cyst, and renal parenchymal volumes, using fast electron-beam computerized tomography scanning, and to determine the rate of change of these volumes. Nine patients with autosomal dominant polycystic kidney disease (ADPKD) and serum creatinine < or = 1.3 mg/dl and/or an initial iothalamate clearance > or = to 60 ml/min per 1.73 m(2) were imaged weekly over a 3-wk period (total of 3 times). Approximately 8 yr later, they returned for follow-up studies. The kidney volume estimation technique involved a manual segmentation (perimeter drawing) of the kidneys and a semiautomatic threshold approach, using a histogram analysis of the peak densities of renal parenchyma and renal cysts. At entry, total kidney and renal cyst volumes correlated positively with age, while renal parenchymal volumes and GFR correlated negatively with age. The average coefficient of variation values for the three initial consecutive measurements of total kidney, renal cyst (actual and as a percent of total volume), and renal parenchymal volume were 3.4, 7.2, 5.3, and 5.6%, respectively. During the 8 yr of follow-up, total kidney and renal cyst volumes increased, while renal parenchymal volumes and GFR declined. The rate of increase in total kidney and renal cyst volumes varied markedly from patient to patient. There was a significant correlation between rate of increase in renal cyst volume and the rate of decline in GFR. The patients with an initial urine protein/osmolality ratio >0.13 mg/L per mosmol per kg had a significantly higher increase in renal volume and decline in GFR than those with a lower ratio. In summary, the results of this pilot study suggest that: (1) electron-beam computerized tomography is capable of measuring total kidney, renal cyst, and renal parenchymal volumes reproducibly; (2) total kidney and renal cyst volumes increase, while parenchymal volumes decrease with time; (3) the increase in cyst volume correlates best with the decline in renal function; and (4) renal volumes appear to be good surrogate markers for disease progression in ADPKD.     

Fenestrated endovascular aneurysm repair-induced acute kidney injury does not result in chronic renal dysfunction

ObjectiveAcute kidney injury (AKI) is a common physiologic complication after fenestrated endovascular aneurysm repair (FEVAR). This investigation was initiated to determine the unknown impact of post-FEVAR AKI on long-term renal function after index hospital discharge.MethodsA retrospective review was performed of an institutional FEVAR database capturing preoperative, intraoperative, and postoperative variables related to the implantation of consecutive Zenith Fenestrated endografts (ZFEN; Cook Medical, Bloomington, Ind) between October 2012 and April 2018. AKI in this study was bimodally defined as qualification by either Risk, Injury, Failure, Loss of kidney function, and End-stage (RIFLE) criteria or a postoperative serum creatinine (sCr) concentration increase of 0.5 mg/dL from baseline. Glomerular filtration rate (GFR) was calculated using the validated Modification of Diet in Renal Disease (MDRD) study equation.ResultsDuring the study period, 120 FEVARs were performed at our institution. Twenty-four (20%) patients exhibited postoperative AKI by our established definitions. Two in-hospital deaths occurred in the AKI cohort compared with none in the remaining FEVARs (P = .04). Four (16.7%) AKI patients required perioperative (<30-day) renal replacement therapy, three of whom were successfully weaned before discharge. FEVARs uncomplicated by AKI exhibited no differences in sCr concentration from baseline to 1-month, 6-month, 1-year, and 2-year follow-up (mean, 1.8 ± 1.4 years). In contrast, patients exhibiting AKI experienced an sCr concentration increase of 57.1% (P = .01) at 1 month after the procedure. This elevation decreased to 14.3% (P = .35) at 6 months after the procedure and was maintained at baseline values at 1- and 2-year office visits (follow-up, 1.3 ± 1.5 years). A similar pattern of gradual recovery during follow-up was also observed with respect to calculated GFR.ConclusionsAKI is common after FEVAR but rarely results in permanent renal dysfunction as both sCr concentration and GFR return to baseline by 6 months after the procedure.     

Is Cyctatin C Valuable Marker of Glomerular Filtration Rate in Living Kidney Donors After Uninephrectomy?

BackgroundThe determination of kidney function plays a pivotal role in living donors renal assessment because of the long-term hazards of life with one kidney. Guidelines recommend estimation of glomerular filtration rate (GFR) by the Modification of Renal Disease (MDRD) or Cockroft-Gault equations for people with normal or near-normal renal function. Cystatin C (CysC) has been introduced as an alternative endogenous marker of GFR.ObjectiveThe objective of the study was to evaluate residual renal function among living kidney donors by comparing serum CysC concentrations and estimated GFR according to the MDRD formula or the Cockroft-Gault equation.Patients and methodsForty living kidney donors showed a mean age of 46.14 years. Their GFR was estimated according to the abbreviated MDRD (aMDRD) and Cockroft-Gault formula adjusted for body surface area. Twenty-two donors underwent diethylenetriaminepentaacetic acid (DTPA) renal studies. Serum CysC concentrations were measured during the last follow-up visit. GFR values according to Cockroft-Gault formula and MDRD formula were correlated with CysC concentrations using Pearson's linear correlation.ResultsMean GFR according to the aMDRD formula and Cocroft-Gault formula decreased after nephrectomy. The Cockroft-Gault formula overestimated the DTPA GFR in our study. No significant differences were observed between DTPA GFR and GFR estimated using the aMDRD equation. The rate of GFR decrease was approximately 0.8 mL/min/1.73m² per year. No significant correlation was observed between serum CysC concentration and GFR. Microalbuminuria was observed in one patient after nephrectomy.ConclusionsaMDRD equation to estimate GFR is more precise than Cockroft-Gault formula and cystatin C in living kidney donors after nephrectomy and should be preferred model in these patients.     

Quantitative X-ray Computed Tomography Peritoneography in Malignant Peritoneal Mesothelioma Patients Receiving Intraperitoneal Chemotherapy

Background

Intraperitoneal chemotherapy is used to treat peritoneal surface-spreading malignancies. We sought to determine whether volume and surface area of the intraperitoneal chemotherapy compartments are associated with overall survival and posttreatment glomerular filtration rate (GFR) in malignant peritoneal mesothelioma (MPM) patients.

Methods

Thirty-eight MPM patients underwent X-ray computed tomography peritoneograms during outpatient intraperitoneal chemotherapy. We calculated volume and surface area of contrast-filled compartments by semiautomated computer algorithm. We tested whether these were associated with overall survival and posttreatment GFR.

Results

Decreased likelihood of mortality was associated with larger surface areas (p = 0.0201) and smaller contrast-filled compartment volumes (p = 0.0341), controlling for age, sex, histologic subtype, and presence of residual disease >0.5 cm postoperatively. Larger volumes were associated with higher posttreatment GFR, controlling for pretreatment GFR, body surface area, surface area, and the interaction between body surface area and volume (p = 0.0167).

Discussion

Computed tomography peritoneography is an appropriate modality to assess for maldistribution of intraperitoneal chemotherapy. In addition to identifying catheter failure and frank loculation, quantitative analysis of the contrast-filled compartment’s surface area and volume may predict overall survival and cisplatin-induced nephrotoxicity. Prospective studies should be undertaken to confirm and extend these findings to other diseases, including advanced ovarian carcinoma.

     

Living Kidney Transplantation: Evaluation of Renal Function and Morphology of Potential Donors

The evaluation of potential living kidney donors requires an accurate study of renal function and morphology. The gold standard to assess renal function is the measurement of glomerular filtration rate (GFR). However, GFR is often estimated from serum creatinine (SCr), cystatin C (SCys), or creatinine clearance (CCr). Otherwise, GFR is predicted using formulas based on SCr or SCys. Ultrasound scanning evaluates morphology and dimensions, while scintigraphy provides information on morphofunctional symmetry of kidneys. The aim of this study in 79 potential donors was to assess the accuracy of the tests employed to estimate GFR and the utility of renal ultrasound and scintigraphy for morphofunctional evaluation of potential donors. GFR (clearance of ^99mTc-DTPA) was compared with estimates obtained with Cockcroft and Gault (CG-CCr) and Modification of Diet in Renal Disease (MDRD-GFR) formulas, and from SCys (Cys-GFR). The correlation with GFR was statistically significant for SCys and for all estimates, but not for SCr. CCr showed a poor agreement with GFR, with a large range of agreement and a marked and significant overestimation of GFR (33.8 mL/min). The accuracy of CG-CCr and MDRD-GFR as indicators of a GFR < 80 mL/min was better than that of Cys-GFR and CCr. However, their mean prediction errors versus GFR were relevant. Renal dimensions, particularly renal volume, showed a good correlation with GFR. The correlation was higher than that of all prediction equations. The direct measurement of GFR remains the reference method to assess renal function in potential kidney donors. The measurement of renal dimensions can provide useful information also on renal function.     

Determination of functional kidney volume by single-photon emission computed tomography in patients with insulin-dependent diabetes mellitus.

Functional parenchymal kidney volume was determined by single-photon emission computed tomography (SPECT) for 99mTc-dimercaptosuccinic acid (DMSA) using a rotating gamma camera in phantom experiments and in patients with insulin-dependent diabetes mellitus (IDDM). The results from the patient examinations were corrected according to the phantom studies and were thereafter set in relation to renal haemodynamics, blood pressure, and urinary albumin excretion. Functional parenchymal kidney volume was significantly greater in diabetic patients compared to that of 11 healthy controls (P < 0.003). Urinary albumin excretion was increased and glomerular filtration rate (GFR) per renal parenchymal volume significantly less in patients with a duration of diabetic disease of more than 15 years compared to patients with shorter duration of disease (P < 0.03 and P < 0.05 respectively). Diabetic patients with a GFR of more than 120 ml/min had greater renal parenchymal volume than patients with lower GFR (P < 0.02). Patients with increased GFR, renal plasma flow (RPF), renal blood flow, or filtration fraction had significantly greater functional parenchymal volume than the healthy subjects (P < 0.01 for all comparisons). We conclude that by application of SPECT for DMSA we were able to show that IDDM patients have greater renal parenchymal volumes than healthy subjects. GFR/kidney volume was increased in IDDM patients with a duration of disease of < 15 years compared to patients with long-standing diabetes. The SPECT technique seems suitable for prospective long-term follow-up studies of functional kidney volume in IDDM patients.     

Factors related to renal haemodynamics in young type-1 diabetes mellitus patients

The influence of metabolic control (HbA_1c), noradrenaline (NA) and insulin-like growth factors (IGF-I and IGF-II) on renal function and size was investigated in 11 insulin-dependent diabetes mellitus patients aged 11–17 years. Renal function was evaluated in terms of glomerular filtration rate (GFR) and effective renal plasma flow (ERPF). Renal size was determined as renal parenchymal volume (RPV) by ultrasonography. The patients' HbA_1c values ranged from 8.2% to 12.9% (normal range 5.5–8.5%) and their GFR and ERPF were higher than normal. Their IGF-II values were higher, and NA and IGF-I levels were lower than those of healthy controls. Inverse correlations between NA and GFR (r=–0.66) and NA and ERPF (r=–0.63) were found. No correlation was found between serum IGF-I and renal functional parameters. The IGF-II values correlated with GFR and HbA_1c (r=0.63,r=0.70 respectively). There were linear correlations between RPV and GFR, RPV and ERPF, HbA_1c and GFR, and ERPF and RPV. Decreased NA concentrations and increased IGF-II values appear to be factors contributing to renal hyperfunction in these patients.     

Long-Term Outcomes of Renal Function After Adult Intestinal Transplantation at a Single Small-Volume Center: 2 Cases of Renal Transplantation

PurposeRenal dysfunction more frequently occurs after intestinal transplantation (ITx) than after heart, lung, or liver transplantation. We provide a clinical analysis of renal function after adult ITx.MethodsWe retrospectively analyzed 8 adult ITx patients who survived for at least 6 months between 2004 and 2018. Glomerular filtration rate (GFR) measurements were performed at baseline, at 3 and 6 months post-transplantation, and yearly. The median follow-up duration was 53.5 months.ResultsAll cases were isolated ITx; 3 received living-donor ITx, and 5 received deceased-donor ITx. The mean baseline GFR was 97 mL/min/1.73 m². The GFR had decreased by more than 50% of baseline at 1 year post-transplant. Renal dysfunction was observed in 4 patients. Two patients developed acute kidney injury due to acute rejection and sepsis. One of these patients fully recovered renal function, but the second patient died. Another 2 patients developed chronic kidney disease and required hemodialysis (HD) within 6 and 3 years, respectively. The first living-donor ITx patient lost renal function progressively over 6 years after ITx. She received a renal graft from the same living donor as for the ITx after 3 years of HD. The other patient (deceased-donor ITx) received a kidney from his daughter at 5 months after HD.ConclusionsTo obtain an accurate assessment of renal function, frequent direct measurements of GFR should be performed to facilitate early diagnosis of renal impairment and to determine subsequent strategies to improve renal function after ITx.     

Correlation of the Renal Cortex Volume With the Glomerular Filtration Rate in Live Donors for Renal Transplantation

Introduction

As a pretransplantation evaluation, renal function is determined by the glomerular filtration rate (GFR) with the use of renal scintigraphy (RS) and the estimated glomerular filtration rate (eGFR). To date, there are few studies that correlate renal cortex volume with eGFR determined with renal gammagram (GR) and eGFR by equations (Cockroft-Gault, Modification of Diet in Renal Disease, and Chronic Kidney Disease Epidemiology Collaboration equation) in Latin American living donors.

Comparison between renal parenchymal sonographic volume, renal parenchymal urographic area, glomerular filtration rate and renal plasma flow in children

A comparison of renal size, expressed as ultrasonographic renal parenchymal volume and urographic renal parenchymal area, and renal function, measured as glomerular filtration rate (GFR) and effective renal plasma flow (ERPF), was made in two groups of children: (1) 21 patients with normal urograms and no signs of current disease and (2) 26 children with recurrent urinary tract infections or asymptomatic bacteriuria. Renal parenchymal volume was calculated using a water delay ultrasonographic device (Octoson). Renal parenchymal area was measured urographically. GFR and ERPF were determined from the clearances of inulin and PAH, respectively. In both groups a good correlation was found between both GFR and ERPF and total renal parenchymal volume as well as renal parenchymal area. The determination of renal parenchymal volume could possibly replace the determination of GFR and ERPF in healthy children and in children with urinary tract infections with normal and abnormal urograms.     

Is There a Correlation with Pre-donation Kidney Volume and Renal Function in the Renal Transplant Recipient?: A Volumetric Computed Tomography Study

PurposeThe aim of this study is to determine the correlation between the predonation computed tomography (CT)-based calculated kidney volume and post-transplant renal function in recipients of renal transplants and to compare two different CT techniques.Material and methodsThe study group is comprised of 55 paired living kidney donor-recipients transplants. The total parenchymal renal volumes were calculated by using two CT-based techniques (3-dimensional renal volume [3DRV] and voxel-based volume calculation). Post-transplant creatinine and estimated glomerular filtration rate (eGFR) levels for the recipients at hospital discharge and sixth month were obtained. We tested the association with eGFR and creatinine by adjusting the renal volume to body weight and body mass index. For the creatinine levels above 1.5 mg/dL at discharge, a threshold value for renal volume-to-weight ratio on receiver operating characteristic curve (ROC) analysis and odds ratio (OR) were calculated.ResultsThe renal volumes adjusted to weight were found to be moderately correlated with eGFR and creatinine levels at discharge (r = 0.51 and r = −0.54 for voxel-based calculation; r = 0.52 and r = −0.52 for 3DRV calculation, P < .001, respectively) and at sixth month (r = 0.55 and r = −0.58 for voxel-based calculation; r = 0.51 and r = −0.54 for 3DRV calculation, P < .001 respectively). A threshold value of 1.84 mL/kg was calculated for parenchymal volume-to-recipient weight ratio on ROC analysis (AUC±SE, 0.760 ± 0.078, P = .008). The likelihood of creatinine elevation above 1.5 mg/dL was found to be nine times greater for smaller renal volume-to-recipient weight ratios (OR = 9.6; 95% CI, 1.8–50.6)ConclusionsPredonation renal volume adjusted to recipient weight may estimate the renal function at discharge and 6 months after transplantation.     

Kidney function is inversely associated with coronary artery calcification in men and women free of cardiovascular disease: the Framingham Heart Study

BACKGROUND: Among patients with end-stage renal disease (ESRD), the risk of cardiovascular disease is 10 to 20 times higher than the general population. Adults with ESRD have increased coronary-artery calcification (CAC) detected by electron-beam computed tomography (EBCT). Because the risk of coronary heart disease is increased even at moderate declines in kidney function, we sought to test whether high CAC scores are seen among those with mild reductions in kidney function. METHODS: Men and women free of symptomatic cardiovascular disease underwent EBCT. Coronary calcium was quantified using the method described by Agatston. Renal function was estimated by glomerular filtration rate (GFR). Spearman correlation coefficients were used to test the association between GFR and CAC. RESULTS: Three hundred nineteen subjects (162 men/157 women), mean age 60, were included. Mean GFR was 86 +/- 23 mL/min/1.73 m2 (range 31-169; 10% with GFR <60 mL/min/1.73 m2). The median CAC scores by quartile of GFR were 85.9, 48.1, 7.9, and 2.7. Overall, the unadjusted correlation of GFR and CAC was -0.28 (P < 0.0001). This remained significant after adjustment for age and sex (-0.11, P < 0.05), and additionally after adjustment for body mass index (-0.11, P < 0.05), hypertension (-0.11, P < 0.05), or total cholesterol (-0.12, P= 0.04). A similar correlation was noted after multivariable adjustment (-0.10, P < 0.08). CONCLUSION: Mild declines in kidney function are associated with subclinical coronary artery calcification in a sample of subjects free of clinically apparent cardiovascular disease. This might help explain the increased risk of cardiovascular disease among individuals with renal dysfunction. Larger ongoing studies are needed to better quantify this finding.     

三维影像重建测量积水肾体积参数在评估肾功能中的应用

目的探讨三维影像重建技术测量积水肾体积参数在评估肾功能中的应用价值。方法回顾性分析2018年1月至2019年4月北京大学第一医院收治的46例肾积水患者的病例资料。测定所有患者肾小球滤过率,对泌尿系增强CT进行三维影像重建后测量肾实质体积、肾积水体积、肾总体积及肾积水体积比例,并对上述指标进行统计分析。结果单侧肾积水患者积水肾和健侧肾在肾实质体积、肾积水体积、肾总体积及肾积水体积比例等指标上的差异均存在统计学意义(P<0.05)。积水侧肾实质体积与肾小球滤过率(GFR)呈线性正相关(r=0.438,P<0.01);肾积水体积(r=-0.385,P<0.05)、肾积水体积比例与GFR(r=-0.417,P<0.01)呈线性负相关。不同程度肾功能受损组间肾实质体积、肾积水体积、肾积水体积比例差异均具统计学意义(P<0.01)。相较其他肾体积参数指标,肾实质体积在诊断区分不同程度肾功能分组之间的诊断效能较高,取肾实质体积为105.69、92.32 mL时,诊断区分肾功能正常与肾功能受损组肾脏、肾功能轻度受损与重度受损组肾脏之间的敏感性和特异性较高。结论三维影像重建技术测量积水肾体积参数在评估肾功能中有一定临床价值,其中肾实质体积在区分不同程度肾功能分组之间的诊断效能较好,值得临床推广应用。     

Differential contribution of the factors determining long-term renal function after partial nephrectomy over time

PurposeTo define how much of renal function was determined by the preserved renal parenchymal volume and the ischemic insult during partial nephrectomy (PN) long after surgery.MethodsWe analyzed the data of 530 consecutive patients who had undergone PN. For all patients, renal function was measured preoperatively and again at 3 postoperative months, then annually using ^99mTc-diethylenetriaminepentaacetic acid renal scan. Perioperative variables potentially affecting the long-term ipsilateral glomerular filtration rate (GFR) and their time-varying contribution were assessed using a linear mixed model.ResultsThe mean preoperative ipsilateral GFR was 42.9 ml/min, which decreased by 27.3% at 3 months but began to recover thereafter continuing until 4 years (Δ% GFR at 1, 2, 3, 4, and 5 years: 22.3%, 18.5%, 14.7%, 10.0%, and 9.6%, respectively). Parenchymal volume reduction and ischemic time were significantly associated with postoperative ipsilateral GFR throughout observation period unvarying with time. Diabetes and proteinuria were not significant determinants of ipsilateral function at 3 months but became significant at 5 years. In multivariate analysis regarding recovery slope, volume reduction (β = ?0.026, SE 0.006, P < 0.0001), preoperative ipsilateral GFR (β = ?0.021, SE 0.007, P = 0.0012), proteinuria (β = ?0.942, SE 0.372, P = 0.0116), and diabetes (β = ?0.396, SE 0.197, P = 0.0447) were independently significant.ConclusionIpsilateral renal function continued to improve until 5 years after PN. Parenchymal volume loss was the major determinant and its impact on long-term ipsilateral renal function remained constant while ischemic time affected early GFR reduction with its impact diminishing over time. Patient-related factors including diabetes and proteinuria gained significance over time and became independent determinants of recovery slope.     

Changes of renal function after retrograde intrarenal surgery using flexible ureteroscope in renal stone patients

BackgroundRetrograde intrarenal surgery (RIRS) is widely performed for renal stones. Theoretically, removing renal stones could prevent the deterioration of renal function. However, two studies reported that not all patients would see an increase in renal function after RIRS. The aim of our study was to evaluate the change of renal function of the operative site, and to identify predictors of improvement or deterioration of renal function after RIRS.MethodsWe retrospectively reviewed renal stones patients who received RIRS and single-photon emission computed tomography (SPECT) before and after surgery. Improved renal function was defined as the change of glomerular filtration rate (GFR) >10% postoperatively, and that <−10% was regarded as deteriorated renal function. Logistic and least absolute shrinkage and selection operator regression analyses were used to identify predictors for the improvement or deterioration of renal function, and predictive nomogram models were built.ResultsA total of 120 renal stone patients were included. Twenty-one (17.5%), 79 (65.8%) and 20 (16.7%) patients had improved, stable and deteriorated renal function of operative site after surgery, respectively. Lower alkaline phosphatase, lower low-density lipoprotein, lower GFR of the operative site, thicker renal parenchyma, higher serum creatinine, and extracorporeal shock wave lithotripsy (SWL) history were associated with the improved renal function. The predictive accuracy of the model for the improved renal function was 0.800. Additionally, older age, longer flexible ureteroscopic time, thinner renal parenchyma and existence of ureteral stones were risk factors for deteriorated renal function. The predictive accuracy of the model for the deteriorated renal function was 0.725.ConclusionsThe renal function of most renal stone patients did not decrease after RIRS. For patients with potential deterioration of renal function postoperatively, urologists could shorten flexible ureteroscopic time to prevent the occurrence of this outcome.     

Donor Kidney Volume and Outcomes Following Live Donor Kidney Transplantation

Pre-donation kidney volume and function may be crucial factors in determining graft outcomes in kidney transplant recipients. We measured living donor kidney volumes by 3D helical computed tomography scanning and glomerular filtration rate (GFR) by (125)I-iothalamate clearances in 119 donors, and correlated these values with graft function and incidence of acute rejection at 2 years post-transplantation. Kidney volume strongly correlated with GFR (Pearson r= 0.71, p < 0.001). Body size and male gender were independent correlates of larger kidney volumes, and body size and age were predictors of kidney function. The effects of transplanted kidney volume on graft outcome were studied in 104 donor-recipient pairs. A transplanted kidney volume greater than 120 cc/1.73 m(2) was independently associated with better estimated GFR at 2 years post-transplant when compared to recipients of lower transplanted kidney volumes (64 +/- 19 vs. 48 +/- 14 mL/min/1.73 m(2), p < 0.001). Moreover, recipients of lower volumes had a higher incidence of acute cellular rejection (16% vs. 3.7%, p = 0.046). In conclusion, kidney volume strongly correlates with function in living kidney donors and is an independent determinant of post-transplant graft outcome. The findings suggest that (1) transplantation of larger kidneys confers an outcome advantage and (2) larger kidneys should be preferred when selecting from otherwise similar living donors.     

Determination of glomerular filtration rate per unit renal volume using computerized tomography: correlation with conventional measures of total and divided renal function

PURPOSE: Previous studies suggest that functional computerized tomography (CT) can measure glomerular filtration rate (GFR) per unit renal volume. We compared this index with conventionally determined GFR measurements. MATERIALS AND METHODS: A total of 16 men and 8 women 63.3 +/- 14.9 years old (range 31 to 88) were studied using with contrast enhanced CT. A single slice of kidney was scanned sequentially after bolus injection (0.5 to 1.0 ml. per second(-1)) of 20 ml. iopamidol (300 mg. iodine per ml.(-1)). GFR per volume of kidney was calculated using a Patlak graphical analysis, and this index was multiplied by renal volume on CT to yield global GFR (ml. per minute(-1)). Divided function was also calculated. GFR and divided renal function were calculated in all cases from radioisotope renography with 99m diethylenetetraminepentaacetic acid. In 12 subjects in whom 24-hour urine collection was possible GFR was also calculated from creatinine clearance. RESULTS: A strong correlation was observed between divided renal function, expressed with respect to the right kidney calculated from CT (52.7 +/- 14.8%, range 19.9% to 97.4%) and by radioisotope renography (51.7 +/- 14.6%, range 18.9% to 92.6%, r = 0.97, p <0.0001). A strong correlation (r = 0.92, p <0.0001) was also seen between global GFR determined by CT (80.1 +/- 43.9 ml. per minute(-1), range 38.2 to 197.9) and creatinine clearance (72.4 +/- 47.5, range 14.6 to 168.5), and was stronger than the correlation between the radioisotope and creatinine clearance method (r = 0.67, p = 0.02) in the same patients. CONCLUSION: Functional CT using nonionic contrast material can measure GFR normalized to renal volume and is an accurate alternative to conventional methods of renal function evaluation.     

Two-year evaluation of fenestrated and parallel branch endografts for the treatment of juxtarenal,suprarenal, and thoracoabdominal aneurysms at a single institution

ObjectiveDespite numerous recent pivotal and small-scale trials, real-world endovascular management of juxtarenal aneurysms (JRA), suprarenal aneurysms (SRA), and thoracoabdominal aortic aneurysms (TAAA) remains challenging without consensus best practices. This study evaluated the mortality, graft patency, renal function, complication, and reintervention rates for fenestrated and parallel endografts in complex aortic aneurysms repairs.MethodsThis retrospective review of consecutive included patients with JRA, SRA, or TAAA who underwent complex endovascular repair from August 2014 to March 2017 at one high-volume institution. Treatment modality was a single surgeon decision based on patients anatomy and the urgency of the repair. Patient demographics, hospital course, and follow-up visits inclusive of imaging were analyzed. Ruptured aneurysms were excluded. Survival rates and outcomes were determined using the Kaplan-Meier method with log-rank tests.ResultsSeventy complex endovascular aortic repairs were performed; 38 patients with TAAA were treated with snorkel/sandwich parallel endografts (21 celiac, 28 superior mesenteric arteries, 58 renal arteries) and 32 patients with JRA/SRA were treated by fenestrated endovascular aneurysm repair (FEVAR) with 94 total fenestrations (2 celiac, 30 SMA, 62 renal). The mean patient age was 74.8 ± 10.0 years. Sixty percent were male, and the mean aortic aneurysm diameter was 6.0 ± 1.4 cm. Perioperative mortality was 3.1% (1/32) for FEVAR compared with 2.6% (1/38) for parallel endografts (P = .9). All-cause reintervention rates were 15.6% in FEVAR (5/32) vs 23.6% with parallel endografts (9/38; P = .4). Branch reintervention rates per each branch endograft were 4.3% for FEVAR (4/94; 2 renal stent occlusions, 1 colonic ischemia without technical issue found on reintervention, 1 perinephric hematoma) vs 3.7% for parallel endografts (4/107; 2 renal and 1 celiac stent thromboses, and 1 renal stent kink; P = .41). The endograft branch thrombosis rate was 2.1% in FEVAR (2/94) vs 2.7% in parallel endografts (3/109; P = .77). Reinterventions owing to endoleaks were performed in five patients (2 type I, 2 type III, and 1 gutter endoleak; 13.1%) with parallel grafts vs no endoleak reinterventions in FEVAR. The overall survival and freedom from aneurysm-related mortality at 24 months was 78% and 96.9% in FEVAR vs 73% and 93.4% for parallel endografts (P = .8 and P = .6). The median follow-up was 12 months (range, 1-32 months).ConclusionsParallel and fenestrated endografts have acceptable and comparable mortality and patency rates in endovascular treatment of JRA, SRA, and TAAA. This study reaffirms that parallel endografts are a safe and viable alternative to fenestrated devices for complex aortic aneurysmal disease despite often treating more urgent patients and more complicated anatomy unable to be treated with FEVAR.     

Ultrasonographic renal volume measurements in early autosomal dominant polycystic disease: Comparison with CT-scan renal volume calculations

PurposeTo investigate the correlation and concordance between the ellipsoid volume calculated by ultrasonography measurements (Vol3DUS) and the reference kidney volume measured by CT (VolTDM) in early autosomal dominant polycystic kidney disease (ADPKD).Materials and methodsProspective study of the correlation and concordance of renal volumes in 24 patients with early ADPKD (48 kidneys analysed separately), with calculation of Vol3DUS using the formula for an ellipsoid in three different manners and VolTDM measurement by manual contouring. Calculations of correlation coefficients (r) and coefficients of intra-class correlation (ICC) with confidence intervals at 95%.ResultsThe US volume was strongly correlated with the CT volume by using the maximum width in a transverse section (r = 0.83) with a mean Vol3DUS = 692 ± 348 ml [180; 2069]. The most reproducible ultrasonography measurement was the height. When the kidney volume exceeded 800 ml, US underestimated the volume. However, the median error was −57.5 ml [−1090; 183] and 85% of the Vol3DUS calculated differed by more than 5% from the reference measurement.ConclusionThe correlation between the US calculated volumes and the CT volumes was strong. However, the median error with ellipsoid US volume was too high to detect a small renal variation in early ADPKD.     

螺旋CT平扫测量肾实质体积和厚度评价慢性梗阻侧肾脏肾小球滤过率的价值

目的 探讨螺旋CT平扫测量肾实质体积和厚度判断梗阻侧肾小球滤过率(glomerular filtration rate,GFR)的价值,并比较2种肾实质形态学指标与梗阻侧GFR之间的关系.方法 利用螺旋CT平扫测量71例慢性单侧上尿路梗阻性疾病患者的肾实质体积和厚度.①肾实质体积测量:扫描双肾,逐层标示各横断面面积,结合扫描层厚计算肾实质体积,并计算梗阻侧肾实质体积占总的肾实质体积百分比(%CTvol).②肾实质厚度测量:选择包含肾脏集合系统的第一个和最后一个层面的内、外、后3个位置测量肾实质厚度,取平均值作为肾实质厚度,并计算梗阻侧肾实质厚度占总的肾实质厚度百分比(%CTt).采用99Tcm-DTPA肾动态显像技术,应用Gates法测定分肾及总的GFR值,计算梗阻侧肾GFR的百分比(%GFR),采用Pearson相关分析行%CTvol、%CTt与%GFR之间的相关分析.结果 71例患者%CTvol、%CTt与%GFR之间均有明显的相关性,r值分别为0.80(t=11.20,P＜0.05)和0.66(t=7.24,P＜0.05),直线回归方程分别为%GFR=0.05+0.80×%CTvol(F=125.48,P＜0.05)和%GFR=0.12+0.66×%CTt(F=52.36,P＜0.05).结论螺旋CT平扫测量肾实质体积和厚度可以作为临床上评价慢性梗阻侧肾GFR的方法,肾实质体积较肾实质厚度更准确.

Abstract：

Objective To evaluate the value of renal parenchymal volume and thickness by non-contrast spiral CT in evaluating the differential glomerular filtration rate (GFR) for chronic obstructed kidneys, and to compare the correlations between the two morphologic indices of renal parenchyma and the GFR for chronic obstructed kidneys. Methods Seventy-one patients who had a diagnosis of unilateral chronic upper urinary tract obstruction were included in this analysis. (1) The renal parenchymal volume was mea-sured by non-contrast spiral CT. Both kidneys were scanned by non-contrast spiral CT. The renal parenchymal area of each section was marked manually. Renal parenchymal volume was calculated as the sum of renal parenchymal area multiplied by the width of each section. The volume percentage of obstructed kidney (%CTvol) was also calculated. (2) Renal parenchymal thickness was measured on the first and last non-contrast CT image levels from the anterior, posterior and lateral locations of the kidney that clearly contained the collecting system. The mean of these measurements was defined as the renal parenchymal thickness. The differential renal parenchymal thickness of the obstructed kidney (%CTt) was defined as the percentage of the obstructed renal parenchymal thickness to the total renal parenchymal thickness for both kidneys. GFR was determined with 99Tcm-DTPA dynamic imaging system by Gates method. The differential GFR for obstructed kidney (%GFR) was the GFR percentage of obstructed kidney to the total GFR for both kidneys. The Pearson relation test was carried out between the %CTvol, %CTt and the %GFR respectively. Results %CTvol and %CTt correlated well with %GFR in chronic obstructed kidneys among the 71 test group patients. Pearson correlation coefficient r was 0.80 (t=11.20, P＜0.05) and 0.66 (t=7.24, P＜0.05), respectively. The linear correlation equation respectively was %GFR=0.05+0.80×%CTvol (F=125.48, P＜0.05) and %GFR=0.12+0.66×%CTt (F=52.36, P＜0.05). Conclusions Renal parenchymal volume and thickness by non-contrast spiral CT might be used as clinical practical parameters to evaluate the differential GFR for chronic obstructed kidneys. Renal parenchymal volume is more accurate than renal parenchymal thickness.