Imaging of haemodialysis: renal and extrarenal findings

The risk factors for arteriovenous fistula dysfunction in maintenance hemodialysis patients: A cross-sectional study

INTRODUCTION

Arteriovenous fistula (AVF) dysfunction is a prevalent complication among maintenance hemodialysis patients. However, the factors influencing AVF patency remain unclear. To address this, we conducted a study aimed at identifying factors contributing to AVF dysfunction in this patient population.

METHODS

The study compared clinical data, vascular calcification score, and laboratory data focusing on blood cell composition and coagulation in 100 maintenance hemodialysis patients in whom an AVF had been inserted from January through September of 2022. The patients were divided into a group in which the AVF functioned without issues and a group in which the AVF was dysfunctional, defined as not able to provide a blood flow of greater than 200 mL/min.

FINDINGS

Patients in the 2 groups (56 in the dysfunctional AVF group and 44 in the group with satisfactory AVF function) were similar demographically. Compared with the normally functioning AVF group, the AVF dysfunction group exhibited significantly higher Agatston calcium scores (20.5 [1.28, 298] median [Q1, Q3] vs. 1.14 [0.00, 11.6]; p = 0.01), elevated triglyceride levels (1.1 [0.6, 1.2] mmol/L vs. 0.5 [0.3, 0.8]; p < 0.01), increased prothrombin activity (113 ± 22.1% vs. 99.4 ± 23.1; p < 0.01), lower prothrombin time (10.4 [9.8, 10.8] s vs. 11.0 [10.3, 11.5]; p < 0.01), higher red blood cell (RBC) counts (3.5 ± 0.7 · 1012/L vs. 3.0 ± 0.7; p < 0.01), and elevated hemoglobin levels (98.0 ± 21.8 g/L vs. 84.9 ± 24.2; p < 0.01). Higher C-reactive protein (20.2 [3.3, 20.2] mg/L vs. 17.8 [6.2, 17.8]; p = 0.01) and procalcitonin levels (0.9 [0.4, 0.9] ng/mL vs. 0.5 [0.2, 0.7]; p < 0.01) were also noted. Logistic regression analysis indicated that platelet/lymphocyte ratio, monocyte/lymphocyte ratio, and RBC count were factors associated with AVF dysfunction. Increased monocyte/lymphocyte ratio and RBC count correlated with higher risk, while a higher platelet/lymphocyte ratio was associated with lower risk.

DISCUSSION

Arteriovenous fistula dysfunction in maintenance hemodialysis patients is associated with higher proportions of specific hematological parameters, particularly elevated RBC count, and altered platelet/lymphocyte and monocyte/lymphocyte ratios.

Evaluation of Hepatic/Renal and Splenic/Renal Echointensity Ratio Using Ultrasonography in Diabetic Nephropathy

The objective of this study is to assess the hepatic/renal and splenic/renal echointensity ratios in ultrasonography in patients with and without diabetic nephropathy. This retrospective study included patients with diabetes mellitus who underwent ultrasound examinations at our hospital between January 2023 and May 2023. Ultrasound examinations were conducted using renal cortical echogenicity and corticomedullary differentiation by using B-mode ultrasonography. The hepatic/renal and splenic/renal echo intensity ratios were compared among study groups (diabetic patients with diabetic nephropathy and without nephropathy). The diabetic nephropathy group exhibited significantly higher right renal echointensity and left renal echointensity compared to the non-nephropathic group. Additionally, the splenic/renal echointensity ratio and hepatic/renal echointensity ratio were significantly lower in the diabetic nephropathy group. Urinary microalbumin levels were significantly correlated with right renal echointensity (r = 0.65, p < 0.001) and left renal echointensity (r = 0.69, p < 0.001). There was also a significant inverse correlation between the urinary albumin and splenic/renal echointensity ratio (r = -0.58, p < 0.001). Ultrasonography, specifically the assessment of hepatic/renal and splenic/renal echointensity ratios, shows promise as a noninvasive and cost-effective method for evaluating morphological changes in the kidneys in patients with diabetic nephropathy. These findings suggest that ultrasonography can be a valuable tool for monitoring the progression of diabetic nephropathy and contributing to its early detection and management.

Imaging Patients with Kidney Failure

The approach to imaging a patient with kidney failure continues to evolve. Overstatement of the risk of iodinated contrast material-induced (ie, contrast-induced) acute kidney injury and new guidelines for administration of gadolinium-based contrast media affect screening and the choice of contrast material. Treatment of kidney failure requires dialysis or a kidney transplant. Pretransplant imaging includes assessment for the feasibility of performing a transplant and evaluation for underlying malignancy and peripheral vascular disease. Patients with kidney failure are at high risk for renal cell carcinoma. Subtypes that occur exclusively or more commonly in patients with kidney failure, such as acquired cystic kidney disease, renal cell carcinoma, and clear cell papillary renal cell carcinoma, have specific clinical-pathologic characteristics, with indolent behavior. Performing US for dialysis planning increases the success of placement of an arteriovenous fistula, while postoperative US evaluation is essential in assessment of access dysfunction. Systemic manifestations in patients with kidney failure are multifactorial and may relate to the underlying cause of renal failure or may be secondary to treatment effects. Disturbances in mineral and bone metabolism and soft-tissue and vascular calcifications are seen in patients with chronic kidney disease and mineral bone disorder. Neurologic and cardiothoracic complications are also common. The authors provide a comprehensive overview of imaging considerations for patients with kidney failure, including the appropriate use of CT, MRI, and US with their respective contrast agents; the use of imaging in transplant workup and dialysis assessment; and the common renal and extrarenal manifestations of kidney failure. ©RSNA, 2023 Quiz questions for this article are available in the supplemental material.

Frequency of Acquired Renal Cystic Disease in Patients on Long-Term Hemodialysis and Associated Renal Cell Carcinoma

Background

Acquired cystic renal disease is one of the complications of end-stage renal disease (ESRD) patients on dialysis. We aimed to define the prevalence of acquired cystic renal disease in a dialysis center in a tertiary care setup in Pakistan.

Materials and methods

We conducted a cross-sectional study of 246 patients with ESRD from October 1, 2017, to March 30, 2018. We collected patient demographic data, comorbidities, duration (years), frequency (sessions/week), length of each dialysis session (hours), ultrasound findings, cystic renal disease occurrence, and associated complications for analysis.

Results

Our patient population consisted of 115 women (46.7%) and 131 men (53.3%) and had a mean age of 55.9 ± 15.1 years. Thirty-seven patients were on dialysis for one year, 78 (31.7%) for two years, and 131 (53.3%) for three or more years, as its more common with increasing duration. The mean dialysis duration was 2.3 ± 0.7 years. Of 246 patients, 49 (19.9%) had acquired cystic renal disease.

Conclusions

Given improved health care facilities, an increasing number of patients have a good survival on dialysis and develop long-term complications associated with end-stage renal disease, such as acquired cystic renal disease. Because the acquired renal cystic disease is associated with renal cell carcinoma, physicians should evaluate dialysis patients for renal cell carcinoma, especially after three to five years of dialysis.

Acquired Cystic Kidney Disease: A Hidden Complication in Children on Chronic Hemodialysis

Objective

To determine the frequency of acquired cystic kidney disease (ACKD) in children on chronic hemodialysis.

Material and methods

In this single-center cross-sectional study, 150 children were included who were on chronic hemodialysis for six months. Ultrasound was done to see the renal cysts. Cystic changes that could not fulfill the criteria for ACKD were also noted and analyzed.

Results

The mean age was 14.5 ± 3.5 years, of these 63 (42%) were males. Acquired cysts were detected in 53 (35%) of the patient and 18 patients (12%) had solitary cysts. The distribution of these entities was similar across all age groups. The underlying etiologies in the descending order were unknown 64 (43%), stone disease 31 (21%), each of the congenital anomalies of the kidney and urinary tract, and glomerulonephritis 23 (15%), and others nine (6%). A higher frequency of ACKD was detected in the children on renal replacement therapy for more than two years (33 out of 53 children, 63% with a p-value of 0.004).

Conclusion

The ACKD was found in one-third of our hemodialysis children and its frequency increases with the duration of hemodialysis. This percentage may not reflect the true prevalence as there is a lack of consensus on the definition of ACKD. Periodic assessment of chronic kidney disease patients for the development of ACKD especially on chronic hemodialysis is required to reduce the morbidity.

Determining the Frequency of Acquired Cystic Kidney Disease in End Stage Renal Disease Patients on Hemodialysis at Dialysis Centre of Tertiary Care Hospital

Objectives

To determine the frequency of acquired cystic kidney disease (ACKD) among patients of end-stage renal disease.

Methods

This cross-sectional study was conducted at the University of Lahore Teaching Hospital after approval from the ethical review committee. About 150 patients with end-stage renal disease fulfilling the inclusion criteria and undergoing three hemodialysis sessions per week for six months were approached. The patients underwent ultrasonography by the same consultant radiologist and the presence of acquired polycystic kidney disease was noted in the proforma. Data was stratified for age, gender and duration of hemodialysis and the chi-square test was applied.

Results

The mean age of the study participants was 47.31±9.44 years and males were majority in number with 92 (61.3%). The acquired cystic kidney disease was noted in 20 (13%) participants. There was significant difference noted in different age groups as six (6.5%) patients in the 18-40 age group and 14 (24%) patients in the 40-80 age group have acquired kidney disease (p-value=0.002). No important association between ACKD, age, and gender were found. None of these patients had evidence of renal cell carcinoma, extrarenal cysts, retroperitoneal or intrarenal hemorrhage.

Conclusion

There was a significant correlation between acquired cystic kidney disease and the duration of hemodialysis, and the chances of the development of acquired cystic kidney disease rise progressively with increasing time on hemodialysis.

Early Left Ventricular Dysfunction Detected by Speckle Tracking in Long-Term Hemodialysis Patients with Valvular Calcification

Purpose: Cardiac valve calcification (VC) is very common in patients on hemodialysis. However, the definite effect of VC on left ventricular (LV) geometry and function in this population is unknown, especially when LV ejection fraction (LVEF) is normal. The aim of this study was to determine the effect of VC on LV geometry and function in long-term hemodialysis patients by conventional echocardiography and two-dimensional speckle tracking echocardiography (2D-STE). Methods: A total of 47 hemodialysis patients (2–3 times weekly for 5 years or more) were enrolled in this study. Cardiac VC was defined as bright echoes of more than 1 mm on one or more cusps of the aortic valve or mitral valve or mitral annulus using echocardiography as the screening method. LV longitudinal global strain (GLS) was assessed on the apical four-chamber view and calculated as the mean strain of 6 segments. LV global circumferential strain was acquired on the LV short axis view at the level of papillary muscles. Results: Twenty-five patients with VC had higher mean values of interventricular septum thickness, LV posterior wall thickness, LV mass index, relative wall thickness, and LV mass/end-diastolic volume than 22 patients without VC (p < 0.05, respectively), indicating more obvious LV hypertrophy (LVH). VC patients had higher mitral annular E/E′ values, especially at the septal side representing increased LV filling pressure compatible with diastolic dysfunction, while only the E/E′ ratio of the septal side was significantly different between the 2 groups (16.7 ± 4.1 vs. 12.3 ± 4.4, p < 0.01). When assessed by GLS, LV longitudinal systolic function was also lower in in patients with VC compared with those without VC (–0.18 ± 0.03 vs. –0.25 ± 0.04; p < 0.01). Conclusions: Cardiac VC diagnosed by echocardiography when it occurs in long-term hemodialysis patients may indicate more severe LVH, myocardial damage, and worse heart function in comparison to those without VC. Tissue Doppler imaging and 2D-STE can detect the subtle change of heart function in this population in the early stage of LV dysfunction when LVEF is normal.

Imaging Features of Soft-Tissue Calcifications and Related Diseases: A Systematic Approach

Soft-tissue calcification refers to a broad category of lesions. Calcifications are frequently identified by radiologists in daily practice. Using a simple algorithm based on the distribution pattern of the lesions and detailed clinical information, these calcified lesions can be systematically evaluated. The distribution pattern of the calcific deposits enables initial division into calcinosis circumscripta and calcinosis universalis. Using laboratory test results (serum calcium and phosphate levels) and clinical history, calcinosis circumscripta can be further categorized into four subtypes: dystrophic, iatrogenic, metastatic, and idiopathic calcification. This pictorial essay presents a systematic approach to the imaging features of soft-tissue calcifications and related diseases.

Spontaneous perirenal hemorrhage in hemodialysis patient treated with selective embolization: A case series and review of the literature

INTRODUCTION

Spontaneous perirenal hemorrhage (SPH) or Wunderlich syndrome, is a rare but potentially life-threatening condition. It is characterized by an unexpected bleeding in the kidneys and usually presents as an abdominal pain. Angiography and more recently selective renal arterial embolization are emerging as effective modalities for the diagnosis and treatment of SPH. In this article, we report a total of three cases of SPH in hemodialysis (HD) patients.

METHODS

This is the experience of diagnosis and treatment of SPH in HD patients.

FINDINGS

All three were female, between 37 and 54 years of age and were undergoing HD for end stage renal disease (ESRD). Two of patients presented with left flank or abdominal pain after termination of HD therapy, while the third patient presented with left abdominal pain during the dialysis session. All patients received anti-coagulation therapy for HD, but no abnormal levels of coagulation index were found. These patients were diagnosed using CT and two of them were diagnosed with acquired cystic kidney disease (ACKD). Selective renal arterial embolization was performed in the case of active bleeding.

DISCUSSION

We are aware that HD patients have elevated risk of bleeding related complications, additionally the presence of an acute abdominal pain increases the suspicion of SPH as a possible cause. ACKD can be considered one of the possible risk factors for SPH in long-term HD patients. Interventional treatment for kidney injury is useful and safe for active bleeding in most cases.