Diana Kaya

Cardiac Magnetic Resonance Assessment of Left Ventricular Mass in Autosomal Dominant Polycystic Kidney Disease

BACKGROUND AND OBJECTIVES Autosomal dominant polycystic kidney disease (ADPKD) is associated with a substantial cardiovascular disease burden including early onset hypertension, intracranial aneurysms, and left ventricular hypertrophy (LVH). A 41% prevalence of LVH has been reported in ADPKD, using echocardiographic assessment of LV mass (LVM). The HALT PKD study was designed to assess the effect of intensive angiotensin blockade on progression of total kidney volume and LVM. Measurements of LVM were performed using cardiac magnetic resonance (MR). DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS Five hundred forty-three hypertensive patients with GFR >60 ml/min per 1.73 m(2) underwent MR assessment of LVM at baseline. LVM was adjusted for body surface area and expressed as LVM index (LVMI; g/m(2)). RESULTS Baseline BP was 125.1 ± 14.5/79.3 ± 11.6 mmHg. Average duration of hypertension was 5.79 years. Prior use of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers was present in 59.5% of patients. The prevalence of LVH assessed using nonindexed LVM (g) was 3.9% (n = 21, eight men and 13 women) and 0.93% (n = 5, one man and four women) using LVMI (g/m(2)). In exploratory analyses, the prevalence of LVH using LVM indexed to H(2.7), and the allometric index ppLVmass(HW), ranged from 0.74% to 2.23% (n = 4 to 12). Multivariate regression showed significant direct associations of LVMI with systolic BP, serum creatinine, and albuminuria; significant inverse associations with LVMI were found with age and female gender. CONCLUSIONS The prevalence of LVH in hypertensive ADPKD patients <50 years of age with short duration of hypertension, and prior use of angiotensin-converting enzyme inhibitors/angiotensin receptor blockers is low. Early BP intervention in ADPKD may have decreased LVH and may potentially decrease cardiovascular mortality.

Semiautomated Segmentation of Kidney From High-Resolution Multidetector Computed Tomography Images Using a Graph-Cuts Technique

Objectives: To develop a semiautomated segmentation method based on a graph-cuts technique from multidetector computed tomography images for kidney segmentation and to evaluate and compare it with the conventional manual delineation segmentation method. Materials and Methods: We have developed a semiautomated segmentation method that is based on a graph-cuts technique with enhanced features including automated seed growing. Multidetector computed tomography images were obtained from 15 consecutive patients who were being evaluated as possible living donors for kidney transplant. Two observers independently performed the segmentation of the kidney from the multidetector computed tomography images using the manual and semiautomated methods. The efficiency of the 2 methods were measured by segmentation processing times and then compared. The interobserver and method reproducibility was determined by Dice similarity coefficient (DSC), which measures how closely 2 segmented volumes overlap geometrically and the coefficient of variation of volume measurements. Results: The mean segmentation processing time was (manual vs semiautomated, P < 0.001) 96.8 ± 13.6 vs 13.7 ± 3.5 minutes for observer 1 and 44.3 ± 4.7 vs 16.2 ± 5.1 minutes for observer 2. The mean interobserver reproducibility was (manual vs semiautomated, P < 0.001) 93.6 ± 1.6% vs 97.3 ± 0.9% for DSC and 5.3 ± 2.6% vs 2.2 ± 1.3% for coefficient of variation, indicating higher interobserver reproducibility with the semiautomated than manual method. The agreement between the 2 segmentation methods was high (mean intermethod DSC 95.8 ± 1.0% and 94.9 ± 0.8%) for both observers. Conclusions: The semiautomated method was significantly more efficient and reproducible than the manual delineation method for segmentation of kidney from MDCT images.

Pneumatosis intestinalis versus pseudo-pneumatosis: review of CT findings and differentiation

Pneumatosis intestinalis is defined as the presence of gas within the wall of the gastrointestinal tract. Originally described on plain abdominal radiographs, it is an imaging sign rather than a specific diagnosis and it is associated with both benign and life-threatening clinical conditions. The most common life-threatening cause of pneumatosis intestinalis is bowel ischaemia. Computed tomography (CT) is usually requested to detect underlying disease. The presence of pneumatosis intestinalis often leads physicians to make a diagnosis of serious disease. However, an erroneous diagnosis of pneumatosis intestinalis may be made (i.e. pseudo-pneumatosis) when intraluminal beads of gas are trapped within or between faeces and adjacent mucosal folds. The purpose of this pictorial essay is to review and describe the CT imaging findings of pneumatosis and pseudo-pneumatosis intestinalis and to discuss key discriminatory imaging features.

Dual‐echo arteriovenography imaging with 7T MRI

To implement a dual‐echo sequence MRI technique at 7T for simultaneous acquisition of time‐of‐flight (TOF) MR angiogram (MRA) and blood oxygenation level‐dependent (BOLD) MR venogram (MRV) in a single MR acquisition and to compare the image qualities with those acquired at 3T.

Dual-Echo Arteriovenography Imaging with 7 Tesla MR

To implement a dual‐echo sequence MRI technique at 7T for simultaneous acquisition of time‐of‐flight (TOF) MR angiogram (MRA) and blood oxygenation level‐dependent (BOLD) MR venogram (MRV) in a single MR acquisition and to compare the image qualities with those acquired at 3T.

Longitudinal Assessment of Left Ventricular Mass in Autosomal Dominant Polycystic Kidney Disease

Introduction The high burden of cardiovascular morbidity and mortality in autosomal dominant polycystic kidney disease (ADPKD) is related to development of hypertension and left ventricular hypertrophy. Blood pressure reduction has been shown to reduce left ventricular mass in ADPKD; however, moderators and predictors of response to lower blood pressure are unknown. Methods This was a post hoc cohort analysis of HALT PKD study A, a randomized placebo controlled trial examining the effect of low blood pressure and single versus dual renin−angiotensin blockade in early ADPKD. Participants were hypertensive ADPKD patients 15 to 49 years of age with estimated glomerular filtration rate (eGFR) > 60 ml/min per 1.73 m2 across 7 centers in the United States. Predictors included age, sex, baseline eGFR, systolic blood pressure, total kidney volume, serum potassium, and urine sodium, potassium, albumin, and aldosterone. Outcome was left ventricular mass index (LVMI) measured using 1.5-T magnetic resonance imaging at months 0, 24, 48, and 60. Results Reduction in LVMI was associated with higher baseline systolic blood pressure and larger kidney volume regardless of blood pressure control group assignment (P < 0.001 for both). Male sex and baseline eGFR were associated with a positive annual slope in LVMI (P < 0.001 and P = 0.07, respectively). Conclusion Characteristics associated with higher risk of progression in ADPKD, including higher systolic blood pressure, larger kidney volume, and lower eGFR are associated with improvement in LVMI with intensive blood pressure control, whereas male sex is associated with a smaller slope of reduction in LVMI.

Conditional survival of patients with small renal masses undergoing active surveillance

To determine conditional survival for patients with small renal masses (SRMs) undergoing active surveillance (AS).

Safety of Same-day Pegfilgrastim Administration in Metastatic Castration-resistant Prostate Cancer Treated With Cabazitaxel With or Without Carboplatin

Micro‐Abstract Although myeloid growth factors are commonly used to treat metastatic castration‐resistant prostate cancer, the optimal timing of administration has not been well studied. We demonstrate that same‐day pegfilgrastim administration after cabazitaxel treatment with or without carboplatin in patients with metastatic castration‐resistant prostate cancer is feasible. Furthermore, we observed that the rate of urinary tract inflammation was higher than that reported anecdotally. Introduction: Although myeloid growth factors are commonly used to treat metastatic castration‐resistant prostate cancer (mCRPC), the optimal timing of administration has not been well studied. We assessed the effects of same‐day pegfilgrastim, a neutrophil stimulator, after cabazitaxel treatment with or without carboplatin in patients with mCRPC. We also evaluated the frequency of urinary tract inflammation during treatment. Patients and Methods: Between September 2010 and September 2014, 151 consecutive patients with mCRPC underwent cabazitaxel treatment with or without the addition of carboplatin at a single institution. We assessed absolute neutrophil count recovery, incidence of neutropenia, neutropenic fever, antibiotic usage, treatment delays or discontinuation, dose reduction, and hospitalization with pegfilgrastim administration. Radiologists blinded to therapy reviewed computed tomography scans to detect urinary tract inflammation. Results: The median patient age was 69 years (range, 41‐88 years); 78% of patients were white, and 54% had a Gleason score ≥ 9. Median overall survival was 9 months (95% confidence interval, 8‐11 months). One patient (< 1%) had neutropenia; 38 patients (25%) had infection. During cycle 1, a significantly higher proportion of patients receiving pegfilgrastim after 24 hours developed infection than did those receiving pegfilgrastim the same day (26% vs. 6%; P = .01). Conclusion: Same‐day pegfilgrastim administration after cabazitaxel treatment with or without carboplatin in patients with mCRPC is feasible. The urinary tract inflammation rate (21%) was higher than that reported anecdotally. Results need to be prospectively validated.

Evaluation of the added value of imaging the pelvis in patients with hepatocellular cancer

The study aims to evaluate added value of the pelvic portion of the computed tomography (CT) and magnetic resonance imaging (MRI) examination in patients with a primary diagnosis of hepatocellular cancer (HCC).

Dual-echo arteriovenography imaging with 7T MRI: CODEA with 7T

To implement a dual‐echo sequence MRI technique at 7T for simultaneous acquisition of time‐of‐flight (TOF) MR angiogram (MRA) and blood oxygenation level‐dependent (BOLD) MR venogram (MRV) in a single MR acquisition and to compare the image qualities with those acquired at 3T.