Electronic poster

Tuesday 13:30-15:30 Computer 99

13:30 4682. Effect of Octreotide on Intra-Renal Oxygenation as Estimated by BOLD MRI in Rats

Lu-Ping Li¹, Joann Carbray¹, Pottumarthi V. Prasad<sup>1

1</sup>Radiology, Northshore University Healthsystem, Evanston, IL, United States

Previous observations have shown lower intra-renal oxygenation as early as two days after induction of type I diabetes. In order to test the hypothesis that this may be related to the direct effect of hyperglycemia, the infusion of glucose solution was used in healthy rats. However comparable levels of blood glucose levels and R2* values in diabetic rats were observed only in animals pretreated with an insulin inhibitor (octeotride). Because octeotride is associated with vasoconstriction, it is necessary to know the magnitude of any direct effect of octeotride on renal oxygenation. That was the motivation for the present study.

14:00 4683. BOLD Changes After Revascularization in Renal Artery Stenosis Patients - Preliminary Results

Iosif Alexandru Mendichovszky¹, Constantina Chrysochou², David L. Buckley³, Alan Jackson¹, Phil A. Kalra<sup>2

1</sup>Wolfson Molecular Imaging Centre, The University of Manchester, Manchester, United Kingdom; ²Renal Department, Salford Royal Hospital, Salford, United Kingdom; ³University of Leeds, Leeds, United Kingdom

Atheromatous renovascular disease is a commonly encountered yet challenging disease to manage. The aim of the current study was to investigate renal parenchymal BOLD response to renal artery revascularization in patients with severe renal artery stenosis and correlate imaging findings with changes in SK-GFR (as measured by radioisotope techniques). No significant differences were found regarding baseline SK-GFR between kidneys that improved, remained stable, deteriorated or controls. R2* values were significantly higher in kidneys whose renal function subsequently improved vs. those who stayed stable, deteriorated or controls. In addition, the ratio of R2* to SK-GFR was significantly greater in improver kidneys.

14:30 4684. Long Term Follow-Up of Human Transplanted Kidneys by DWI and BOLD Imaging

Peter Vermathen¹, Tobias Binser¹, Chris Boesch¹, Ute Eisenberger², Harriet C. Thoeny<sup>3

1</sup>Dept. Clinical Research, University Bern, Bern, Switzerland; ²Dept. of of Nephrology and Hypertension, University Hospital of Bern, Bern, Switzerland; ³Dept. of Radiology, University Hospital of Bern, Bern, Switzerland

Previously, we performed a DWI and BOLD MRI study in renal allograft recipients with good allograft function and determined short term reproducibility of diffusion and oxygenation parameters. In the current study, nine patients of our initial study were measured again 32±2 months after the initial scan to assess long term effects on diffusion parameters and on R2*. The functional parameters were markedly stable after 32 months with a slight tendency towards reduced oxygenation in eight of the nine patients, who still had good allograft function. In contrast, one subject with decreased GFR indicative of renal dysfunction demonstrated strongly altered MR-parameters.

15:00 4685. Performance of Generalized Factor Analysis of Dynamic Sequence (GFADS) in the Automated Characterization of Renal Function and Tissue Enhancement in Dynamic Magnetic Resonance Imaging (MRI)

Ruth Lim¹, Jinsong Ouyang¹, Matthew D. Schmitz¹, Michael S. Gee¹, Ranu Shailam¹, Raul N. Uppot¹, Georges El Fakhri<sup>1

1</sup>Department of Radiology, Massachusetts General Hospital / Harvard Medical School, Boston, MA, United States

We assessed the performance of a novel generalized factor analysis of dynamic sequences (GFADS) in dynamic, contrast-enhanced renal magnetic resonance imaging (MRI). By detecting unique time-intensity curves for each renal tissue/compartment type, this technique automates the creation of regions of interest (ROIs) around and within the kidneys, and obviates the need for manually-drawn ROIs. These time factor curves are computed from entire factor images and are significantly less affected by noise than time-intensity curves computed within regions of interest that span a few voxels. In this study, we found that GFADS software can successfully, semi-automatically, and rapidly identify the renal cortex, medulla, and collecting system on dynamic contrast-enhanced renal MRI studies while obviating the need to use manually-drawn regions of interest. This enables detailed quantitative assessment of cortical and medullary renal function in normal and abnormal kidneys.

Wednesday 13:30-15:30 Computer 99

13:30 4686. Contrast-Enhanced Kidney MRI at 7Tesla: Initial Results

Lale Umutlu¹, Stephan Orzada², Sonja Kinner, Stefan Maderwald², Irina Brote², Andreas K. Bitz², Oliver Kraff², Susanne C. Ladd², Gerald Antoch, Mark E. Ladd², Harald H. Quick², Thomas C. Lauenstein

¹Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen , Essen, Germany; ²Erwin L.Hahn Institute for Magnetic Resonance Imaging

Aim of this study was to assess the feasibility of contrast-enhanced kidney MRI at 7T. 8 healthy subjects were examined at a 7T whole-body MR system utilizing a custom-built 8-channel RF transmit/receive body coil. Qualitative analysis showed best overall image quality for T1w 2D FLASH imaging and strongest artifact impairment for T2w TSE imaging. Quantitative analysis showed continuous increase of SNR after iv. Gadolinium administration on T1w images and best corticomedullar differentiation in the arterial phase. This first attempt of 7T kidney imaging reveals the diagnostic potential, but also challenges of 7T abdominal MRI.

14:00 4687. Renal Angiomyolipoma Fat Content Estimated on Pretreatment MRI as a Predictor of Response to Embolization

Joseph Abrams¹, Timothy W. Clark¹, Rahmin A. Rabenou², Hersh Chandarana<sup>1

1</sup>Radiology, NYU Langone Medical Center, New York, NY, United States; ²Nephrology, NYU Langone Medical Center, New York, NY, United States

Transarterial embolization prevents hemorrhage of renal angiomyolipoma (AML) by decreasing the tumor’s angiogenic component. Our aim was to determine whether baseline AML lipid content, as estimated by AML-to-psoas signal ratio on T1 fat-saturated non-contrast acquisition, could help predict embolization response, as measured by changes in volume and enhancement on gadolinium contrast enhanced MRI (CE-MRI). Moderately good correlations were seen between baseline lipid content and change in volume and change in enhancement. These results suggest that AMLs with higher fatty components, as determined on MRI, are less likely to respond to embolization.

14:30 4688. MRI Characterization of Liver Involvement in Autosomal-Dominant Polycystic Kidney Disease

Wei Zhang¹, Jon D. Blumenfeld², Stephanie Donahue², Honglei Zhang³, Martin R. Prince<sup>3

1</sup>Radioloty, Weill Cornell Medical College, new york, NY, United States; ²Internal Medicine, Weill Cornell Medical Center and The Rogosin Institute, new york, NY, United States; ³Radioloty, Weill Cornell Medical College, new york, NY, United States

135 ADPKD patients underwent abdominal MRI using a body array coil. Organ volumes and cyst volumes were measured on T2 images.RESULTS: There is significant correlation between HV and HCV, HV and HCF, HV and SPV, HCF and age, HCF and GFR, HCF and Sex, HCF and BRV, HCF and BECV, BRV and BCV at P=0.01 level. Hepatic cyst fraction was significantly higher in female.Discussion and Conclusion:Our research prove that hepatic cysts in ADPKD are more prevalent in women than men, and women experience a larger burden of hepatic cysts than men in a younger age, implicating gender-specific hormones works in the pathogenesis of hepatic cyst involvement in ADPKD.

15:00 4689. Intra-Observer and Inter-Observer Variability of Renal Volume Measurements in Polycystic Kidney Disease Utilizing a Semi-Automated MR Segmentation Algorithm with HASTE and TrueFISP Sequences

Benjamin A. Cohen¹, Irina Barash², Danny Kim¹, Emilio Vega¹, Matthew D. Sanger¹, Michael Bloom¹, Hersh Chandarana<sup>1

1</sup>Radiology, NYU Langone Medical Center, New York, NY, United States; ²Nephrology, NYU Langone Medical Center

In Polycystic Kidney Disease (PKD), total renal volume and changes in kidney volume have been identified as sensitive markers of disease progression and, perhaps, response to future novel therapeutics. The aim of this study was to assess the intra-observer and inter-observer variability of a semi-automated MR renal volumetric algorithm in PKD employing fluid sensitive pulse sequences emphasizing cyst conspicuity, specifically HASTE and TrueFISP. This algorithm provided excellent intra-observer (median agreement greater than 97-98%) and very good inter-observer (median agreement greater than 93%) reproducibility. Automated techniques, in development, will hopefully decrease inter-observer variability and processing time to support longitudinal analysis.

Thursday 13:30-15:30 Computer 99

13:30 4690. Sodium MR Imaging of Kidney and Other Abdominal Organs Using a Dual-Tuned Body RF Coil at 7T

Kyongtae Ty Bae¹, Jung-Hwan Kim¹, Chan Hong Moon¹, Alessandro Furlan¹, Bumwoo Park¹, Tiejun Zhao<sup>2

1</sup>University of Pittsburgh, Pittsburgh, PA, United States; ²MR Research Support, Siemens Healthcare, Pittsburgh, PA, United States

We performed dual-tuned 23Na/1H MR imaging of human abdominal organs at 7T and demonstrated the spatial distribution of sodium in the kidney using sodium MR imaging. Future development of 23Na MR imaging will be focused on clinical application of sodium MR imaging in the abdomen to assess a variety of physiological and pathological conditions accompanied with changes in sodium concentration.

14:00 4691. Quantitative Evaluation of Acute Renal Transplant Dysfunction with Low-Dose 3D MR Renography

Akira Yamamoto¹, Jeff Lei Zhang¹, Henry Rusinek¹, Hersh Chandarana¹, James Babb¹, Thomas Diflo², Devon John², Judith Benstein³, Pierre H. Vivier¹, David Stoffel¹, Vivian S. Lee<sup>1

1</sup>Radiology, New York University School of Medicine, New York, United States; ²Surgery, New York University School of Medicine, New York, United States; ³Medicine, New York University School of Medicine, New York, United States

60 patients (31 clinically normal-functioning transplanted kidney, 29 acute dysfunction transplanted kidney) were examined to assess quantitative low-dose 3D MR renography to diagnose acute transplant dysfunction. Acute rejection showed higher ratio of vascular mean transit time to whole kidney (MTT-A/K) and lower tubular transit time fraction (MTT-T/K) compared to ATN. In particular, the diagnostic test that classified patients as acute rejection when MTT-A/K 9.0% and as ATN otherwise achieved 100% diagnostic accuracy. Our method of MR renography is promising for the diagnosis of acute transplant renal dysfunction and can be performed as a component of routine anatomic imaging of the transplanted kidney.

14:30 4692. Evaluation of the Feasibility and Reproducibility of Renal DTI MRI in Healthy Volunteers

Marica Cutajar¹, Stephen D. Marks¹, Jonathan D. Clayden¹, Christopher A. Clark¹, Isky Gordon<sup>1

1</sup>Radiology and Physics, UCL Institute of Child Health, London, United Kingdom

The aim of this study was to determine the reproducibility and robustness of Diffusion Tensor Imaging (DTI) in the kidney, to in turn justify the utility of this method in the clinical environment. DTI provides structural parameters relatively unstudied in kidney, the Apparent Diffusion Coefficient (ADC) and the Fractional Anisotropy (FA). The ADC gives an indication of the overall extent of diffusion, while the FA characterises the directionality of water diffusion in the tissue of interest. Initial studies have found a clear difference between the renal cortex and medulla for both ADC and FA values and both parameters were reproducible.

15:00 4693. Renal Blood Flow Changes in Autosomal-Dominant Polycystic Kidney Disease

Wei Zhang¹, Jon D. Blumenfeld², Stephanie Donahue², Honglei Zhang¹, Martin R. Prince<sup>1

1</sup>Radiology, Weill Cornell Medical College, new york, NY, United States; ²Internal Medicine, Weill Cornell Medical Center and The Rogosin Institute, new york, NY, United States

Purpose: To assess how renal blood flow changes in autosomal-dominant polycystic kidney disease (ADPKD) and its correlation with renal parenchymal volume and function.Methods: 41 ADPKD patients underwent MRA of the renal arteries using 2D cine Phase Contrast besides routine abdominal MRI.Results: GFR to both kidneys correlated directly with total blood flow.Conclusion:Our research suggest that measuring total flow to bilateral kidneys may represent an effective way to monitor renal function in ADPKD patients.

NSF & Body Diffusion

Hall B Monday 14:00-16:00 Computer 100

14:00 4694. Comparative Stability of Nonionic Linear and Ionic Macrocyclic Gadolinium Chelates in Renally-Impaired Rats

Jean-Marc Idée¹, Nathalie Fretellier¹, Anne Dencausse¹, Nicolas Poveda¹, Gaëlle Jestin¹, Claire Hollenbeck¹, Marc Port¹, Jean-Sébastien Raynaud¹, Philippe Robert¹, Claire Corot<sup>1

1</sup>Research, Guerbet, Roissy-Charles de Gaulle cedex, France

In rats with subtotal nephrectomy receiving single injections (2.5 mmol/kg) of gadodiamide (Omniscan) for 5 consecutive days, 62 +15% of the total plasma gadolinium concentration measured at sacrifice was found to be free while the free Gd3+ concentration in plasma was < limit of detection for gadoterate (Dotarem). Relaxometry study of the skin and the bone indicate gradual in vivo dechelation and release of free Gd3+ in rats receiving the linear GC gadodiamide (increase in the r1 relaxivity constant over time in the skin and higher r1 value vs. ex vivo matrix in skin and bone), while gadoterate remained stable.

14:30 4695. Hyperphosphataemia Reveals Skin Lesions in Gadodiamide-Treated Rats with Low Renal Function

Jean-Marc Idée¹, Nathalie Fretellier¹, Sylviane Guerret², Marie-Christine De Goltstein¹, Anne Dencausse¹, Nicolas Poveda¹, Claire Hollenbeck¹, Walter Gonzalez¹, Cécile Factor¹, Claire Corot<sup>1

1</sup>Research, Guerbet, Roissy-Charles de Gaulle cedex, France; ²Novotec, Lyon, France

Rats with subtotal nephrectomy received a normal or high-phosphate diet and were allocated to single injections of 2.5 mmol/kg of gadodiamide (Omniscan) or saline for 5 consecutive days. Hyperphosphataemia enhanced histological lesions (increase in dermal cellularity, abnormalities in dermal collagen fibres and TGF-beta-1 immunostaining) and revealed macroscopic skin lesions. In the gadodiamide + high phosphate diet group, the total plasma gadolinium concentration was higher in the rats with skin lesions than in the rats without lesions as well as the free Gd3+ concentration.

15:00 4696. Mortality and Frequency of Nephrogenic Systemic Fibrosis

Giles Roditi¹, Tara Collidge², Peter Thomson², Jamie Traynor², Patrick Mark³, Scott Morris², Keith Simpson<sup>2

1</sup>Radiology, Glasgow Royal Infirmary, Glasgow, Scotland, United Kingdom; ²Nephrology, Glasgow Royal Infirmary, Glasgow, Scotland, United Kingdom; ³Nephrology, Western Infirmary Glasgow, Glasgow, Scotland, United Kingdom

Nephrogenic systemic fibrosis (NSF) mortality was compared to a matched renal replacement therapy (RRT) population. Records searched with NSF and GBCA exposure identified and onset of RRT with survival to death or census. 1826 patients with RRT, 1812 with outcome data. Total 17 cases of NSF. Survival for GBCA exposed and NSF cohort measured by RRT onset or post scan survival not significantly different between these groups. Frequency of NSF cases over years studied follows the number of CE-MRA scans performed suggesting GBCA exposure causally implicated in development of NSF

15:30 4697. A Retrospective Analysis of Nephrogenic Systemic Fibrosis in a Population Undergoing Renal Magnetic Resonance Angiography Stratified by EGFR

Giles Roditi¹, Tara Collidge², Peter Thomson², Keith Simpson², Scott Morris², Brown Michaela², Anirudh Rao<sup>2

1</sup>Radiology, Glasgow Royal Infirmary, Glasgow, Scotland, United Kingdom; ²Nephrology, Glasgow Royal Infirmary, Glasgow, Scotland, United Kingdom

NSF associates with the administration of gadolinium contrast in renal impairment. Of 481 patients who underwent renal CE-MRA 3 patients were identified as having NSF. 2 had AKI when imaged, third had deteriorating CKD (eGFR 16.1) and developed NSF three years later when on dialysis following further CE-MRA. All cases of gadodiamide-associated NSF from our unit (n=16) 13 were established on dialysis, 2 had AKI and one had eGFR of 8.3 ml/min. All patients developing NSF have AKI or stage 5 CKD, we found no NSF cases with an eGFR >15 ml/min.

Tuesday 13:30-15:30 Computer 100

13:30 4698. Renal Cell Carcinoma: 3.0-T Diffusion-Weighted MR Imaging for Subtypes Differentiation

Haiyi Wang¹, Aitao Guo², Dianjun Wang², Yuangui Gao¹, Xu Zhang³, Huiyi Ye<sup>1

1</sup>Radiology, PLA General Hospital, Beijing, China; ²Pathology, PLA General Hospital, Beijing, China; ³Urology, PLA General Hospital, Beijing, China

Renal cell carcinoma (RCC) is the most common malignant renal tumor in adults, with the three major subtypes, clear cell RCC, papillary RCC, and chromophobe RCC. Because of clincal needs for RCC subtypes differentiation, this study explores the ADC values of pathologically-proved clear cell, papillary, and chromophobe RCC subtypes, and the conclusion is drawn that they possess different diffusion characteristics that can be distinguished using DWI on the basis of the ADC, with high sensitivity and specificity, potentially improving the accuracy of pretreatment diagnosis and selection of clinical therapy.

14:00 4699. Evaluation of 3.0T MR Diffusion-Weighted Imaging in Diagnosis and Short-Term Therapeutic Effect of Renal Clear Cell Carcinoma

Xiao-duo Yu¹, Meng Lin¹, Han Ouyang<sup>1

1</sup>Department of Diagnostic Imaging, Cancer Hospital,Peking Union Medical College,Chinese Academy of Sciences, Beijing, China

DWI and ADC value in 3.0T MRI has widely used in tumor, but applied to clinical practice limitedly for overlap between benign and malignant tumor. 51 cases with renal clear cell carcinoma proved by operation were studied. Set ADC value at 1.8×10-3mm²/s to divide the cohort into two groups. Significant differences were found between histological grade, clinical stage. After follow-up more than one year, tumor short-term control rate of the group with ADC value more than and equal to 1.8×10-3mm²/s was better than that of the group with ADC value less than 1.8×10-3mm²/s.Therefore DWI and ADC value help to evaluate prognosis potentially.

14:30 4700. Diffusion Weighted Imaging with Biexponential Analysis of Intravoxel Incoherent Motion in Assessment of Renal Lesions: Preliminary Experience

Hersh Chandarana¹, Vivian S. Lee¹, Elizabeth Hecht^1,2, Bachir Taouli^1,3, Eric E. Sigmund<sup>1

1</sup>Radiology, NYU Langone Medical Center, New York, NY, United States; ²Radiology, University of Pennsylvania, United States; ³Radiology, Mount Sinai Medical Center, New York, NY, United States

Movement of blood in microvasculature can be modeled as pseudo-diffusion also known as intravoxel incoherent motion. Perfusion effect can be separated if diffusion imaging is performed with low and high b values. The purpose of our study was to calculate perfusion fraction (fp) and tissue diffusivity (Dt) parameters obtained with biexponential analysis of multi-b DWI and determine if these parameters can distinguish enhancing from non-enhancing renal lesions. fp was higher and Dt lower in enhancing renal lesions; both these parameters had higher accuracy in detection of enhancing renal lesion compared to apparent diffusion coefficient (ADC) obtained with monoexponential fit.

15:00 4701. Loss of Renal Diffusion Anisotropy in Patients with Chronic Kidney Disease

Yu-Chun Lin^1,2, Koon-Kwan Ng¹, Tzung-Hai Yen³, Yu-Min Chen³, Hsiang-Yang Ma², Jiun-Jie Wang<sup>4

1</sup>Department of Diagnostic Radiology, ChangGung Memorial Hospital, KweiShan, Taoyuan, Taiwan; ²Department of Electrical Engineering, ChangGung University, KweiShan, Taoyuan, Taiwan; ³Department of Nephrology, ChangGung Memorial Hospital, Taiwan; ⁴Department of Medical Imaging and Radiological Science, ChangGung University, KweiShan, Taoyuan, Taiwan

Diffusion Tensor Imaging in kidney for patients with chronic kidney disease indicated a significant reduction of diffusion anisotropy. Images from 6 CKD patients and 6 normal subjects were acquired in a 3 Tesla MR scanner. Regions of interest were located bilaterally in medulla and cortex. The results showed decreases in diffusion anisotropy and associated increase in radial diffusivity, noticeably in medulla in patients. We concluded that renal DTI is feasible in 3T MR scanner and furthermore, sensitive to changes in diffusivities in patients with chronic kidney disease.