Khalil Salman

Decreased incidence of NSF in patients on dialysis after changing gadolinium contrast-enhanced MRI protocols.

To retrospectively determine the incidence of nephrogenic systemic fibrosis (NSF) in patients on dialysis administered either a lower dose high‐relaxivity linear gadolinium‐chelate, gadobenate dimeglumine (MultiHance, MH), compared to a standard dose linear gadolinium chelate, gadodiamide (Omniscan, OM).

Gadolinium-Enhanced MRI for Tumor Surveillance Before Liver Transplantation: Center-Based Experience

OBJECTIVE The purpose of this study was to evaluate prospectively acquired institutional results to determine the accuracy of gadolinium-enhanced MRI in liver tumor surveillance before transplantation. SUBJECTS AND METHODS One hundred fifteen patients underwent MRI of the abdomen within 90 days before liver transplantation. Images were acquired with gadolinium-enhanced 3D gradient-echo sequences in the arterial, venous, and delayed phases. Detection of hepatocellular carcinoma (HCC) was based on the imaging criteria arterial phase enhancement, delayed phase hypointensity, and development of an enhancing outer margin capsule. Imaging findings were compared with findings at histopathologic evaluation of the explanted liver. RESULTS Thirty-six HCCs in 27 patients were detected at histopathologic evaluation. Patient-based analysis showed the sensitivity of MRI was 88.9% (24/27); specificity, 97.7% (false-positive findings in two patients); and accuracy, 95.7%. MRI depicted 28 of 36 HCCs, resulting in a lesion-based sensitivity of 77.8%. Although all 18 HCCs 2 cm or larger were depicted with MRI, only 10 of 18 HCCs smaller than 2 cm were correctly diagnosed. However, two HCCs measuring smaller than 2 cm at pathologic examination were rated as dysplastic nodules on MRI. CONCLUSION Contrast-enhanced MRI can be used as a primary diagnostic method for accurate detection and characterization of HCC 2 cm or larger as required by the criteria of the Model for End-Stage Liver Disease used by the United Network for Organ Sharing. MRI can be considered a standard tool for surveillance before liver transplantation. Reduction in cost and risk may be derived from the diminished need for other diagnostic imaging studies and biopsy and the avoidance of use of iodinated contrast agents in imaging of patients with cirrhosis, many of whom have impaired renal function.

Acute abdominal pain: Is there a potential role for MRI in the setting of the emergency department in a patient with renal calculi?

Acute flank pain is a frequent clinical presentation encountered in emergency departments, and a work‐up for obstructive urolithiasis in this setting is a common indication for computed tomography (CT). However, imaging alternatives to CT for the evaluation of renal colic are warranted in some clinical situations, such as younger patients, pregnancy, patients that have undergone multiple prior CT exams and also patients with vague clinical presentations. MRI, although relatively insensitive for the direct detection of urinary calculi, has the ability to detect the secondary effects of obstructive urolithiasis. Using rapid, single shot T2‐weighted sequences without and with fat saturation provides an abdominopelvic MR examination that can detect the sequelae of clinically active stone disease, in addition to alternate inflammatory processes that may mimic the symptoms of renal colic. In addition, MR nephro‐urography (MRNU) has the ability to provide quantitative analysis of renal function that has the potential to direct clinical management in the setting of obstructing calculi. This review describes the potential utility and limitations of MRI in the emergency setting for diagnosing causes of flank pain and renal colic, particularly in patients with unusual presentations or when an alternative to CT may be warranted. J. Magn. Reson. Imaging 2010;32:1012–1023.

Optimization of single injection liver arterial phase gadolinium enhanced MRI using bolus track real-time imaging.

To measure contrast agent enhancement kinetics in the liver and to further evaluate and develop an optimized gadolinium enhanced MRI using a single injection real‐time bolus‐tracking method for reproducible imaging of the transient arterial‐phase.

Kidney transplantation: Structural and functional evaluation using MR nephro-urography

End‐stage‐renal disease (ESRD) is a major health issue in the United States, and the Medicare costs of ESRD totaled nearly

Magnetic resonance nephrourography: current and developing techniques.

21 billion in 2005. Renal transplantation has emerged as the treatment of choice in this patient population, providing improved quality of life and lower healthcare costs compared with other treatment options. Imaging evaluation of a graft kidney plays a critical role in the postoperative care of the renal transplant patient. In the past, diagnostic evaluation of the transplant kidney has depended upon a combination of ultrasonography, computed tomography, MRI, and biopsy, used in conjunction with the patients clinical presentation. However, new and developing advances in MR technology has lead to the development of MR Nephro‐Urography (MRNU), which provides both anatomic and functional evaluation of the kidney in a single examination. It is expected that the increasing use of MRNU will have a significant impact on the management of renal transplant patients. This review describes MRNU methodology, examines known posttransplant complications, and highlights the utility of MRNU as a comprehensive imaging examination to diagnose both surgical and medical complications of the transplant kidney. J. Magn. Reson. Imaging 2008;28:805–822.

Reversible heterogeneous arterial phase liver perfusion associated with transient acute hepatitis: Findings on gadolinium-enhanced MRI†

MR nephrourography (MRNU) makes it possible to obtain structural and functional data within a single imaging examination without using ionizing radiation. The functional data available with MRNU allows renal physiology to be examined in ways that were not possible previously. Coupled with the exquisite soft-tissue contrast provided by standard MR images, MRNU can provide a comprehensive study that yields critical diagnostic information on structural diseases of the kidneys and collecting system, including congenital and acquired diseases, and also on the full range of the causes of dysfunction in the transplanted kidney.

Magnetic resonance imaging evaluation of renal structure and function related to disease: Technical review of image acquisition, postprocessing, and mathematical modeling steps

To assess a possible correlation between active acute hepatitis and the development of abnormal liver perfusion demonstrated as heterogeneous enhancement on arterial phase gadolinium‐enhanced MRI. Dynamically‐enhanced MRI of the liver can detect reversible perfusion abnormalities that correlate with acute hepatitis.

Liver MRI and histological correlates in chronic liver disease on multiphase gadolinium‐enhanced 3D gradient echo imaging

Kidney disease represents a leading cause of morbidity, with high healthcare costs. The existing methods used to evaluate renal function include measures of glomerular filtration rate (GFR), yet the clinical methods are generally inaccurate and poorly reproducible. A method that improves measures of renal function as part of a comprehensive examination that also evaluates renal structure represents an important unmet clinical need. Use of dynamic contrast‐enhanced magnetic resonance imaging (MRI) for the evaluation of renal function has been undergoing development by several groups. The methodology has been referred to as MR Urography (MRU) or MR Nephro‐urography (MRNU). MRU/MRNU shows promise for providing new insights into the evaluation of renal structure and function in relation to important disease processes, including urinary obstruction and in relation to renal transplantation. MRU/MRNU generally requires consideration of imaging acquisition technique, image postprocessing strategies, and subsequent kinetic mathematical modeling of the data in reference to specific physiological renal processes, such as renal blood flow and GFR. Here we review the specifics of proposed methods in light of the overall strengths and limitations of each of these strategies. The overall objective is to provide a roadmap for future developments in this evolving field of novel MRI applications. J. Magn. Reson. Imaging 2011;33:1270–1283.

No Incidence of Nephrogenic Systemic Fibrosis after Gadobenate Dimeglumine Administration in Patients Undergoing Dialysis or Those with Severe Chronic Kidney Disease

To evaluate intrinsic hepatic enhancement patterns on multiphase, gadolinium‐enhanced, fat‐suppressed, 3D T1‐weighted, gradient echo magnetic resonance imaging (MRI) as a quantitative correlate for severity of pathological changes in chronic liver disease (CLD).