MRI of the kidney—state of the art

Ultrasound and computed tomography (CT) are modalities of first choice in renal imaging. Until now, magnetic resonance imaging (MRI) has mainly been used as a problem-solving technique. MRI has the advantage of superior soft-tissue contrast, which provides a powerful tool in the detection and characterization of renal lesions. The MRI features of common and less common renal lesions are discussed as well as the evaluation of the spread of malignant lesions and preoperative assessment. MR urography technique and applications are discussed as well as the role of MRI in the evaluation of potential kidney donors. Furthermore the advances in functional MRI of the kidney are highlighted

MAGNETIC RESONANCE IMAGING OF THE KIDNEY

This chapter describes the imaging techniques for the examination of the kidney using magnetic resonance (MR), from the fundamental morphologic sequences to the advanced applications. The basic MR features of vascular and infectious renal diseases, solid benign and malignant renal tumors, and cystic renal tumors are described. Advanced MR applications are described as a generai introduction to the following chapters describing the different renal pathologies. Cross-sectional imaging plays a criticai role in the detection and workup of renal pathologies. Even if computed tomography (CT) is stili playing the leader, the role of magnetic resonance imaging (MRI) is increasing, thanks to its better tissue contrast resolution and the absence of radiation exposure. Furthermore, MRI can be used as a problem-solving modality when CT findings are nondiagnostic. While MRI has been shown to be useful in the detection and characterization of renal masses, in the staging of cancers, and in the evaluation of urinary tract anomalies and obstructive disease, attempts are being made to use it for assessment of renal function, such as perfusion, glomerular filtration rate, and intrarenal oxygen measurement. Although the nephrogenic systemic fibrosis has been recently recognized, gadolinium contrast agents are still considered safe. They can be used even in atopic patients and in patients with moderate impairment of renal function (estimateci glomerular filtration rate >30 mL/ min/1.73 m2 )