Isolated renal lymphoma is rare due to the absence of lymphoid tissue in kidneys. Secondary involvement occurs more frequently and is reported in up to 1/3 of the autopsies of patients who died from lymphoma. Some authors believe this is actually the only existing form of renal lymphoma. The involvement of the kidney by lymphoma would occur through hematogenic metastasis or direct tumor invasion of the perirenal space. These different types of involvement determine the several forms of renal lymphoma presentation: multiple nodules, solitary mass, renal invasion from contiguous retroperitoneal disease, perirenal disease and diffuse infiltration. In this study the imaging findings features of the different forms of involvement are presented and discussed.

Keywords: Kidney, Lymphoma, Computed tomography

Primary urethral calculi are uncommon in the Western world. Stone formation is frequently associated with prior disorders affecting the urinary flow such as urethral diverticula, stenosis of the urethra and impacted foreign bodies. The authors report a case of a 77-year-old man, who complained of acute urinary retention and pain on the genital area. The diagnosis of urethral lithiasis was established and radiological studies revealed a wood cylindrical foreign body inside the stone.

Keywords: Calculus, Urethra, Foreign body

OBJECTIVE: The present study was aimed at describing a case series where a preoperative diagnosis of intestinal complications secondary to accidentally ingested dietary foreign bodies was made by multidetector-row computed tomography (MDCT), with emphasis on complementary findings yielded by volume rendering techniques (VRT) and curved multiplanar reconstructions (MPR). MATERIALS AND METHODS: The authors retrospectively assessed five patients with surgically confirmed intestinal complications (perforation and/or obstruction) secondary to unsuspected ingested dietary foreign bodies, consecutively assisted in their institution between 2010 and 2012. Demographic, clinical, laboratory and radiological data were analyzed. VRT and curved MPR were subsequently performed. RESULTS: Preoperative diagnosis of intestinal complications was originally performed in all cases. In one case the presence of a foreign body was not initially identified as the causal factor, and the use of complementary techniques facilitated its retrospective identification. In all cases these tools allowed a better depiction of the entire foreign bodies on a single image section, contributing to the assessment of their morphology. CONCLUSION: Although the use of complementary techniques has not had a direct impact on diagnostic performance in most cases of this series, they may provide a better depiction of foreign bodies' morphology on a single image section.

Keywords: Foreign bodies; Intestinal perforation; Intestinal obstruction; Multidetector computed tomography.

OBJECTIVE: To assess the practical aspects of the use of various gadolinium-based contrast agents (GBCAs) by radiologists. MATERIALS AND METHODS: Ten experienced radiologists from different regions of Brazil participated in a Delphi panel querying their use of various GBCAs, including linear and macrocyclic classes (1.0 and 0.5 M), in terms of the choice of agent, volume and dosage of the agents, and associated safety concerns. RESULTS: The response rate was 100% for all questions. GBCAs are safe in terms of acute adverse reactions, and nephrogenic systemic fibrosis is rare. The deposition of gadolinium in the brain and other tissues is a concern among the experts. Macrocyclic agents are preferable to linear agents; an injection volume below 0.1 mL/kg of a 1.0 M agent could result in good-quality images with additional long-term safety, but there is no published evidence to support this recommendation. The majority of experts preferred not to administer GBCAs to pregnant patients. CONCLUSION: When choosing a GBCA, it is important to consider the characteristics of the gadolinium deposition in patient tissues and minimize potential risks. Furthermore, medical education programs are needed to increase the awareness of the potential risks of gadolinium deposition and thus avoid instances of overexposure to the contrast agent.

Keywords: Contrast media; Gadolinium; Magnetic resonance imaging; Gadolinium-based contrast agents; Safety.