Genitourinary fluoroscopic contrast examinations: what role do they have today?
Genitourinary fluoroscopic contrast examinations: what role do they have today?
Dr Valeria Ninivaggi, Dr Giampaolo Bianchi, Dr. Antonello Fabbri, Dr Luigi Zugaro, Ospedale SS. Filippo e Nicola , Avezzano , Italia
Defining the current role of fluoroscopic contrast examinations in the adult patient by analyzing the appropriateness of the clinical question, the choice of examination technique by limiting the dose, the choice of contrast agent, the examination procedure, the image interpretation.
Type of contrast agents Non-ionic and ionic intravascular-endoluminal organo-iodinated contrast agents are used: • radiopacity due to the ability to absorb radiation • Good viscosity of the agent • History of hypersensitivity: treatment of allergic reaction or prefer another contrast medium [1]. Radiation dose Following the directives, radiation dose should be measured and reduced as possible for every diagnostic examination [2]. Suggestions for radiation dose reduction are: • Limitation of fluoroscopy time • image intensifier should be closer to the patient. • Reduce the pulsed fluoroscopy frame rate • Use the “Save image” feature to avoid a spot fluoroscopic image • Use a radiation badge to track the exposure [3]. Urinary tract Fluoroscopic study of the urinary tract is still requested for a wide range of clinical questions because of the simplicity of execution and the anatomical and functional information it can give: • Dysfunctional voiding • Obstruction • Study of anatomy and anomalies of urogenital tract for pathologies or operative settings (such as renal transplant) • Postoperative evaluation (cystectomy and reconstructive surgery, research of fistula or dehiscence) • Suspected neoplasm or hematuria (rarely, CT is preferred) • Trauma (rarely; CT is preferred) Urethra Ascending and descending urethrography can provide information about the appearance of the pre-and post-operative urethra and guide patient management. Retrograde urethrography • A Foley catheter is secured a few centimeters into the urethra and a pre contrast image is acquired • The urethra is opacified retrograde by 20-30 ml of iodinated contrast agent. • Acquisition of oblique projection when the urethra is sufficiently opacified and distended by the contrast agent. Anterograde urethrography • A Foley catheter is secured into the bladder; a pre contrast image is acquired • the bladder is filled with a contrast agent by foley catheter • The catheter is then removed, and oblique images are acquired during active voiding when the urethra is opacified in oblique projections. Bladder Cystography • The bladder is filled with contrast agents by foley catheter; a pre-contrast image is acquired. • The bladder is filled with contrast: small filling, and large filling should be obtained to assess the extensibility, the morphology of the organ, and ureteral reflux. Lateral and voiding images could complete the evaluation. [4, 5] Uterus and Fallopian Tubes Hysterosalpingography is an important radiologic procedure in the investigation of infertility which demonstrates the morphology of the uterine cavity, the lumina, and the patency of the fallopian tubes. Due to recent advances of reproductive medicine, it is commonly requested. Hysterosalpingography • The procedure is performed in the first half of the menstrual cycle with proliferative phase of endometrium. Negative pregnancy test is mandatory to avoid eventually irradiation and negative vaginal swab for most common pathogens are necessary to avoid ascending infections. • After speculum placement a catheter is fixed at the cervical ostium. • Endoluminal organo-iodined contrast agent is injected in uterine cavity by the catheter at low pressure • Uterine cavity, fallopian tubes and their adjacent peritoneum are normally opacified [6, 7].
Cystography: a) pre contrast image. B) small filling c) large filling d) oblique projection. Good distension of the bladder walls; no reflux detected.
Voiding cystography: after bladder filling, oblique projections of the ureteral profile are acquired. No alterations of the urethral tracts are appreciated.
Patient with difficulty urinating and recurrent urinary tract infections. At the ascending cystography, a focal stenosis (arrow) is appreciated at the middle III of the prostatic and membranous urethra (a),that appears normal by subsequent voiding cystography (b).
Kidney transplant candidate. Retrograde cystography required for assessment of wall distensibility and bladder capacity which appear normal. At medium filling of the bladder, right ureteral reflux is appreciated.
Patient with recurrent urinary tract infections: bladder appears regular when filling . At initial filling, reflux and opacification of ureterocele are appreciated (arrow).
Patient with recent prostatectomy, suspected anastomotic leak. After retrograde administration of contrast medium, extravasation of contrast medium into the surgical bed is appreciated .
Patient with infertility: regular opacification of the uterine cavity after administration of contrast medium. The left tube is filiform, with regular passage of contrast agent through the peritoneum (arrowhead). The left tube is filiform and convoluted with delayed passage of contrast agent into the peritoneum, suspect of adhesions.
The ability to perform genitourinary contrast fluoroscopy exams remains an important skill for the daily clinical practice of young radiologists in modern radiology departments.
