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Études d’Imagerie VI : Cysto-urétrographie mictionnelle et cystographie
La cysto-urétrographie mictionnelle (CUM) et la cystographie sont des procédures radiographiques spécialisées utilisées pour examiner la structure et…
Une cysto-uréthrographie mictionnelle, ou VCUG, est une étude d’imagerie qui évalue la fonction de la vessie, le col de la vessie et l’urètre. Il aide à détecter le reflux vésico-urétéral, l’obstruction du col de la vessie et l’urine résiduelle post-mictionnelle.
La procédure commence par l’insertion d’un cathéter lubrifié à travers l’urètre dans la vessie. Un produit de contraste est ensuite introduit pour mettre en évidence les voies urinaires.
Des images fluoroscopiques sont capturées au fur et à mesure que la vessie se remplit, ce qui permet une évaluation en temps réel de sa structure.
Le cathéter est ensuite retiré et le patient est invité à uriner. Pendant la miction, des images supplémentaires sont prises pour évaluer le flux d’urine à travers le col de la vessie et l’urètre.
Après la miction, une autre image est prise pour vérifier la présence d’urine résiduelle.
Ensuite, la cystographie est similaire à la VCUG ; Il se concentre principalement sur le diagnostic des anomalies de la vessie à l’aide d’images radiographiques statiques sans capturer d’images en temps réel pendant la miction.
Dans la cystographie, un agent de contraste est injecté dans la vessie par un cathéter urinaire pour mettre en évidence les défauts structurels, tels que les diverticules ou les traumatismes.
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Q1: What does a voiding cystourethrogram evaluate?
A VCUG is an imaging study that evaluates bladder function, the bladder neck, and the urethra. It helps detect vesicoureteral reflux, which is the backward flow of urine into the ureters, bladder neck obstruction, and post-void residual urine. This procedure provides real-time assessment of lower urinary tract structure and function during filling and emptying.
Q2: How does cystography differ from VCUG?
Cystography focuses primarily on diagnosing bladder structural abnormalities using static X-ray images without capturing real-time images during urination. Unlike VCUG, which evaluates bladder function during voiding, cystography captures images when the bladder is filled with contrast dye and after it empties, making it useful for identifying diverticula, tumors, trauma, or rupture.
Q3: What is the first step in performing a VCUG?
The procedure begins with inserting a lubricated catheter through the urethra into the bladder. A contrast agent is then introduced to highlight the urinary tract. Fluoroscopic images are captured as the bladder fills, allowing real-time assessment of its structure and any abnormalities present.
Q4: What imaging occurs during the voiding phase of VCUG?
After the catheter is removed, the patient is asked to urinate while additional X-ray images are captured to assess urine flow through the bladder neck and urethra. Following urination, another image is taken to check for residual urine in the bladder, which helps determine if it has emptied completely.
Q5: What pre-procedure preparation is required for these imaging studies?
Patients must provide informed consent after the healthcare provider explains the procedure, risks, and benefits. Allergy assessment is essential, especially to contrast agents, iodine, or latex. Patients are asked to empty their bladder before the procedure begins to ensure accurate imaging during filling and voiding phases.
Q6: What happens after cystography is completed?
After the procedure, patients may experience a burning sensation during urination, which usually resolves within a few hours. Drinking fluids is recommended to flush out the contrast dye and reduce irritation. Healthcare providers may schedule a follow-up appointment to review imaging results and plan the next steps in treatment.
Q7: How long does a cystography procedure typically take?
The entire cystography procedure usually takes 30 to 60 minutes. During this time, topical anesthesia is applied to the urethra to minimize discomfort, a catheter is inserted into the bladder, and contrast agent is injected to provide clear X-ray images at specific stages of bladder filling and emptying.