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Estudos de Imagem VI: Cistouretrografia Miccional e Cistografia
A Cistouretrografia Miccional (CUM) e a Cistografia são procedimentos radiográficos especializados usados para analisar a estrutura e a função da bexi…
Um uretrograma miccional, ou VCUG, é um estudo de imagem que avalia a função da bexiga, o colo da bexiga e a uretra. Ajuda a detectar refluxo vesicoureteral, obstrução do colo vesical e urina residual pós-miccional.
O procedimento começa com a inserção de um cateter lubrificado através da uretra na bexiga. Um agente de contraste é então introduzido para destacar o trato urinário.
As imagens fluoroscópicas são capturadas à medida que a bexiga se enche, permitindo a avaliação em tempo real de sua estrutura.
O cateter é então removido e o paciente é solicitado a urinar. Durante a micção, imagens adicionais são tiradas para avaliar o fluxo de urina através do colo da bexiga e da uretra.
Após a micção, outra imagem é tirada para verificar se há urina residual.
Em seguida, a cistografia é semelhante à VCUG; ele se concentra principalmente no diagnóstico de anormalidades da bexiga usando imagens estáticas de raios-X sem capturar imagens em tempo real durante a micção.
Na cistografia, um agente de contraste é injetado na bexiga através de um cateter urinário para destacar defeitos estruturais, como divertículos ou traumas.
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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.