Practical Guide to VI-RADS: MRI Protocols, Lesion Characterization, and Pitfalls.

Urothelial carcinoma is the most common type of bladder cancer (BC), accounting for approximately 90% of all cases. Evaluating the depth of tumor invasion in the bladder wall (tumor staging) is essential for determining the treatment and prognosis in patients with BC. Neoadjuvant therapy followed by radical cystectomy is the most common treatment of localized muscle-invasive BC (MIBC). Therefore, it is vital to differentiate non-MIBC from MIBC. Transurethral resection of bladder tumor (TURBT) is the reference standard to determine the extent of tumor invasion into the bladder wall through tissue sampling. However, this diagnostic and therapeutic method may not adequately sample the muscularis propria, leading to a higher risk of residual disease, early recurrence, and tumor understaging in approximately 50% of patients during the initial TURBT. Multiparametric MRI can overcome some of the limitations of TURBT when evaluating BC, particularly regarding tumor staging. In this context, the Vesical Imaging Reporting and Data System (VI-RADS) classification was developed to establish standards for bladder multiparametric MRI and interpretation. It uses a 5-point scale to assess the likelihood of detrusor muscle invasion. T2-weighted MR images are particularly useful as an initial guide, especially for categories 1-3, while the presence of muscular invasion is determined with diffusion-weighted and dynamic contrast-enhanced sequences. Diffusion-weighted imaging takes precedence as the dominant method when optimal image quality is achieved. The presence of a stalk or a thickened inner layer and no evidence of interruption of the signal intensity of the muscular layer are central for predicting a low likelihood of muscle invasion. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material. See the invited commentary by Hoegger in this issue.

Pancreatic collision tumor: mucinous cystadenoma and celar cell renal cell carcinoma metastasis

We present a clinical, radiological, surgical, and pathological correlation case of a 49-year-old woman with a prior nephrectomy due to a clear cell renal cell carcinoma, who was then diagnosed with a multilocular cystic lesion in the pancreatic tail after a routine ultrasound. Computed tomography and magnetic resonance cholangiopancreatography showed a multilocular cystic lesion with a hypervascular wall nodule in the pancreas. The patient underwent a distal pancreatectomy and had a final diagnosis of pancreatic mucinous cystadenoma with an associated component of clear cell renal cell carcinoma (collision tumor of the pancreas). (AU)

An unusual presentation of gastric diverticulum: a rare form of diverticulum of the gastrointestinal tract

Report of two cases of gastric diverticulum (GD) documented by upper gastrointestinal contrast radiographic studies and computed tomography (CT).

Esophageal stricture assessment by esophagogram: a pictorial review of differential diagnosis

The purpose of this article is to review the most frequent conditions associated with esophageal strictures on esophagogram. The most common causes include caustic ingestion, radiation therapy, malignancy, extrinsic compression, gastroesophageal reflux disease, infectious esophagitis, systemic diseases and membranes and rings. Adequate characterization of the stricture is necessary for formulation of the best diagnostic hypothesis and can be used to distinguish between malignant and non-malignant conditions. (AU)