MRI-detected extramural venous invasion of rectal cancer: Multimodality performance and implications at baseline imaging and after neoadjuvant therapy.
Akitoshi InoueShannon P SheedyJay P HeikenPayam MohammadinejadRondell P GrahamHee Eun LeeScott R KelleyStephanie L HanselDavid H BruiningJeff L FidlerJoel G FletcherPublished in: Insights into imaging (2021)
MRI is routinely used for rectal cancer staging to evaluate tumor extent and to inform decision-making regarding surgical planning and the need for neoadjuvant and adjuvant therapy. Extramural venous invasion (EMVI), which is intravenous tumor extension beyond the rectal wall on histopathology, is a predictor for worse prognosis. T2-weighted images (T2WI) demonstrate EMVI as a nodular-, bead-, or worm-shaped structure of intermediate T2 signal with irregular margins that arises from the primary tumor. Correlative diffusion-weighted images demonstrate intermediate to high signal corresponding to EMVI, and contrast enhanced T1-weighted images demonstrate tumor signal intensity in or around vessels. Diffusion-weighted and post contrast images may increase diagnostic performance but decrease inter-observer agreement. CT may also demonstrate obvious EMVI and is potentially useful in patients with a contraindication for MRI. This article aims to review the spectrum of imaging findings of EMVI of rectal cancer on MRI and CT, to summarize the diagnostic accuracy and inter-observer agreement of imaging modalities for its presence, to review other rectal neoplasms that may cause EMVI, and to discuss the clinical significance and role of MRI-detected EMVI in staging and restaging clinical scenarios.
Keyphrases
- contrast enhanced
- rectal cancer
- diffusion weighted
- magnetic resonance imaging
- locally advanced
- magnetic resonance
- computed tomography
- diffusion weighted imaging
- deep learning
- high resolution
- convolutional neural network
- lymph node
- optical coherence tomography
- decision making
- dual energy
- climate change
- radiation therapy
- stem cells
- cell migration
- low dose
- mass spectrometry
- bone marrow
- cell therapy
- smoking cessation