الفهرس 
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Abstract
Colorectal cancer is the third most frequent cancer diagnosed both in men and women in the United States outside of skin malignancies (The American Cancer Society, 2022).
Rectal cancer is mostly caused by adenocarcinomas (more than 67%), of which mucinous adenocarcinomas account for 20 percent (most aggressive type).
Five-year survival rates for rectal cancer still remain around 50% despite improvements in detection and therapy. The survival rate increases to 83 percent to 90 percent for tumors confined to the gut wall and falls to fewer than 10 percent if there are distant metastases, emphasizing the need of early identification and treatment.
Endorectal ultrasound (EUS), computed tomography (CT), magnetic resonance imaging (MRI), and fusion imaging (PET/CT) are imaging techniques used to stage rectal cancer.
Due to its high soft tissue contrast resolution, which provides excellent information on the location and size of the tumor, the depth of mural and extramural tumor spread, actively involve of the circumferential resection margin, the extent of any sphincteral involvement, extramural vascular invasion (EMVI), and lymph nodes, MRI imaging has proven to be the modality of choice for precisely staging rectal cancer.
A precise radiological response assessment is urgently required in light of recent advancements in rectal therapy. The two primary signs of response that can be seen on morphological (T2-weighted) MRI and used to help direct the treatment strategy before and especially after CRT are a reduction in volume and fibrotic transformation. This is an increasingly significant clinical issue given recent paradigm shift in rectal cancer treatment toward organ-preserving treatments.
Treatment options include neoadjuvant treatment followed by TME or complete mesorectal excision (TME), which has a free resection margin (involved resection margin). As an alternative to TME, local excision with no radiation or after nCRT in the case of satisfactory clinical response might be used to treat superficial tumors with minimal risk of lymph node spread. this preventative measure is combined with earlier drastic treatment, which lowers quality of life.
In our work, we employed a phased-array surface coil, which produces high spatial resolution pictures, allowing us to fully assess the layers of the rectal wall. It also has the benefit of a wide field of view.
The T2 weighted image sequence, which best represents the architecture of the rectal wall, is the most appropriate MR sequence for staging rectal cancer. Accurate tumor stage and CRM relationship identification is facilitated by proper angulation along the rectal wall at the tumor location. IV gadolinium and fat suppression are unnecessary since they don’t increase the accuracy of the diagnosis.
In other situations when it was difficult to clearly see the relationship between the tumor and the rectal, rectal contrast was required. Rectal contrast, however, dilates the lumen, making it challenging to identify mesorectal LN and CRM involvement.
30 individuals with a clinical suspicion of colorectal cancer participated in our research. On a 1.5T magnet with a pelvic phased array coil, all patients had a pelvic MRI evaluation. In According to the study’s findings, correct rectal cancer staging, the prediction of negative CRMs, and the involvement of the perirectal and pelvic LNs all contribute to determining the optimum treatment plan.
Future research in rectal cancer imaging should be focused on
In bigger clinical studies including patients with rectal cancer, the function of phased array surface coil MR imaging for detecting the CRM and local tumor size will be consolidated.
(b) Improving the capacity to detect lymph node metastases, particularly when using substances that are unique to those nodes, such iron oxide.