To provide a comprehensive review of anatomical landmarks of rectal and perirectal region. To revise common and uncommon conditions in this complex anatomic region. To highlight the imaging clues for their accurate diagnosis.
Rectum and perirectal space can be affected by a wide variety of tumours and tumour-like conditions,
which may present with similar symptoms to those of rectal adenocarcinoma,
such as hematochezia,
or change in bowel habits. On the other hand,
tumours of the perirectal space are commonly congenital,
asymptomatic and they are malignant only in 20-35% of cases (1) Anatomical characteristics of perirectal space are complex and magnetic resonance (MR) is the modality of choice for its...
Findings and procedure details
ANATOMY The rectum is approximately 15cm in length and layers can be well depicted by MR ( Fig. 1 ): Inner hyperintense layer,
mucosa and submucosa (differentiation may be difficult) Intermediate hypointense layer,
muscularis propria Outer hyperintense layer,
perirectal fat tissue. Mesorectum ( Fig. 1 ) contains lymph nodes,
and several fibrous septa,
and is surrounded by the mesorectal fascia,
that represents the circumferential resection margin (CRM) when total mesorectal excision...
Anatomical characteristics of perirectal space are complex and magnetic resonance is the modality of choice for the evaluation of the entire bowel wall thickness and the perirectal tissues. Radiologists should be able to recognize the key radiological features of conditions of the rectum and perirectal space,
so they can help the clinicians in their diagnosis and management.
José Miguel Escudero-Fernández Department of abdominal imaging Hospital Universitari Materno-Infantil Vall d’Hebron,
Institut català de la Salut. Passeig de la Vall d’Hebron 119-129 08035 Barcelona Spain Email: firstname.lastname@example.org
Kalady MF et al.
Benign and malignant tumors of the rectum and perirectal region.
Abdom Imaging (2014) 39(4): 824-52 Okuno T,
Koyama K et al.
Value of FDG-PET/CT Volumetry After Chemoradiotherapy in Rectal Cancer.
Dis Colon Rectum.
2018 Mar; 61(3): 320-327 Park HJ,
Primary Anorectal Melanoma: MRI Findings and Clinicopathologic Correlations.
AJR 2018;211: W98-W108 Guniganti P,
Rosen A et al.
Imaging of acute anorectal conditions with CT...