Perianal Sepsis in Hematologic Malignancy: MR Imaging Appearances and Distinction from Cryptoglandular Infection in Immunocompetent Patients

Abstract

MRCP, FRCR Purpose:To use magnetic resonance (MR) imaging to document the appearance of perianal infection in patients with a hematologic malignancy (HM) compared with that in immunocompetent control patients. Materials and Methods:After an ethical waiver was obtained, 38 patients with an HM were matched by age and sex to 38 control patients with no history of immunocompromise or Crohn disease. Both groups had undergone MR imaging for perianal symptoms and/or systemic sepsis. Two radiologists who were blinded to the diagnosis independently reviewed the MR images and recorded the size and distribution of abscesses and/or fistula tracts, the extent of perianal edema, and the likely diagnosis. Groups were compared by using the Mann-Whitney-Wilcoxon, x 2 , or Fisher exact test. Receiver operating characteristic (ROC) curves were constructed to estimate the ability of MR imaging to help distinguish patients with an HM from control patients. Results:Patients with an HM had significantly greater perianal edema than did control patients (mean arc angle of anal canal involved, 220° vs 60°; P , .001). However, they had significantly lower rates of fistula (15 [ Conclusion:Perianal infection in patients with an HM is more likely to cause diffuse perianal edema and is less likely to cause fistulas than in immunocompetent patients. MR imaging can help distinguish patients with an HM from those without immunocompromise.q RSNA, 2015

Perianal sepsis in neutropaenic patients with haematological malignancies: the role of magnetic resonance imaging and surgery

“…In a recent study of patients with haematological malignancy who were referred for pelvic MRI, 44% had findings consistent with perianal abscess . Similarly, Plumb et al . found that MRI frequently detects perianal abscess in patients with haematological malignancy, which is irrespective of the severity of neutropenia.…”

“…found that MRI frequently detects perianal abscess in patients with haematological malignancy, which is irrespective of the severity of neutropenia. However, haematological malignancy often augments MRI findings, extensive local inflammatory change is more common and fistulous disease is a less common finding compared to immunocompetent patients …”

“…The American Society of Colon and Rectal Surgeons advocates the selected use of computed tomography or magnetic resonance imaging (MRI) to better assess the anatomy and underlying collection . MRI successfully identifies the pathological anatomy of all forms of anorectal disease with an accuracy of up to 90% . Recent evidence suggests that there is a role for MRI in evaluating the perianal area in patients with haematological malignancy, particularly in cases of suspected complex perianal abscess or fistulous disease .…”

“…MRI successfully identifies the pathological anatomy of all forms of anorectal disease with an accuracy of up to 90% . Recent evidence suggests that there is a role for MRI in evaluating the perianal area in patients with haematological malignancy, particularly in cases of suspected complex perianal abscess or fistulous disease . However, further studies are required to validate MRI findings in the setting of neutropenia and correlate this to surgical outcomes.…”

Diagnostic performance of intravoxel incoherent motion diffusion-weighted imaging and dynamic contrast-enhanced MRI for assessment of anal fistula activity

“…T2-weighted sequences provide high contrast for anatomical assessment of the different layers of the anal sphincter, whereas gadolinium-enhanced T1-weighted sequences reveal areas with increased vascularity such as the wall of active fistulas and abscesses [ 4 ]. When interpreted in combination, T2-weighted [ 18 ] and gadolinium-enhanced T1-weighted sequences allow differentiation between fluid, inflammatory, and fibrotic tissues [ 4 , 19 – 21 ]. Recent studies have suggested that diffusion-weighted imaging (DWI) sequences, which reflects motion of water molecules and their interactions with macromolecules and cell membranes, may be helpful for the diagnosis of anal fistulas [ 22 , 23 ] and abscesses complicating anal fistulas by revealing restricted diffusion of water molecules due to viscous pus [ 24 – 26 ].…”