Barium Defecating Proctography and Dynamic Magnetic Resonance Proctography: Their Role and Patient's Perception

Abstract

Objectives: The objectives of the study were to compare the imaging findings and patient's perception of barium defecating proctography and dynamic magnetic resonance (MR) proctography in patients with pelvic floor disorders.

Material and methods: This is a prospective study conducted on patients with pelvic floor disorders who consented to undergo both barium proctography and dynamic MR proctography. Imaging findings of both the procedures were compared. Inter-observer agreement (IOA) for key imaging features was assessed. Patient's perception of these procedures was assessed using a short questionnaire and a visual analog scale.

Results: Forty patients (M: F =19:21) with a mean age of 43.65 years and range of 21-75 years were included for final analysis. Mean patient experience score was significantly better for MR imaging (MRI) (p < 0.001). However, patients perceived significantly higher difficulty in rectal evacuation during MRI studies (p = 0.003). While significantly higher number of rectoceles (p = 0.014) were diagnosed on MRI, a greater number of pelvic floor descent (p = 0.02) and intra-rectal intussusception (p = 0.011) were diagnosed on barium proctography. The IOA for barium proctography was substantial for identifying rectoceles, rectal prolapse and for determining M line, p < 0.001. There was excellent IOA for MRI interpretation of cystoceles, peritoneoceles, and uterine prolapse and substantial to excellent IOA for determining anal canal length and anorectal angle, p < 0.001. The mean study time for the barium and MRI study was 12 minutes and 15 minutes, respectively.

Conclusion: Barium proctography was more sensitive than MRI for detecting pelvic floor descent and intrarectal intussusception. Although patients perceived better rectal emptying with barium proctography, the overall patient experience was better for dynamic MRI proctography.

Keywords: Accuracy; Barium proctography; Diagnosis; Imaging; Magnetic resonance proctography; Pelvic floor.

Figure 1:

Flow diagram of patients included in the study.

Figure 2:

T2W sagittal section of the pelvic magnetic resonance imaging depicting the normal pubococcygeal line (PCL) (yellow), H line (red) and the M line (blue). PCL is between the inferior margin of symphysis pubis and the tip of the coccyx. H-line is the distance between the inferior border of the pubic symphysis and the posterior wall of the rectum at the level of the anorectal junction and indicates the width of the levator hiatus. M-line is the vertical line drawn perpendicularly from the PCL to the posterior end of the H line. Mline indicates the degree of decent of the levator hiatus or the degree of pelvic floor laxity.

Figure 3:

Comparison of patient’s perception of barium and magnetic resonance imaging proctography.

Figure 4:

Spot radiographs of Barium proctography study of a 36-year-old lady with constipation at rest (a), pelvic lift (b), straining (c) and defecating (d). There is a small anterior rectocele (asterisk) and moderate pelvic floor descent depicted by descent of the anorectal junction below the ischial tuberosity during strain and defecation (black arrow). Magnetic resonance imaging proctography did not demonstrate these findings.

Figure 5:

Spot radiographs of the Barium proctography study at (a) rest (b) pelvic lift (c) straining and (d) defecation of a 48-year-old lady with difficulty in defecation and micturition showed infolding of the rectal wall with a filling defect suggestive of rectorectal intussusception (arrows) and pelvic floor descent.

Figure 6:

Magnetic resonance imaging proctography of the same patient as in Figure 5 showed significant pelvic floor descent with additional findings of grade 2 cystocele (red line) however could not demonstrate the intussusception. The black line depicts the pubococcygeal line.

Figure 7:

Spot radiographs of the Barium proctography study at (a) rest (b) pelvic lift (c) straining and (d) defecation of a 40 year old female with suspected obstructed defecation syndrome and history of digital evacuation of faeces shows recto-anal intussusception (arrow in d), small anterior rectocele with barium trapping during defecation (asterisk) and moderate pelvic floor descent.

Figure 8:

Magnetic resonance imaging proctography of the same patient as in Figure 7 showed an anterior rectocele (asterisk), moderate pelvic floor descent and additionally depicted a grade 2 cystocele (red line). The black line depicts the pubococcygeal line.

Multimedia 1:

Dynamic magnetic resonance imaging proctography of a 40 year old female with difficulty in defecation and micturition, in the pelvic lift phase (a), straining phase (b and c) and in the defecation phase (d) showing pelvic floor descent, widening of the pelvic cavity, small cystocele and urethral hypermobility. Video is accessible from the portal.

Multimedia 2:

Dynamic magnetic resonance imaging proctography (of same patient as in Figure 5 in the straining (a) and defecation phase (b) showing severe pelvic floor descent, urethral hypermobility and moderate cystocele. Video is accessible from the portal.