case_images: PMC11171721_01
case_images: Pelvic MRI findings revealed piriformis pyomyositis on admission. (A) Axial DWI. The arrow indicates the nodal high-signal area within the piriformis muscle. (B) ADC. The arrow indicates a low-signal nodular area within the piriformis muscle is seen, a reasonable finding in the acute myositis. (C) Axial T2WI. The circle indicates a high-signal region with irregular edges in part of the left piriformis muscle, thought to be a finding of acute pyomyositis. DWI, diffusion-weighted imaging; ADC, apparent diffusion coefficient; T2WI, T2-weighted image.
case_images: fmed-11-1381555-g001.jpg
case_images: PMC11171721_01_fmed-11-1381555-g001.jpg
case_images: fig1
case_images: Imaging studies showed no specific findings on contrast-enhanced computed tomography (CT); however, MRI showed a high signal on diffusion-weighted imaging (DWI) localized within the left piriformis muscle (Figure 1A), with a low-signal apparent diffusion coefficient (ADC) map in the same area (Figure 1B). T2 weighted image (T2WI) showed increased signal and irregularity in part of the left piriformis muscle (Figure 1C), thought to be a finding of acute pyomyositis.
case_images: Follow-up pelvic MRI findings suggested piriformis pyomyositis and pyogenic sacroiliitis on the 9th hospital day. (A) Axial DWI. The arrow indicates an intra-articular nodular high-signal area in the piriformis muscle on the previous MRI, which tended to shrink. (B) Axial, fat-suppressed T2WI (C) Coronal fat-suppressed T2WI. The circle shows an elevated signal at the left sacroiliac joint site, suggesting pyogenic sacroiliitis. Additionally, fluid collection was noted on the ventral side. DWI, diffusion-weighted imaging; T2WI, T2-weighted image.
case_images: fmed-11-1381555-g002.jpg
case_images: PMC11171721_01_fmed-11-1381555-g002.jpg
case_images: fig2
case_images: The high DWI high signal in the left piriformis muscle tended to shrink slightly (Figure 2A). In addition, the iliac and sacral signals across the left sacroiliac joint increased on fat suppressed T2WI (Figures 2B,C), which suggested sacroiliac arthritis, and fluid collection was noted on the ventral side, suggestive of bursitis.
case_images: Longitudinal ulcer of the sigmoid colon. A 5 cm longitudinal ulcer lesion was found in the sigmoid colon on the anorectal side. The lesion was confined to the sigmoid colon.
case_images: fmed-11-1381555-g003.jpg
case_images: PMC11171721_01_fmed-11-1381555-g003.jpg
case_images: fig3
case_images: Upper GI endoscopy revealed no abnormal findings; in contrast, lower GI endoscopy revealed a longitudinal ulcer covered with creamy white moss in the sigmoid colon (Figure 3), which were considered findings of the healing process of Salmonella enteritis.