On-line Table: Summary of imaging findings and impact on management in 23 patients Change in Patient Age Clinical History and Prior MRI (Yes/No)? Diagnostic Change in No. (yr) Sex Duration of Symptoms Findings Preimaging Clinical Differential Pertinent Findings? Pertinent MRN Findings Thinking Management 1 28 F 1 yr Urinary symptoms, lower 1) Tethered cord None 1) No, CES Yes No, continue PFPT extremity numbness, 2) PFD 2) Mild LϾR trochanteric PFD 3) Coccydynia bursitis 2 73 M 2.5 yr Defecatory and urinary 1) Cauda equina nerve root injury Yes, and sacral Tarlov cysts 1) S1 and S2 ganglionopathies Yes Yes, referral to pain symptoms after Tarlov 2) Recurrent Tarlov cysts with residual Tarlov cysts management cyst operation, PFD 3) PFD 332Mϳ3 yr Urinary retention with left 1) Demyelinating disease None 1) Large sacral lipomyelocele Yes Yes, referred to sacral neurologic 2) Cauda equina syndrome with tethered cord neurosurgery deficits 2) Sacral dysraphism 480Fϳ1 yr Sensory and defecatory 1) S2–3 neuropathy/radiculopathy Yes, anterolisthesis L3–L4 and 1) Mild L femoral neuropathy Yes Yes, sent to pelvic PT symptoms, Tarlov 2) Left lower lumbar radiculopathy impingement on left 2) Mild L sciatic neuropathy for her sacral/ cysts S2–3, left leg 3) PFD L3 nerve root 3) Left L5–S1 radiculopathy pelvic floor pain radiculopathy and 4) Tarlov cysts present but PFD without cauda equina compromise 5 61 F 2 yr Gluteal/ischial/pelvic pain, 1) Lumbosacral radiculopathy No (MRI after MRN failed to 1) Arachnoiditis at L4–L5 level Yes Yes, chronic CES and constipation, prior L 2) Concern for lumbar stenosis reveal arachnoiditis) 2) Enhancing soft-tissue neurosurgical spine operation or CES thickening, right epidural decompression space at L4–L5 level and resection of markedly compressing epidural lesion thecal sac to left, likely granulation tissue and scarring 659Fϳ1.5 yr Vaginal pain/numbness 1) Bilateral sacral polyradiculopathies Yes, outside MRI not in 1) Right piriformis syndrome Yes Yes, medication after Tarlov cyst 2) PFD imaging system with mild right sciatic management and operation, right gluteal 3) Piriformis syndrome neuropathy PFPT for PFD and pain/spasm 2) No, Tarlov cyst remnants neuropathic pain and piriformis syndrome 7 39 F 25 yr, worsening for Pregnant with bilateral 1) Bilateral L2–3 radiculopathy Yes, a remote postop MRI not 1) Small disc protrusion at No None 4mo radiculopathies, history 2) CES available in imaging system L5–S1 of unstable 3) Meralgia paresthetica 2) Right meralgia

JRA Neuroradiol J Am AJNR retrolisthesis L2–3 4) SI pain and dysfunction paresthetica 8 44 M 8 mo Pelvic pain, urinary 1) CES No 1) Extensive upper abdominal Yes Yes, final diagnosis symptoms, history of 2) Infectious (discitis or epidural lymphadenopathy was Hodgkin HIV with decreased abscess) given HIV history 2) Mild left ilioinguinal lymphoma; nerve sphincter tone and 3) PFD and left pudendal abnormalities were sacral nerve root neuropathies never treated deficits and PFD given malignant diagnosis 9 53 M 7 mo Defecatory and urinary 1) Incomplete CES No 1) Moderate arachnoiditis Yes Yes, CT-guided symptoms with pelvic 2) Pelvic floor dysfunction 2) Moderate right genitofemoral

● pain and numbness genitofemoral nerve block, :

●● after spinal operation, neuropathy at the prior referral to PFD hernia site repair due to operation for GF perineural fibrosis neurectomy/ re-implantation, 07www.ajnr.org 2017 spinal cord stimulator trial 10 61 F Chronic, but worsened Buttock/perineal 1) Incomplete CES Yes, L5–S1 moderate central 1) Moderate arachnoiditis Yes Yes, pelvic PT to work 2yrago numbness, pelvic pain, 2) PFD and bilateral 2) Bilateral pudendal on pudendal constipation after neuroforaminal stenosis neuropathy with bilateral neuropathy and spinal operation, sacral with nerve root perineural scarring ischiofemoral nerve root deficits and impingements 3) Bilateral ischiofemoral impingement, PFD impingements referral to neurosurgery (continued) E1 E2 Petrasic On-line Table: Continued Change in Patient Age Clinical History and Prior MRI (Yes/No)? Diagnostic Change in

● No. (yr) Sex Duration of Symptoms Findings Preimaging Clinical Differential Pertinent Findings? Pertinent MRN Findings Thinking Management

07www.ajnr.org 2017 11 43 F Severe worsening ϫ1 yr Frequent urinary 1) PFD Yes, heavily 1) Intradural mass likely No Yes, neurosurgery symptoms, history of 2) Cauda equina compromise calcified intrathecal lesions at representing benign referral known L3–4 calcified L3–4 level partially cystic lesions of unclear ependymoma, displacing etiology, PFD CE nerve roots but with no abnormal signal changes in nerve roots 12 72 F 15 mo Vaginal pain, urinary 1) Incomplete CES Yes, outside MRI 1 yr prior, not 1) Moderate arachnoiditis at Yes Yes, referred to retention, right more 2) PFD in imaging system L4–L5, at the site of prior neurosurgery, than left radiculopathy operation ganglion impar after spinal operation, 2) Mild pudendal neuropathies, block, and offered PFD on exam rightϾleft spinal cord stimulator 13 58 M 2 yr Urinary symptoms, 1) CES None since prior spine 1) Moderate arachnoiditis, Yes Yes, referral to constipation, leg operation worse at L4–L5 level neurology and weakness after 2) Downstream lumbosacral neurosurgery, spinal operation plexopathies and bilateral offered spinal cord sciatic and femoral stimulator; referral neuropathies, worse to neurourology, on right learned to catheterize 14 29 F 6–12 mo RLQ pain, constipation, 1) MS-related symptoms No, multiple cervical and 1) Mild degenerative disease No No, continued pelvic history of MS, sacral 2) PFD thoracic MRIs to follow of the lower lumbar spine PT and did well nerve root deficits on 3) MS plaque in the conus patient’s known MS right and PFD 15 56 F 6 mo Defecatory and urinary 1) Incomplete CES Yes, no pertinent findings 1) Mild-to-moderate Yes Yes, referral to symptoms, LLQ pain, 2) Radiation arachnoiditis at the neurosurgery, less left buttock/vaginal cystitis/proctitis surgical level (L3–4) emphasis on numbness after spinal 2) Mild left sciatic radiation effects operation and radiation neuropathy causing her for colorectal cancer, symptoms LϾR sacral nerve root (stopped urethral deficits dilations and proctitis treatments) 16 44 F Chronic, worsened Pelvic pain, known small 1) PFD Yes, several small perineural 1) Multiple lumbosacral Yes Yes, referral to 1–2 yr ago sacral perineural cysts, 2) Sacral radiculopathy cysts in sacral foramina neuropathies (left L5, neurosurgical history of multiple 3) Pudendal neuropathy bilaterally bilateral S1, left S2, specialist regarding cancers and pelvic 4) Radiation plexopathy and right S3) Tarlov cysts; radiation, PFD 2) Multiple Tarlov cysts treatment focused 3) Right pudendal on LMN neuropathy dysfunction 17 56 M 5 yr Urinary symptoms that 1) Pelvic floor dysfunction No 1) Findings compatible No No, pain improved started in childhood, 2) Ilioinguinal or genitofemoral with R ilioinguinal and with pelvic PT right groin/testicular neuropathy genitofemoral alone, no pain after hernia repair, 3) SBO/tethered cord or other neuropathies explanation for PFD cauda equina compromise urinary retention found 18 57 F 6 yr Defecatory and urinary 1) PFD No 1) Left S1 and S3 neuropathies Yes Lost to follow-up symptoms requiring 2) CES 2) Bilateral pudendal catheterizations, severe neuropathies PFD and sacral nerve root deficits (continued) On-line Table: Continued Change in Patient Age Clinical History and Prior MRI (Yes/No)? Diagnostic Change in No. (yr) Sex Duration of Symptoms Findings Preimaging Clinical Differential Pertinent Findings? Pertinent MRN Findings Thinking Management 19 57 F 12 yr, worsened Rectal pain after spinal 1) Incomplete CES No 1) Moderate canal stenosis No Yes, stopped pelvic ϳ3moago operation, bilateral 2) Left piriformis syndrome and right neuroforaminal PT radiculopathies and left 3) Left SIJ pain/dysfunction narrowing at L3–L4 piriformis tenderness 2) Findings of tethered cord on exam 3) Left piriformis muscle atrophy 20 50 F 4 yr Urinary and fecal 1) PFD Yes, L5–S1, 3- to 4-mm 1) Mild left sciatic Yes Yes, CT-guided incontinence, low back 2) Myofascial back pain posterior central disc neuropathy diagnostic sciatic and left leg pain after 3) CES or sacral radiculopathy herniation mildly indents nerve block MVC, PFD and reduced after MVC the thecal sac recommended anal sphincter tone 21 33 F 8 yr Urinary retention after pelvic 1) PFD No 1) Mild right S1 traction injury Yes lost to follow-up trauma, PFD 2) CES and right S2 neuroma in continuity 2) Downstream pudendal and sciatic neuropathies 22 79 F 10 yr Left gluteal/rectal pain 1) CES Yes, no pertinent findings 1) CES with arachnoiditis and Yes Yes, referred to after spinal operation, 2) Lumbar radiculopathy neuropathies of left- interventional constipation, urinary sided L4, S1, and S2 nerves spine for injections incontinence, and left sacral nerve root JRA Neuroradiol J Am AJNR deficits 23 53 M 12 yr, worsened in Rectal pain, history of 1) Lumbar arachnoiditis Yes, clumping of intrathecal 1) Moderate arachnoiditis Yes Yes, CT-guided recent mo paraplegia (complete T5 2) Vertebral discitis/osteomyelitis nerve roots at L5–S1 level, 2) Bilateral pudendal pudendal nerve spinal cord injury), no likely arachnoiditis and right inferior blocks ϫ3 movement or sensation hemorrhoidal below the level of neuropathies injury, known lumbar arachnoiditis and possible discitis/ osteomyelitis of the

● lumbar spine : ●● Note:—PFPT indicates pelvic floor physiotherapy; PFD, pelvic floor dysfunction; PT, physical therapy; RLQ ϭ right lower quadrant; SIJ, sacroiliac joint; SBO, small bowel obstruction; MVC, motor vehicle crash; postop, postoperative; SI, sacroiliac; CE, cauda equina; LLQ, left lower quadrant; R, right; L, left; LMN, lower motor neuron; GF, genitofemoral. 07www.ajnr.org 2017 E3