Table 2. First Generated List of Expert Responses. Likert-Type Scale. Category or Criterion. Rationale or Comments (1) (2) (3) (4)

Table 2. First Generated List of Expert Responses. Likert-Type Scale Category or Criterion Anatomical Structures and Features Skeletal Structures and Features (1) (2) (3) (4) Rationale or Comments 1. Bones of the pelvis: ilium 1 2 3 4 2. Bones of the pelvis: pubic bone 1 2 3 4 3. Bones of the pelvis: ischial bone 1 2 3 4 4. Bones of the pelvis: sacrum 1 2 3 4 5. Bones of the pelvis: coccyx 1 2 3 4 6. Pubic symphysis 1 2 3 4 7. Sacroiliac joint 1 2 3 4 8. Sacrotuberous ligament 1 2 3 4 9. Sacrospinous ligament 1 2 3 4 10. Greater sciatic foramen 1 2 3 4 11. Lesser sciatic foramen 1 2 3 4 12. Obturator foramen 1 2 3 4 13. Ischial spine 1 2 3 4 14. Ischial tuberosity 1 2 3 4 15. Iliac crest 1 2 3 4 16. Anterior superior iliac spine (ASIS) 1 2 3 4 17. Anterior inferior iliac spine (AIIS) 1 2 3 4 18. Ischiopubic ramus 1 2 3 4 19. Superior pubic ramus 1 2 3 4

20. Inferior pubic ramus 1 2 3 4 21. Anterior longitudinal ligament 1 2 3 4 22. Acetabulum 1 2 3 4 23. Femoral heads 1 2 3 4 24. Pelvic inlet 1 2 3 4 25. Pelvic outlet 1 2 3 4 26. Pubic tubercle 1 2 3 4 27. Pubic crest 1 2 3 4 28. Pectineal line 1 2 3 4 29. Iliac fossa 1 2 3 4 30. Anterior sacral foramina 1 2 3 4 31. Posterior sacral foramina 1 2 3 4 32. Sacral hiatus 1 2 3 4 33. Arcus tendineus fascia pelvis 1 2 3 4 34. [any additional structures?] 1 2 3 4 35. [any additional structures?] 1 2 3 4 Muscular Structures and Features 36. Pelvic floor and its component muscles 1 2 3 4 37. Pelvic diaphragm and its component muscles 1 2 3 4 38. Tendinous arch of levator ani muscle 1 2 3 4 39. Obturator internus muscle 1 2 3 4 40. Obturator externus muscle 1 2 3 4 41. Piriformis muscle 1 2 3 4 42. External urethral sphincter 1 2 3 4

43. Perineal flexure 1 2 3 4 44. Perineal membrane 1 2 3 4 45. Superficial perineal pouch 1 2 3 4 46. Perineal body 1 2 3 4 47. Peritoneum 1 2 3 4 48. Cremasteric fascia and muscle 1 2 3 4 49. Abdominal wall muscles 1 2 3 4 50. [any additional structures?] 1 2 3 4 51. [any additional structures?] 1 2 3 4 Organs and Other Soft Tissue Structures 52. Fascia (fibroelastic muscular tissue) 1 2 3 4 53. Sigmoid colon 1 2 3 4 54. Rectum 1 2 3 4 55. Anal canal 1 2 3 4 56. Anal columns 1 2 3 4 57. Anal valves 1 2 3 4 58. Pectinate line 1 2 3 4 59. Ureters and their parts 1 2 3 4 60. Urinary bladder 1 2 3 4 61. Urinary bladder neck 1 2 3 4 62. Urinary bladder trigone 1 2 3 4 63. Pubovesical ligament 1 2 3 4 Male-Specific Organs and Structures 64. Ductus deferens 1 2 3 4

65. Prostatic urethra 1 2 3 4 66. Membranous urethra 1 2 3 4 67. Penile urethra 1 2 3 4 68. Puboprostatic ligament 1 2 3 4 69. Prostate gland 1 2 3 4 70. Seminal vesicles 1 2 3 4 71. Ejaculatory ducts 1 2 3 4 72. Testes 1 2 3 4 73. Epididymis 1 2 3 4 74. Scrotum 1 2 3 4 75. Penis 1 2 3 4 Female-Specific Organs and Structures 76. Ovaries 1 2 3 4 77. Suspensory ligament of the ovary 1 2 3 4 78. Ligament of the ovary 1 2 3 4 79. Fallopian tubes (Oviducts) 1 2 3 4 80. Broad ligament and its parts 1 2 3 4 81. Cardinal ligaments 1 2 3 4 82. Uterus and its parts 1 2 3 4 83. Round ligament of the uterus 1 2 3 4 84. Uterosacral ligament 1 2 3 4 85. Internal os 1 2 3 4 86. External os 1 2 3 4 87. Vagina 1 2 3 4

88. Vaginal fornices 1 2 3 4 89. Urethra 1 2 3 4 90. [any additional structures?] 1 2 3 4 91. [any additional structures?] 1 2 3 4 Vasculature 92. Abdominal aorta bifurcation 1 2 3 4 93. Common iliac arteries 1 2 3 4 94. Internal iliac arteries and their branches 1 2 3 4 95. External iliac arteries 1 2 3 4 96. Ovarian arteries 1 2 3 4 97. Testicular arteries 1 2 3 4 98. Ovarian veins 1 2 3 4 99. Testicular veins 1 2 3 4 100. Dorsal venous complex 1 2 3 4 101. Deep dorsal vein of the clitoris 1 2 3 4 102. Deep dorsal vein of the penis 1 2 3 4 103. Prostatic plexus of veins 1 2 3 4 104. Pelvic plexus 1 2 3 4 105. [any additional structures?] 1 2 3 4 106. [any additional structures?] 1 2 3 4 Nerves 107. Obturator nerve 1 2 3 4 108. Sciatic nerve 1 2 3 4 109. Pudendal nerve 1 2 3 4

110. Ilioinguinal nerve 1 2 3 4 111. Hypogastric nerve 1 2 3 4 112. Genitofemoral nerve 1 2 3 4 113. Femoral nerve 1 2 3 4 114. Lumbosacral plexus 1 2 3 4 115. [any additional structures?] 1 2 3 4 116. [any additional structures?] 1 2 3 4 Spaces 117. Retropubic space 1 2 3 4 118. Vesicovaginal space 1 2 3 4 119. Rectovaginal space 1 2 3 4 120. Left and right perirectal spaces 1 2 3 4 121. Left and right perivesical spaces 1 2 3 4 122. [any additional spaces?] 1 2 3 4 123. [any additional spaces?] 1 2 3 4 3D Relationships Between Structures 124. Tissue plans and their relationships 1 2 3 4 125. Relationships between muscles 1 2 3 4 126. Relationships between contents of the superficial and deep pouches 127. Relationships between anatomy of inguinal hernias (clinical correlation) 128. Relationships of ureters to gynecological structures (e.g., fallopian tubes and uterus) 129. Relationships of bladder to gynecological structures 130. Relationships between the urethra and urogenital diaphragm 131. Relationships between the bladder and rectum 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4

132. Relationships of bowel to gynecological structures 133. Relationships of ureter, uterine tubes, and uterine arteries and veins to urinary bladder 134. Relationship between the prostate and rectum 135. Relationship between the pelvic plexus and prostate 136. Relationships of the urethra to the prostate gland 137. Relationships between testicular arteries and veins and ureters 138. Relationships of vascular structures to other structures 139. Relationships between pelvic floor and pelvis musculature 140. Relationships of structures within musculature and bony skeleton of the pelvis 141. Relationships of pelvic bony landmarks to other structures 142. Relationships between pubic bones, ischial bones, ilia, sacrum, coccyx, ischial tuberosity, pubic tubercle, and pubic symphysis to internal reproductive organs 143. [any additional 3D relationships between structures?] 144. [any additional 3D relationships between structures?] Key Views, Orientations, and/or Positions 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 145. Anterior view down into pelvis 1 2 3 4 146. Superior view down into pelvis 1 2 3 4 147. Lateral view down into pelvis 1 2 3 4 148. Lateral view down into pelvis with nearer 1 2 3 4 pelvic bone removed 149. Sagittal view 1 2 3 4 150. Midline sagittal (median) view 1 2 3 4 151. Anterior-posterior view 1 2 3 4 152. Axial (transverse) view 1 2 3 4

153. Lateral-medial view 1 2 3 4 154. Lateral-anterior view 1 2 3 4 155. Lateral-posterior view 1 2 3 4 156. Coronal view 1 2 3 4 157. Oblique view 1 2 3 4 158. Abdominal view 1 2 3 4 159. Lithotomy/vaginal perspective/position 1 2 3 4 160. Prone position 1 2 3 4 161. Supine position 1 2 3 4 162. View internally into the pelvic ring 1 2 3 4 163. View externally (pelvic inlet and outlet 1 2 3 4 views) 164. View of pelvic floor from above and 1 2 3 4 below 165. Anterolateral view of viscera, particularly 1 2 3 4 the uterus and its ligaments 166. Rotations in all positions 1 2 3 4 167. CT/MRI oriented sections (coronal view) 1 2 3 4 168. CT/MRI oriented sections (median view) 1 2 3 4 169. CT/MRI oriented sections (axial view) 1 2 3 4 170. Radiographic imaging slices at all levels 1 2 3 4 171. [any additional key views, orientations, 1 2 3 4 and/or positions?] 172. [any additional key views, orientations, 1 2 3 4 and/or positions?] For each criterion item, the recruited experts were asked to provide a rating (1 = not important, 2 = somewhat important, 3 = quite important, and 4 = highly important), and they were given the option of providing a rationale or comment for each rating. This table was divided into three overarching sections, including Anatomical Structures and Features, 3D Relationships Between Structures, and Key Views, Orientations, and/or Positions. The items within the Anatomical Structures and Features section were grouped into six categories, including Skeletal Structures and Features, Muscular

Structures and Features, Organs and Other Soft Tissue Structures, Vascular, Nerves, and Spaces. The items within the Organs and Other Soft Tissue Structures category included those structures found within both male and female humans as well as Male- Specific and Female-Specific Organs and Structures. Two additional rows within each overarching section and each category were provided in case experts considered other items that were not included in the first-round survey and in case they wanted to write or type them for inclusion in the second generated list. Those items which are typed in italics and highlighted in the peach color are structures that have a tissue density that is too low to be viewed on computerized tomography (CT) images. These items were denoted to make the experts aware that some items, though important, may not be visualized in a pelvis model that will be generated from CT scans.

Table 3. Delphi Method Round 3 Expert Ratings and Content Validity Indices. Category or Criterion Expert 1 Expert 2 Anatomical Structures and Features Expert 3 Expert 4 Expert 5 Expert 6 I-CVI Skeletal Structures and Features Bones of the pelvis: ilium 4 4 4 4 4 4 1.0 Bones of the pelvis: pubic bone Bones of the pelvis: ischial bone Bones of the pelvis: sacrum Bones of the pelvis: coccyx 4 4 4 4 4 4 1.0 4 4 4 4 4 4 1.0 4 4 4 4 4 4 1.0 4 3 4 4 4 2 0.83 Pubic symphysis 4 4 4 4 4 4 1.0 Sacroiliac joint 4 3 4 4 4 4 1.0 Sacrotuberous ligament 1 4 4 4 4 4 0.83 Sacrospinous ligament 1 4 4 4 4 4 0.83 Greater sciatic foramen 4 4 4 4 4 4 1.0 Lesser sciatic foramen 4 4 4 4 4 4 1.0 Obturator foramen 4 4 4 4 4 4 1.0 Ischial spine 4 4 4 4 4 4 1.0 Ischial tuberosity 4 4 4 4 3 4 1.0 Iliac crest 4 4 4 4 4 4 1.0

Anterior superior iliac spine (ASIS) 4 4 4 4 4 4 1.0 Anterior inferior iliac spine (AIIS) 4 4 4 4 4 3 1.0 Ischiopubic ramus 4 4 4 4 4 4 1.0 Superior pubic ramus 4 4 4 3 4 1 0.83 Inferior pubic ramus 4 4 4 3 4 1 0.83 Anterior longitudinal ligament 4 4 4 4 2 1 0.67 Acetabulum 4 4 4 4 4 4 1.0 Femoral heads 4 2 4 4 4 4 0.83 Pelvic inlet 4 4 3 4 4 4 1.0 Pelvic outlet 4 4 3 4 4 4 1.0 Pubic tubercle 4 4 4 4 4 4 1.0 Pubic crest 4 2 4 4 4 4 0.83 Pectineal line 4 2 4 4 4 3 0.83 Iliac fossa 4 2 4 3 3 4 0.83 Anterior sacral foramina 4 4 3 3 3 2 0.83 Posterior sacral foramina 4 4 3 3 3 2 0.83 Sacral hiatus 4 4 3 4 3 2 0.83 Arcus tendineus fascia pelvis 2 4 4 3 3 2 0.67 Muscular Structures and Features Pelvic floor and its 2 4 4 4 4 3 0.83

component muscles Pelvic diaphragm and its component muscles Tendinous arch of levator ani muscle 2 4 4 4 4 3 0.83 2 4 4 4 3 3 0.83 Obturator internus muscle 2 2 4 4 3 2 0.50 Obturator externus muscle 2 2 4 4 3 2 0.50 Piriformis muscle 2 2 3 4 4 4 0.67 External urethral sphincter 4 4 3 4 4 1 0.83 Perineal flexure 0 2 1 3 2 3 0.33 Perineal membrane 3 2 1 4 2 1 0.33 Superficial perineal pouch 0 2 1 4 4 3 0.50 Perineal body 4 4 4 3 4 2 0.83 Peritoneum 1 4 2 4 2 1 0.33 Cremasteric fascia and muscle 0 4 0 3 4 1 0.50 Abdominal wall muscles 2 4 4 4 3 4 0.83 Organs and Other Soft Tissue Structures Fascia (fibroelastic muscular tissue) 4 4 4 3 2 1 0.67

Sigmoid colon 3 4 4 4 4 4 1.0 Rectum 4 4 4 4 4 4 1.0 Anal canal 4 4 3 4 4 2 0.83 Anal columns 0 2 1 3 2 1 0.17 Anal valves 0 2 1 3 2 1 0.17 Pectinate line 0 2 1 3 2 1 0.17 Ureters and their parts 4 4 4 4 4 3 1.0 Urinary bladder 4 4 4 4 4 4 1.0 Urinary bladder neck 2 4 3 4 4 4 0.83 Urinary bladder trigone 2 4 3 4 3 2 0.67 Pubovesical ligament 2 3 1 3 2 1 0.33 Male-Specific Organs and Structures Ductus deferens 3 4 3 4 4 3 1.0 Prostatic urethra 4 4 3 4 4 3 1.0 Membranous urethra 3 4 3 4 4 3 1.0 Penile urethra 3 4 3 3 4 2 0.83 Puboprostatic ligament 0 4 0 3 2 1 0.33 Prostate gland 4 4 4 4 4 3 1.0 Seminal vesicles 2 4 0 4 4 3 0.67 Ejaculatory ducts 2 4 0 4 4 2 0.50 Testes 4 4 4 4 4 1 0.83 Epididymis 3 4 4 4 4 1 0.83 Scrotum 4 4 4 3 4 1 0.83 Penis 4 4 4 4 4 4 1.0

Female-Specific Organs and Structures Ovaries 4 4 4 4 4 4 1.0 Suspensory ligament of the ovary 2 4 3 4 4 0 0.67 Ligament of the ovary 2 4 1 4 4 0 0.50 Fallopian tubes (Oviducts) 2 4 2 4 4 4 0.67 Broad ligament and its parts 3 4 3 4 4 0 0.83 Cardinal ligaments 4 4 3 4 4 3 1.0 Uterus and its parts 4 4 4 4 4 4 1.0 Round ligament of the uterus 2 4 4 4 4 1 0.67 Uterosacral ligament 4 4 4 3 4 3 1.0 Internal os 4 4 1 3 2 3 0.67 External os 2 4 1 3 4 3 0.67 Vagina 4 4 4 3 4 4 1.0 Vaginal fornices 1 4 1 4 4 3 0.67 Urethra 4 4 4 4 4 4 1.0 Vasculature Abdominal aorta bifurcation 4 4 4 4 4 3 1.0 Common iliac arteries 4 4 4 4 4 3 1.0 Internal iliac arteries and their branches 4 4 4 4 4 3 1.0

External iliac arteries 4 4 4 4 2 3 0.83 Ovarian arteries 2 4 4 4 4 3 0.83 Testicular arteries 2 4 4 4 4 1 0.67 Ovarian veins 0 4 2 4 2 1 0.33 Testicular veins 0 4 0 4 2 1 0.33 Dorsal venous complex 0 4 0 3 2 1 0.33 Deep dorsal vein of the clitoris Deep dorsal vein of the penis 0 4 0 3 2 1 0.33 0 4 0 3 2 1 0.33 Prostatic plexus of veins 0 4 0 3 2 1 0.33 Pelvic plexus 4 4 0 3 2 1 0.50 Nerves Obturator nerve 4 4 3 4 2 2 0.67 Sciatic nerve 4 4 4 4 4 2 0.83 Pudendal nerve 4 4 4 4 4 2 0.83 Ilioinguinal nerve 1 4 4 4 2 1 0.50 Hypogastric nerve 1 4 4 4 2 1 0.50 Genitofemoral nerve 1 4 4 4 3 1 0.67 Femoral nerve 4 4 4 4 2 2 0.67 Lumbosacral plexus 4 4 3 4 4 2 0.83 Spaces Retropubic space 4 4 4 4 2 1 0.67 Vesicovaginal space 4 4 4 4 2 1 0.67

Rectovaginal space 4 4 4 4 2 1 0.67 Left and right perirectal spaces Left and right perivesical spaces 4 4 4 3 2 1 0.67 4 4 4 3 2 1 0.67 3D Relationships Between Structures Tissue plans and their relationships Relationships between muscles 4 0 0 4 4 0 0.50 4 4 3 4 2 0 0.67 Relationships between contents of the superficial and deep pouches 4 4 3 4 4 3 1.0 Relationships between anatomy of inguinal hernias (clinical correlation) 4 4 4 4 4 2 0.83 Relationships of ureters to gynecological structures (e.g., fallopian tubes and uterus) 4 4 4 4 4 3 1.0 Relationships of bladder to gynecological structures 4 4 3 4 4 3 1.0

Relationships between the urethra and urogenital diaphragm Relationships between the bladder and rectum 4 4 3 4 4 3 1.0 4 4 4 3 4 3 1.0 Relationships of bowel to gynecological structures 3 4 4 3 4 3 1.0 Relationships of ureter, uterine tubes, and uterine arteries and veins to urinary bladder Relationship between the prostate and rectum 3 4 3 4 4 3 1.0 3 4 4 3 4 4 1.0 Relationship between the pelvic plexus and prostate 4 4 4 4 4 2 0.83 Relationships of the urethra to the prostate gland 4 4 4 4 4 2 0.83 Relationships between testicular arteries and veins and ureters 2 4 0 3 4 1 0.50 Relationships of vascular structures to other structures 0 4 4 3 4 0 0.67

Relationships between pelvic floor and pelvis musculature 0 4 4 3 4 4 0.83 Relationships of structures within musculature and bony skeleton of the pelvis 2 4 4 3 4 4 0.83 Relationships of pelvic bony landmarks to other structures 4 4 4 3 4 4 1.0 Relationships between pubic bones, ischial bones, ilia, sacrum, coccyx, ischial tuberosity, pubic tubercle, and pubic symphysis to internal reproductive organs Key Views, Orientations, and/or Positions 4 4 4 3 4 4 1.0 Anterior view down into pelvis Superior view down into pelvis 4 4 4 4 4 4 4 1.0 4 3 4 4 4 1.0 Lateral view down into pelvis Lateral view down into pelvis with nearer pelvic 4 4 3 4 4 2 0.83 4 3 4 4 0 0.83

bone removed 4 Sagittal view 4 4 4 4 4 2 0.83 Midline sagittal (median) view 4 4 4 4 4 4 1.0 Anterior-posterior view 4 4 4 4 4 4 1.0 Axial (transverse) view 0 4 4 4 4 0 0.67 Lateral-medial view 1 4 3 4 4 0 0.67 Lateral-anterior view 1 2 3 4 4 0 0.50 Lateral-posterior view 1 2 3 4 4 0 0.50 Coronal view 4 4 4 4 4 0 0.83 Oblique view 3 4 3 3 4 0 0.83 Abdominal view 3 2 3 4 4 0 0.67 Lithotomy/vaginal perspective/position 3 4 4 4 4 4 1.0 Prone position 3 4 3 4 4 0 0.83 Supine position 3 4 3 4 4 0 0.83 View internally into the pelvic ring 3 2 3 4 4 3 0.83 View externally (pelvic inlet and outlet views) 3 2 4 4 4 0 0.67 View of pelvic floor from above and below 3 2 4 4 4 3 0.83 Anterolateral view of viscera, particularly the 4 3 4 4 4 1.0

uterus and its ligaments 3 Rotations in all positions 4 4 4 4 4 3 1.0 CT/MRI oriented sections (coronal view) CT/MRI oriented sections (median view) CT/MRI oriented sections (axial view) Radiographic imaging slices at all levels 4 4 4 4 4 3 1.0 4 4 4 4 4 3 1.0 4 4 4 4 4 3 1.0 4 4 4 4 4 2 0.83 S-CVI/Ave 0.79 Criterion items with an I-CVI less than 0.80 warrant removal from the overall list. Criterion items with an I-CVI 0.80 warrant retention in the overall list. Experts 1 through 3 include clinicians while experts 4 through 6 include basic scientists. Ratings of 0 denote items for which experts did not provide a response. The I-CVI values were rounded to the nearest tenth s or hundredth s place according to the rules for significant figures. I-CVI = item-level content validity index, S-CVI/Ave = average scale-level content validity index

Table 4. Delphi Method Round 4 Expert Ratings and Content Validity Indices. Category or Criterion Expert 1 Exper t 2 Anatomical Structures and Features Expert 3 Expert 4 Expert 5 Expert 6 I-CVI Skeletal Structures and Features Bones of the pelvis: ilium 4 4 4 4 4 4 1.0 Bones of the pelvis: pubic bone 4 4 4 4 4 4 1.0 Bones of the pelvis: ischial bone 4 4 4 4 4 4 1.0 Bones of the pelvis: sacrum 4 4 4 4 4 4 1.0 Bones of the pelvis: coccyx 4 4 4 4 4 3 1.0 Pubic symphysis 4 4 4 4 4 4 1.0 Sacroiliac joint 4 3 4 4 4 4 1.0 Sacrotuberous ligament 1 3 4 4 4 4 0.83 Sacrospinous ligament 1 4 4 4 4 4 0.83 Greater sciatic foramen 4 3 4 4 4 4 1.0 Lesser sciatic foramen 4 3 4 4 4 4 1.0 Obturator foramen 4 3 4 4 1 4 0.83 Ischial spine 4 4 4 4 4 4 1.0 Ischial tuberosity 4 4 4 4 4 4 1.0 Iliac crest 4 4 4 4 4 4 1.0 Anterior superior iliac spine (ASIS) 4 4 4 4 4 4 1.0

Anterior inferior iliac spine (AIIS) 4 3 3 4 4 2 0.83 Ischiopubic ramus 4 3 4 3 4 4 1.0 Superior pubic ramus 4 3 4 3 4 2 0.83 Inferior pubic ramus 4 3 4 3 4 2 0.83 Anterior longitudinal ligament 1 3 4 4 1 2 0.50 Acetabulum 4 3 3 4 1 4 0.83 Femoral heads 4 3 3 4 1 4 0.83 Pelvic inlet 4 4 3 4 4 2 0.83 Pelvic outlet 4 4 3 4 4 3 1.0 Pubic tubercle 4 4 3 4 4 3 1.0 Pubic crest 4 3 3 4 4 2 0.83 Pectineal line 4 3 3 4 4 2 0.83 Iliac fossa 4 3 3 3 0 4 0.83 Anterior sacral foramina 4 4 3 3 3 1 0.83 Posterior sacral foramina 4 4 3 3 3 1 0.83 Sacral hiatus 4 3 3 3 3 2 0.83 Arcus tendineus fascia pelvis 1 4 4 3 4 2 0.67 Muscular Structures and Features Pelvic floor and its component muscles 2 4 4 4 4 4 0.83 Pelvic diaphragm and its component muscles 2 4 4 4 4 4 0.83

Tendinous arch of levator ani muscle 2 3 4 4 4 2 0.67 Obturator internus muscle 2 3 4 4 2 4 0.67 Obturator externus muscle 2 3 4 4 2 1 0.50 Piriformis muscle 2 3 4 4 4 4 0.83 External urethral sphincter 2 4 2 3 4 1 0.50 Perineal flexure 2 3 2 3 2 2 0.33 Perineal membrane 2 3 2 4 2 1 0.33 Superficial perineal pouch 2 3 2 4 2 3 0.50 Perineal body 2 4 3 4 2 1 0.50 Peritoneum 2 4 2 4 2 1 0.33 Cremasteric fascia and muscle 2 4 2 3 2 1 0.33 Abdominal wall muscles: rectus abdominis muscles 1 4 4 4 3 1 0.67 Abdominal wall muscles: external oblique muscles 1 4 4 4 3 1 0.67 Abdominal wall muscles: internal oblique muscles 1 4 4 4 3 1 0.67 Abdominal wall muscles: transversus abdominis muscles 1 4 4 4 3 1 0.67 Organs and Other Soft Tissue Structures

Fascia (fibroelastic muscular tissue) 1 4 3 3 2 1 0.50 Sigmoid colon 4 4 4 4 4 4 1.0 Rectum 4 4 4 4 4 4 1.0 Anal canal 4 4 4 4 4 4 1.0 Anal columns 1 3 2 4 1 1 0.33 Anal valves 1 3 2 4 1 1 0.33 Pectinate line 1 3 3 4 1 1 0.50 Ureters and their parts 4 4 4 4 4 4 1.0 Urinary bladder 4 4 4 4 4 4 1.0 Urinary bladder neck 2 4 4 4 4 4 0.83 Urinary bladder trigone 2 4 3 4 4 2 0.67 Pubovesical ligament 2 4 2 3 2 1 0.33 Male-Specific Organs and Structures Ductus deferens 1 4 4 4 4 3 0.83 Prostatic urethra 4 4 4 4 4 3 1.0 Membranous urethra 3 4 4 4 4 2 0.83 Penile urethra 3 4 4 4 4 2 0.83 Puboprostatic ligament 1 4 4 3 2 1 0.50 Prostate gland 4 4 4 4 4 4 1.0 Seminal vesicles 2 4 4 4 4 4 0.83 Ejaculatory ducts 2 4 4 4 4 2 0.67 Testes 4 4 4 4 4 3 1.0 Epididymis 2 4 4 4 4 1 0.67

Scrotum 4 4 4 4 4 1 0.83 Penis 4 4 4 4 4 4 1.0 Female-Specific Organs and Structures Ovaries 4 4 4 4 4 4 1.0 Suspensory ligament of the ovary 2 4 4 4 2 2 0.50 Ligament of the ovary 2 4 0 4 2 2 0.33 Fallopian tubes (Oviducts) 2 4 2 4 4 4 0.67 Broad ligament and its parts 2 4 3 4 2 2 0.50 Cardinal ligaments 4 4 4 4 2 1 0.67 Uterus and its parts 4 4 4 4 4 4 1.0 Round ligament of the uterus 2 4 4 4 2 1 0.50 Uterosacral ligament 4 4 4 3 2 1 0.67 Internal os 4 4 2 3 4 3 0.83 External os 2 4 2 3 4 3 0.67 Vagina 4 4 4 3 4 4 1.0 Vaginal fornices 1 4 2 4 4 3 0.67 Urethra 4 4 4 4 4 4 1.0 Vasculature Abdominal aorta bifurcation 4 4 4 4 4 4 1.0 Common iliac arteries 4 4 4 4 4 4 1.0 Internal iliac arteries 4 4 4 4 4 4 1.0

and their branches External iliac arteries 4 4 4 4 2 4 0.83 Ovarian arteries 2 4 4 4 4 2 0.67 Testicular arteries 2 4 4 4 4 2 0.67 Ovarian veins 2 4 4 4 3 2 0.67 Testicular veins 2 4 4 4 3 2 0.67 Dorsal venous complex 2 4 4 3 3 1 0.67 Deep dorsal vein of the clitoris 2 4 4 3 3 1 0.67 Deep dorsal vein of the penis 2 4 4 3 3 2 0.67 Prostatic plexus of veins 2 4 4 3 3 1 0.67 Pelvic plexus 4 4 4 3 3 1 0.83 Nerves Obturator nerve 4 4 4 4 1 2 0.67 Sciatic nerve 4 3 4 4 4 4 1.0 Pudendal nerve 4 4 4 4 4 2 0.83 Ilioinguinal nerve 2 4 4 3 2 1 0.50 Hypogastric nerve 2 4 4 3 2 1 0.50 Genitofemoral nerve 2 4 4 3 2 1 0.50 Femoral nerve 4 4 4 4 4 3 1.0 Lumbosacral plexus 4 4 4 4 4 3 1.0 Spaces Retropubic space 4 4 4 4 4 1 0.83

Vesicovaginal space 4 4 4 4 4 1 0.83 Rectovaginal space 4 4 4 4 4 1 0.83 Left and right perirectal spaces 4 4 4 3 4 2 0.83 Left and right perivesical spaces 4 4 4 3 4 1 0.83 3D Relationships Between Structures Tissue plans and their relationships 0 4 0 4 2 1 0.33 Relationships between muscles 0 4 4 4 2 2 0.50 Relationships between contents of the superficial and deep pouches 0 4 4 4 4 3 0.83 Relationships between anatomy of inguinal hernias (clinical correlation) 4 4 4 4 4 3 1.0 Relationships of ureters to gynecological structures (e.g., fallopian tubes and uterus) 4 4 4 4 4 3 1.0 Relationships of bladder to gynecological structures 4 4 4 4 4 2 0.83 Relationships between the urethra and urogenital diaphragm 4 4 4 4 4 2 0.83

Relationships between the bladder and rectum 4 4 4 4 4 2 0.83 Relationships of bowel to gynecological structures 3 4 4 4 4 2 0.83 Relationships of ureter, uterine tubes, and uterine arteries and veins to urinary bladder 3 4 4 4 4 2 0.83 Relationship between the prostate and rectum 3 4 4 4 4 2 0.83 Relationship between the pelvic plexus and prostate 3 4 4 4 4 1 0.83 Relationships of the urethra to the prostate gland 2 4 4 4 4 4 0.83 Relationships between testicular arteries and veins and ureters 2 4 4 4 4 2 0.67 Relationships of vascular structures to other structures 2 4 4 4 4 0 0.67 Relationships between pelvic floor and pelvis musculature 2 4 4 4 4 0 0.67 Relationships of structures within musculature and bony skeleton of the pelvis 2 4 4 4 4 4 0.83 Relationships of pelvic bony landmarks to other structures 4 4 4 4 4 4 1.0

Relationships between pubic bones, ischial bones, ilia, sacrum, coccyx, ischial tuberosity, pubic tubercle, and pubic symphysis to internal reproductive organs Key Views, Orientations, and/or Positions 4 4 4 4 4 4 1.0 Anterior view down into pelvis 4 4 3 4 4 0 0.83 Superior view down into pelvis 4 4 3 4 4 3 1.0 Lateral view down into pelvis 4 4 3 4 4 0 0.83 Lateral view down into pelvis with nearer pelvic bone removed 4 4 3 4 4 0 0.83 Sagittal view 4 4 4 4 4 3 1.0 Midline sagittal (median) view 4 4 4 4 4 4 1.0 Anterior-posterior view 4 4 4 4 4 0 0.83 Axial (transverse) view 4 4 4 4 4 4 1.0 Lateral-medial view 1 4 2 4 4 0 0.50 Lateral-anterior view 1 3 2 4 4 0 0.50 Lateral-posterior view 1 3 2 4 4 0 0.50

Coronal view 4 4 4 4 4 0 0.83 Oblique view 3 4 4 4 4 0 0.83 Abdominal view 3 4 0 4 4 0 0.67 Lithotomy/vaginal perspective/position 3 4 4 4 4 4 1.0 Prone position 3 4 3 4 4 0 0.83 Supine position 3 4 0 4 4 3 0.83 View internally into the pelvic ring 3 4 3 4 4 0 0.83 View externally (pelvic inlet and outlet views) 3 4 3 4 4 4 1.0 View of pelvic floor from above and below 3 4 4 4 4 2 0.83 Anterolateral view of viscera, particularly the uterus and its ligaments 3 4 3 4 4 4 1.0 Rotations in all positions 4 3 4 4 4 2 0.83 CT/MRI oriented sections (coronal view) 4 4 4 4 4 4 1.0 CT/MRI oriented sections (median view) 4 4 4 4 4 4 1.0 CT/MRI oriented sections (axial view) 4 4 4 4 4 4 1.0 Radiographic imaging slices at all levels 4 4 4 4 4 0 0.83 S-CVI/Ave 0.79 Criterion items with an I-CVI less than 0.80 warrant removal from the overall list. Criterion items with an I-CVI 0.80 warrant retention in the overall list. Experts 1 through 3 include clinicians while experts 4 through 6 include basic scientists. Ratings of 0 denote items for which experts did not provide a response.

The I-CVI values were rounded to the nearest tenth s or hundredth s place according to the rules for significant figures. I-CVI = item-level content validity index, S-CVI/Ave = average scale-level content validity index

Table 5. Items Not in Agreement Between Rounds 3 and 4 and Their Average Content Validity Indices (Avg. I-CVI). Category or Criterion Round 3 I-CVI Round 4 I-CVI Avg. I-CVI Anatomical Structures and Features Skeletal Structures and Features Arcus tendineus fascia pelvis 0.83 0.67 0.75 Muscular Structures and Features Tendinous arch of levator ani muscle 0.83 0.67 0.75 Piriformis muscle 0.67 0.83 0.75 External urethral sphincter 0.83 0.50 0.66 Perineal body 0.83 0.50 0.66 Abdominal wall muscles* 0.83* 0.67* 0.75* Organs and Other Soft Tissue Structures Male-Specific Organs and Structures Seminal vesicles 0.67 0.83 0.75 Epididymis 0.83 0.67 0.75 Female-Specific Organs and Structures Broad ligament and its parts 0.83 0.50 0.66 Cardinal ligaments 1.0 0.67 0.83 Uterosacral ligament 1.0 0.67 0.83 Internal os 0.67 0.83 0.75 Vasculature Ovarian arteries 0.83 0.67 0.75 Pelvic plexus 0.50 0.83 0.66

Nerves Femoral nerve 0.67 1.0 0.83 Spaces Retropubic space 0.67 0.83 0.75 Vesicovaginal space 0.67 0.83 0.75 Rectovaginal space 0.67 0.83 0.75 Left and right perirectal spaces 0.67 0.83 0.75 Left and right perivesical spaces 0.67 0.83 0.75 3D Relationships Between Structures Relationships between pelvic floor and pelvis musculature 0.83 0.67 0.75 Key Views, Orientations, and/or Positions Axial (transverse) view 0.67 0.83 0.75 Supine position 0.83 0.67 0.75 View externally (pelvic inlet and outlet views) 0.67 1.0 0.83 All items in this table were removed from the criteria list, except for the four items with average I-CVI values of 0.83. Since these average I-CVI values were greater than 0.80, these respective items were retained in the final list of criteria. The average I-CVI values were rounded to the nearest hundredth s place according to the rules for significant figures. *Note: In the third round, the abdominal wall muscles were listed as a single item including all four muscles. In the fourth round, each of the four individual abdominal wall muscles was listed as a separate item. The I-CVI value (0.83) of the abdominal wall muscles item in the third round was averaged with each of the four I-CVI values of the individual abdominal wall muscles (rectus abdominus muscles, external oblique muscles, internal oblique muscles, and transversus abdominus muscles). The I-CVI value for each of these muscles in the fourth round was calculated to be 0.67. The average I-CVI value for each of these muscles then was calculated to be 0.75, warranting the removal of each of these four items from the criteria list. I-CVI = item-level content validity index

Table 6. Items Removed from the Final Criteria List and Their Average Content Validity Indices (Avg. I-CVI). Category or Criterion Round 3 I-CVI Anatomical Structures and Features Round 4 I-CVI Avg. I-CVI Skeletal Structures and Features Anterior longitudinal ligament 0.67 0.50 0.58 Arcus tendineus fascia pelvis 0.67 0.67 0.67 Muscular Structures and Features Tendinous arch of levator ani muscle 0.83 0.67 0.75 Obturator internus muscle 0.50 0.67 0.58 Obturator externus muscle 0.50 0.50 0.50 Piriformis muscle 0.67 0.83 0.75 External urethral sphincter 0.83 0.50 0.66 Perineal flexure 0.33 0.33 0.33 Perineal membrane 0.33 0.33 0.33 Superficial perineal pouch 0.50 0.50 0.50 Perineal body 0.83 0.50 0.66 Peritoneum 0.33 0.33 0.33 Cremasteric fascia and muscle 0.50 0.33 0.41 Abdominal wall muscles: rectus abdominis muscles* 0.83* 0.67* 0.75* Abdominal wall muscles: external oblique muscles* x 0.67* 0.75* Abdominal wall muscles: internal oblique muscles* x 0.67* 0.75* Abdominal wall muscles: transversus abdominis muscles* x 0.67* 0.75*

Organs and Other Soft Tissue Structures Fascia (fibroelastic muscular tissue) 0.67 0.50 0.58 Anal columns 0.17 0.33 0.25 Anal valves 0.17 0.33 0.25 Pectinate line 0.17 0.50 0.33 Urinary bladder trigone 0.67 0.67 0.67 Pubovesical ligament 0.33 0.33 0.33 Male-Specific Organs and Structures Puboprostatic ligament 0.33 0.50 0.41 Seminal vesicles 0.67 0.83 0.75 Ejaculatory ducts 0.50 0.67 0.58 Epididymis 0.83 0.67 0.75 Female-Specific Organs and Structures Suspensory ligament of the ovary 0.67 0.50 0.58 Ligament of the ovary 0.50 0.33 0.41 Fallopian tubes (Oviducts) 0.67 0.67 0.67 Broad ligament and its parts 0.83 0.50 0.66 Round ligament of the uterus 0.67 0.50 0.58 Internal os 0.67 0.83 0.75 External os 0.67 0.67 0.67 Vaginal fornices 0.67 0.67 0.67 Vasculature Ovarian arteries 0.83 0.67 0.75 Testicular arteries 0.67 0.67 0.67

Ovarian veins 0.33 0.67 0.50 Testicular veins 0.33 0.67 0.50 Dorsal venous complex 0.33 0.67 0.50 Deep dorsal vein of the clitoris 0.33 0.67 0.50 Deep dorsal vein of the penis 0.33 0.67 0.50 Prostatic plexus of veins 0.33 0.67 0.50 Pelvic plexus 0.50 0.83 0.66 Nerves Obturator nerve 0.67 0.67 0.67 Ilioinguinal nerve 0.50 0.50 0.50 Hypogastric nerve 0.50 0.50 0.50 Genitofemoral nerve 0.67 0.50 0.58 Spaces Retropubic space 0.67 0.83 0.75 Vesicovaginal space 0.67 0.83 0.75 Rectovaginal space 0.67 0.83 0.75 Left and right perirectal spaces 0.67 0.83 0.75 Left and right perivesical spaces 0.67 0.83 0.75 3D Relationships Between Structures Tissue plans and their relationships 0.50 0.33 0.41 Relationships between muscles 0.67 0.50 0.58 Relationships between testicular arteries and veins and ureters 0.50 0.67 0.58 Relationships of vascular structures to other structures 0.67 0.67 0.67

Relationships between pelvic floor and pelvis musculature 0.83 0.67 0.75 Key Views, Orientations, and/or Positions Lateral-medial view 0.67 0.50 0.58 Lateral-anterior view 0.50 0.50 0.50 Lateral-posterior view 0.50 0.50 0.50 Abdominal view 0.67 0.67 0.67 Criterion items with an I-CVI less than 0.80 warrant removal from the overall list. Criterion items with an I-CVI 0.80 warrant retention in the overall list. The average I-CVI values were rounded to the nearest hundredth s place based on the rules for significant figures. *Note: In the third round, the abdominal wall muscles were listed as a single item including all four muscles. Therefore, the I-CVI value for the rectus abdominus muscles in the third round actually represents the I-CVI value for all abdominal wall muscles collectively. As a result, the other abdominal wall muscles (denoted by the letter x) do not have I-CVI values from the third round listed since they were not rated by experts separately. In the fourth round, each of the four individual abdominal wall muscles was listed as a separate item. Thus, the I-CVI value (0.83) of the abdominal wall muscles item in the third round was averaged with each of the four I-CVI values of the individual abdominal wall muscles (rectus abdominus muscles, external oblique muscles, internal oblique muscles, and transversus abdominus muscles) from the fourth round. The I- CVI value for each of these muscles in the fourth round was calculated to be 0.67. The average I-CVI value for each of these muscles then was calculated to be 0.75, warranting the removal of each of these four items from the criteria list. I-CVI = item-level content validity index

Table 7. Final List of Retained Items and Their Content Validity. Category or Criterion Round 3 I-CVI Anatomical Structures and Features Round 4 I-CVI Avg. I-CVI Skeletal Structures and Features Bones of the pelvis: ilium 1.0 1.0 1.0 Bones of the pelvis: pubic bone 1.0 1.0 1.0 Bones of the pelvis: ischial bone 1.0 1.0 1.0 Bones of the pelvis: sacrum 1.0 1.0 1.0 Bones of the pelvis: coccyx 0.83 1.0 0.91 Pubic symphysis 1.0 1.0 1.0 Sacroiliac joint 1.0 1.0 1.0 Sacrotuberous ligament 0.83 0.83 0.83 Sacrospinous ligament 0.83 0.83 0.83 Greater sciatic foramen 1.0 1.0 1.0 Lesser sciatic foramen 1.0 1.0 1.0 Obturator foramen 1.0 0.83 0.91 Ischial spine 1.0 1.0 1.0 Ischial tuberosity 1.0 1.0 1.0 Iliac crest 1.0 1.0 1.0 Anterior superior iliac spine (ASIS) 1.0 1.0 1.0 Anterior inferior iliac spine (AIIS) 1.0 0.83 0.91 Ischiopubic ramus 1.0 1.0 1.0 Superior pubic ramus 0.83 0.83 0.83

Inferior pubic ramus 0.83 0.83 0.83 Acetabulum 1.0 0.83 0.91 Femoral heads 0.83 0.83 0.83 Pelvic inlet 1.0 0.83 0.91 Pelvic outlet 1.0 1.0 1.0 Pubic tubercle 1.0 1.0 1.0 Pubic crest 0.83 0.83 0.83 Pectineal line 0.83 0.83 0.83 Iliac fossa 0.83 0.83 0.83 Anterior sacral foramina 0.83 0.83 0.83 Posterior sacral foramina 0.83 0.83 0.83 Sacral hiatus 0.83 0.83 0.83 Muscular Structures and Features Pelvic floor and its component muscles 0.83 0.83 0.83 Pelvic diaphragm and its component muscles 0.83 0.83 0.83 Organs and Other Soft Tissue Structures Sigmoid colon 1.0 1.0 1.0 Rectum 1.0 1.0 1.0 Anal canal 0.83 1.0 0.91 Ureters and their parts 1.0 1.0 1.0 Urinary bladder 1.0 1.0 1.0 Urinary bladder neck 0.83 0.83 0.83 Male-Specific Organs and Structures Ductus deferens 1.0 0.83 0.91

Prostatic urethra 1.0 1.0 1.0 Membranous urethra 1.0 0.83 0.91 Penile urethra 0.83 0.83 0.83 Prostate gland 1.0 1.0 1.0 Testes 0.83 1.0 0.91 Scrotum 0.83 0.83 0.83 Penis 1.0 1.0 1.0 Female-Specific Organs and Structures Ovaries 1.0 1.0 1.0 Cardinal ligaments 1.0 0.67 0.83 Uterus and its parts 1.0 1.0 1.0 Uterosacral ligament 1.0 0.67 0.83 Vagina 1.0 1.0 1.0 Urethra 1.0 1.0 1.0 Vasculature Abdominal aorta bifurcation 1.0 1.0 1.0 Common iliac arteries 1.0 1.0 1.0 Internal iliac arteries and their branches 1.0 1.0 1.0 External iliac arteries 0.83 0.83 0.83 Nerves Sciatic nerve 0.83 1.0 0.91 Pudendal nerve 0.83 0.83 0.83 Femoral nerve 0.67 1.0 0.83 Lumbosacral plexus 0.83 1.0 0.91

3D Relationships Between Structures Relationships between contents of the superficial and deep pouches 1.0 0.83 0.91 Relationships between anatomy of inguinal hernias (clinical correlation) 0.83 1.0 0.91 Relationships of ureters to gynecological structures (e.g., fallopian tubes and uterus) 1.0 1.0 1.0 Relationships of bladder to gynecological structures 1.0 0.83 0.91 Relationships between the urethra and urogenital diaphragm 1.0 0.83 0.91 Relationships between the bladder and rectum 1.0 0.83 0.91 Relationships of bowel to gynecological structures 1.0 0.83 0.91 Relationships of ureter, uterine tubes, and uterine arteries and veins to urinary bladder 1.0 0.83 0.91 Relationship between the prostate and rectum 1.0 0.83 0.91 Relationship between the pelvic plexus and prostate 0.83 0.83 0.83 Relationships of the urethra to the prostate gland 0.83 0.83 0.83 Relationships of structures within musculature and bony skeleton of the pelvis 0.83 0.83 0.83 Relationships of pelvic bony landmarks to other structures 1.0 1.0 1.0 Relationships between pubic bones, ischial bones, ilia, sacrum, coccyx, ischial tuberosity, pubic tubercle, and pubic symphysis to internal reproductive organs 1.0 1.0 1.0 Key Views, Orientations, and/or Positions Anterior view down into pelvis 1.0 0.83 0.91

Superior view down into pelvis 1.0 1.0 1.0 Lateral view down into pelvis 0.83 0.83 0.83 Lateral view down into pelvis with nearer pelvic bone removed 0.83 0.83 0.83 Sagittal view 0.83 1.0 0.91 Midline sagittal (median) view 1.0 1.0 1.0 Anterior-posterior view 1.0 0.83 0.91 Axial (transverse) view 0.67 1.0 0.83 Coronal view 0.83 0.83 0.83 Oblique view 0.83 0.83 0.83 Lithotomy/vaginal perspective/position 1.0 1.0 1.0 Prone position 0.83 0.83 0.83 Supine position 0.83 0.83 0.83 View internally into the pelvic ring 0.83 0.83 0.83 View externally (pelvic inlet and outlet views) 0.67 1.0 0.83 View of pelvic floor from above and below 0.83 0.83 0.83 Anterolateral view of viscera, particularly the uterus and its ligaments 1.0 1.0 1.0 Rotations in all positions 1.0 0.83 0.91 CT/MRI oriented sections (coronal view) 1.0 1.0 1.0 CT/MRI oriented sections (median view) 1.0 1.0 1.0 CT/MRI oriented sections (axial view) 1.0 1.0 1.0 Radiographic imaging slices at all levels 0.83 0.83 0.83 S-CVI/Ave 0.92 Since all of the average I-CVI values of items in this table were greater than or equal to 0.80, these items were retained in the final list of criteria.

The average I-CVI values were rounded to the nearest tenth s or hundredth s place according to the rules for significant figures. I-CVI = item-level content validity index, S-CVI/Ave = average scale-level content validity index