The Abdomen Lecture 1 PDF

2025-01-18 The Abdomen RADIOGRAPHIC PROCEDURES 4 142-B44-DW Lecture 1 Original slides by: Kathy Mailly / W2023 version by: Mary Ann Hoskin 1 1 ...

2025-01-18 The Abdomen RADIOGRAPHIC PROCEDURES 4 142-B44-DW Lecture 1 Original slides by: Kathy Mailly / W2023 version by: Mary Ann Hoskin 1 1  2025-01-18 Required Textbooks Merrill’s Atlas of Radiographic Positions and Radiologic Procedures, 14th Ed., Vol. 1 Workbook for Merrill’s Atlas of Radiographic Positions and Radiologic Procedures, 14th Ed. Comprehensive Radiographic Pathology, R.L. Eisenberg & N.M. Johnson, 7th Ed. Radiographic Image Analysis, McQuillen Martensen, 5th Ed. Workbook for Radiographic Image Analysis, McQuillen Martensen, 5th Ed. Sectional Anatomy for Imaging Professionals, Kelley & Peterson, 4th Ed. Workbook for Sectional Anatomy for Imaging Professionals, Kelley & Peterson, 4th Ed. ADDITIONAL RESOURCE: Radiographic Positioning and Related Anatomy, Bontrager and Lampignano, 10th Ed. 2 2  2025-01-18  Addison’s planes  Transpyloric vs. subcostal plane  Abdominopelvic regions  Abdominopelvic quadrants  Abdominopelvic cavity  Abdominal wall muscles  Respiratory diaphragm Anatomy of the Abdomen 3 3  2025-01-18 ADDISON’S PLANES Surface lines that divide abdominopelvic cavity into 9 regions 2 horizontal planes – Transpyloric – Transtubercular (intertubercular) 2 vertical planes – Right vertical (lateral) – Left vertical (lateral) http://studyingmed.com/wiki/images/thumb/d/da/1HMBAnat22.png/400px-1HMBAnat22.png 4 4  2025-01-18 Transpyloric vs. Subcostal Planes https://basicmedicalkey.com/wp-content/uploads/2016/06/B9781416050131500183_gr3.jpg TRANSPYLORIC SUBCOSTAL Midway between jugular Older method notch & pubic symphysis Palpable along inferior margins Passes through L1 & 9th costal of 10th costal cartilages cartilages Passes through L3 5 5  2025-01-18 Transpyloric Plane https://upload.wikimedia.org/wikipedia/commons/3/3e/Gray1225.png Factors affecting the location of organs: respiration, body position & body habitus 6 6  2025-01-18 Transtubercular Plane https://basicmedicalkey.com/wp-content/uploads/2016/06/B9781416050131500183_gr3.jpg A.K.A. Intertubercular plane Midway between transpyloric plane and upper border of pubic symphysis Corresponds to a line drawn through tubercles of iliac crests Passes through L5, on same horizontal plane as confluence of common iliac veins (origin of IVC) 7 7  2025-01-18 Right & Left Vertical Planes A.K.A. Lateral planes or mid-clavicular planes/lines Each follows a line joining mid-clavicular point to mid- inguinal point Midway between ASIS & MSP, // to MSP Roughly corresponds to lateral border of rectus http://studyingmed.com/wiki/images/thumb/d/da/1HMBAnat22.png/400px-1HMBAnat22.png abdominis muscle 8 8  2025-01-18 ADDISON’S PLANES Anatomically most accurate 4 planes criss-cross to form a ‘tic-tac-toe’ pattern = 9 abdominopelvic regions https://prod-images- static.radiopaedia.org/images/37087447/ff0f58abafcce96cb166ffa150ff43_big_gallery.jpeg 9 9  2025-01-18 ABDOMINOPELVIC REGIONS 10 10  2025-01-18 Abdominopelvic Regions 11 11  2025-01-18 Coronal CT Abdominopelvic Regions Rt Lt Hypochondriac Epigastric Hypochondriac Liver Stomach Spleen Rt Lumbar (Lateral) Umbilical Transverse colon Lt Lumbar (Lateral) Gallbladder Some duodenum Descending colon Ascending colon jejunum & ilium Lt kidney Rt kidney Ureters Rt Iliac (Inguinal) Hypogastic Lt Iliac (Inguinal) Cecum (Pubic) Sigmoid colon Appendix Sigmoid colon Lt iliac fossa Rt iliac fossa Rectum Lt ovary Rt ovary Bladder reproductive 12 12  2025-01-18 ABDOMINOPELVIC QUADRANTS 2 lines divide abdominopelvic cavity into 4 quadrants – Vertical line = median plane (MSP) – Horizontal line = transumbilical plane passing at level of umbilicus (L4-L5) / iliac crest Localization method used by physicians & clinicians (ex. RUQ pain) https://prod-images- static.radiopaedia.org/images/37087455/eb3bba196334a28c474556af481b6b_big_gallery.jpeg 13 13  2025-01-18 Abdominopelvic Quadrants 14 14  2025-01-18 Abdominopelvic Quadrants RT UPPER QUADRANT LT UPPER QUADRANT Liver Stomach Gallbladder Spleen Duodenum Lt colic flexure Head of pancreas Transverse colon Rt adrenal gland Body & tail of pancreas Upper pole of Rt kidney Lt adrenal gland Rt colic flexure Upper pole of Lt kidney Upper ascending colon Transverse colon RT LOWER QUADRANT LT LOWER QUADRANT Cecum Jejunum Ascending colon Descending colon Appendix Sigmoid colon Ilium Lower pole of Lt kidney Lower pole of Rt kidney Lt lower ureter Rt lower ureter Lt ovary (females) Rt ovary (females) Spermatic cord (males) Rt uterus (variable) Left uterus (variable) Rt side of bladder Lt side of bladder Rt side of rectum Lt side of rectum 15 15  2025-01-18 ABDOMINOPELVIC REGIONS / QUADRANTS https://prod-images- https://prod-images- static.radiopaedia.org/images/37087447/ff0f58abafcce96cb166ffa150ff43_big_gallery.jpeg static.radiopaedia.org/images/37087455/eb3bba196334a28c474556af481b6b_big_gallery.jpeg 16 16  2025-01-18 COMPARING ABDOMINAL IMAGES AXIAL CT CONVENTIONAL CORONAL CT RADIOGRAPHY RECONSTRUCTION AP PROJECTION 17 17  2025-01-18 ABDOMINOPELVIC CAVITY Abdominal cavity boundaries – Superiorly = RESPIRATORY DIAPHRAGM – Inferiorly = SACRAL PROMONTORY (pelvic inlet) Pelvic cavity is located inferior to this = TRUE PELVIS https://healthiack.com/wp-content/uploads/Pictures-of-Abdominopelvic-Cavity-42.jpg 18 18  2025-01-18 Abdominopelvic Cavity https://www.eos-imaging.com/wp-content/uploads/2020/12/eos-full-body-xray-1.png https://healthiack.com/wp-content/uploads/Pictures-of-Abdominopelvic-Cavity-42.jpg 19 19  2025-01-18 Anterior Boundaries 20 20  2025-01-18 Lateral Boundaries ILIACUS M. + PSOAS M. = ILIOPSOAS M. 3 ABDOMINAL MUSCLES ILIACUS PSOAS MUSCLE MUSCLE ILIACUS ILIAC PORTION OF MUSCLE INNOMINATE BONE https://www.lower-back-pain-answers.com/images/Iliopsoas.jpg 21 21 21  2025-01-18 Posterior & Superior Boundaries VERTEBRAL COLUMN PSOAS QUADRATUS DIAPHRAGM MUSCLE LUMBORUM & CRURA MUSCLE 22 22  2025-01-18 ABDOMINAL WALL MUSCLES 23 23  2025-01-18 Axial CT Abdominal Wall Muscles 24 24  2025-01-18 Purpose of Abdominal Wall Muscles Protect abdominal organs (viscera) Stabilize vertebral bodies Important for breathing, coughing & vomiting Assist in defecation, urination (micturition) & childbirth (parturition) Contraction of muscles =  intra-abdominal pressure 25 25  2025-01-18 ANTERIOR VERTICAL MUSCLES https://www.aafp.org/content/dam/brand/aafp/pubs/afp/issues/2018/1001/p429-f1.jpg 26 26  2025-01-18 Rectus Abdominis Muscles Paired muscles located anteriorly Muscle fibers run longitudinally Tendinous midline linea alba separates R & L muscles Bound laterally by tendinous linea semilunaris 3 anterior horizontal fibrous bands (tendinous intersections) separate muscles into individual bellies = “six pack” Functions: trunk flexion, compression of abdominal viscera, expiration Origin: pubic symphysis & crest Insertion: costal cartilages of ribs 5-7 & xiphoid process 27 27  2025-01-18 Coronal MRI Rectus Abdominis M. / Linea Alba & Semilunaris INSERTION OF RECTUS ABDOMINIS MUSCLE (not demonstrated, but occurs here) RECTUS LINEA ABDOMINIS ALBA MUSCLE LINEA SEMILUNARIS ORIGIN OF RECTUS ABDOMINIS MUSCLE Image courtesy of K. Mailly 28 28  2025-01-18 Pyramidalis Muscles Very small, paired triangular muscles of anterior wall Absent in 20% of population Function: tenses linea alba Origin: pubic crest, pubic symphysis Insertion: linea alba 29 29  2025-01-18 LATERAL FLAT MUSCLES https://www.aafp.org/content/dam/brand/aafp/pubs/afp/issues/2018/1001/p429-f1.jpg 30 30  2025-01-18 External Oblique Muscles Outermost & largest of 3 lateral flat abdominal wall muscles Lateral & superficial to rectus abdominis Fibers run at a 45° angle (infero-medially) Inferior margins form inguinal ligaments - extend from pubic tubercles to ASIS Functions: – BILATERAL = trunk flexion, compression of abdominal viscera, expiration – UNILATERAL = trunk lateral flexion (ipsilateral), trunk rotation (contralateral) = “opposite-side rotators” Origin: external surfaces of 5th - 12th ribs Insertion: linea alba, pubic tubercle & ant. ½ of iliac crest 31 31  2025-01-18 Sagittal CT External Oblique M. AIR IN LUNGS EXTERNAL OBLIQUE MUSCLE ABDOMINAL FAT (ADIPOSE) BONE A P Image courtesy of K. Mailly 32 32  2025-01-18 Internal Oblique Muscles Intermediate lateral flat abdominal wall muscles Fibers run at a 45° angle (supero-medially), perpendicular to external oblique m. In men, caudal fibers extend to spermatic cord Functions: – BILATERAL = trunk flexion, compression of abdominal viscera, expiration – UNILATERAL = trunk lateral flexion (ipsilateral), trunk rotation (ipsilateral) = “same-side rotators” Origin: T-L fascia, anterior iliac crest, inguinal ligament Insertion: inferior borders of 10th - 12th ribs, linea alba, pectineal line of pubis 33 33  2025-01-18 Coronal MRI Crossing of External & Internal Oblique Muscles RT LT EXTERNAL EXTERNAL OBLIQUE OBLIQUE MUSCLE MUSCLE \\\ /// RT LT INTERNAL INTERNAL OBLIQUE OBLIQUE MUSCLE MUSCLE /// \\\ Image courtesy of K. Mailly 34 34  2025-01-18 Transversus Abdominis Muscles Deepest of 3 lateral flat abdominal wall muscles Fibers run transversely (latero-medially) Functions: – BILATERAL = compression of abdominal viscera, expiration – UNILATERAL = trunk rotation (ipsilateral) Origin: costal cartilages of 7th - 12th ribs, thoracolumbar fascia, anterior iliac crest, iliopectineal arch Insertion: linea alba, aponeurosis of internal abdominal oblique m., pubic crest, pectineal line of pubis 35 35  2025-01-18 PROPERITONEAL FAT STRIPES A.K.A. Flank stripes (lines) Shadows of properitoneal fat pads seen laterally on a radiographic image of the abdomen Outline ascending & descending colons Symmetrically concave (or slightly convex in obese subjects) Loss of or bulging flank lines is associated with excess intraperitoneal fluid (ex. ascites, blood) and infections Can mimic pneumoperitoneum or pneumoretroperitoneum  free air https://prod-images- static.radiopaedia.org/images/4804464/f5bf673204e38ac3 998fdae737f898_jumbo.jpg 36 36  2025-01-18 Properitoneal Fat Stripes NORMAL ABNORMAL LOSS - ASCITES https://prod-images- https://prod-images- static.radiopaedia.org/images/5088166/0fdb0c54979c5f89d9253f42ae9fe3_jumbo.JPG static.radiopaedia.org/images/10498050/ae0efc1b552ff28df1ac70c0351393_gallery.jpeg 37 37  2025-01-18 Properitoneal Fat Stripes  Identify the 3 layers of lateral flat muscles …  38 38  2025-01-18 POSTEROLATERAL ABDOMINAL WALL MUSCLES  Present in 60% of population Quadratus lumborum https://teachmeanatomy.info/wp-content/uploads/Muscles-of-the-Posterior-Abdominal-Wall.jpg https://www.google.com/url?sa=i&url=https%3A%2F%2Fbackmusclesoluti ons.com%2Fblogs%2Fthe-ql-blawg%2Fquadratus-lumborum- function&psig=AOvVaw19pCqpeJ7o- CqVYx8udF3a&ust=1673283392549000&source=images&cd=vfe&ved=0CA 39 0QjRxqFwoTCNCgj8u4uPwCFQAAAAAdAAAAABA2 39  2025-01-18 Psoas Major Muscles Psoas (Gr.) = muscle of the loin Long, thick, fusiform muscles (wide in middle and tapers at both ends) located in lumbar region of trunk Lateral to vertebral column & medial to quadratus lumborum muscles Merge with iliacus muscles to form iliopsoas muscles Functions: hip joints - trunk/thigh flexion, lateral rotation of thigh; lateral flexion of trunk Origin: vertebral bodies & intervertebral discs of T12-L4, transverse processes of L1-L5 vertebrae Insertion: lesser trochanter of femur (iliopsoas tendon) 40 40  2025-01-18 Psoas Major Muscles 41 41  2025-01-18 Quadratus Lumborum Muscles Deepest muscles of posterior abdominal wall - NOT back muscles! Irregular in shape, but mostly quadrangular = quadratus (L.) Lie posterior to iliopsoas muscles Functions: – BILATERAL = fixes 12th ribs during inspiration, trunk extension – UNILATERAL = lateral flexion of trunk (ipsilateral) Origin: iliac crest, iliolumbar ligament Insertion: inferior border of 12th rib, transverse processes of L1-L4 vertebrae 42 42  2025-01-18 Quadratus Lumborum Muscles 43 43  2025-01-18 Erector Spinae Muscles Intermediate layer of deep (intrinsic) back muscles Located on either side of vertebral column, extending between base of cranium superiorly & pelvis inferiorly 3 groups Functions: – BILATERAL = spine extension – UNILATERAL = lateral flexion of spine (ipsilateral) https://cdn- aolkg.nitrocdn.com/JEsNUzsMoDdLqhSXkopLhNFWnBniacqf/assets/ – Maintain posture by steadying spine static/optimized/rev-e53dc90/wp- content/uploads/2018/05/erector-spinae-muscle-mom-h.jpg on pelvis during walking 44 44  2025-01-18 ABDOMINAL WALL MUSCLES http://www.studyblue.com/notes/note/n/abdomen-pelvis-and-perineum/deck/1022704 45 45  2025-01-18 ABDOMINAL WALL MUSCLES 46 46  2025-01-18 Sagittal CT Abdominal Wall Muscles AIR IN DIAPHRAGM LUNGS RT KIDNEY LIVER UPPER POLE (more posterior & medial) RECTUS ABDOMINIS ERECTOR SPINAE MUSCLE MUSCLE ABDOMINAL QUADRATUS FAT LUMBORUM MUSCLE SMALL INTESTINE PSOAS (soft tissue / fluid) MAJOR MUSCLE ILIOPSOAS MUSCLE BONE (merged iliacus & psoas m.) Image courtesy of K. Mailly 47 47  2025-01-18 RESPIRATORY DIAPHRAGM Unpaired, dome-shaped musculotendinous structure It separates thoracic & abdominal cavities from each other by closing inferior thoracic aperture Functions: depresses costal cartilages, primary muscle of breathing (inspiration) Origins: – STERNAL PART = posterior aspect of xiphoid process – COSTAL PART = internal surfaces of lower costal cartilages & ribs 7-12 – LUMBAR PART = lumbocostal arches, bodies of vertebrae L1-L3, anterior longitudinal ligament Insertion: central tendon of diaphragm 48 48  2025-01-18 Respiratory Diaphragm 2 domes - Rt is higher than Lt due to liver Openings: – AORTIC HIATUS (aorta, azygos vein, thoracic duct) – ESOPHAGEAL HIATUS (esophagus, vagus nerve) – CAVAL FORAMEN (inferior vena cava) https://firstaidteam.com/wp-content/uploads/2020/03/35293.png 49 49  2025-01-18 Crura of Respiratory Diaphragm psoas psoas CRUS (singular) = leg (L.) 2 tendinous structures that extend below diaphragm to anterior vertebral column Together they form a tether for muscular contraction 50 50