Abnormal Fetal GI Tract PDF

ULTR‐3014 OBGYN Sonography 3 Module O.12: Abnormal Fetal Heart & Abdomen 4 Abnormal Fetal GI Tract 1 2 Fetal Abdomen textbook reference Module O.12 Abnormal Fetal Heart & Abdomen • • Curry 5th Edition Chapter 22 (p. 402, 404, 406) Abnormal GI Tract • • 3 Rumack 5th Edition Chapter 38 4 Ab...

ULTR‐3014 OBGYN Sonography 3 Module O.12: Abnormal Fetal Heart & Abdomen 4 Abnormal Fetal GI Tract 1 2 Fetal Abdomen textbook reference Module O.12 Abnormal Fetal Heart & Abdomen • • Curry 5th Edition Chapter 22 (p. 402, 404, 406) Abnormal GI Tract • • 3 Rumack 5th Edition Chapter 38 4 Abnormal Abdomen Abnormal GI Tract • Liver • GI tract anatomy • Spleen • Stomach • Gallbladder & biliary tree • Intra‐abdominal cysts • Adrenals • Situs inversus • Abdominal vessels • Bowel • Other GI tract atresias • Echogenic bowel 5 6 Abnormal Abdominal Wall • Anterior abdominal wall • Physiologic midgut umbilical herniation • Congenital anomalies • AFP screening • Amniotic band syndrome GI Tract Anatomy 1 ULTR‐3014 OBGYN Sonography 3 Module O.12: Abnormal Fetal Heart & Abdomen 4 Abnormal Fetal GI Tract 7 8 GI Tract Anatomy 1: esophagus 1 2: stomach Stomach 3: small bowel 2 4: large bowel (colon) 4 3 Textbook of Diagnostic Sonography, 7th Edition (Hagen‐Ansert fig 13‐1) 9 10 Stomach 2 1 • General anatomy Stomach – anatomy • Sonographic features 1: esophagus • Abnormalities 2: fundus 3: rugae 3 4 5 4: pylorus 5: duodenum Atlas of Human Anatomy, 7th Edition (Netter plate 277) 11 12 Stomach – sonographic features • Seen reliably by end of 1st trimester • Follow up if not seen • Anechoic, cystic structure in left upper quadrant • “Stomach bubble” • Size varies significantly with GA and filling/emptying • Size increases with GA Normal stomach • AC view (transverse) 1: stomach 2: portal vein 3: aorta 2 3 1 2 ULTR‐3014 OBGYN Sonography 3 Module O.12: Abnormal Fetal Heart & Abdomen 4 Abnormal Fetal GI Tract 13 14 Normal stomach • Coronal fetus • Stomach inferior to diaphragm S: stomach B: bladder H: heart GB: gallbladder Normal stomach liver • Parasagittal left fetus • Stomach inferior to diaphragm 1 GB 1: stomach 2: aorta : diaphragm 15 2 16 Stomach – abnormalities • Absent stomach • Stomach echoes Absent Stomach 17 18 Delayed filling of stomach • Coronal • Stomach not seen at 10:37 a.m. • bladder heart See next slide… e.g. anencephaly 3 ULTR‐3014 OBGYN Sonography 3 Module O.12: Abnormal Fetal Heart & Abdomen 4 Abnormal Fetal GI Tract 19 20 Delayed filling of stomach IUGR & chronic oligohydramnios • Sagittal left • Transverse AC level • Stomach now seen at 11:29 a.m. • Difficult to see abdominal anatomy • Is the stomach absent? 21 22 Stomach echoes – causes • Blood in amniotic fluid (swallowed) • Placental abruption • Amniocentesis • Cordocentesis • Third trimester • Prominent rugae • Vernix caseosa NB: follow up if significant echoes seen Stomach Echoes 23 Cordocentesis Umbilical cord blood sampling 24 Stomach echoes • 18 weeks GA • Sagittal • Clump of debris in stomach (arrow) • Debris seen moving • Resolved on follow‐up “gastric pseudomass” Intra‐abdominal Cysts 4 ULTR‐3014 OBGYN Sonography 3 Module O.12: Abnormal Fetal Heart & Abdomen 4 Abnormal Fetal GI Tract 25 26 Intra‐abdominal cysts – differential diagnoses • Physiological cysts • Pathological cysts without colour flow • Pathological cysts with colour flow 27 Intra‐abdominal cysts – physiological • Stomach dilatation • Gastric outlet obstruction • Normal fetal gallbladder 28 Intra‐abdominal cysts – physiological Intra‐abdominal cysts – physiological Causes for stomach enlargement: • Duodenal atresia • Pyloric/gastric atresia Atresia Absence or abnormal closure of a body orifice or passageway Most common Normal stomach Enlarged stomach Due to pyloric stenosis (more on atresia later in this module) 29 30 Intra‐abdominal cysts – pathological without colour flow • Ovarian cyst Most common • Choledochal cyst • Hepatic cyst • Hydronephrosis/other renal anomalies • Megacystitis Enteric • Enteric cysts Of or relating to • Urachal cysts the small intestine Intra‐abdominal cysts – pathological without colour flow • Transverse abdomen • Choledochal cyst (arrow) S: stomach L: liver Diagnostic Ultrasound, 5th Edition (Rumack fig 38.21) 5 ULTR‐3014 OBGYN Sonography 3 Module O.12: Abnormal Fetal Heart & Abdomen 4 Abnormal Fetal GI Tract 31 32 Intra‐abdominal cysts – pathological without colour • Long abdomen • Intra‐abdominal cysts – pathological with colour flow • Umbilical venous varix • Cystic appearance – not actually a cyst Hepatic cyst Bladder and varix Diagnostic Ultrasound, 5th Edition (Rumack fig 38.19) 33 with CD Varix A varicose vein 34 Situs Inversus Situs Inversus 35 • Complete • Partial 36 Complete situs inversus Partial situs inversus • Complete transposition of thoracic and abdominal organs and great vessels • Partial transposition of organs • e.g. Chest is normal, abdomen reversed • Usually an isolated anomaly – good prognosis • Frequently associated with cardiac and splenic anomalies Tip: always correlate fetal lie with the head & spine – don’t assume the stomach is on the left side! 6 ULTR‐3014 OBGYN Sonography 3 Module O.12: Abnormal Fetal Heart & Abdomen 4 Abnormal Fetal GI Tract 37 38 Partial situs inversus Situs solitus (normal) • Reversal of organs within the abdomen • Stomach on right side • Also exhibited polysplenia syndrome and myelomeningocele (arrows) Complete situs inversus 39 40 Bowel Bowel 41 • General anatomy • Sonographic features • Abnormalities 42 Bowel – anatomy • Small bowel centrally located in mid to lower abdomen (after 20 weeks) • Colon (large bowel) peripherally located and “frames” the small bowel Bowel – anatomy • Small bowel begins after the stomach and terminates at the colon 7 ULTR‐3014 OBGYN Sonography 3 Module O.12: Abnormal Fetal Heart & Abdomen 4 Abnormal Fetal GI Tract 43 44 Bowel – anatomy • Small bowel – sonographic features Colon begins after the ileum and terminates at the anus 45 • Ill‐defined, heterogeneous structure with mixed echogenicity • Fluid‐filled loops may be seen in short segments in the 3rd trimester • Peristalsis may be observed 46 Normal small bowel • • Colon – sonographic features 18 weeks GA • Hypoechoic tubular structure with haustral feature • Colon diameter increases significantly with GA • ± Peristalsis Coronal 47 48 Normal colon • 32 weeks GA Normal colon • 36 weeks GA • Showing normal descending and sigmoid colon (arrows) SB SB: small bowel (echogenic) bl: bladder 8 ULTR‐3014 OBGYN Sonography 3 Module O.12: Abnormal Fetal Heart & Abdomen 4 Abnormal Fetal GI Tract 49 50 Bowel – abnormalities • Small bowel obstruction • Duodenal atresia • Meconium ileus • Meconium peritonitis • Anorectal atresia Small Bowel Obstruction 51 52 Small bowel obstruction – causes • Atresia • Midgut volvulus • Intussusception • Cystic fibrosis (meconium ileus) May result in bowel perforation Small bowel obstruction – atresia Intussusception • Volvulus Twisting (malrotation) Only 1/3 of small bowel obstructions are jejunal or ileal • Duodenal atresia has specific findings and will be discussed later in this section • Most common intestinal atresia Volvulus Intussusception Telescoping inward Ileus Lack of movement resulting in a buildup of material 53 54 Small bowel obstruction – sonographic features • Dilated fluid‐filled loops of bowel • > 7 mm diameter • Enlarged stomach • With high level obstructions • Increased peristalsis “High level” small • Polyhydramnios bowel obstruction • With high level obstructions Closer to the mouth Jejunal atresia • Transverse mid abdomen • Dilated fluid filled loop of small bowel • Enlarged stomach and polyhydramnios also present S: spine 9