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Fetal Imaging of Gatrointestinal Fetal Imaging of Gatrointestinal TractTract

DisordersDisordersMaria A. CalvoMaria A. Calvo--Garcia, MD, Beth M KlineGarcia, MD, Beth M Kline--Fath, MD, Fath, MD,

Leann E Linam, MD, Eva E. Rubio, MD.Leann E Linam, MD, Eva E. Rubio, MD.

Department of RadiologyDepartment of RadiologyCincinnati ChildrenCincinnati Children’’s Hospital Medical Centers Hospital Medical Center

University Hospital Cincinnati, OhioUniversity Hospital Cincinnati, Ohio

Goals & ObjectivesGoals & Objectives•• To review the normal appearance of the To review the normal appearance of the

gastrointestinal tract utilizing fetal MRI.gastrointestinal tract utilizing fetal MRI.

•• To display the spectrum of fetal GI anomalies To display the spectrum of fetal GI anomalies with the aid of MRI and with postnatal with the aid of MRI and with postnatal radiologic and operative images.radiologic and operative images.

•• To test your knowledge with clinical cases.To test your knowledge with clinical cases.

Sections of This PosterSections of This PosterThis electronic poster has 3 sections.This electronic poster has 3 sections.

Section 1Section 1 will briefly review the embryology, will briefly review the embryology, physiology and the MRI anatomy of the fetal GI physiology and the MRI anatomy of the fetal GI tract.tract.Section 2Section 2 will review the assessment of fetal GI will review the assessment of fetal GI pathologic processes. pathologic processes.

Section 3Section 3 will give you clinical cases for you to will give you clinical cases for you to practice.practice.

You can click on the section you want and skip the one you may You can click on the section you want and skip the one you may already know.already know.Sect.

1Sect.

2Sect.

3

BackgroundBackground

US is the imaging modality of choice in US is the imaging modality of choice in pregnancy.pregnancy.

US advantages:US advantages:Noninvasive and safeNoninvasive and safeRelatively low costRelatively low costWidely availableWidely available

Sect. 1

Sect. 2

Sect. 3

BackgroundBackground

Due to intrinsic US limitations and to the advances in Due to intrinsic US limitations and to the advances in fetal medicine and surgery, fetal MRI has become a fetal medicine and surgery, fetal MRI has become a clinically useful supplement to US. clinically useful supplement to US.

Fetal MR has an emerging role in the diagnosis of fetal Fetal MR has an emerging role in the diagnosis of fetal GI tract anomalies. GI tract anomalies.

Fetal MR shows specific and different signals of the Fetal MR shows specific and different signals of the normal content of small and large bowel improving the normal content of small and large bowel improving the assessment of the GI tract anatomy.assessment of the GI tract anatomy.

Anatomical/Physiological Anatomical/Physiological Development of the Fetal GI TractDevelopment of the Fetal GI Tract

In order to understand fetal bowel imaging we need to In order to understand fetal bowel imaging we need to know the anatomic and physiologic development of the know the anatomic and physiologic development of the GI tract.GI tract.

The anatomic development happens during the 1The anatomic development happens during the 1stst

trimester. trimester.

The enzymatic and functional development happens The enzymatic and functional development happens during the 2during the 2ndnd and 3and 3rdrd trimesters.trimesters.

http://sprojects.mmi.mcgill.ca/embryology/gi/pgm.htm

AnatomicalAnatomical/Physiological /Physiological Development of the Fetal GI TractDevelopment of the Fetal GI Tract

By the end of the 5By the end of the 5thth

menstrual week the menstrual week the primitive gut has formed. primitive gut has formed. It is a hollow tube It is a hollow tube extending from the extending from the bucopharyngeal bucopharyngeal membrane to the cloaca.membrane to the cloaca.

It is made of 3 parts: It is made of 3 parts: foregut, midgut and foregut, midgut and hindgut.hindgut.


The bucopharyngeal membrane will rupture, the The bucopharyngeal membrane will rupture, the tracheoesophageal septum will separate the tracheoesophageal septum will separate the esophagus from the trachea. After a 90esophagus from the trachea. After a 90ºº rotation rotation the stomach will show its typical appearance by the stomach will show its typical appearance by the 10the 10thth menstrual week.menstrual week.

The midgut will grow in length and will undergo The midgut will grow in length and will undergo a 270a 270ºº counter clock rotation to assume the counter clock rotation to assume the adult configuration. adult configuration.


The caudal hindgut The caudal hindgut connects with the connects with the cloaca.cloaca.The urorectal septum The urorectal septum forms and by the 8forms and by the 8thth

menstrual week fuses menstrual week fuses with the cloacal with the cloacal membrane, dividing membrane, dividing the cloaca into:the cloaca into:

Urogenital sinusUrogenital sinus

and rectumand rectum

8th menstrual week 11-12th menstrual w

From: Gray SW et al. “Embryology for surgeons”. WB Saunders, 1972


At the same time, At the same time, there is also caudal there is also caudal retraction of the retraction of the cloacal membrane, so cloacal membrane, so the urogenital and the urogenital and rectal membranes are rectal membranes are no longer part of the no longer part of the abdominal wall.abdominal wall.Urogenital and rectal Urogenital and rectal membranes, then, membranes, then, open.open.

8th menstrual week 11-12th menstrual w

From: Gray SW et al. “Embryology for surgeons”. WB Saunders, 1972

Anatomical/Anatomical/PhysiologicalPhysiologicalDevelopment of the Fetal GI TractDevelopment of the Fetal GI Tract

Intestinal peristalsisIntestinal peristalsis begins by 11 menstrual weeks begins by 11 menstrual weeks and and fetal swallowfetal swallow starts shortly thereafter. starts shortly thereafter.

By 12 weeks, on US, the stomach can be identified as a By 12 weeks, on US, the stomach can be identified as a fluid filled structure in the LUQ.fluid filled structure in the LUQ.

The GI tract starts also its The GI tract starts also its secretory functionsecretory function(stomach, pancreas and small bowel) and (stomach, pancreas and small bowel) and absorption absorption (large bowel).(large bowel).

Anatomical/Anatomical/PhysiologicalPhysiologicalDevelopment of the Fetal GI TractDevelopment of the Fetal GI Tract

As a result of all these functions (swallowing, peristalsis, As a result of all these functions (swallowing, peristalsis, absorption and secretion) absorption and secretion) meconiummeconium starts forming in starts forming in the small bowel around the 14the small bowel around the 14thth week. week.

It will slowly migrate from the small bowel to the colon It will slowly migrate from the small bowel to the colon and rectum.and rectum.

Visualization of meconium in the distal bowel depends Visualization of meconium in the distal bowel depends on adequate development and preservation of all these on adequate development and preservation of all these functions throughout the pregnancy.functions throughout the pregnancy.

Fetal GI Anatomy/PhysiologyFetal GI Anatomy/PhysiologyFetal MRIFetal MRI

In the fetal setting there are 2 In the fetal setting there are 2 types of natural types of natural ““contrast contrast mediamedia”” that allow us to depict that allow us to depict the intestinal anatomy.the intestinal anatomy.

Amniotic fluidAmniotic fluid swallowed swallowed by the fetus (Bright T2 SI)by the fetus (Bright T2 SI)MeconiumMeconium (Bright T1 (Bright T1 SI), produced by the SI), produced by the bowel.bowel.

The distribution of this The distribution of this ““contrast mediacontrast media”” correlates correlates with fetal development.with fetal development.

T2T1

Fetal GI Anatomy/PhysiologyFetal GI Anatomy/PhysiologyFetal MRI: Fetal MRI: EsophagusEsophagus

We will be able to We will be able to see intermittent see intermittent fluid distention of fluid distention of segments of the segments of the esophagus during esophagus during fetal swallowing.fetal swallowing.

21w GA

29w GA

T

esophagus

Fetal GI Anatomy/PhysiologyFetal GI Anatomy/PhysiologyFetal MRI: Fetal MRI: Small BowelSmall Bowel

The fetal abdomen will The fetal abdomen will present a characteristic present a characteristic spotty appearance prior spotty appearance prior to 25 GW, as no to 25 GW, as no significant amniotic fluid significant amniotic fluid enters the fetal bowel enters the fetal bowel (except for the stomach). (except for the stomach).

21w GA


Gastric emptying starts Gastric emptying starts around the 24 GW.around the 24 GW.Increased swallowed AF Increased swallowed AF is noted by 25 GW is noted by 25 GW

By 26By 26--27 GW, fluid filled 27 GW, fluid filled small bowel loops small bowel loops become apparent, become apparent, predominantly in the predominantly in the LUQ.LUQ.

26w GA


26w GA

By 26By 26--27 GW 27 GW intermediate signal can intermediate signal can also be seen in the also be seen in the jejunum (may reflect the jejunum (may reflect the secretorysecretory activity of the activity of the proximal bowel, liver and proximal bowel, liver and pancreas)pancreas)


Beyond 30 GW, longer , Beyond 30 GW, longer , fluid filled jejunal loops fluid filled jejunal loops will be constantly will be constantly visualized with diameters visualized with diameters up to 7up to 7--8mm.8mm.The bowel wall itself can The bowel wall itself can be visualized as well.be visualized as well.

36w GA

Progression of Small Bowel Signal Progression of Small Bowel Signal T2 WIT2 WI

The small bowel first contains meconium (initial spotty The small bowel first contains meconium (initial spotty abdomen) and then fills with ingested amniotic fluid.abdomen) and then fills with ingested amniotic fluid.

21w GA 26w GA 36w GA

Fetal GI Anatomy/PhysiologyFetal GI Anatomy/PhysiologyFetal MRI: Fetal MRI: Large BowelLarge Bowel

Meconium will be well Meconium will be well evaluated with T1WI evaluated with T1WI (bright signal).(bright signal).

It is hypointense on T2 It is hypointense on T2 WI. WI.

It has intermediate signal It has intermediate signal on steadyon steady--state free state free precession sequences precession sequences (2D FIESTA).(2D FIESTA).

T2 2D FIESTAT1


After 20w we expect After 20w we expect to see meconium to see meconium filled rectum.filled rectum.

Meconium will fill Meconium will fill and distend the and distend the rectum and colon in rectum and colon in a caudocranial a caudocranial progression.progression.

21 w


Around the 27 GW Around the 27 GW the whole colon is the whole colon is filled with meconium.filled with meconium.

The cecum is position The cecum is position at the level of the iliac at the level of the iliac crest, as in the crest, as in the newborn.newborn.

28w


The maximum colon The maximum colon diameter increases with diameter increases with advancing age:advancing age:

33--4mm by 20w4mm by 20w88--15mm at term.15mm at term.

Malas MA et al.. Early Malas MA et al.. Early Hum Dev 2004;78:1Hum Dev 2004;78:1--1313

We see also development We see also development of colonic haustra after of colonic haustra after 2525--26w, starting on the 26w, starting on the right colon.right colon.

Meconium by 36w GA, T1 imagingMeconium by 36w GA, T1 imaging


The distance from the The distance from the bladder base/neck to the bladder base/neck to the rectal culrectal cul--dede--sacsacincreases with the GA increases with the GA (10mm or greater, (10mm or greater, Saguintaah M, et al Ped Saguintaah M, et al Ped Radiol 2002).Radiol 2002).Important in the Important in the assessment of anorectal assessment of anorectal malformationsmalformations


NORMAL PATIENT FOR COMPARISON

PERSISTENT CLOACA

Assessment of Fetal GI TractAssessment of Fetal GI TractDisordersDisorders

Proximal GI Disorders:Proximal GI Disorders:

Esophageal atresia/TEFEsophageal atresia/TEF

Stomach malposition/ Abnormal stomach Stomach malposition/ Abnormal stomach size.size.

Duodenal obstruction.Duodenal obstruction.


Small bowel disorders:Small bowel disorders:Bowel obstructionBowel obstructionMeconium peritonitis/meconium Meconium peritonitis/meconium pseudocystpseudocystIntestinal cystic disease Intestinal cystic disease (also affecting (also affecting proximal and distal bowel, but less frequently):proximal and distal bowel, but less frequently):

Enteric duplication cystEnteric duplication cystMesenteric/omental cyst (lymphatic Mesenteric/omental cyst (lymphatic malformations)malformations)


Large bowel abnormalities:Large bowel abnormalities:

Colonic atresiaColonic atresia

Anorectal malformationsAnorectal malformations

CloacaCloaca

Fetal Imaging of GI TractFetal Imaging of GI TractDisordersDisorders


Esophageal Esophageal atresiaatresia/TEF (/TEF (tracheotracheo--esophageal fistula)esophageal fistula)

Stomach: malposition/Abnormal stomach Stomach: malposition/Abnormal stomach sizesize

Duodenal obstructionDuodenal obstruction

Esophageal Atresia and/or TEFEsophageal Atresia and/or TEF

It results from abnormal It results from abnormal development of the development of the tracheoesophageal tracheoesophageal septum ( a process that septum ( a process that normally is completed by normally is completed by 8 weeks).8 weeks).

www.learningradiology.com/.../tefdiagram.jpg

Esophageal Atresia and/or TEF Esophageal Atresia and/or TEF DiagnosisDiagnosis

Sonographic diagnosis of Esophageal Sonographic diagnosis of Esophageal AtresiaAtresia (EA) with (EA) with or w/o TEF can be suspected based on:or w/o TEF can be suspected based on:

Absent or small stomach, usually associated to poly Absent or small stomach, usually associated to poly after 20w. after 20w. Polyhydramnios with IUGRPolyhydramnios with IUGR

Proximal esophageal pouch: Proximal esophageal pouch: ““the pouch signthe pouch sign””(transient)(transient)

Direct visualization of upper esophageal Direct visualization of upper esophageal pouch on MRI. RT lung agenesis.pouch on MRI. RT lung agenesis.

Transient distention of upper pouch!!!

PostnatalPostnatalDOL#1DOL#1

Esophageal atresia +TEF, RT lung agenesis+ segmentation vertebral anomaly.

Prenatal (34w GA)



Esophageal atresia/TEFEsophageal atresia/TEF

Stomach:Stomach: malposition/Abnormal stomach malposition/Abnormal stomach sizesize


Abnormal Stomach PositionAbnormal Stomach Position

Abnormal intraabdominal position: situs anomaly.

Intrathoracic stomach: LT CDH

Abnormal Stomach SizeAbnormal Stomach Size

Enlarged stomach is characteristic of proximal Enlarged stomach is characteristic of proximal obstruction.obstruction.

Enlarged Stomach and PolyhydramniosEnlarged Stomach and Polyhydramnios

Proximal Obstruction (Duodenal Atresia)Proximal Obstruction (Duodenal Atresia)


Enlarged stomach is characteristic of proximal Enlarged stomach is characteristic of proximal obstruction.obstruction.Persistent small fluid distention of the stomach, Persistent small fluid distention of the stomach, in the absence of adjacent mass, should raise in the absence of adjacent mass, should raise concern for:concern for:

Esophageal atresia/TEFEsophageal atresia/TEF (especially if (especially if polyhydramnios after 20w).polyhydramnios after 20w).

Small Stomach and PolyhydramniosSmall Stomach and Polyhydramnios

Micrognathia.Micrognathia.Esophageal Atresia and TEF w/o Direct SignsEsophageal Atresia and TEF w/o Direct Signs


Enlarged stomach is characteristic of proximal Enlarged stomach is characteristic of proximal obstruction.obstruction.Persistent small fluid distention of the stomach, Persistent small fluid distention of the stomach, in the absence of adjacent mass, should raise in the absence of adjacent mass, should raise concern for:concern for:

Esophageal atresia/TEF (especially if Esophageal atresia/TEF (especially if polyhydramnios after 20w).polyhydramnios after 20w).Congenital microgastriaCongenital microgastria (typical normal amniotic (typical normal amniotic fluid in 3fluid in 3rdrd Trimester). Trimester).

Small Stomach, Normal AF, Dilated Esophagus:Small Stomach, Normal AF, Dilated Esophagus:Congenital Microgastria (28w)Congenital Microgastria (28w)

Dilated tortuous esophagus microgastria

Congenital Microgastria Congenital Microgastria DOL#1DOL#1

Congenital Microgastria: UGICongenital Microgastria: UGI

Very dilated tortuous esophagus, incompetent lower esophageal sphincter (severe GER seen during the exam).

Congenital MicrogastriaCongenital Microgastria

Small sliding hiatal hernia, small midline vertical stomach and malrotation.

Congenital MicrogastriaCongenital MicrogastriaPre and Postnatal Imaging CorrelationPre and Postnatal Imaging Correlation


Microgastria

Duodenal dilatation

Malrotation

Duodenal stenosis (at surgery as well with annular pancreas and preduodenal portal vein)


Congenital Congenital MicrogastriaMicrogastria

It is a rare anomaly usually associated with other It is a rare anomaly usually associated with other malformations, especially VACTERL association, malformations, especially VACTERL association, asplenia (right asplenia (right ––sided isomerism) malrotation, sided isomerism) malrotation, congenital heart disease and musculoskeletal anomalies.congenital heart disease and musculoskeletal anomalies.Due to arrested foregut development, the normal Due to arrested foregut development, the normal rotation of the stomach does not occur. A small tubular rotation of the stomach does not occur. A small tubular midline stomach remains with incompetent cardias and midline stomach remains with incompetent cardias and dilated esophagus (GER).dilated esophagus (GER).Feeding difficulties: surgical management.Feeding difficulties: surgical management.


Proximal GI Disorders:Proximal GI Disorders:Esophageal atresia/TEFEsophageal atresia/TEFStomach: malposition/ Abnormal stomach sizeStomach: malposition/ Abnormal stomach sizeDuodenal obstructionDuodenal obstruction

Intrinsic:Intrinsic: atresiaatresia/stenosis/stenosis

Obstructive midgut malrotation (band, volvulus)Obstructive midgut malrotation (band, volvulus)

Extrinsic: preduodenal portal vein, annular pancreas, Extrinsic: preduodenal portal vein, annular pancreas, duodenal duplication, choledocal cyst.duodenal duplication, choledocal cyst.

Duodenal ObstructionDuodenal ObstructionDuodenal atresiaDuodenal atresia

Duodenal atresia is usually a blind end atresia and less Duodenal atresia is usually a blind end atresia and less likely a diaphragm or membrane that interrupts the likely a diaphragm or membrane that interrupts the duodenal lumenduodenal lumen

A previous cited explanation was failure of reA previous cited explanation was failure of re--vacuolization of the duodenal lumen from 8vacuolization of the duodenal lumen from 8--10 weeks 10 weeks of gestation. However other authors suggest that it is of gestation. However other authors suggest that it is result of vascular impairment during gut development.result of vascular impairment during gut development.

Duodenal ObstructionDuodenal ObstructionDuodenal atresiaDuodenal atresia

Polyhydramnios occurs in all cases of typical duodenal Polyhydramnios occurs in all cases of typical duodenal atresia during 3atresia during 3rdrd T (if earlier, EA (esophageal T (if earlier, EA (esophageal atresiaatresia) ) associated should be suspected).associated should be suspected).

Associated anomalies (Aprox 50% ): Associated anomalies (Aprox 50% ): Skeletal (vertebral/rib, sacral agenesis, radial Skeletal (vertebral/rib, sacral agenesis, radial anomalies, talipes equinovarus)anomalies, talipes equinovarus)GI: EA, jejunoGI: EA, jejuno--ileal atresia, biliary atresia, pancreatic ileal atresia, biliary atresia, pancreatic ductal atresia, anoductal atresia, ano--rectal atresia.rectal atresia.Cardiovascular, Genitourinary.Cardiovascular, Genitourinary.Chromosomal: T21 in 30Chromosomal: T21 in 30--40%, although conversly 40%, although conversly in T21 DA is seen in 5%)in T21 DA is seen in 5%)

Duodenal Atresia+ polyhydramniosDuodenal Atresia+ polyhydramnios31w GA: Maternal IDDM and T 2131w GA: Maternal IDDM and T 21

11stst day of life (31w day of life (31w premature). T 21premature). T 21Replogle in stomach.Replogle in stomach.Air in stomach and Air in stomach and duodenal bulb. Not in duodenal bulb. Not in other segments.other segments.Prominent heart size Prominent heart size (Congenital Heart (Congenital Heart Disease)Disease)



IntrinsicIntrinsic

Obstructive midgut malrotation (band, Obstructive midgut malrotation (band, volvulus)volvulus)

ExtrinsicExtrinsicCholedocal cystCholedocal cyst

Choledocal Cyst: 21 w GA Referred as r/o Choledocal Cyst: 21 w GA Referred as r/o Duodenal AtresiaDuodenal Atresia

Choledocal Cyst: 21 w GA Referred as r/o Choledocal Cyst: 21 w GA Referred as r/o Duodenal AtresiaDuodenal Atresia

The stomach and duodenum drape over the cyst, anteriorly. No biliary ductal dilatation.

Choledocal Cyst: Postnatal correlationCholedocal Cyst: Postnatal correlation

21w GA Postnatal: 1 ½ months of age

Choledocal Cyst: Introperative CholangiogramCholedocal Cyst: Introperative Cholangiogram


Small bowel disorders:Small bowel disorders:

Bowel obstructionBowel obstruction

Meconium peritonitis/meconium pseudocystMeconium peritonitis/meconium pseudocystIntestinal cystic diseaseIntestinal cystic disease (also affecting proximal (also affecting proximal and distal bowel, but less frequently):and distal bowel, but less frequently):


Small Bowel ObstructionSmall Bowel ObstructionBowel AtresiaBowel Atresia

JejunoJejuno--ilealileal atresia and stenosis usually result atresia and stenosis usually result from vascular impairment during embryologic from vascular impairment during embryologic developmentdevelopment

SporadicSporadicSecondary to a predisposing disorder such as Secondary to a predisposing disorder such as volvulusvolvulus or or gastroschisisgastroschisis..AppleApple--peel atresia, which peel atresia, which may be may be familialfamilial, probably , probably results from oclussion of a branch of the SMA. This results from oclussion of a branch of the SMA. This type can be associated to other malformations type can be associated to other malformations (Congenital Heart Disease,(Congenital Heart Disease,……))


Type I: mucosal diaphragm Type I: mucosal diaphragm with intact wall (20%)with intact wall (20%)Type II: blind ends of bowel Type II: blind ends of bowel connected by a fibrous band connected by a fibrous band (32%)(32%)Type III A, blind ends of Type III A, blind ends of bowel separated by a bowel separated by a mesenteric gap (48%)mesenteric gap (48%)Grosfeld added 2 additional Grosfeld added 2 additional types:types:

Type III B, Type III B, ““apple peelapple peel”” atresiaatresiaType IV, multiple atresiasType IV, multiple atresias

III A is the most frequent type.III A is the most frequent type.

www.cincinnatichildrens.org


The sites of small bowel atresia are:The sites of small bowel atresia are:Proximal jejunum (31%)Proximal jejunum (31%)Distal jejunum (20%)Distal jejunum (20%)Proximal ileum (13%)Proximal ileum (13%)Distal ileum (36%)Distal ileum (36%)

More than one site involved (6%).More than one site involved (6%).

Small Bowel ObstructionSmall Bowel ObstructionJejunal Atresia (37w)Jejunal Atresia (37w)

Small Bowel ObstructionSmall Bowel ObstructionJejunal Atresia (DOL#1)Jejunal Atresia (DOL#1)

The baby was born the next day, was transferred and got surgery on DOL#1, w/o any further imaging!!!!

Type I Jejunal Atresia and MalrotationType I Jejunal Atresia and Malrotation

Small Bowel ObstructionSmall Bowel ObstructionGastroschisis/VolvulusGastroschisis/Volvulus

Gastroschisis with dilated eviscerated bowelGastroschisis with dilated eviscerated bowel

Small Bowel ObstructionSmall Bowel ObstructionGastroschisis/VolvulusGastroschisis/Volvulus

Complicated gastroschisis. Dilated eviscerated bowel Complicated gastroschisis. Dilated eviscerated bowel w/o mechonium in rectum, supporting obstruction.w/o mechonium in rectum, supporting obstruction.

Atresia vs volvulus.Atresia vs volvulus.Dilated stomach due to obstruction or tight Dilated stomach due to obstruction or tight anterior abdominal wall defect.anterior abdominal wall defect.

One week later the bowel was normal in caliber on One week later the bowel was normal in caliber on outside F/U US, and this specific event was considered outside F/U US, and this specific event was considered consistent with volvulus.consistent with volvulus.

Possibly, as a result of that, however, bowel atresia was Possibly, as a result of that, however, bowel atresia was found at birth.found at birth.


Small bowel disorders:Small bowel disorders:Bowel obstruction Bowel obstruction Meconium peritonitisMeconium peritonitis/meconium /meconium pseudocystpseudocystIntestinal cystic diseaseIntestinal cystic disease (also affecting proximal (also affecting proximal and distal bowel, but less frequently):and distal bowel, but less frequently):


Meconium PeritonitisMeconium Peritonitis

Sterile chemical peritonitis results usually from Sterile chemical peritonitis results usually from in utero bowel perforation in the setting of in utero bowel perforation in the setting of obstruction.obstruction.It can also be seen in the setting of persistent It can also be seen in the setting of persistent cloaca.cloaca.Idiopathic vascular impairment Idiopathic vascular impairment (occlusion/thrombosis of mesenteric arteries) (occlusion/thrombosis of mesenteric arteries) and cocaine exposure are also potential and cocaine exposure are also potential etiologies.etiologies.Iatrogenic.Iatrogenic.

Meconium PeritonitisMeconium Peritonitis

Ascitis might be the only finding in the acute Ascitis might be the only finding in the acute phase.phase.Calcifications could be seen after 1Calcifications could be seen after 1--2weeks.2weeks.Overtime the inflammatory response may Overtime the inflammatory response may sealsealthe perforation spontaneously.the perforation spontaneously.It can lead to It can lead to meconium pseudocystmeconium pseudocyst formation: formation: contained bowel perforation.contained bowel perforation.

Iatrogenic Meconium PeritonitisIatrogenic Meconium PeritonitisTTTS with prior amnioreduction TTTS with prior amnioreduction (20w GA)(20w GA)

Blood clot Blood clot surrounding surrounding recipientrecipient’’s body, s body, not seen on not seen on prior US.prior US.

Iatrogenic Meconium PeritonitisIatrogenic Meconium Peritonitis

26w premature (recipient twin)26w premature (recipient twin)

Iatrogenic Meconium PeritonitisIatrogenic Meconium Peritonitis26w premature (recipient twin)26w premature (recipient twin)

No microcolon. Normal retrograde filling of the small bowel.

Sealed perforation. No surgery required.


Small bowel disorders:Small bowel disorders:Bowel obstruction Bowel obstruction Meconium peritonitis/Meconium peritonitis/meconium meconium pseudocystpseudocystIntestinal cystic diseaseIntestinal cystic disease (also affecting proximal (also affecting proximal and distal bowel, but less frequently):and distal bowel, but less frequently):


Meconium PseudocystMeconium PseudocystBowel Atresia (ileal)Bowel Atresia (ileal)

US at 27wMR at 28w

Complex cyst with fluid-fluid level

Meconium PseudocystMeconium PseudocystBowel Atresia (ileal)Bowel Atresia (ileal)

Only meconium in distal rectum!



Bowel obstruction Bowel obstruction Meconium peritonitis/meconium pseudocystMeconium peritonitis/meconium pseudocystIntestinal cystic disease:Intestinal cystic disease:

Enteric duplication cystEnteric duplication cyst

Mesenteric/omental cyst (lymphatic Mesenteric/omental cyst (lymphatic malformations)malformations)

Enteric Duplication CystEnteric Duplication Cyst

May develop anywhere along May develop anywhere along the course of the digestive the course of the digestive tract although the stomach is tract although the stomach is the least frequent site of the least frequent site of involvement.involvement.

Located on the mesenteric Located on the mesenteric side of the intestine, most side of the intestine, most often in the ileum and do not often in the ileum and do not usually communicate with the usually communicate with the normal gut, unless tubular in normal gut, unless tubular in type.type.Spherical cysts>tubular. Spherical cysts>tubular. Multiple cysts can be seen.Multiple cysts can be seen.

Postnatal US: duodenal duplication cyst

Small Ileal Duplication CystSmall Ileal Duplication Cyst



Bowel obstructionBowel obstruction

Meconium peritonitis/meconium Meconium peritonitis/meconium pseudocystpseudocyst

Intestinal cystic disease:Intestinal cystic disease:

Enteric duplication cystEnteric duplication cystMesenteric/omental cystMesenteric/omental cyst (lymphatic (lymphatic malformations)malformations)

Mesenteric/Omental CystMesenteric/Omental Cyst(Lymphatic Malformations)(Lymphatic Malformations)

Mesenteric/omental cysts usually represent Mesenteric/omental cysts usually represent abdominal lymphatic malformations.abdominal lymphatic malformations.

The most common location is the small bowel The most common location is the small bowel mesentery, followed by the large bowel mesentery , mesentery, followed by the large bowel mesentery , omentum and retroperitoneum.omentum and retroperitoneum.Typically: large septated cystic mass with preferential Typically: large septated cystic mass with preferential left location.left location.When the cyst is When the cyst is unilocularunilocular, the differential diagnosis , the differential diagnosis will include other abdominal cystic masses.will include other abdominal cystic masses.

Mesenteric Cyst LUQ 31w GA (Vascular Mesenteric Cyst LUQ 31w GA (Vascular Malformation, Lymphatic Type)Malformation, Lymphatic Type)

Several Episodes of Bilious Emesis Soon After Several Episodes of Bilious Emesis Soon After Birth. Proximal Obstruction.Birth. Proximal Obstruction.

DOL#1 (35w)DOL#1 (35w)

Mesenteric Cyst LUQ (Vascular Mesenteric Cyst LUQ (Vascular Malformation, Lymphatic Type)Malformation, Lymphatic Type)

Complex cystic abdominal mass.Complex cystic abdominal mass.Proximal obstruction with bilious emesis.Proximal obstruction with bilious emesis.Surgery on DOL#1: Surgery on DOL#1: Example of complication of mesenteric Example of complication of mesenteric cyst, leading to volvulus/atresiacyst, leading to volvulus/atresia. This happened after the MR . This happened after the MR and prior to delivery . 180and prior to delivery . 180--270 degree torsion of the proximal 270 degree torsion of the proximal jejunum on the cyst pedicle with a focal area of atresia.jejunum on the cyst pedicle with a focal area of atresia.





CloacaCloaca

Colonic AtresiaColonic Atresia

Dilated bowel (1st detected at 23w US). Echogenic content and haustral pattern to level of expected distal transverse colon. AFI was normal (18.7cm at 30w)

30w GA with Colonic Atresia30w GA with Colonic Atresia

Meconium has not reached the colon as a sign of obstruction. There is, however, no proximal bowel dilatation or polyhydramnios.



The hugely dilated segment has relatively bright T1 signal The hugely dilated segment has relatively bright T1 signal (probably amniotic fluid mixed with meconium)(probably amniotic fluid mixed with meconium)

Final diagnosis was transverse colonic atresiaFinal diagnosis was transverse colonic atresia


Rare disease of ischemic mechanism.Rare disease of ischemic mechanism.AFI in colonic atresia could be normal.AFI in colonic atresia could be normal.Note also that in this case there was no proximal Note also that in this case there was no proximal bowel dilatation.bowel dilatation.Increased mortality seems to be correlated with Increased mortality seems to be correlated with surgical treatment performed after 72h of life surgical treatment performed after 72h of life (Etensel et al. 2005). This highlights the interest (Etensel et al. 2005). This highlights the interest of prenatal diagnosis.of prenatal diagnosis.





CloacaCloaca

Persistent CloacaPersistent Cloaca

Cloaca is defined as a Cloaca is defined as a defect in which the defect in which the urinary tract, the vagina urinary tract, the vagina and the rectum are fused, and the rectum are fused, creating a single creating a single common channel.common channel.It can lead to bladder It can lead to bladder obstruction, obstruction, hydrometrocolpos or hydrometrocolpos or colonic dilatation.colonic dilatation.

A. Pena, M Levitt. Seminars in Neonatology 2003, 8;249-253


Typically affects Typically affects females with an females with an incidence of 1/50,000 incidence of 1/50,000 live births.live births.

The perineum will The perineum will present a single present a single opening.opening.


It is thought to be due to It is thought to be due to failure of the urorectal failure of the urorectal septum to join the septum to join the cloacal membrane during cloacal membrane during the 4th to 6th weeks of the 4th to 6th weeks of embryonic development.embryonic development.

Patients with cloaca Patients with cloaca present a wide anatomic present a wide anatomic spectrum depending on spectrum depending on when the arrested when the arrested development happens.development happens.


The length of the The length of the common channel has common channel has prognostic and prognostic and theraupetic implications.theraupetic implications.

Common channel <3 cm Common channel <3 cm (63%): associated urologic (63%): associated urologic defects in 59%defects in 59%Common channel>3cm Common channel>3cm (38%): 91% associated (38%): 91% associated urologic defects, complex urologic defects, complex surgical repair, decreased surgical repair, decreased potential for urinary potential for urinary controlcontrol


Persistent CloacaPersistent CloacaPrenatal diagnosis allows Prenatal diagnosis allows time fortime for

Parental counselingParental counselingPlanning of the delivery at Planning of the delivery at a Tertiary Center a Tertiary Center (equipped with neonatal (equipped with neonatal intensive care and intensive care and pediatric surgical and pediatric surgical and urologic facilities)urologic facilities)Timely diagnosis of Timely diagnosis of cloacal anomalies and cloacal anomalies and associated complications associated complications will improve the outcome. will improve the outcome.

Persistent Cloaca Persistent Cloaca US Prenatal DiagnosisUS Prenatal Diagnosis

Hydrocolpos can develop: This is not specific!!!!Hydrocolpos can develop: This is not specific!!!!Cystic pelvic mass, often septated in association with Cystic pelvic mass, often septated in association with oligohydramnios and impaired fetal growth.oligohydramnios and impaired fetal growth.



Cloacal anomaly is being Cloacal anomaly is being reported as simulating reported as simulating megacystis in the 1megacystis in the 1stst

trimester. (trimester. (Taipale P et al J Clin Taipale P et al J Clin Ultrasound 2004;32:419Ultrasound 2004;32:419--422)422)

FluidFluid--debris level are debris level are considered highly considered highly suggestive (mucous, suggestive (mucous, descamated epithelium descamated epithelium and meconium).and meconium).


Sometimes transient ascitis develops (urine scaping from Sometimes transient ascitis develops (urine scaping from the cloaca via the fallopian tubes). Also not specific! the cloaca via the fallopian tubes). Also not specific!

Ambiguous genitalia, hydronephrosis and absent distention Ambiguous genitalia, hydronephrosis and absent distention of the urinary bladder are additional findings.of the urinary bladder are additional findings.

Placenta

Hydrocolpos Ascitis


Presence of Presence of intraluminal calcificationsintraluminal calcifications in the in the fetal abdomen (result of mixing of urine and fetal abdomen (result of mixing of urine and meconium) would be meconium) would be the most specific sign of the most specific sign of rectorecto--urinary fistulaurinary fistula

Fetal MRIFetal MRIAnorectal AssessmentAnorectal Assessment

The rectal culThe rectal cul--dede--sac will be expected to be higher than sac will be expected to be higher than in normal patients, especially with a high anorectal in normal patients, especially with a high anorectal malformation or in a cloaca with long common malformation or in a cloaca with long common channel.channel.

29w

31w38w

28w: persistent cloaca with long common channel

Normal examples

Distal rectum!!!

Fetal MRIFetal MRIAnorectal AssessmentAnorectal Assessment

With imperforated anus with rectoWith imperforated anus with recto--urinary fistula and with urinary fistula and with persistent cloaca we could see fluid in the distal bowel due to persistent cloaca we could see fluid in the distal bowel due to the the communication with the urinary system. (Saguintaah M, et al Ped communication with the urinary system. (Saguintaah M, et al Ped Radiol 2002). Mandell J et al J Pediatr Surg 1992;27:82Radiol 2002). Mandell J et al J Pediatr Surg 1992;27:82--84.84.

Mildly dilated distal bowel with fluid and meconium signal, also noted within a bilobed bladder

Clinical CasesClinical Cases

Sect. 1

Sect. 2

Sect. 3

Case #1Case #1

Clinical history:Clinical history:Dextrocardia (congenital heart disease), Dextrocardia (congenital heart disease), polyhydramnios and persistently small polyhydramnios and persistently small stomach. stomach. Clinical concern for esophageal atresia.Clinical concern for esophageal atresia.GA: 27wGA: 27w

Case #1Case #1

Case #1Case #1

Did you see the findings?Did you see the findings?The next slide will review them and will give you The next slide will review them and will give you the diagnosis.the diagnosis.

Esophageal Atresia with TEFEsophageal Atresia with TEF: Direct Visualization : Direct Visualization of Upper Esophageal Pouch on MRIof Upper Esophageal Pouch on MRI

Transient distention of upper pouch!!!

Minimal gastric distention

Case #2Case #2

Clinical history:Clinical history:30 week gestation with polyhydramnios and 30 week gestation with polyhydramnios and persistent gastric and duodenal distention.persistent gastric and duodenal distention.Amniocentesis: Trisomy 21Amniocentesis: Trisomy 21Maternal diabetes.Maternal diabetes.

Case #2Case #2

Case #2Case #2

Same patient Same patient close to the end close to the end of the exam.of the exam.

Case #2Case #2

Do you have a diagnosis?Do you have a diagnosis?What happened close to the end of the exam?What happened close to the end of the exam?On next slide we will review the findings.On next slide we will review the findings.

Duodenal AtresiaDuodenal Atresia and Fetal Vomitingand Fetal Vomiting

Hyperperistaltic gastroduodenal fluid dilatation. Eventually decompressed!!!!!!

Case #3Case #3

Clinical history:Clinical history:34w gestation with abnormal brain findings 34w gestation with abnormal brain findings on US. MRI was performed to better define. on US. MRI was performed to better define. We will be presenting images from the We will be presenting images from the abdominal assessment.abdominal assessment.

Case #3Case #3

Case #3Case #3

Do you have a diagnosis?Do you have a diagnosis?Next slide will review the findings.Next slide will review the findings.

Case #3Case #3

Fluid filled bowel on the right (small bowel)

Case #3Case #3

Meconium filled bowel on the left (colon)

Example of MalrotationExample of Malrotation Undetected on USUndetected on US

Case #4Case #4

Clinical history:Clinical history:Dilated bowel 1Dilated bowel 1stst detected at 23w US.detected at 23w US.Normal gastric distention and normal Normal gastric distention and normal amniotic fluid at 28w.amniotic fluid at 28w.28w GA at the time of fetal MRI28w GA at the time of fetal MRI

Case #4Case #4

Case #4Case #4

SAGITAL

Case #4Case #4

Is there an obstructive pattern?Is there an obstructive pattern?We will review the signs on the next slide.We will review the signs on the next slide.

Obstructive Pattern ConfirmedObstructive Pattern Confirmed

Bowel dilatation involving a few loops (proximal), with meconium.

SAGITAL

Minimal meconium in the rectum, absent in the colon.

35w newborn 135w newborn 1stst day of lifeday of life28w GA

Contrast Enema DOL#1Contrast Enema DOL#1

Microcolon but contrast refluxed into large portion of nondilated small bowel. The working diagnosis was jejunal atresia.

Final Diagnosis: Jejunal Atresia

Jejunal AtresiaJejunal Atresia

28w GA DOL#1

Case #5Case #5

Clinical history:Clinical history:Congenital heart disease (CHD).Congenital heart disease (CHD).LT Multicystic Dysplastic kidney (MCDK).LT Multicystic Dysplastic kidney (MCDK).Normal amniotic fluid.Normal amniotic fluid.GA at the time of US and MRI: 26wGA at the time of US and MRI: 26w

Case #5Case #5

Bladder

Case #5Case #5

Case #5Case #5

The MRI shows an additional finding, not The MRI shows an additional finding, not suspected on US. Did you see it?.suspected on US. Did you see it?.On the next slides we will review the findings.On the next slides we will review the findings.

Case #5Case #53v cord. Mildly distended bladder. No hydrocolpos. Normal AF.

Case #5Case #5

Normal RK, MCD LKNormal RK, MCD LKNo bowel dilatation identified.No bowel dilatation identified.

The rectal cul-de-sac is high, at the level of the bladder neck and not beyond, as expected in normal patients.

High T2 signal in the distal bowel is suggesting abnormal fluid content (communication with urinary system is suspected!!!)

NORMAL PATIENT FOR COMPARISON

Working diagnosis should be ano-rectal malformation, most likely cloaca.

2D FIESTASSFSE

SSFSEFSPGR (T1)

FSPGR (T1)

US: DOL#1US: DOL#1

Distal bowel

bladder

No hydrocolpos

3 month old status post diverting 3 month old status post diverting colostomy. Cloacagramcolostomy. Cloacagram

Common channel

Distal bowelDistal bowel

Common channel

Bladder

Müllerian remnant

Bladder

Müllerian remnant

Catheters in mucous fistula, and through the common channel in the bladder and distal rectum

3 month old status post diverting 3 month old status post diverting colostomy. Cloacagramcolostomy. Cloacagram

Distal bowel

Common channel

Bladder

Müllerian remnant

Cloaca with relatively long common channel (3.5cm)

Case #6Case #6

Clinical history:Clinical history:Cystic abdominoCystic abdomino--pelvic mass first detected at pelvic mass first detected at 12 weeks.12 weeks.Female fetus.Female fetus.Rule out cloaca.Rule out cloaca.20 w 5d GA at the time of this work up.20 w 5d GA at the time of this work up.

Case #6Case #6

Case #6Case #6

Case #6Case #6

1. Is this cyst a hydrocolpos or enlarged bladder?1. Is this cyst a hydrocolpos or enlarged bladder?2. Is the rectum filled with meconium as we 2. Is the rectum filled with meconium as we would expect in a normal 20 w gestation?would expect in a normal 20 w gestation?3. Are you concern about cloaca, or would you 3. Are you concern about cloaca, or would you consider another differential diagnosis?consider another differential diagnosis?4. The answers will be reviewed in the next 4. The answers will be reviewed in the next slides.slides.

Case #6Case #6

Case #6Case #6

1. A normal bladder is identified.

The cyst is not extending posterior to the bladder as expected for hydrocolpos

Bladder

Case #6: Hepatic CystCase #6: Hepatic Cyst

2. Normal meconium

3. No concern for cloaca

Differential diagnosis was hepatic cyst, mesenteric/omental cyst, ovarian cyst. Final diagnosis: Hepatic cyst

Case #7Case #7

Clinical history:Clinical history:Bladder outlet obstruction since 11w GA.Bladder outlet obstruction since 11w GA.Bilateral hydronephrosis.Bilateral hydronephrosis.2 vessel cord.2 vessel cord.Normal amniotic fluid.Normal amniotic fluid.Congenital heart disease.Congenital heart disease.Clubfeet.Clubfeet.Female fetus.Female fetus.MRI performed at 28w GA.MRI performed at 28w GA.

Ano-rectal assessment:

Is the rectal cul-de-sac normally located?

POSTNATAL VCUG (baby has a single perineal opening)

Do you have now a diagnosis?bladder

Distal bowel

SAG

POSTNATAL VCUG

Cloaca with long common channel

Can you summarize the findings on this baby with an acronym?

V

R

C

A

TE

L

Segmentation anomaly (scoliosis)

Ano-rectal malformation

Heart disease Esophageal

atresia-TEF

Renal and limb anomalies

MRI, when indicated, in combination with US MRI, when indicated, in combination with US is helping prenatal care: is helping prenatal care:

Improving counseling of the patientImproving counseling of the patientGuiding management.Guiding management.Helping clinicians to be prepared for critically Helping clinicians to be prepared for critically ill neonates.ill neonates.

ReferencesReferences ::Couture D (2008): Couture D (2008): ““Fetal Gastrointestinal Tract: US and MRFetal Gastrointestinal Tract: US and MR””. In: . In: Gastrointestinal Tract Gastrointestinal Tract SonographySonography in Fetuses and Children. Springerin Fetuses and Children. Springer--VerlagVerlag, pp 1, pp 1--84.84.

BruggerBrugger PC, Prayer D. Fetal abdominal magnetic resonance imaging. EJR PC, Prayer D. Fetal abdominal magnetic resonance imaging. EJR (2006) 57:278(2006) 57:278--293. 293.

VeyracVeyrac C, et al. MRI of the fetal GI tract abnormalities. C, et al. MRI of the fetal GI tract abnormalities. AbdomAbdom Imaging Imaging (2004) 29:411(2004) 29:411--420.420.

SaguintaahSaguintaah M, et al. MRI of the fetal Gastrointestinal tract. Pediatric M, et al. MRI of the fetal Gastrointestinal tract. Pediatric RadiolRadiol (2002) 32:395(2002) 32:395--404.404.

Warne S. et al. Prenatal diagnosis of cloacal anomalies. BJU International (2002), 89:78-81.