Presentation on theme: "Fetal Abnormalities and Anomalies"— Presentation transcript:
1Fetal Abnormalities and Anomalies In this presentation will be discussing various issues related to imaging of the fetus including some discussion about the evaluation of fetal abnormalities and anomalies.
2Fetal Abnormalities Detectable by Ultrasound BrainAnencephalyHydrocephalusChiari deformitiesEncephaloceleSpineSpina bifida cysticaMyelomeningoceleRenalHydronephrosisRenal agenesisCardiacChambersOrientationGeneralAbdominal wall defectsLung abnormalitiesA variety of fetal abnormalities may be detected by a variety of imaging techniques including ultrasound. Abnormalities of the brain including anencephaly, hydrocephalus, Chiari deformities and encephalocele might be detected prenatally by ultrasound. Additionally abnormalities of the spine including spina bifida cystic, and myelomeningocele maybe evaluated prenatally by ultrasound. Abnormalities of the kidneys including hydronephrosis or the absence of a kidney renal agenesis are identifiable by ultrasound. Cardiac abnormalities including abnormal chamber development and orientation can also be evaluated by ultrasonography. A variety of abdominal wall defects and possibly lung abnormalities are also detectable by ultrasound.
3Hydrocephalus Dilated ventricles Large sausage like hypoechoic area represents dilated lateral ventricleIn this later pregnancy we demonstrate the presence of hydrocephalus as demonstrated by the presence of dilated ventricles presenting on the images . These appear as large sausage like hypoechoic areas representing the dilated lateral ventricles. Note the dilated lateral ventricle between the two arrow heads.
4Intestinal Tract Abnormalities Detectable by Ultrasound OmphaloceleAbdominal wall defects and gastroschisisMidgut malrotationFocal intestinal atresiaA variety of abnormalities of the intestinal tract may be detectable by ultrasound. Others will require the use of barium or plain film imaging following birth. Omphalocele, abdominal wall defects and gastroschisis are easily detectable by ultrasound techniques prenatally. Midgut malrotation will require barium evaluation following birth and intestinal atresias may be detected by plain film evaluation or other methods following delivery.
5Normal Development of Intestinal Tract At 9 weeks there is physiologic herniation of the small bowel into the umbilical cordThe small bowel rotates 90 degrees counterclockwise around the superior mesenteric arteryAt 12 weeks the small bowel returns into the abdominal cavity while rotating an additional 180 degrees counterclockwise around the superior mesenteric arteryTotal rotation of 270 degreesIf you recall, in embryologic development, normally at 9 weeks, there is a physiologic herniation of the small bowel into the root of the umbilical cord. During the course of the gestational process the small bowel rotates 90 degrees counterclockwise about the superior mesenteric artery. At 12 weeks of gestation the small bowel returns into the abdominal cavity while rotating an additional 180 degrees counterclockwise around the superior mesenteric artery. The total rotation being 270 degrees.
6Omphalocele Midline defect Covering membrane Contains organs or bowel Cord from apex of massDiagrammatically on this slide we demonstrate the presence of Omphalocele. A midline defect with a covering membrane, the two most important features of this abnormality. This midline defect contains organ or bowel and will have the umbilical cord at the apex of the projection from the anterior bowel wall.
7Omphalocele Axial view mid-abdomen Soft tissue mass extending to right Abdominal contents outside the fetal abdomenNote: enclosed by a membrane (arrows)Ultrasonographically here as a demonstration of an axial view through the midportion of the fetal abdomen note the soft tissue mass extending to the right on this image. Abdominal contents are outside of the fetal abdomen, but are enclosed by a membrane as indicated by the arrows.FetalAbdomen
8Gastroschisis Defect of anterior wall Lateral to umbilicus Bowel loops float in amniotic fluidCord separateContrast the findings of Omphalocele with the findings of gastroschisis as seen on this line diagram. Also a defect in the anterior abdominal wall, this defect however occurs lateral to the umbilicus. Bowel loops are noted to be free floating within the amniotic fluid. The cord has a separate, but normal insertion into the anterior bowel wall and there are no membranes covering the intestinal content.
9Gastroschisis Lobulated echogenic mass Free floating loops of bowel in the amniotic fluidAbdominalContentsFetalAbdomenHere, ultrasonographically we have a demonstration of gastroschisis. A lobulated echogenic mass representing abdominal contents as indicated by the arrows, a normal insertion of the umbilical cord into the apex of the fetal abdomen and free-floating loops of bowel in the amniotic fluid.UmbilicalCord
10Normal UGI, Small BowelSmall bowel distributed throughout the abdomen primarily to the leftLet’s talk a little bit about abnormalities of the small bowel and how they might be imaged. On this normal upper GI examination, we note the small bowel is distributed throughout the abdomen primarily in the center and left portions.
11Mid-gut Malrotation Barium UGI Stomach normal position Small bowel completely on right side of abdomenContrast the normal with this individual with a midgut malrotation. In this individual on the barium upper GI examination we note that the stomach is in a normal position, but that the small intestine is crowded entirely on the right side of the abdomen. Conversely the unopacified area in the left abdomen represents the colon
12Normal Barium Enema Normal colon frames the margins of the abdomen Here we see a normal barium enema examination where the colon frames the margins of the abdomen.
13Mid-gut Malrotation Barium enema Colon located entirely on the left side of the abdomenSame case as earlier mal-rotation caseContrast the normal barium enema to this finding of the midgut malrotation. In this case on the barium enema examination we note that the colon is located entirely on the left side of the abdomen. We also note that gas within small intestine is noted on the right. This is the same patient that we saw on the earlier case of malrotation.
14Duodenal Atresia Plain film upright abdomen “Double bubble” sign Air distended stomach and proximal duodenumAtresia involves second portion of the duodenumDuodenal atresia is another entity that can be demonstrated by the use of imaging techniques. In this case we identify the presence of two air collections or a “double bubble” sign on the frontal abdomen. Air is within the distended stomach and also within the distended proximal portion of the duodenum. An intrauterine event having led to an occlusion of the duodenumImage donated by Dr. Nancy Fitzgerald – Texas Children’s Hospital Houston Texas
15Skeletal Development Long Bones Diaphysis ossified at birth (shaft of long bone)Epiphysis radiolucent (cartilage) at birth except for distal femoral epiphysisDevelop Epiphyseal Ossification Centers (EOC) later in lifeI’d like to talk a little bit next about skeletal development of the long bones as detected by imaging. Recall that the diaphyses of long bones are ossified at birth. I am referring to the shafts of the long bones such as femurs, lower legs, humeri and forearms. The epiphysis at birth will be radiolucent cartilage except for the distal femoral epiphyses which should begin to calcify about the time of birth. The remainder of the epiphyseal ossification centers will develop later in life.
16Skeletal Development Long Bones PhysisCartilaginous plate between EOC and metaphysisResponsible for growth in lengthWhen ossifies (closes) – longitudinal growth stopsWeak point in the boneMetaphysisActive bone formation via formation and calcification of osteoidThe physis represents a cartilaginous plate that exists between the EOC and metaphysis. It is responsible for growth bone length. When this ossifies or closes, longitudinal bone growth will stop. Until this takes place, additional bone growth can be anticipated. The physis represents a weak point and therefore is subject to possible disruption and fracture under stressful situations. We will talk with a little bit more about that when we talk about fractures. The metaphysis represents the area of active bone formation. This occurring via formation and calcification of osteoid being laid down at the physis
17Bone Growth Abnormalities Cartilage growth deficiencyExample: AchondroplasiaOssification growth deficiencyExample: Osteogenic imperfectaMetabolic defectExample: HypophosphatasiaA variety of bone growth abnormalities can detected by imaging. Cartilaginous growth deficiency can be demonstrated by achondroplasia, the achondroplastic dwarf that I am sure you have at various times have identified on the street. Ossification growth deficiencies can also be detected such as osteogenesis imperfecta. Individuals present with blue sclera, a defect of bone formation having very soft fragile bones who may be born with multiple healed or healing fractures. Sometimes we can actually detect this intrautero. A variety of metabolic defects for example, hypophosphatasia and hyperparathyroidism and others can also lead to bone growth changes
18Osteogenesis Imperfecta Deficient peri- and endosteal ossificationMultiple fracturesHealing with deformities of bonesLimb shorteningHere is imaging of an individual with osteogenesis imperfecta. Because of the deficient peri and endosteal ossification process, this individual has soft bones subject to frequent fractures and considerable bowing of both femurs noted here as result of multiple fractures in various stages of healing. The healing takes place in these individuals with considerable deformity. They tend to have considerable limb shortening as well
19Achondroplasia Dwarfism Deficient cartilage growth Lower limbs with ruler to measure leg lengthShort limb bones with flaring metaphysesIn another individual with dwarfism, an achondroplastic dwarf, we identify a process of deficient cartilaginous growth. These individuals are having their lower limbs measured in order to measure leg length. On this particular image the appearance of achondroplasia includes flaring of the metaphysis with short length to the long bones.
20Cardiovascular System- Developmental Abnormalities Congenital heart diseaseIntra-cardiac septal defect (VSD, ASD)Patent ductus arteriosus (PDA)Tetralogy of Fallot (VSD, Pulmonary stenosis, Overiding Aorta, RV hypertrophy)Endocardial cushion defectPulmonary stenosis (PS)Congenital vessel anomalyCoarctation of aortaTransposition of the great vesselsThe cardiovascular system is also subject to a variety of developmental abnormalities that can be detected by imaging. These include such things as congenital heart disease, including intracardiac septal defects, ventricular septal defect, atrial septal defects, cardiac cushion defects, patent ductus arteriosus the tetralogy of Fallot and ventricular septal defect with pulmonary stenosis, overriding aorta and right ventricular hypertrophy representing the four components of the tetralogy. Endocardial cushion defects I mentioned just a moment ago, pulmonary stenosis and a variety of congenital vessel anomalies may also be detected by imaging techniques, including such entities as coarctation of the aorta and transposition of the great vessels.
21Normal Cardiac Anatomy Right heart borderUpper portion - SVC and ascending aortaLower portion – right atriumLeft heart borderUpper portion – aortic archMid portion – main pulmonary arteryLower middle portion – left atriumLower portion – left ventricleLet’s review for a moment, normal cardiac anatomy. Recall that the right heart border in its upper portion is made up of the superior vena cava and the ascending aorta is indicated by the subsequent arrows. The lower portion is made up of the borders of the right atrium that typically are not seen extending beyond the margin of spine. The left heart border in its upper aspect is made up of the aortic arch. Just beneath the aortic arch there is a concavity representing the aortic pulmonary window. This area is an area we look at for the development of adenopathy in the presence of lymphoma and metastases. The midportion of the left border, the second convexity represents the main pulmonary artery and the lower portion is made up of, first the left atrium and the lowermost aspect, the left ventricle.
22Normal Chest Lateral Anterior heart border Upper portion – aortic arch Mid portion – pulmonary arteryLower portion – right ventriclePosterior heart borderUpper portion – left atriumLower portion – left ventricle and IVCSimilarly on lateral projection we can identify the various portions of the cardiac silhouette. The anterior heart border being made up in its upper aspect by the aortic arch, in its midportion the origins the main pulmonary artery and finally the right ventricle just beneath the sternum. The posterior cardiac border being made up in its upper aspect by the left atrium and in its inferior aspect the left ventricle and finally, with a concavity directed posteriorly, the inferior vena cava as it arises from the posterior abdominal cavity and moves anteriorly to join into the right atrium.
23Atrial Septal Defect Increased pulmonary vascularity Small aortic arch Large main pulmonary arteryRight atrial and ventricular hypertrophyLet’s look at an atrial septal defect case. In this case there is increased pulmonary vascularity as a result of the atrial septal defect and diversion of left atrial blood into the right atrium. Also note a small aortic arch for the same reason. A portion of blood destined for the systemic circulation is being diverted through the atrial septal defect into the pulmonic circulation. Similarly a large main pulmonary artery is the result of the increased blood flow into the right atrium and ventricle. Finally the right atrial contours and the ventricular contours demonstrate the presence of hypertrophy and are increased in size as result of the increased blood flow into these chambers.
24Tetralogy of Fallot “Boot-shaped” heart Pulmonic stenosis (infundibulum)VSDRight ventricular hypertrophyOverriding aortaPulmonary circulation decreasedAnother individual, in this case, demonstrating a patient with tetralogy of Fallot. Tetralogy of Fallot, sometimes described as having a radiographic appearance of a boot-shaped heart is made up of pulmonic stenosis at the infundibulum, ventricular septal defect, right ventricular hypertrophy and an overriding aorta. This combination supports life but with significant issues with blood aeration as the pulmonary circulation is decreased in these individuals
25Renal Abnormalities Anomalies in size and form Anomalies in position Horseshoe kidneyAnomalies in positionMalrotationEctopiaAnomalies in structurePolycystic kidneyAnomalies of drainage systemDuplicated kidney, ureterWe are able to evaluate a number of renal abnormalities using imaging techniques including ; anomalies in size and form including such things as horseshoe kidney, anomalies in position including malrotations and ectopia, anomalies in structure including polycystic kidney disease and anomalies of the draining system including duplication of portions or all of the kidneys and duplications of the ureters.
26Normal Kidney Intravenous urogram Opacification of collecting systems and uretersThe iodine contrast material is excreted by the kidneys allowing us to opacify the renal collecting system, pelvis and ureters and portions of the bladder
27Duplication of Kidney Both kidneys with 2 collecting systems Right and Left upper system dilatedLower units smallerUreters join before bladderWhen we are evaluating this patient with a duplicated kidney we note that both kidneys have two separate collecting systems as indicated by the three arrows on the right and the two arrows on the left. We also note that the right and left upper systems are dilated in this instance. This as the result of partial obstruction which is typical of this type of situation. Also note that the lower units are somewhat smaller than the upper units. The ureters which are duplicated are noted to join in both cases before reaching the bladder. As indicated by the arrows.
28Horseshoe Kidney Horseshoe kidney Joined at inferior aspect Moderate hydronephrosisHere is an example of an individual with a horseshoe kidney. We have outlined the kidney for you. Note that the lower poles are connected. Joining at the lower pole is a very typical finding in the horseshoe kidney. Also note moderate hydronephrosis as a result of partial obstruction to the outlet of both kidneys.
29Horseshoe KidneysAxial images demonstrate kidneys joined across the midline anterior to the aorta and inferior vena cavaCT scanning can also be useful in evaluation for horseshoe kidneys. In this axial image we demonstrate the kidneys joined across the midline anterior to the aorta and inferior vena cava. This is best seen on the third picture in the lower aspect of your image.
30Pelvic Kidney AP tomogram Both kidneys in the pelvis Pelvic kidneys can be identified by a variety of techniques including ultrasound, x-ray, intravenous urography, and CT scanning. In this AP tomogram in the pelvic region both kidneys are noted to be in the pelvis. We would need history in this individual to make sure that a double kidney transplant into the pelvis has not been performed
31Polycystic Kidneys Axial scan with contrast Enlarged lobulated kidneys Multiple cystsVarying sizePolycystic renal disease can be demonstrated by variety of imaging techniques including CT scanning. In this contrast enhanced axial scan we identify large lobulated kidneys with multiple low-attenuation areas present in both kidneys representing the presence of numerous cysts.Within the kidneys these cysts vary in size there is some stool functioning kidney present as we note the collection of contrast material within the collecting system.
32CT Multiple Cysts Multiple Renal Cysts In another patient we note multiple, not as numerous, but multiple cysts involving both kidneys. There is a variety of size and locations as easily discerned on the CT scan.
33CT Renal CystsIn an additional patient we also note, a different appearance to renal cysts, including renal cysts which are incorporated into the peripelvic region as seen at the black arrow. These can sometimes be identified on the intravenous urogram, by their impression upon the adjoining collecting system.
34Ultrasound Renal CystRenal ultrasound is one of the tools for evaluating for renal cysts. On these examples a single peripelvic cyst and a peripheral cyst are demonstrated by the dark areas arising within the central portion of the kidneys and on the periphery.
35Renal Abnormalities Hydronephrosis Hypoechoic (Dark areas)Thinning of renal cortex indicates long standing processIn another individual we demonstrate the presence of hydronephrosis. The dark areas representing a dilatation of the renal collecting system and calyces. There is thinning of the renal cortex indicating that this is a long-standing process causing the destruction of the overlying renal cortex.
36Hydronephrosis Massive Hydronephrosis In our last slide we see massive hydronephrosis involving both kidneys in an individual as seen both on the longitudinal scan as well as an axial or cross section through the kidneys where we can see the renal pelvis distended as well as the dilated calyces.