PEDIATRIC SONOGRAPHY(소아과)

서론 <DIV align=justify>기존의 방사선과, 산부인과 위주의 초음파 검사에서 소아과,비뇨기과 등 좀더 세분화된 application이 점차 확대 되고 있다. 여기서는 소아과에 관련되는 부분들을 다뤄보고자 한다 신생아의 두개 내 출혈이나 저 산소증에 의한 뇌손상, 수두증, 각종 선천 성 기형 등을 진단하고 치료 후 추적 검사하는데 초음파가 좋은 검사 방 법으로 사용하고 있다. 또한 Doppler검사를 이용하여 혈역학적 정보를 얻을 수 있다는 점도 장점이다. 다음 내용들은 해외 임상 교육 자료로 활용하기 위해 영문으로 작성 하였다. </DIV>   본론 1. Introduction - Area of interest in children are less deeply located than are similar area of interest in adult - Less abdominal fat and small organ size, perivisceral fat - US shows more reliable in children than in adults. - US is better than CT and MRI for investigating cystic or other benign lesions, - Radiation free - Little or no preparation necessary - Possible without sedation Transducer - Medium focused (3~7cm ) transducer - Mechanical sector scanner (contacted area is smaller than adult) - Usually start with 5Mhz transducer - 3.5Mhz for large or obese patient - Higher Mhz in the neonates Preparation - Fasting 4 hours for infant 6 hours for young children ( 1-2 years) 8 hours for older children - Sedation (esp. Doppler exam. Aspiration Bx) Chloral Hydrate, Pocral Oral or rectal, 0.5cc/kg - Maintenance of body temperature in small baby (radiant warmer) Clinical information Abd pain, vomiting, HPS, RAPS hepatosplenomegaly, jaundice, biliary atresia, neonatal hepatitis, Wilms', neuroblastoma, appe, FUO, mass, OTI, UPJ obst, hematuria, NS, Nut-cracker synd, neurogenic bladder MMC, sepsis, shunt malfunction, CDH, ICH, hydrocephalus, undesended testis, trauma Most frequently requested for pediatric patient 1. Eval‎uation of suspected renal pediatric patient 2. Eval‎uation of abdominal, hepatic of pelvic mass 3. Detection of pancreas 4. Eval‎uation of some chest mass 5. Detection of intracranial hemorrhage   2. US APPLICATION IN PEDIATRIC DISORDER LIVER AND BILIARY TRACK - GB : Variable size and shape Ovoid of elliptical 1.5 ~ 3.0 cm in length (infant) 3.0 ~ 7.0 cm in length (older children) - CBD : Diameter not exceed 2mm in infant (usually not demonstrable) 4mm in older children 7mm in adolescents - Echogenicity Liver echo = renal cortex in neonate Liver echo > renal cortex by 6 months of age Hepatoblastoma - most common liver tumor in children - large echogenic mass in the right of the liver - tumor extent and vascular invasion - ill define echogenic mass - under the age of 2 years Hemangioma - may appear similar to the hepatoblastoma - hypoechoic hepatic defect - most common benign tumor of the liver in children Hematoma - moderately echogenic texture upper abdominal trauma Abscess - space occupying mass in the liver Biliary atresia - resulting in stenosis and narrowing of the bile duct - no evidence of the intrahepatic ducts dilatation - periportal irregular echo in 4 ~ 5 months - small of nonvisualization of GB < 1.5 cm - irregular elongated lumen Neonatal hepatitis - 1 ~ 3 month old infant with persistent jaundice - male and premature infants more commonly affected - normal GB Choledochal cyst - abnormal formation. Pancreatic duct, CBD junction - large cystic mass in porta hepatis - round or fusiform dilatation of CBD with/without IHD dilatation Hydrops of the GB - acute massive dilatation of GB with normal bile duct - large size and abnormally round shape - Kawasaki disease Rhabdomyosarcoma of the biliary tract - typically in children between 1 and 5 years old with obstructive jaundice - obstruction by grape like mass - proximal bile duct dilatation - presence of fluid around the tumor in the porta hepatis Glycogen storage disease - disease affecting carbohydrate metabolism - enlargement of the liver - diffuse parenchymal abnormality - no focal defact Lymphoma - hepatosplenomegaly - single of multiple hypoechoic nodules - diffuse involvement : inhomogeneous echo Situs inversus - liver filling the entire left side of the abdomen - dextrocardia 3. KIDNEY - In neonates and infant renal cortical echo usually to equal to liver echo - Hypoechoic prominent medullary pyramid can be misinterpreted for hydronephrosis or renal cyst - small cortico medullary ratio - Less echogenic renal sinus due to paucity of sinus fat - In premature infant renal cortical echo may be more echogenic than the liver echo - Adult renal parenchymal echo pattern by 4 ~ 6 months of age Kidney size 0 ~ 12 m 5 cm 1 yr 6 cm 5 yr 8 cm 10 yr 10 cm Neonatal and infant - Hydronephrosis Most common cause of abdominal mass in the neonate - multicystic kidney 2nd most abdominal mass in the neonate a produce palpable abdominal mass older infant and child Rena cystic disease 1. infantile polycystic kidney - bilat large kidney - increased echo by numerous dilated tubules - small cyst - liver involvement 2. Multicystic dysplastic kidney - associated with obstruction lesion in ureter - usually unilateral - multiple cyst of varing size - displastic renal parenchyma Wilms tumor - peak incidence between the age of 1 and 3 years - most common abdominal solid tumor - arise from primitive embryonal renal tissue - sharply demarcated, large mass of echogenicity slightly greater than liver - intra renal echogenic mass - predominantly solid, but frequent areas of cystic necrosis and hemorrhage - usually unilat Ureteropelvic Junction Obstruction - not demonstrate a dilated proximal ureter Hydronephrosis (infected hydronephrosis) - poor renal function and palpable abdominal mass - s huge lucent sac with marked thinning of the renal parenchyma Pyonephrosis (infected hydronephrosis) - one cause of poor renal function - dependent echos within the dilated collecting system - dilated pelvocalyceal system containing multiple echo ARF (Acute Renal Failure) - kidney can appear enlarged CRF (Choronic Renal Failure) - renal parenchyma is more echogenic than the liver Renal vein thrombosis - Doppler study - Detect lack of flow in the renal vein Renal mass - neonate - nephroblastoma - young child - Wilms tumor Abscess - a well marginated anechoic mass - debris within the mass - acoustic enhancement - us guided aspiration Trauma - sonolucent of echogenic retroperitoneal hematoma - hypoechoic parenchymal hematoma - renal fracture Neurogenic bladder - unstable bladder in children - myelomeningocele a most common cause of neurogenic bladder Kidney Bx - nephritic syndrome - perirenal hematoma 4. ADRENAL GLAND - Almost always visualized at birth - Neonatal adrenal gland Medulla : thin hyperechoic cord Cortex : thick hypoechoic rim Adrenal hemorrhage - in the new born generally is attributed to blunt trauma - enlarged, round and complex echo pattern - calcification frequently occurs Neuroblastoma - most common solid extracranial tumor in infant and children - the 3rd malignant tumor of children after leukemia and brain tumor - usually arise in the adrenal gland - adrenal mass (50 ~ 60%) - palpable mass along with abdominal distention - poory defined margine - solid with mixed echo - calcification with posterior shadow and anechoic cystic area 5. PANCREAS AND SPLEEN - More satisfactory exam in children than in adult (thin body habitus, relatively large left lobe of the liver) - Less echogenic than echo in adult (low fat content) Acute pancreatitis - pancreas will be enlarged - relatively hypoechoic - pancreatic duct dilatation Chronic pancreatitis - small atropic pancreas - course echogenicity - pancreatic duct dilatation - calcification of parenchyma Pseudocyst - antwhere in the abdomen - hypoechoic mass Hematoma - trauma to the upper abdomen - hypoechoic Splenomegaly - congestive splenomaly - inflammatory splenomegaly 6. PELVIS - Urinary bladder should be distended - May not be possible in neonates : catheterization 7. UTERUS - different shape and size - uterus identified in 90% of full infant girls during the first week of life - increase in size after 7 years of age 8. OVARY - ovaries are small - 3 ~ 2.5 ~ 15 mm at birth - small follicle within the ovary - difficult to identify in girl under 5 years of age (high position of ovary, small size, homogeneous echo) Ovarian cyst - infant girl up to 2 years ago - cystic ovarian mass - solid pelvic mass : rare Teratoma - 5 ~ 15 years of age - most common type of pelvic mass Ovarian torsion - 30% malignant - massive enlargement of the ovary - 9.TESTIS - 1.5 ~ 1.0 cm at birth - 2.0 ~ 1.2 cm at 3 months of age - increase again in size after 6 years of age Undescended testis - failure of the testis to descend into the scrotum Hydrocele - a collection of fluid in the tunicavaginalis of the testis - anechoic fluid collection surrounding testis Trauma - eval‎uate the integrity of the testis Epididimitis - cause of scrotal pain and swelling - diffuse or focal epididymal swelling Ambigenous genitalia 10. NECK - Hemangioma - Cystichygroma Developmental abnormalities of the lymphatic system Occur in the head and neck region Multilocular fluid collection - Lymph node 11. OTHERS Chest - cystic chest mass and pleural fluid collection a guided aspiration - pericardiac lesion - diaphragmatic abnormality Spine - normal spinal cord within the spinal canal - examination for meningocele, lipomyelomeningocele, myelocele - post op : residual lipoma, fluid collection, cord pulsation Enlarged L/N - Solid mass within the abdomen Hip - joint effusion - septic arthritis - toxic synovitis - congenital dislocation a early detection and treatment 12. US IN VOMITING CHILDREN Intussuception - complex mass within the abdomen - sonolucent doughnut sign and pseudo kidney sign - saline reduction under ultrasound guidance Hypertophic pyloric stenosis - Pylorus : 2.4 cm in cross section Elongated of pylorus canal > 15 mm Thickness of pyloric muscle > 4 mm Pyloric diameter > 15mm doughnut sign or target sign 13. US IN GI TRACT Appendicitis and periappendiceal abscess (RLQ) - asymmetric thickening of appendiceal wall - localized fluid collection around appendix Inflammatory bowel disease - tuberculosis, Crohn's disease, ulcerative colitis - hypoechoic wall thickening Intestinal obstruction - distended bowel at proximal portion - hyperperistalsis - bowel wall edema - peritoneal fluid Necrotizing enterocolitis - dilatation of bowel loop - bowel wall thicking - intramural gas a portal vein gas - ascites Doppler study - renal vein thrombosis - portal vein thrombosis - deep vein thrombosis - post cardiac cath - Nut - Cracker syndrome - Transplanted kidney - Liver transplantation - intra op, post op 14. BRAIN Coronal scan - last ventricle - caudate nucleus - choroid plexus - corpus callosum - cerebellum Sagittal scan - corpus callosum - lat, forth ventricle - pons - thalamus - choroids plexus Intracanial hemorrhage - GMH (Germinal Matrix Hemorrhage) - IVH (Intra Ventricula Hemorrhage ) - Intra parenchymal Hemorrhage Thin walled rich vascular stroma and loose supporting tissue Hemorrhage - resolving - cystic change Intracranial infection 1. meningitis - increased echos over the lat ventricle - disruption of brain parenchyma, - compatible with necrosis or abscess 2. ventriculitis - increased ventricle size - increased ventricle wall echogenisity Hydrocephalus - congenital or acquired due to intraventricular abstruction Ventriculomegaly - increased ventricle volume - lat ventricle : less than 10 mm in transverse diameter (normal size) Periventricular leukomalacia (PVL) Location of shunt catheter - after insertion of a shunt catheter Congenital anomaly - agenesis of corpos callosum - Dandy-Waiker malformation - Holoprosencephaly - Hydranencephaly Grading criteria of intracranial hemorrhage Grade I : hemorrhage limited to the germinal matrix Grade II : GMH/IVH without ventricular dilatation Grade III : GMH/IVH resulting acute ventricular dilatation Grade IV : GMH/IVH extending into adjacent brain parenchyma Periventricular leukomalasia - hemorrhage complication - increased brain parenchyma echogenicity - cystic change - prriventricular white matter anechoic cystic lesion   결론 현재 나와있는 임상자료가 산부인과,복부초음파 위주로 되어 있어 그 외 application 부분에서의 자료가 항상 부족한 상태이다. 소아과 분야의 초음파 관련내용 뿐만 아니라 병리학적인 부분까지 정리한 것으로 위의 자료가 임상 study를 하는데 있어서 조금이라도 도움이 될 수 있기를 바란다. 위의 자료를 바탕으로 내용은 계속적으로 update가 될 것이다.