Pediatric Imaging:
Transcription
Pediatric Imaging:
10/09/2012 Pediatric Imaging: Cases from the Emergency Department E. Mann Hospital for Sick Children, Toronto, Canada Conflict of Interest I have no commercial or financial interests related to the subject matter of this presentation. Objectives • Review several common and a few unusual pediatric emergency presentations. • Discuss differential diagnoses and highlight important findings to reach most likely diagnosis. Case 1 • • • • • 17 day old neonate Palpable deformity of the scalp Not regressing Firm on palpation Prolonged delivery • Mass does not cross beyond the sagittal suture line (blue arrow) • Soft tissue periosteal elevation (yellow arrow) • No skull fracture • Sharply demarcated soft tissue density parietal Mirror image artifact can be confusing regarding underlying brain and possible epidural process 1 10/09/2012 Later presentation – same diagnosis • Continuity of the outer periosteum with peripheral calcification (yellow arrow) • No true internal vascularity Outer border may calcify as a rim Sag – Parietal Cor – Parietal Caput Succedaneum Differential diagnoses 1. Caput succedaneum 2. Subgaleal hemorrhage 3. Cephalohematoma 4. Soft tissue tumour NYD Subgaleal hemorrhage • Occurs immediately after vaginal delivery Subcutaneous hemorrhage requiring no intervention • Typically not imaged – clinical diagnosis • Not limited by suture lines • Typically soft puffy swelling • May be associated with discoloration/ bruising • Heals spontaneously within a few days Subgaleal hemorrhage • Bleeding into the subaponeurotic space from rupture of emissary veins • Crosses suture lines • Covers a larger area typically compared with cephalohematoma • Potentially life-threatening • Associated with vacuum assisted delivery 2 10/09/2012 Cephalohematoma • • • • • Soft tissue periosteal elevation No skull fracture Sharply demarcated soft tissue density Mass does not cross suture line Continuity of the outer periosteum with peripheral calcification • Outer border may calcify as a rim • May take many months to regress Soft tissue tumour • Many prenatally diagnosed • Variable presentations depending on type of tumour • Hemangioma in this case with flow voids, vascular tumour and phleboliths Ultrasound Right Neck Case 2 • Subcutaneous • • • • • 3 month old with torticollis Palpable mass in neck Noticed shortly after birth Gradual increase in size No skin discoloration • Echogenic • Heterogeneous • No calcification • Lobulated welldefined, soft tissue mass Yellow arrow: SCM muscle Blue arrow: lobulated margins Internal vascularity No vascular tangle Echogenicity similar to fat Yellow arrow: SCM muscle T1-weighted MR • Defined, lobulated subcutaneous lesion • No flow voids/ large vessels • Fat tissue within • Heterogeneous intermediate to low T1 SI tissue/ fibrous septa 3 10/09/2012 T1 W MR T1 W MR +FS T1 W FS + Gad • Fat globules suppress • No fat enhancement • Periphery and septations enhance Differential diagnoses • Subcutaneous fat necrosis • Lipoblastoma • Fibromatosis colli • Infantile fibrosarcoma Subcutaneous Fat Necrosis • Usually history of difficult delivery • Firm palpable masses appear days to weeks after birth • Can have increased vascularity • Moderately well-defined margins • Lobulated, hypoechoic areas • Can be complicated by hypercalcemia – nephrocalcinosis/ nephrolithiasis Echogenic, lobulated, subcutaneous fat Normal contralateral subcutaneous tissues 4 10/09/2012 Lipoblastoma • Typically subcutaneous, well-defined • Variable soft tissue and mature fat • Can be indistinguishable from a lipoma or liposarcoma • Immature and fibrous components are low T1, high T2 SI and enhance • Macroscopic fat does not enhance • Usually < 3 years of age at presentation Fibromatosis Colli • Benign manifestation of infantile fibromatosis • Mass-like fusiform enlargement of the sternocleidomastoid muscle • Ipsilateral torticollis • Can be associated with shoulder dystocia • Proximal and distal muscle fibers extend into the lesion • Mildly hypervascular • No calcifications or cystic areas Fibromatosis Colli Infantile Fibrosarcoma • • • • • Solitary, rapidly enlarging firm mass Frequently involves a striated muscle May have areas of hemorrhage or necrosis Vascular Relatively homogeneous mass with equal to minimal increased T1 signal intensity compared to muscle • Increased T2 signal intensity compared to both muscle and fat • Avidly enhances post gadolinium 5 10/09/2012 Infantile Fibrosarcoma of the SCM T1 W MR Case 3 • 18 month old • 1 month of neck pain and decreased ROM • No trauma • Head tilt • No fever • Destructive lesion involving C4 vertebral body with vertebra plana • Fracture/ dislocation of right C4 lamina • Permeative appearance of the right sided posterior elements T1 W MR + Gad • Flattening of the C4 vertebral body • Permeative bone • Displacement of C3/4 at the spinolaminar line • Straightening of physiologic lordosis • Prominent anterior soft tissues • Expansile, exophytic, soft tissue involving the right lateral process, pedicle and lamina of the C4 vertebral body • Displaces the right vertebral artery • Soft tissue component anterior to the vertebral body • Mild indentation of the thecal sac at T4 6 10/09/2012 Diffuse metastatic disease Differential diagnoses • Metastatic disease • Langerhans Cell Histiocytosis (EG) • Fracture • Osteomyelitis • Neuroblastoma metastases • Leukemic involvement • Other childhood primary lesions with invasion • Sclerotic margins not usually a feature of metastatic disease Langerhans Cell Histiocytosis • • • • • • Beveled edges of the lytic skull lesions Lytic lesions with geographic margins Unifocal or multifocal osteolysis +/- path #s Not typically confluent Associated bone edema Lesions enhance Bone scan: lesions may be hot or cold Radiolucent areas with endosteal erosion (+/periosteal reaction) Vertebra plana 7 10/09/2012 Differential Diagnosis of Vertebra Plana “FETISH” F – Fracture E – EG (Langerhans’) T – Tumour (mets eg. NBL or other) I – Infection S – Steroid Use H - Hemangioma Case 4 • • • • • • • • 5 year old boy Right flank pain Fever Possible renal mass on outside ultrasound Right kidney lesion Ill-defined, echogenic region within kidney Relatively reduced perfusion Some mass effect No cystic region or calcification Mid-pole lesion Normal parenchyma upper pole 8 10/09/2012 Differential diagnoses • Acute pyonephrosis • Mesoblastic nephroma • Renal abscess • Focal pyelonephritis Acute pyonephrosis - PUV • Debris within the dilated collection systems • Perinephric fluid • Bilateral process • Echogenic parenchyma • Hydronephrosis Acute pyonephrosis • Infected, obstructed urinary tract • May be due to UPJO, stone or potentially bladder outlet (PUV) • Requires decompression • Potential need for nephrostomy tube, depending on level of obstruction Acute pyonephrosis - PUV • • • • Bladder trabeculation Circumferentially thick wall Dilated posterior urethra Small caliber anterior urethra on VCUG Mesoblastic Nephroma • Commonly found in the neonatal period (less than 3 months of age) • Hamartomatous lesion • Commonly mimics Wilm’s tumour • No malignant potential • Usually a large, non-tender mass at presentation • Can be heterogeneous if hemorrhage or necrosis Mesoblastic Nephroma 9 10/09/2012 Mesoblastic Nephroma STIR T1 T1 FS + Gad Early abscess formation – fluid component, avascular Renal Abscess • • • • Well defined region Avascular component with necrosis Progress from focal pyelonephritis +/- Perinephric fluid Further necrosis, abscess Focal Pyelonephritis • • • • Pseudo-mass with ill-defined margins Indistinct cortical-medullary differentiation No cystic change within region Renal size discrepancy may be greater than 1 cm • Focal area with relatively reduced vascularity • +/- Perinephric fluid • Can lead to focal renal scarring 10 10/09/2012 Case 5 • • • • • Rapid onset scrotal swelling Very painful to touch Reddish discoloration Bilateral Afebrile Fountain-like, striated appearance of edema and hypervascularity Marked, homogeneous thickening of the scrotal wall – skin and subcutaneous tissues Differential Diagnoses • • • • Acute Idiopathic Scrotal Edema • • • • • Erythema and swelling of the scrotum Usually bilateral, may be asymmetric More common in children than adults Ultrasound is diagnostic Increased blood flow in the scrotal soft tissues and on colour Doppler – “fountain sign” • Not associated with dysuria – self limiting Acute idiopathic scrotal edema Testicular torsion Leukemic infiltration Appendix testis torsion Acute Testicular Torsion • True surgical emergency • Often in peripubertal boys, young adults • Often associated with reactive hydrocele and thickening of scrotal skin (surrounding regions may be hyperemic) 11 10/09/2012 Acute Testicular Torsion • If the grey scale appearance is normal, testis is likely viable • Abnormal echotexture may indicate edema/infarction • Twisted cord can be seen as a heterogeneous mass superior to the testis (torsion knot) • Absent or decreased vascularity relative to normal side RIGHT Similar size and echogenicity R L Different vascularity R>L Torsion knot – twisted spermatic cord cranial to testis • Neonatal torsion • Difficulty in interpreting Doppler • Bilateral hydroceles • Inhomogeneous left testicle RIGHT LEFT LEFT Leukemic Infiltration of Testes • Enlarged, hypoechoic testicles • Asymmetric, may be heterogeneous texture • May have associated slightly red scrotum (hyperemia) • Hypervascular on Doppler exam • Clinical history of leukemia (ALL, etc.) Left testicle : 3.1 X 2.1 X 1.7 cm Right testicle: 1.6 X 1.1 X 0.9 cm 12 10/09/2012 Torsion of the Appendix Testis Midline scrotum transverse • Diminished or avascular hypoechoic mass typically near the epididymal head • May have reactive hyperemia of the epididymis and testis • May have associated hydrocele • Self limiting • Unilateral Case 6 • • • • Fall on outstretched hand Elbow pain Limited range of motion Assess for fracture CRITOL Capitellum Radius Internal (medial) epicondyle Trochlea Olecranon Lateral epicondyle O I L T C R 13 10/09/2012 Medial epicondyle avulsion Differential Diagnoses • • • • Medial epicondyle avulsion Supracondylar fracture Monteggia fracture Lateral condyle fracture • Intra-articular displacement of avulsed medial epicondyle • Pseudo trochlea ossification center Supracondylar Fracture Most common elbow fracture in children Effusions around the joint elevate fat pads, raise concern for intraarticular fracture Monteggia Fracture • Fracture ulna – dislocation radial head • Orthogonal views to assess radius – capitellum relationship Lateral Condyle Fracture • Oblique views may best demonstrate • Fracture cleft may not be apparent initially • Suspect intra-articular fracture due to effusion Thanks for your attention! 14 10/09/2012 Suggested Reading Suggested Reading • Mangurten HH. Birth injuries. In: Fanaroff AA, Martin FJ eds. Neonatal-Perinatal Medicine: Diseases of the Fetus and Infant. 9th ed. Philadelphia, Pa: Mosby Elsevier; 2010. • Kan JH, Kleinman PK, Gebhardt MC, Kocher MS. Pediatric and Adolescent Musculoskeletal MRI – A Case-Based Approach. New York: Springer; 2007. • George HL, Unnikrishnan PN, James LA et al. Lipoblastoma – an unfamiliar but important diagnosis. A case series and literature review. Acta Orthop Belg 2009; 75: 533-536. • Srinath G, Cohen M. Imaging findings in subcutaneous fat necrosis in a newborn. Pediatr Radiol 2006; 36: 361-363. • Vasireddy S, Long SD, Sacheti B, Mayforth RD. MRI and US findings of subcutaneous fat necrosis of the newborn. Pediatr Radiol 2009; 39: 73-76. • Azouz EM, Saigal G, Rodriguez MM, Podda A. Langerhans’ cell histiocytosis: pathology, imaging and treatment of skeletal involvement. Pediatr Radiol 2005, 35(2): 103-115. • Ilyas M, Mastin ST, Richard GA. Age-related radiological imaging in children with acute pyelonephritis. Pediatr Nephrol 2002, 17(1):3034. • Subcommittee on Urinary Tract Infection; Steering Committee on Quality Improvement and Management. Urinary Tract Infection: Clinical Practice Guideline for the Diagnosis and Management of the Initial UTI in Febrile Infants and Children 2 to 24 Months. Pediatrics. August 28, 2011. • Lee A, Park SJ, Lee HK et al. Acute idiopathic scrotal edema: ultrasonographic findings at an emergency unit. Eur Radiol 2009; 29:2075-2080. Suggested Reading • Aso C, Enriquez G, Fite M, et al. Gray-Scale and Color Doppler Sonography of Scrotal Disorders in Children: An Update. Radiographics 2005; 25:1197-1214. • Yerkes EB, Robertson FM, Gitlin J et al. Management of Perinatal Torsion: Today, Tomorrow or Never? J Urol 2005; 174:1579-1583. • Geiger J, Epelman M, Darge K. The Fountain Sign. A novel Color Doppler Sonographic Finding for the Diagnosis of Acute Idiopathic Scrotal Edema. J Ultrasound Med 2010; 29(8):1233-1237. 15