Superficial Lumps and Bumps: Ultrasound Assessment

Transcription

1 Posterior knee Superficial Lumps and Bumps: Ultrasound Assessment Walter Mak, MD Department of Medical Imaging St. Michael s Hospital SM SM MGas MGas MGas MGas Synovial lined Synovial cyst: extrusion of joint fluid Bursa: synovial lined potential space between osseous surfaces, ligaments or tendons SM: Semimembranosus MGas: Medial head of gastrocnemius Posterior knee Posterior knee SM MGas SM MGas MGas SM: Semimembranosus MGas: Medial head of gastrocnemius Septations, internal debris, peripheral Doppler flow SM: Semimembranosus MGas: Medial head of gastrocnemius 1

2 Anterior hip Anterior shoulder IPs IPs BT BT Peripheral Doppler flow - synovitis BT: Biceps tendon IPs: Iliopsoas Antecubital fossa Antecubital fossa BT BT BT BT BT BT Rad BT: Biceps tendon Rad: Radius Peripheral/intratendinous Doppler flow BT: Biceps tendon Finger, near proximal phalanx * * 2

3 Mucoid/myxomatous degeneration of periarticular connective tissue dominant cyst Result of repetitive microtrauma Common in hand/wrist, foot/ankle Close association with joint or tendon sheath Dorsal radial wrist Dorsal radial wrist S L Contiguous with scapholunate ligament S: Scaphoid L: Lunate S Scapholunate ligament tear Peripheral Doppler flow SA Teefeyet al., AJR 2008; 191: L S L S: Scaphoid L: Lunate Volar radial wrist Dorsal radial wrist L Contiguous with scapholunate ligament Slightly complex, collapsed S: Scaphoid L: Lunate S Non-compressible Visible neck in only 25-35% SA Teefeyet al., AJR 2008; 191: G Wang et al., J Ultrasound Med 2007; 26: Internal Doppler flow? 3

4 FCR RA FCR RA Pitfall: artifactual flow from adjacent radial artery RA: radial artery FCR: flexor carpi radialis Mature adipocytes and uniform nuclei identical to normal adult (white) fat Arise within subcutaneous tissue 80% <5 cm; 99% 10 cm MJ Kransdorf et al., Radiology 2002;224: MD Murphey et al., RadioGraphics 2004; 24: Periscapular region Parallel to skin surface Elliptical Linear echogenic striations No internal Doppler flow <5 cm Anterior knee Supraclavicular region May be hyperechoic, isoechoic, or hypoechoic Uniform echogenicity Parallel to skin surface Elliptical Linear echogenic striations 4

5 Radial aspect elbow Shoulder w/o compression w/ compression Compressible Parallel to skin surface Parallel to skin surface Linear echogenic striations Slightly heterogenous Deep (intramuscular) Needs additional imaging Shoulder Linear echogenic striations Variable echogenicity Deep (intramuscular) Needs additional imaging T1 T2FS Medial anterior thigh Lower back Heterogeneous Deep (intramuscular) Needs additional imaging Heterogeneous >10 cm Exuberant Doppler flow Needs additional imaging T1 T2FS T1FS+C 5

6 Calf T1 T2FS T1 T2FS Upper back Epithelial lined, keratincontaining cysts Causes: Squamous metaplasia Deep growth after obstruction of hair follicle Post traumatic implantation into dermis HK Kim et al., Skeletal Radiol (2011) 40: Ovoid, sharply marginated Curvilinear echogenic keratin Hypoechoic clefts May scallop overlying skin Tip of finger Hypoechoic No internal Doppler flow Cortical disruption 6

7 Proximal lateral thigh Degloving injury of proximal thigh Separation of fascia from subcutaneous tissue and vascular/lymphatic disruption Collection containing blood, lymph, fat Proximal lateral thigh Proximal lateral thigh Chronic: fusiform, hypoechoic Globules of echogenic fat No internal Doppler flow May be complex Globules of echogenic fat No internal Doppler flow Proximal lateral thigh Proximal calf, near knee w/o compression w/ compression Morel-Lavallée also observed about the knee SG Tejwani et al., Am J Sports Med 2007; 35: Globules of echogenic fat Compressible Acute: may be lobulated, heterogeneous Globules of echogenic fat 7

8 Proximal forearm Congenital vascular lesion resulting from aberrant vessel angiogenesis High flow: arterial component Low flow: venous malformation hemangioma Bluish discolouration of overlying skin Dorsal to metacarpal Lateral Knee Hypoechoic vascular channels Echogenic phleboliths Doppler flow w/o compression w/ compression Hypoechoic vascular channels Doppler flow Compressible Deep, intramuscular lesions MRI Dorsal wrist ED ED Pigmented villonodular tenosynovitis Localized synovial proliferation ED ED: Extensor digitorum 8

9 Volar Thumb Volar finger Hypoechoic Peripheral flow Longitudinal contact with tendon Does not move with digital flexion/extension Hypoechoic Longitudinal contact with tendon Circumferential contact with tendon Sole of foot PF PF PF: Plantar fascia ABH Ledderhose disease (feet) Dupuytren s contracture (hands) Benign proliferation of fibrous tissue Right plantar midfoot same patient Left plantar midfoot Fusiform, hypoechoic Continuous with plantar fascia No internal Doppler flow May be bilateral 9

10 Plantar midfoot Volar ring finger May be multiple Fusiform, hypoechoic Palpable Superficial to flexor tendon Volar distal palmar crease near 4 th MCP joint Volar forearm Irregular, hypoechoic plaque Superficial to flexor tendon Neoplasms of Schwann cell origin contained within nerve epineurium Malignant lesions: >5cm Ill defined margins Central necrosis 10

11 Lateral hindfoot Volar ulnar wrist SN SN FCU FCU UA UN UN Hypoechoic fusiform mass continuous with nerve Solid masses may show no internal Doppler flow SN: sural nerve MH Lee et al., Skeletal Radiol (2010) 39: P Belli et al, J Ultrasound Med 19: , 2000 Focal fusiform nerve thickening Anechoic, posterior acoustic enhancement No internal Doppler flow UN: ulnar nerve UA: ulnar artery FCU: flexor carpi ulnaris UA FCU Posterior thigh Proximal calf Heterogeneous Large, >5cm Central necrosis PN PN MR for complete assessment Histology for Benign vs. malignant PN PN Communication with tibio-fibular joint Compresses peroneal nerve PN: peroneal nerve Proximal ulnar aspect of forearm Along patellar tendon UN UN Anechoic No internal flow Extends along ulnar nerve UN: ulnar nerve UN Proximal long axis Distal short axis Difficult distinction from peripheral nerve sheath tumour Distal long axis Distal short axis 11

12 Monosodium urate crystal deposition in joints, cartilage, soft tissues Erosion, synovitis, effusion, tophus Suprapatellar knee Distal quadriceps Amorphous, hyperechoic tophus Posterior shadowing Calcified, shadowing tophus Courtesy Dr. Nabil Hussain Proximal patellar tendon (same patient) Dorsal midfoot Heterogeneous tophus, hypoechoic halo Suprapatellar region Intra-articular tophus Hyperechoic, shadowing tophus Hypoechoic halo Achilles tendon 12

13 MCP joint Pubic region P P: Pubis Periarticular erosion Urate icing RG Thiele, Curr Rheumatol Rep (2011) 13: P P Several months later P: Pubis Heterotopic ossification in muscle Thigh, buttocks, elbow, calf, shoulder Time course: Early/active: <2 4 wks Subacute/intermediate: 4 wks 6 mos Mature: >6 mos Anterior elbow Intramuscular Hypoechoic, centrally hyperechoic Uninterrupted muscle fibers 13

14 Peripheral flow in early myositis ossificans M Abate et al., J Clin Ultrasound VOL. 39, NO. 3, MARCH/APRIL 2011 Ultrasound findings predate radiographic findings P Tyler et al., Semin Musculoskelet Radiol 2010;14: Two months later Anterior thigh Medial distal thigh Intramuscular Hypoechoic, centrally hyperechoic Uninterrupted muscle fibers Dense peripheral calcification Posterior acoustic shadowing Anterior ankle - synovial sarcoma Distal forearm - schwannoma 14

15 Finger - angiomyoma Thigh - lymphoma Posterior acoustic enhancement does not imply cyst! MH Lee et al., Skeletal Radiol : Finger - venous malformation Inguinal region - lymphadenopathy Gray scale appearance often nonspecific Lesion location is helpful Relation of lesion to joint, bursa, tendon, or nerve is helpful Entirely superficial Parallel to skin surface Linear echogenic striations Uniform echogenicity <10 cm May show no internal colour/power Doppler flow May show posterior acoustic enhancement Predicting histology based on ultrasound difficult MRI Large, infiltrative lesions Deep solid lesions CT/Plain Film Calcification/ossification Bone erosion 15

16 A Baker s cyst extends between which two structures? A) Semimembranosus and medial head of gastrocnemius B) Semitendinosus and medial head of gastrocnemius C) Semitendinosus and sartorius D) Semitendinosus and gracilis E) Sartorius and gracilis A Baker s cyst is located between which two tendons? A) Semimembranosus and medial head of gastrocnemius B) Semitendinosus and medial head of gastrocnemius C) Semitendinosus and sartorius D) Semitendinosus and gracilis E) Sartorius and gracilis Which of the following is LEAST helpful in ultrasound assessment of a focal mass lesion? A) Relationship to joint, nerve, or tendon B) Presence of internal flow on colour/power Doppler C) Posterior acoustic shadowing D) Posterior acoustic enhancement E) Lesion location Which of the following is LEAST helpful in ultrasound assessment of a focal mass lesion? A) Relationship to joint, nerve, or tendon B) Presence of internal flow on colour/power Doppler C) Posterior acoustic shadowing D) Posterior acoustic enhancement E) Lesion location Thank you. 16