8.1
Introduction
The use of ultrasonography in musculoskeletal imaging has increased during re- cent years. This is partly due to its availability in most departments, the low cost and high patient comfort. Ultrasonography of the sternocostoclavicular (SCC) re- gion has the advantage of showing the soft tissue structures which are not delin- eated by radiography. It is therefore often used as an initial examination, especially in children.
This chapter encompasses the technical aspects and the normal ultrasonogra- phy appearance of the SCC region. It also gives advice to determine the role of ultrasonography in the imaging of the SCC region.
8.2
Technical Aspects
Ultrasonography can be performed with a wide variety of equipment and thereby technical possibilities. Linear or curved-linear probes with a frequency of
Contents
8.1 Introduction . . . 69
8.2 Technical Aspects . . . 69
8.3 Normal Ultrasonography Appearance of the Sternocostoclavicular Region . . . 71
8.4 Indications for Ultrasonography . . . 71
8.5 Conclusions . . . 74
References . . . 74
8 Ultrasonography
Anne Grethe Jurik
Anne Grethe Jurik
7.5–15 MHz are most suitable for imaging the SCC region. Supplementary Dop- pler technique enables the assessment of tissue vascularisation via signals generated by flowing blood cells (Fig. 8.1). However, the blood flow in microvessels may be slow and difficult to detect. The administration of microbubble contrast increases the intensity of Doppler signals from the blood and can rescue or improve a non- diagnostic Doppler examination. More dedicated ultrasonography is appearing in the form of colour/power Doppler. These techniques increase the accuracy of the examination, but irrespective of the technique used, diagnostic ultrasonography is limited to visualisation of soft tissue structures and bone surfaces [10].
Ultrasound-guided biopsy or puncture of soft tissue abnormalities should be performed with dedicated guidance equipment to secure a correct location of the tissue sample.
Fig. 8.1 Chronic recurrent multifocal osteomyelitis in a 6-year-old girl presenting with a swelling at the medial part of the clavicle. a Conventional ultrasonography shows enlarge- ment of the bone, but intact cortical bone (asterisks). There is no fluid collection in soft tissue, but it appears relatively echopenic compatible with oedema. b Colour Doppler shows increased vascularity in the surrounding soft tissue. Conventional radiographs and MRI are displayed in Fig. 13.1
Chapter 8 Ultrasonography
8.3
Normal Ultrasonography Appearance of the Sternocostoclavicular Region
There are few publications describing the normal ultrasonography appearance of the SCC region, mainly focusing on the cartilaginous structure [3]. The costal car- tilages appear less echogenic than the adjacent muscle and are delineated by a thin echogenic anterior margin. From our clinical experience all soft tissue structures can be identified including the ligaments, capsule, cartilages and intra-articular discs anterosuperiorly, but not to the extent possible by MRI.
8.4
Indications for Ultrasonography
Ultrasonography is important as an initial diagnostic tool in children, as the proce- dure is painless and easy to perform. Ultrasonography has been reported used to diagnose important congenital abnormalities such as complete cleft sternum [15], but also minor abnormalities such as superior sternal cleft [2, 11]. Ultrasonogra- phy can provide information not obtained by radiography by showing the extent of non-calcified chest wall abnormalities [9, 11]. The possibilities of evaluating the sternum in the embryo by transabdominal ultrasonography has been proved in a cross-sectional study [16], and the prenatal diagnosis of abnormalities such as cleft sternum has been described [6, 15].
Ultrasonography can be a reliable substitute for radiography in very specific circumstances such as diagnosis of fluid collections in the form of joint effusion, ganglion cyst and soft tissue abscesses [1, 8, 13].
Ultrasonography has also been reported to be of value in the diagnosis of inju-
ries in the form of joint dislocation, stress or undisplaced fractures, such as physealfracture of the sternal end of the clavicle in children (Chapter 11) [1, 4, 7, 8, 12, 13]. It has also been proved helpful during operation for posterior sternoclavicular joint dislocation [14].
Ultrasonography may be valuable as an initial diagnostic tool to clarify the dif- ferential diagnosis of sternoclavicular joint lesions. It can diagnose or exclude the presence of joint inflammation, but the cause of an inflammation is seldom de- tected [5].
Despite the interesting information obtained by ultrasonography, it may be mandatory to compare and prove the findings with other methods such as CT or MRI (Fig. 8.2), especially when suspecting malignancy.
Ultrasonography gives the possibility of performing guided fluid aspiration, in-
jections or biopsy, for example of soft tissue tumours.
Anne Grethe Jurik
Fig. 8.2 Septic arthritis of the sternoclavicular joint in a 48-year-old drug addict. He was ad- mitted due to hip pain and the diagnosis of infectious hip arthritis was established. Clinical examination and chest X-ray (a,b) revealed a swelling in the upper sternal region (arrows) with blurring of the mediastinal structures on the left side. Supplementary ultrasonography (c) disclosed an irregular echopenic mass just inferior to the left sternoclavicular joint and superficially to the first costal cartilage (asterisks) and extended laterally beneath the pecto- ralis muscle. There was also a small intra-articular fluid collection (not shown). MRI, STIR (d) and T2-weighted images (e) semiaxial along the clavicular bone do not delineate the soft tissue involvement better than ultrasonography partly because a postcontrast sequence could not be obtained due to lack of available veins. MRI, however, displayed the extent of osseous inflammation being present in both the manubrium (M) and the clavicle (C).
Also destruction of the first costal cartilage at the bottom of the infected area was detected (arrow)
Chapter 8 Ultrasonography
Anne Grethe Jurik
8.5
Conclusions
Ultrasonography can be a reliable substitute for radiography in very specific cir- cumstances. It is especially useful to establish or exclude disease and congenital variants in children. It can visualise soft tissue structures and diagnose fluid collec- tions or joint effusion. Guided aspiration, injections or biopsy of soft tissue abnor- malities can easily be performed.
References
1. Boll KL, Jurik AG (1990) Sternal osteomyelitis in drug addicts. J Bone Joint Surg Br 72:328–329
2. Carles D, Pelluard F, Alberti EM, Maugey-Laulom B, Lin TY, Saura R, Roux D, Lacombe D (2005) Fetal presentation of PHACES syndrome. Am J Med Genet A 132:110 3. Choi YW, Im JG, Song CS, Lee JS (1995) Sonography of the costal cartilage: normal
anatomy and preliminary clinical application. J Clin Ultrasound 23:243–250
4. Engin G, Yekeler E, Guloglu R, Acunas B, Acunas G (2000) US versus conventional radiography in the diagnosis of sternal fractures. Acta Radiol 41:296–299
5. Ernberg LA, Potter HG (2003) Radiographic evaluation of the acromioclavicular and sternoclavicular joints. Clin Sports Med 22:255–275
6. Fokin AA (2000) Cleft sternum and sternal foramen. Chest Surg Clin N Am 10:261–276
7. Griffith JF, Rainer TH, Ching AS, Law KL, Cocks RA, Metreweli C (1999) Sonogra- phy compared with radiography in revealing acute rib fracture. Am J Roentgenol 173:1603–1609
8. Haber LH, Waanders NA, Thompson GH, Petersilge C, Ballock RT (2002) Sternocla- vicular joint ganglion cysts in young children. J Pediatr Orthop 22:544–547
9. Herman TE, Siegel MJ (2001) Superior congenital sternal cleft. J Perinatol 21:334–335 10. Klauser A, Demharter J, De Marchi A, Sureda D, Barile A, Masciocchi C, Faletti C,
Schirmer M, Kleffel T, Bohndorf K (2005) Contrast enhanced gray-scale sonography in assessment of joint vascularity in rheumatoid arthritis: results from the IACUS study group. Eur Radiol 15:2404–2410
11. Mazzie JP, Lepore J, Price AP, Driscoll W, Bohrer S, Perlmutter S, Katz DS (2003) Supe- rior sternal cleft associated with PHACES syndrome: postnatal sonographic findings.
J Ultrasound Med 22:315–319
12. Rainer TH, Griffith JF, Lam E, Lam PK, Metreweli C (2004) Comparison of thoracic ultrasound, clinical acumen, and radiography in patients with minor chest injury.
J Trauma 56:1211–1213
13. Sferopoulos NK (2003) Fracture separation of the medial clavicular epiphysis: ultraso- nography findings. Arch Orthop Trauma Surg 123:367–369
Chapter 8 Ultrasonography
14. Siddiqui AA, Turner SM (2003) Posterior sternoclavicular joint dislocation: the value of intra-operative ultrasound. Injury 34:448–453
15. Twomey EL, Moore AM, Ein S, McAuliffe F, Seaward G, Yoo SJ (2005) Prenatal ultra- sonography and neonatal imaging of complete cleft sternum: a case report. Ultrasound Obstet Gynecol 25:599–601
16. Zalel Y, Lipitz S, Soriano D, Achiron R (1999) The development of the fetal sternum: a cross-sectional sonographic study. Ultrasound Obstet Gynecol 13:187–190
