A. Muda

Multimodality imaging of intraosseous ganglia of the wrist and their differential diagnosis

Intraosseous ganglion (IOG) is the most frequently occurring bone lesion within the carpus and is often an incidental finding on radiographs obtained for other reasons. Two types of IOG have been described: an “idiopathic” form (or type I), the pathogenesis of which has not been completely clarified, and a “penetrating” form (or type II), caused by the intrusion of juxtacortical material (often a ganglion cyst of the dorsal soft tissue) into the cancellous bone compartment. The differential diagnosis for IOG is wide-ranging and complex, including lesions of posttraumatic (posttraumatic cystlike defects), degenerative (subchondral degenerative cysts), inflammatory [cystic rheumatoid arthritis, chronic tophaceous gout (CTG)], neoplastic (benign primary bone tumours and synovial proliferative lesions), ischaemic (Kienböck’s disease or avascular osteonecrosis of the lunate) and metabolic (amyloidosis) origin. Multimodality imaging of IOGs is a useful diagnostic tool that provides complete morphological characterisation and differentiation from other intraosseous cystic abnormalities of the carpus. Thin-slice multidetector computed tomography (MDCT) can provide high-spatial-resolution images of the cortical and cancellous bone compartments, allowing detection of morphological findings helpful in characterising bone lesions, whereas magnetic resonance (MR) imaging can simultaneously visualise bone, articular surfaces, hyaline cartilage, fibrocartilage, capsules and ligaments, along with intra- and periarticular soft tissues.RiassuntoIl ganglio intraosseo (IOG) è la lesione ossea del carpo di più frequente riscontro e spesso rappresenta un reperto occasionale in esami radiografici eseguiti per altri motivi. I IOG vengono distinti in due forme: la forma idiopatica (o tipo I), la cui patogenesi non è stata ancora completamente chiarita, e quella penetrante (o tipo II), determinata dall’intrusione nel compartimento spongioso di materiale juxtacorticale, spesso rappresentato da un ganglio dei tessuti molli dorsali del carpo. La diagnosi differenziale dei IOG è ampia ed articolata, includendo lesioni di origine post-traumatica (difetti simil-cistici post-traumatici, PTCD), degenerativa (cisti subcondrali degenerative, SDC), infiammatoria (artrite reumatoide cistica e gotta cronica tofacea), neoplastica (tumori ossei primitivi e lesioni proliferative sinoviali benigne), ischemica (morbo di Kienbock od osteonecrosi avascolare del semilunare) e metabolica (amiloidosi). L’imaging integrato dei IOG è fondamentale per la loro completa caratterizzazione morfologica e per distinguerli dalle altre lesioni pseudocistiche intraspongiose che si possono sviluppare nelle ossa del carpo. La tomografia computerizzata multi-detettore (MDCT) consente di ottenere immagini ad elevata risoluzione spaziale dei compartimenti ossei corticale e spongioso, permettendo di rilevare elementi morfologici utili ad una precisa caratterizzazione delle lesioni ossee, mentre la risonanza magnetica (RM) offre il vantaggio di visualizzare simultaneamente la componente ossea, le superfici articolari, gli spessori condrali, le strutture fibrocartilaginee, capsulo-legamentose ed i tessuti molli intra- e peri-articolari.

High-resolution ultrasound anatomy of extrinsic carpal ligaments

PurposeCarpal ligaments can be classified as intrinsic and extrinsic. Extrinsic ligaments are often involved in carpal instability. The purpose of this article is to describe the sonographic appearance of extrinsic carpal ligaments on high-resolution ultrasound (HRUS) using magnetic resonance arthrography (MR arthrography) as a reference standard.Materials and methodsWe studied both wrists in 18 healthy volunteers (ten men, eight women, age range 18–58 years, mean age 34 years) with a Philips iU22 US scanner equipped with a high-resolution linear-array broadband transducer (5–17 MHz). The scans were performed along the long axis of the extrinsic dorsal and ventral ligaments to assess their course, thickness and structure. Ten subjects were also studied with MR arthrography of the wrist.ResultsIn all patients, the ligament components could be appreciated as thin fibrillar hyperechoic structures. The course of seven extrinsic carpal ligaments and their relationships with surrounding articular structures could be studied. The radioscapholunate and the ulnar collateral ligaments were not visible on US. MR arthrography depicted all ligaments except for the ulnar collateral, which was never visualised.ConclusionsThe results obtained are consistent with those reported in the literature. HRUS provides good anatomical detail of the extrinsic carpal ligaments, but the role of US in planning the treatment of carpal instability disorders is yet to be demonstrated.RiassuntoObiettivoI legamenti del carpo sono suddivisi in intrinseci ed estrinseci. Questi ultimi sono spesso coinvolti nella patogenesi dell’instabilità carpale. L’obiettivo di questo studio è descrivere l’aspetto ecografico dei legamenti estrinseci del carpo mediante ecografia ad alta risoluzione, utilizzando l’artrografia a risonanza magnetica (artro-RM) come metodica di riferimento.Materiali e metodiAbbiamo studiato entrambi i polsi di 18 soggetti volontari sani (10 maschi, 8 femmine, range 18–58 anni, età media 34 anni) mediante un apparecchio Philips iU22 con trasduttore lineare ad alta risoluzione (5–17 MHz). Sono state effettuate scansioni lungo l’asse lungo dei legamenti estrinseci dorsali e ventrali per poterne valutare il decorso, lo spessore e l’ecostruttura. In 10 casi è stato inoltre eseguito un esame artro-RM di polso.RisultatiIn tutti i soggetti è stato possibile riconoscere le componenti legamentose come sottili strutture fibrillari iperecogene. È stato possibile individuare il decorso di sette legamenti estrinseci del carpo ed i rapporti con le strutture articolari circostanti. I legamenti radioscafolunato e collaterale ulnare non sono risultati visibili ecograficamente. Le immagini artro-RM hanno dimostrato tutti i legamenti estrinseci ad eccezione del legamento collaterale ulnare, mai visualizzato.ConclusioniI dati ottenuti concordano con quelli presenti in letteratura. L’ecografia ad alta risoluzione ci permette di studiare i legamenti estrinseci del carpo con un buon dettaglio anatomico ma il ruolo dell’ecografia nell’iter terapeutico delle patologie da instabilità del carpo rimane da dimostrare.

Multimodal imaging in the differential diagnosis of soft tissue calcinosis

Soft tissue calcinosis is a common radiographic finding, which may be related to different types of pathological processes. Multimodality imaging, combined with analysis of clinical and laboratory data, plays an important role for the differential diagnosis of these conditions. Conventional radiography is considered the first line approach to soft tissue calcinosis; CT and MRI may provide further information to better characterize calcified deposits. Imaging may help to distinguish metabolic calcification, such as primary tumoral calcinosis and the secondary one (associated with acquired disorders of calcium or phosphate regulation), from dystrophic calcification, which is associated to normal blood values of phosphate. The sedimentation sign typical of tumoral calcinosis has been demonstrated by plain film radiography, CT, MRI, and, more recently, by ultrasonography. Other types of soft tissue calcinosis may have a degenerative, metaplastic or neoplastic origin, and their characterization strongly relies on multimodality imaging.

Equipment and examination technique

Ultrasound (US) is one of the best imaging techniques in musculoskeletal radiology because it is low in cost, has high spatial resolution, wide availability in hospitals, is well-tolerated by patients and is not biologically invasive, as it uses sound waves and non ionizing radiation, as in conventional radiology or computed tomography (CT). These features make ultrasound the ideal technique for the diagnosis and follow up of many pathologies and rheumatic syndromes and for the evaluation of the effects of therapy

Normal US Anatomy and Scanning Technique

Ultrasound is a low-cost, quick and non-invasive imaging method, providing an excellent view of peripheral nerve anatomy as well as of surrounding structures. US provides high spatial resolution and the ability to explore long segments of nerve trunks in a single study, also allowing nerves examination in both static and dynamic conditions, during passive or active movements of the extremities. In this chapter, we describe the normal US anatomy and the scanning technique of the most relevant nerves of upper and lower limb also including dedicated anatomic schemes.

Basic Principles of Musculosketal Ultrasound

Tendons are critical biomechanical units in the musculoskeletal system, the function of which is to transmit muscular strength to mobile skeletal segments. Tendons are extremely resistant to traction, almost like bone, being able to bear up to 1000 kg per 10 mm2 transverse section. Conversely, tendons are not very elastic, being only able to tolerate a maximum elongation of 6% before being damaged. Tendons have very slow metabolism, even during action, and it can only be significantly increased by inflammatory conditions and traumas. Tendons macroscopically appear as ribbon-like structures, with extremely variable shape and dimensions, characterized by the presence of dense fibrous tissue arranged in parallel bundles. Primary bundles are assembled to form secondary bundles (representing the tendon’s functional unit), which are in turn clustered in tertiary bundles.

High-resolution ultrasound anatomy of extrinsic carpal ligaments@@@Anatomia ecografica ad alta risoluzione dei legamenti estrinseci del carpo

PurposeCarpal ligaments can be classified as intrinsic and extrinsic. Extrinsic ligaments are often involved in carpal instability. The purpose of this article is to describe the sonographic appearance of extrinsic carpal ligaments on high-resolution ultrasound (HRUS) using magnetic resonance arthrography (MR arthrography) as a reference standard.Materials and methodsWe studied both wrists in 18 healthy volunteers (ten men, eight women, age range 18–58 years, mean age 34 years) with a Philips iU22 US scanner equipped with a high-resolution linear-array broadband transducer (5–17 MHz). The scans were performed along the long axis of the extrinsic dorsal and ventral ligaments to assess their course, thickness and structure. Ten subjects were also studied with MR arthrography of the wrist.ResultsIn all patients, the ligament components could be appreciated as thin fibrillar hyperechoic structures. The course of seven extrinsic carpal ligaments and their relationships with surrounding articular structures could be studied. The radioscapholunate and the ulnar collateral ligaments were not visible on US. MR arthrography depicted all ligaments except for the ulnar collateral, which was never visualised.ConclusionsThe results obtained are consistent with those reported in the literature. HRUS provides good anatomical detail of the extrinsic carpal ligaments, but the role of US in planning the treatment of carpal instability disorders is yet to be demonstrated.RiassuntoObiettivoI legamenti del carpo sono suddivisi in intrinseci ed estrinseci. Questi ultimi sono spesso coinvolti nella patogenesi dell’instabilità carpale. L’obiettivo di questo studio è descrivere l’aspetto ecografico dei legamenti estrinseci del carpo mediante ecografia ad alta risoluzione, utilizzando l’artrografia a risonanza magnetica (artro-RM) come metodica di riferimento.Materiali e metodiAbbiamo studiato entrambi i polsi di 18 soggetti volontari sani (10 maschi, 8 femmine, range 18–58 anni, età media 34 anni) mediante un apparecchio Philips iU22 con trasduttore lineare ad alta risoluzione (5–17 MHz). Sono state effettuate scansioni lungo l’asse lungo dei legamenti estrinseci dorsali e ventrali per poterne valutare il decorso, lo spessore e l’ecostruttura. In 10 casi è stato inoltre eseguito un esame artro-RM di polso.RisultatiIn tutti i soggetti è stato possibile riconoscere le componenti legamentose come sottili strutture fibrillari iperecogene. È stato possibile individuare il decorso di sette legamenti estrinseci del carpo ed i rapporti con le strutture articolari circostanti. I legamenti radioscafolunato e collaterale ulnare non sono risultati visibili ecograficamente. Le immagini artro-RM hanno dimostrato tutti i legamenti estrinseci ad eccezione del legamento collaterale ulnare, mai visualizzato.ConclusioniI dati ottenuti concordano con quelli presenti in letteratura. L’ecografia ad alta risoluzione ci permette di studiare i legamenti estrinseci del carpo con un buon dettaglio anatomico ma il ruolo dell’ecografia nell’iter terapeutico delle patologie da instabilità del carpo rimane da dimostrare.

Anatomia ecografica ad alta risoluzione dei legamenti estrinseci del carpo

PurposeCarpal ligaments can be classified as intrinsic and extrinsic. Extrinsic ligaments are often involved in carpal instability. The purpose of this article is to describe the sonographic appearance of extrinsic carpal ligaments on high-resolution ultrasound (HRUS) using magnetic resonance arthrography (MR arthrography) as a reference standard.Materials and methodsWe studied both wrists in 18 healthy volunteers (ten men, eight women, age range 18–58 years, mean age 34 years) with a Philips iU22 US scanner equipped with a high-resolution linear-array broadband transducer (5–17 MHz). The scans were performed along the long axis of the extrinsic dorsal and ventral ligaments to assess their course, thickness and structure. Ten subjects were also studied with MR arthrography of the wrist.ResultsIn all patients, the ligament components could be appreciated as thin fibrillar hyperechoic structures. The course of seven extrinsic carpal ligaments and their relationships with surrounding articular structures could be studied. The radioscapholunate and the ulnar collateral ligaments were not visible on US. MR arthrography depicted all ligaments except for the ulnar collateral, which was never visualised.ConclusionsThe results obtained are consistent with those reported in the literature. HRUS provides good anatomical detail of the extrinsic carpal ligaments, but the role of US in planning the treatment of carpal instability disorders is yet to be demonstrated.RiassuntoObiettivoI legamenti del carpo sono suddivisi in intrinseci ed estrinseci. Questi ultimi sono spesso coinvolti nella patogenesi dell’instabilità carpale. L’obiettivo di questo studio è descrivere l’aspetto ecografico dei legamenti estrinseci del carpo mediante ecografia ad alta risoluzione, utilizzando l’artrografia a risonanza magnetica (artro-RM) come metodica di riferimento.Materiali e metodiAbbiamo studiato entrambi i polsi di 18 soggetti volontari sani (10 maschi, 8 femmine, range 18–58 anni, età media 34 anni) mediante un apparecchio Philips iU22 con trasduttore lineare ad alta risoluzione (5–17 MHz). Sono state effettuate scansioni lungo l’asse lungo dei legamenti estrinseci dorsali e ventrali per poterne valutare il decorso, lo spessore e l’ecostruttura. In 10 casi è stato inoltre eseguito un esame artro-RM di polso.RisultatiIn tutti i soggetti è stato possibile riconoscere le componenti legamentose come sottili strutture fibrillari iperecogene. È stato possibile individuare il decorso di sette legamenti estrinseci del carpo ed i rapporti con le strutture articolari circostanti. I legamenti radioscafolunato e collaterale ulnare non sono risultati visibili ecograficamente. Le immagini artro-RM hanno dimostrato tutti i legamenti estrinseci ad eccezione del legamento collaterale ulnare, mai visualizzato.ConclusioniI dati ottenuti concordano con quelli presenti in letteratura. L’ecografia ad alta risoluzione ci permette di studiare i legamenti estrinseci del carpo con un buon dettaglio anatomico ma il ruolo dell’ecografia nell’iter terapeutico delle patologie da instabilità del carpo rimane da dimostrare.

Sonographic and power Doppler normal anatomy

Cartilage is a greatly specialized type of connective tissue, mainly composed of water (70–80% by wet weight). It is avascular and aneural. The solid component of cartilage is formed of cells (chondrocytes) that are scattered in a firm gel-like substance (extracellular matrix) consisting of collagen and proteoglycans.Collagen forms a network of fibrils, which resists the swelling pressure generated by the proteoglycans. In the musculoskeletal system there are two types of cartilage: hyaline and fibrocartilage. Compared to hyaline, fibrocartilage contains more collagen and is more resistant at tensile strength.Fibrocartilage is found in intervertebral disks, symphyses, glenoid labra, menisci, the round ligament of the femur, and at sites connecting tendons or ligaments to bones.Hyaline cartilage is the most common variety of cartilage. It is found in costal cartilage, epiphyseal plates and covering bones in joints (articular cartilage). The free surfaces of most hyaline cartilage (but not articular cartilage) are covered by a layer of fibrous connective tissue (perichondrium). Hyaline cartilage structure is not uniform (Fig. 3.1). Instead, it is stratified and divided into four zones: superficial, middle, deep, and calcified. The superficial zone, also called tangential zone, is considered the articular surface and is characterized by flattened chondrocytes, relatively low quantities of proteoglycan, and numerous thicker fibrils arranged parallel to the articular surface in order to resist tension. In articular cartilage this layer acts as a barrier because there is no perichondrium.The middle zone, or transitional zone, in contrast, has round chondrocytes, the highest level of proteoglycan among the four zones, and a random arrangement of collagen.The deep (radiate zone) is the thickest zone, characterized by collagen fibrils that are perpendicular to the underlying bone, acting as an anchor to prohibit separation of zones and in order to resist at torsional and compressive mechanical strength

Imading E Stadio Early

Anche se le articolazioni coinvolte possono essere molteplici, specie nelle fasi avanzate di malattia, come in precedenza sottolineato, sono soprattutto le piccole articolazioni (metacarpo-falangee, metatarso-falangee, interfalangee prossimali delle mani e dei piedi) le sedi di piu precoce interessamento e, pertanto, di piu significativo impatto diagnostico. Risulta pertanto di fondamentale importanza, al fine di stabilire il piu corretto approccio diagnostico, focalizzare l’impatto delle piu avanzate tecniche di imaging nella definizione e nell’analisi delle fasi piu precoci di coinvolgimento reumatoide. Come noto la prorompente evoluzione della moderna diagnostica per immagini ha consentito di ottenere preziosi e, spesso, insostituibili rilievi semeiologici indispensabili per un migliore e piu approfondito inquadramento clinico del paziente. Spetta infatti alla diagnostica per immagini supportare la diagnosi clinica, consentire il piu precoce ed adeguato trattamento terapeutico, valutarne l’efficacia e seguire l’evoluzione di malattia.