MR imaging of entrapment neuropathies of the shoulder

LEARNING OBJECTIVES: To describe the MRI features of most common entrapment neuropathies of the shoulder: - Parsonage-Turner syndrome - quadrilateral space syndrome (axillary neuropathy) - suprascapular nerve syndrome BACKGROUND: Entrapment neuropathies are characterized by alteration of nerve function secondary to compression by mechanical or dynamic forces. The compression may be acute, chronic or intermittent. Not infrequently compressive neuropathies are related to space-occupying lesions such as tumors, cysts, inflammatory processes, or post-traumatic conditions. IMAGING FINDINGS: The MR imaging appearance of Parsonage-Turner syndrome is quite characteristic, with marked edema in the affected muscles of the shoulder, most commonly those innervated by the suprascapular nerve, although deltoid muscle can also be compromised. MR imaging of quadrilateral space syndrome may reveal fatty atrophy or edema isolated to the teres minor muscle. MR imaging of suprascapular nerve syndrome is established when edema or fatty changes of supraspinatus and/or infraspinatus muscle is present along with a cyst or ganglion in the spinoglenoid or suprascapular notch. CONCLUSION: MRI is a powerful diagnostic imaging tool in the diagnosis of entrapment neuropathies of the shoulder and underlying causes, thus excluding other possible causes of shoulder pain. Moreover, MRI may recognize active changes of denervation in muscle from chronic denervation muscle changes or “fatty atrophy” in isolation, and therefore it may change treatment and management

Hippocampal and Amygdalar Volumes Changes in Drug Addicts: A Preliminary Study

Oral comunication for American Society of Neuroradiology 45th Annual Meeting. Chicago, June 9-14 200

Incidentally discovered thyroid nodules: incidence, grey-scale and color Doppler pattern in an adult population screened by real-time compound spatial sonography

Purpose. Our aim was to assess the incidence and ultrasound features of thyroid nodules in an adult population screened by means of high-resolution ultrasonography (HRUS) and to evaluate the contribution of real-time spatial compound sonography (CS) in terms of image quality. Materials and methods. A total of 704 consecutive patients (400 women, 304 men) without thyroid disease underwent HRUS and CS examination of the thyroid gland. Number, size, location, echotexture and colour Doppler pattern of detected nodules were assessed. Two radiologists also assessed image quality of the two techniques. Results. Seven hundred and eleven thyroid nodules (size range 0.18-4.1 cm; mean: 1.1 cm) were detected in 233 subjects (33.1%). Of these, 416 (58.5%) were found in 143 women whereas 295 (41.5%) were detected in 90 men. In both genders, the number of detected nodules increased with age, with the highest prevalence in the seventh decade (p<0.001). There were 461/711 (64.9%) thyroid nodules that were hypoechoic, and 449/711 (63.1%) had peripheral vascularity only (p<0.001). Fine-needle aspiration (FNA) revealed no malignancies. CS was graded better than HRUS in 621/711 (87.3%) cases (p<0.001). Conclusions. The prevalence of benign, small, hypoechoic thyroid nodules with peripheral vascularity was high in our series, thus suggesting a conservative approach. CS provided better image quality compared with HRUS

Avoiding tunnel collisions between fibular collateral ligament and ACL posterolateral bundle reconstruction

PURPOSE: The purpose of this study was to evaluate the risk of tunnel collisions of the fibular collateral ligament (FCL) and posterolateral bundle anterior cruciate ligament (PLB-ACL) tunnels during a combined FCL and double-dundle (DB) ACL reconstruction. METHODS: Thirty-six 4th-generation synthetic femurs (Sawbones, Pacific Research Laboratories, Vashon, WA) were utilized, and two different femur sizes were used. A FCL tunnel and a PLB-ACL tunnel were reamed on each femur. The tunnels of synthetic specimens that did not have a collision were filled with an epoxy resin augmented with BaSO(4) and radiographic evaluation, and Multidetector CT exams of the specimens were performed. RESULTS: The rate of tunnel collision when the FCL tunnel was reamed to a depth of 30 mm was 75 and 69.4% for the 25 mm depth. There was a significantly increased risk of tunnel collision when the FCL tunnel was reamed proximally with coronal angulations of 20° and 40°. No collisions were noted when the FCL tunnel was reamed parallel to the distal condylar line and with axial angulations of 20° and 40°. CONCLUSION: This study provides new insight into tunnel positioning during a combined FCL and DB-ACL reconstruction. The results show that a concomitant FCL injury do not represent a contraindication to perform a DB-ACL reconstruction as long as the FCL tunnel is reamed with no proximal angulation and is directed anteriorly with an axial angulation between 20° and 40°

Imaging con risonanza magnetica delle neuropatie da intrappolamento della spalla

Obiettivi didattici: Descrivere e caratteristiche alla risonanza magnetica (RM) delle neuropatie da intrappolamento comuni della spalla: - sindrome di Parsonage-Turner - sindrome del quadrilatero (neuropatia ascellare) - sindrome del nervo soprascapolare Introduzione: Le neuropatie da intrappolamento sono caratterizzate da alterazione della funzionalità dei nervi secondaria alla compressione da parte di forze meccaniche o dinamiche. La compressione può essere acuta, cronica o intermittente. Non di rado neuropatie compressive sono dovute a lesioni occupanti spazio, come tumori, cisti, processi infiammatori, o condizioni post-traumatiche. Descrizione: L'aspetto RM della sindrome di Parsonage-Turner è abbastanza caratteristico, con edema marcato nei muscoli interessati della spalla, più comunemente quelli innervati dal nervo soprascapolare, anche se può essere compromesso pure il muscolo deltoide. L'imaging RM della sindrome dello spazio quadrilatero può rivelare un'atrofia adiposa o un edema isolato del muscolo piccolo rotondo. L'imaging RM della sindrome del nervo soprascapolare è caratterizzata da edema o degenerazione adiposa del muscolo sovraspinato e/o infraspinato insieme ad una cisti o ganglio dell'incisura spino-glenoidea o di quella soprascapolare. Conclusioni: La RM è fondamentale per la diagnosi delle neuropatie da intrappolamento della spalla e delle relative cause, escludendo così altre possibili cause di dolore alla spalla. Inoltre, la RM permette di distinguere una denervazione acuta da una cronica con atrofia adiposa

Pigmented villonodular synovitis and pigmented villonodular bursitis: Imaging findings and review of the literature

Learning Objectives: To review the pathologic basis of pigmented villonodular synovitis (PVNS) and bursitis (PVNB). To describe the imaging appearances of PVNS and PVNB using conventional radiography (CR), ultrasonography (US) and magnetic resonance (MR) imaging. Background: PVNS is a rare proliferative disorder of the synovial membrane that may occur diffusely or focally. PVNB is the same pathology with the difference that the synovial involvement occurs in an extra-articular site, as a bursa. They primarily involve young adults and appear with non-specific symptoms (swelling, pain) which mimic other pathologies, including traumatic injuries, thus often delaying the correct diagnosis. Imaging Findings: CR imaging may appear normal or reveal a non-specific soft-tissue mass; visible calcifications are rare. US imaging may detect joint effusion, complex heterogeneous echogenic masses, and a markedly thickened hypoechoic synovium. MR imaging may demonstrate the disease extension (particularly in case of bursal involvement) to best advantage, and the predominant low signal intensity of the lesions on T2-weighted images is a characteristic sign of the disease. Moreover, the “blooming artifact” seen on gradient-echo images, caused by the magnetic susceptibility artifact from hemosiderin deposition in these lesions, is a nearly pathognomonic sign of this disease. Conclusion: Detection of disease location and extension are important both for diagnosis and to guide treatment. MR is the best diagnostic imaging tool to identify the presence of haemosiderin deposition within the nodules, thus characterizing the lesion. This information is crucial to guide treatment and to achieve complete surgical resection

Sinovite villonodulare-pigmentosa (PVNS) e borsite villonodulare-pigmentosa (PVNB): imaging e review della letteratura

OBIETTIVI DIDATTICI: Rivedere le basi patologiche della “Sinovite Villonodulare Pigmentosa” (PVNS) e della “Borsite Villonodulare Pigmentosa” (PVNB). Descriverne le caratteristiche alla radiografia convenzionale (RX), all’ecografia (US) ed alla risonanza magnetica (RM). INTRODUZIONE: La PVNS è un raro disordine proliferativo della sinovia articolare che si manifesta in forma diffusa o focale; può insorgere anche nelle borse peri-articolari (PVNB). Entrambe le forme interessano principalmente i giovani adulti e si manifestano con sintomi aspecifici che mimano altre patologie, anche di natura traumatica, ritardando spesso la diagnosi corretta. DESCRIZIONE: Il quadro RX può essere normale o rivelare una massa di significato aspecifico nei tessuti molli. L’US può evidenziare versamento articolare, noduli iperecogeni o un ispessimento della sinovia. La RM dimostra l’estensione della patologia (particolarmente nei casi di coinvolgimento bursale) e la caratteristica ipointensità di segnale sia nelle sequenze T1 che T2-pesate. Inoltre, le sequenze gradient-echo mostrano un segno patognomonico di questa patologia che è rappresentato dall’artefatto di “blooming”, causato dalla suscettibilità magnetica dovuto ai depositi di emosiderina intracellulare. CONCLUSIONI: Per la diagnosi e per il corretto trattamento dei pazienti con PVNS e/o PVNB l’imaging, in particolare la RM, ha un ruolo fondamentale nell’identificare la sede e dimostrare l’estensione della patologia. Inoltre, la presenza di depositi di emosiderina nei noduli aumenta la confidenza diagnostica della RM