Does Immobilization Post Injection Reduce Contrast Extravasation in MR Arthrography of the Shoulder?

BACKGROUND: Contrast leakage after arthrography is common. We sought to investigate if immobilization could prevent it. PURPOSE: The purpose of this study was to determine the effects on contrast extravasation and image quality produced by strict immobilization of the shoulder between arthrography puncture and subsequent MR imaging. MATERIAL AND METHODS: Fifty patients underwent shoulder MR arthrography using a standard shoulder puncture in the anteroinferior quadrant. Ten milliliters of contrast mixture of saline, iodinated contrast, and gadolinium contrast was injected by a senior musculoskeletal (MSK) radiologist using a 21G needle. Half of the patients were immediately immobilized using a shoulder sling, and the other half were allowed to move their shoulder and arm freely during the time before MR imaging. MR arthrography was performed with a 3 T system using standard T1 and PD weighted sequences. The MR images were reviewed independently by 2 MSK radiologists and graded for extravasation using a five-point scale (1: none, 2: less than 2 cm, 3: 2-5 cm, 4: 5-10 cm, 5: more than 10 cm) and for image quality using a 5 point scale (1: poor, 5: good). The Pearson correlation was calculated to assess the correlation between leakage and image quality. RESULTS: There was no significant difference in amount of leakage between both groups, and global image quality was found equal in both groups. A negative correlation was found between leakage and quality assessment. CONCLUSION: This study shows that it cannot be avoided by strict shoulder immobilization and that it negatively affects image quality and interpretation.

Pseudo-tear appearance of the Achilles tendon on MR imaging in normal volunteers.

PURPOSE: The aim of this study was to confirm our clinical observation that a pseudo-tear appearance of the Achilles tendon is commonly seen on MRI and is of no clinical relevance. MATERIALS AND METHODS: Forty-one ankles were imaged on a 3 T MR system, and PD weighted images with fat saturation were obtained in three orthogonal planes (TR, 2969 ms; TE, 30 ms; NA, 2; slice thickness, 2.5 mm). Volunteer exclusion criteria were symptoms of Achilles tendon pathology (such as acute or chronic posterior heel pain), history of trauma or surgery of the Achilles tendon. Internal signal of the Achilles tendon on axial and sagittal images was assessed independently by two observers. Internal signal of the Achilles tendon was classified from homogenously dark to different degree of hyperintense signal, where 0 means no internal hyperintensity, 1-minimal hyperintensity, 2-moderate and 3-marked. Descriptive statistics were calculated. Correlation between the two readers was also assessed. Two fresh cadavers were used in this study, one specimen being sliced in the sagittal plane and one specimen being dissected by an experienced anatomist. RESULTS: Twenty one volunteers (8 men, 13 women), mean age of 24.7 years (19-43 years) were included in the study. On sagittal images both raters appreciated any degree of hyperintense signal in 59% of tendons. On axial images any degree of hyperintensity was seen in almost half of the cases (46 vs. 49%). Minimal hyperintensities were seen most commonly. Cohen's kappa coefficient for sagittal images was 0.964 (almost perfect agreement); for axial images 0.764 (substantial agreement). The anatomical studies demonstrated that the Achilles tendon is made up of different components that are partially separated and twist around each other explaining the pseudo-tear appearance. CONCLUSION: The Achilles tendon is frequently not homogenously dark in normal volunteers as would be expected. Hyperintense signal is common in the long and short axis and related to the underlying anatomical features.

Ankle and midfoot ligaments: Ultrasound with anatomical correlation: A review.

We present a detailed overview of anatomical and US features of ankle and midfoot ligaments based on our own dissections and cadaver studies as well as US imaging in cadavers and volunteers. The ligament anatomy about the ankle and midfoot is complex. Most ligaments are superficial and hence very well accessible for US. US technique to obtain optimal visualization however is difficult and requires a learning curve. We discuss US technique in detail for each individual ligament. We divided the ligaments in different groups: tibiofibular ligaments, Bassett's ligament, lateral collateral ligament complex (anterior talofibular ligament, calcaneofibular ligament, lateral talocalcaneal ligament, posterior talofibular ligament), medial collateral ligament complex, spring ligament, Chopart joint ligaments (bifurcate ligament, dorsal talonavicular ligament, lateral calcaneocuboid ligament, long and short plantar ligaments), Lisfranc ligaments, sinus tarsi ligaments.

High-resolution CT of the sternoclavicular joint and first costochondral synchondrosis in asymptomatic individuals.

OBJECTIVE: To assess CT features of the sternoclavicular joint (SCJ) and first costochondral junction in asymptomatic patients. MATERIALS AND METHODS: In 66 patients transverse and coronal oblique high-resolution multiple detector CT images of the SCJ and first costochondral junction were obtained. Images were reviewed by consensus of two radiologists. Joint space width was measured at three levels, and osteophytes, geodes, and erosions were evaluated. Variants and degree of ossification were noted. Statistical analysis consisted of Shapiro-Wilk test, Pearson's test, and paired sample t test. RESULTS: There were 34 men and 32 women with a mean age of 60 years (age range, 17-98 years). The width of the joint spaces showed a normal distribution. There was no significant difference between the left and right sides. On coronal images the joint space was wider superiorly and on transverse images posteriorly. There was a trend toward decreasing joint space with age, although it did not reach significance (p > 0.05). Clavicular osteophytes were seen in 16 out of 66 patients (24 %) and sternal osteophytes in 16 out of 66 patients. Clavicular geodes were seen in 10 out of 66 patients (15 %) and sternal geodes in 14 out of 66 patients (14 %). No erosions were seen. Clefts of the first costochondral junction were seen in 31 out of 66 patients (47 %). CONCLUSION: In asymptomatic patients, there is no significant asymmetry of the SCJ. The joint spaces did not significantly decrease with age, although such a trend could be observed. Pronounced joint space narrowing with large geodes and osteophytes was not seen. Clefts of the first costochondral junction are common and not significant.

Sclerosing bone dysplasias: genetic, clinical and radiology update of hereditary and non-hereditary disorders.

There is a wide variety of hereditary and non-hereditary bone dysplasias, many with unique radiographic findings. Hereditary bony dysplasias include osteopoikilosis, osteopathia striata, osteopetrosis, progressive diaphyseal dysplasia, hereditary multiple diaphyseal sclerosis and pyknodysostosis. Non-hereditary dysplasias include melorheostosis, intramedullary osteosclerosis and overlap syndromes. Although many of these dysplasias are uncommon, radiologists should be familiar with their genetic, clinical and imaging findings to allow for differentiation from acquired causes of bony sclerosis. We present an overview of hereditary and non-hereditary bony dysplasias with focus on the pathogenesis, clinical and radiographic findings of each disorder.

Unusual CT Appearance of Bony Metastases from Malignant Peripheral Nerve Sheath Tumor.

We present a case of bone metastases from a malignant peripheral nerve sheath tumor (MPNST). While multiple bone lesions typically are suggestive of metastatic disease, especially in combination with a primary tumor and positive PET, the appearance of lesions in this patient was quite atypical. We are not aware of any case of metastatic disease with such atypical doughnut appearance as in our case.

Advanced imaging of the scapholunate ligamentous complex.

The scapholunate joint is one of the most involved in wrist injuries. Its stability depends on primary and secondary stabilisers forming together the scapholunate complex. This ligamentous complex is often evaluated by wrist arthroscopy. To avoid surgery as diagnostic procedure, optimization of MR imaging parameters as use of three-dimensional (3D) sequences with very thin slices and high spatial resolution, is needed to detect lesions of the intrinsic and extrinsic ligaments of the scapholunate complex. The paper reviews the literature on imaging of radial-sided carpal ligaments with advanced computed tomographic arthrography (CTA) and magnetic resonance arthrography (MRA) to evaluate the scapholunate complex. Anatomy and pathology of the ligamentous complex are described and illustrated with CTA, MRA and corresponding arthroscopy. Sprains, mid-substance tears, avulsions and fibrous infiltrations of carpal ligaments could be identified on CTA and MRA images using 3D fat-saturated PD and 3D DESS (dual echo with steady-state precession) sequences with 0.5-mm-thick slices. Imaging signs of scapholunate complex pathology include: discontinuity, nonvisualization, changes in signal intensity, contrast extravasation (MRA), contour irregularity and waviness and periligamentous infiltration by edema, granulation tissue or fibrosis. Based on this preliminary experience, we believe that 3 T MRA using 3D sequences with 0.5-mm-thick slices and multiplanar reconstructions is capable to evaluate the scapholunate complex and could help to reduce the number of diagnostic arthroscopies.

Segond fracture: involvement of the iliotibial band, anterolateral ligament, and anterior arm of the biceps femoris in knee trauma.

OBJECTIVE: To evaluate the involvement of the iliotibial band (ITB), the anterolateral ligament (ALL), and the anterior arm of the biceps femoris in MRI-diagnosed Segond fracture and to evaluate other associated findings of Segond fracture. MATERIALS AND METHODS: We retrospectively reviewed the MRI of 13 cases of Segond fracture. The studies included proton density-weighted, T2-weighted, and proton density-weighted with fat saturation images in the three planes. We studied 2 cadaveric specimens with emphasis on the ALL. One cadaveric specimen was dissected while the other was sectioned in the sagittal plane. RESULTS: The mean age of the patients was 36 years (range, 17-52). There were 7 men and 6 women. The mean size of the Segond bone fragment was 8 × 10 × 2 mm. The distance from the tibia varied from 2 to 6 mm. Associated findings included anterior cruciate ligament (ACL) tear (n = 13), medial collateral ligament (MCL) tear (n = 8), meniscocapsular tear of the posterior horn of the medial meniscus (n = 5), and posterolateral corner involvement (n = 4). Bone marrow edema involved the mid-lateral femoral condyle and the posterior tibial plateau on both the medial and the lateral side. Edema at the Segond area was seen, but was limited. Fibular head edema was also seen. The ITB (11 out of 13) and ALL (10 out of 13) inserted on the Segond bone fragment. The anterior arm of the biceps tendon did not insert on the Segond fracture. CONCLUSION: Associated findings of Segond fracture include ACL tear, MCL tear, medial meniscus tear, and posterolateral corner injury. Both the ITB and the ALL may be involved in the Segond avulsion. The anterior arm of the biceps femoris tendon is not involved.

Ultrasound follow-up of posttraumatic injuries of the sagittal band of the dorsal hood treated by a conservative approach.

Traumatic dislocation of the extensor tendon over the metacarpophalangeal (MCP) joint is a rare problem in patients without rheumatoid disorders. The common extensor tendon is stabilized on the metacarpal head by components of the dorsal hood (DH). A tear in the sagittal bands, allows (sub)luxation of the tendon. To ensure appropriate treatment, the identification of the damaged structures is essential. Ultrasound (US) is a valuable method in the evaluation of DH injuries and in the follow-up for evaluation of healing or lack of healing of the lesions. We report three cases with partial rupture of the sagittal band of the DH: two cases in the index finger and one case in the long finger, which caused pain and swelling and was diagnosed with US. The patients were treated conservatively and the pain resolved after 9 months in case 1, 3 months in case 2 and 6 months in case 3. The follow-up at one year revealed painless full range of motion and no residual subluxation during the dynamic ultrasound.

Advanced imaging of the glenohumeral ligaments.

The glenohumeral ligaments (GHLs) are the most important passive stabilizers of the shoulder joint. Recognition of acute and chronic glenohumeral ligamentous lesions is very important in the preoperative work-up of shoulder instability and trauma. This article describes and depicts the normal anatomy of the GHLs and their appearance during arthroscopy and on MR and computed tomography arthrography (CTA). Pathologic findings of the superior, middle, and inferior GHLs are described and illustrated with MR and CTA and their corresponding intraoperative arthroscopic images. MR arthrography (MRA) is useful for direct visualization of all GHLs including most lesions of their intra-articular portion and associated capsulolabral pathologies. Sprains, midsubstance tears, avulsion, or fibrous infiltration of the GHL can be identified on MRA images using fast spin-echo sequences with and without fat saturation in the three planes. Although CTA is reputed to better depict associated bony and cartilage lesions, CTA allows only indirect evaluation of the GHLs by outlining their contour or showing contrast penetration. Normal variants may create pitfalls that one should be aware of. Signs of GHL pathology on imaging include: discontinuity, nonvisualization, changes in signal intensity (on MRA), contrast extravasation, contour irregularity, thickening, or waviness.

Ultrasound of the knee with emphasis on the detailed anatomy of anterior, medial, and lateral structures.

OBJECTIVE: To describe the detailed ultrasound anatomy of the anterior, medial, and lateral aspects of the knee and present the ultrasound examination technique used. MATERIALS AND METHODS: We present ultrasound using images of patients, volunteer subjects, and cadaveric specimens. We correlate ultrasound images with images of anatomical sections and dissections. RESULTS: The distal quadriceps tendon is made up of different laminas that can be seen with ultrasound. One to five laminas may be observed. The medial retinaculum is made up of three anatomical layers: the fascia, an intermediate layer, and the capsular layer. At the level of the medial patellofemoral ligament (MPFL) one to three layers may be observed with ultrasound. The medial supporting structures are made up of the medial collateral ligament and posterior oblique ligament. At the level of the medial collateral ligament (MCL), the superficial band, as well as the deeper meniscofemoral and meniscotibial bands can be discerned with ultrasound. The posterior part, corresponding to the posterior oblique ligament (POL), also can be visualized. Along the posteromedial aspect of the knee the semimembranosus tendon has several insertions including an anterior arm, direct arm, and oblique popliteal arm. These arms can be differentiated with ultrasound. Along the lateral aspect of the knee the iliotibial band and adjacent joint recesses can be assessed. The fibular collateral ligament is encircled by the anterior arms of the distal biceps tendon. Along the posterolateral corner, the fabellofibular, popliteofibular, and arcuate ligaments can be visualized. CONCLUSION: The anatomy of the anterior, medial, and lateral supporting structures of the knee is more complex than is usually thought. Ultrasound, with its exquisite resolution, allows an accurate assessment of anatomical detail. Knowledge of detailed anatomy and a systematic technique are prerequisites for a successful ultrasound examination of the knee.

Pathology of extrinsic ligaments: a pictorial essay.

The role of the extrinsic ligaments, together with the intrinsic ligaments, appears to be much more important than previously thought in the setting of carpal stability. The anatomy and pathology of the extrinsic wrist ligaments is complex. Magnetic resonance imaging (MRI) with thin slices is essential for visualization. This article describes the pathological appearance of the extrinsic palmar and dorsal radiocarpal and ulnocarpal ligaments on MRI, correlated with arthroscopy (performed by two skilled hand surgeons), clinical findings, and follow-up. High-resolution MRI, especially using isotropic three-dimensional sequences with orthogonal multiplanar reconstructions on 3T MR systems, allows detailed depiction of many of the extrinsic ligaments affected in carpal injuries. Recognition of ligament abnormalities is improved by intra-articular or intravenous injection of contrast before the examination. Both techniques may help to determine the precise localization, size, and extent of dorsal and palmar radiocarpal and ulnocarpal ligament lesions. Further experience with these techniques is needed to define the place of MRI in the management of traumatic wrist injuries.

Magnetic resonance arthrography of glenohumeral lesions: anatomy and arthroscopically confirmed pathology.

Interpretation of magnetic resonance (MR) arthrography images of the glenohumeral ligaments is made difficult by anatomical variations and by the lack of descriptions of signs of pathology of the ligaments. In this review, we describe the normal and pathologic appearance of the glenohumeral ligaments of the shoulder. These ligaments play an important role in stabilization of the shoulder. Both 1.5 and 3 T MR units were used to acquire the MR images. The principal investigator reviewed the imaging reports and arthroscopic reports. All cases were correlated with arthroscopy. Lesions of the superior glenohumeral, middle glenohumeral, and inferior glenohumeral, including humeral avulsion of the glenoid ligament are discussed. Diagnosis of lesions of the glenohumeral ligaments remains a challenge.

Assessment of the long head of the biceps tendon of the shoulder with 3T magnetic resonance arthrography and CT arthrography.

We studied the assessment of proximal biceps tendon lesions including degeneration, tendon luxation, and partial and complete tendon tears with 3T MR arthrography and CT arthrography. Thirty-six patients who underwent both studies, as well as arthroscopy were included in the study. The images were randomized and blinded and independently reviewed by two musculoskeletal radiologists. The pooled sensitivity for lesion detection for CT arthrography was 31% and the specificity 95%. The pooled sensitivity for MR arthrography was 27% and the specificity 94%. There were no statistically significant differences between CT and MR. The interobserver agreement calculated with the kappa statistic was poor for CT and for MR. Both CT arthrography and MR arthrography perform poorly in the detection of biceps tendon pathology of the shoulder.

Case report: imaging findings in a "butterfly" vertebra.

A "butterfly" vertebra is a rare congenital anomaly, presenting as a sagittal cleft in the vertebral body. In the literature it has been described as an isolated finding, but it can also be associated with various syndromes, such as Alagille, Jarcho-Levin, Crouzon and Pfeiffer syndrome. We present a case of a 35-year old man with chronic low back pain. The diagnosis of a butterfly vertebra of S1 with disc space narrowing of L5-S1 was made. Usually the abnormality occurs at the thoracolumbar spine and we are not aware of a description of a sacral butterfly vertebra. Although a butterfly vertebra is usually asymptomatic, it could lead to discal herniation or chronic back pain due to alteration in spinal biomechanics.