Jan L. Gielen

Imaging features of musculoskeletal tuberculosis

Abstract. The purpose of this article is to review the imaging characteristics of musculoskeletal tuberculosis. Skeletal tuberculosis represents one-third of all cases of tuberculosis occurring in extrapulmonary sites. Hematogenous spread from a distant focus elsewhere in the body is the cornerstone in the understanding of imaging features of musculoskeletal tuberculosis. The most common presentations are tuberculous spondylitis, arthritis, osteomyelitis, and soft tissue involvement. The diagnostic value of the different imaging techniques, which include conventional radiography, CT, and MR imaging, are emphasized. Whereas conventional radiography is the mainstay in the diagnosis of tuberculous arthritis and osteomyelitis, MR imaging may detect associated bone marrow and soft tissue abnormalities. MR imaging is generally accepted as the imaging modality of choice for diagnosis, demonstration of the extent of the disease of tuberculous spondylitis, and soft tissue tuberculosis. Moreover, it may be very helpful in the differential diagnosis with pyogenic spondylodiscitis, as it may easily demonstrate anterior corner destruction, the relative preservation of the intervertebral disk, multilevel involvement with or without skip lesions, and a large soft tissue abscess, as these are all arguments in favor of a tuberculous spondylitis. On the other hand, CT is still superior in the demonstration of calcifications, which are found in chronic tuberculous abscesses.

Capitellar erosion caused by a metal radial head prosthesis. A case report.

The long-term results of resection of the radial head for the treatment of a simple radial head fracture have been generally satisfactory1-5. However, some late complications, such as proximal migration of the radius, can disable the patient and are difficult to treat. Proximal migration of the radius is usually asymptomatic3-5, although wrist pain develops in a minority of patients3-8. The options for treatment are limited, and clinical studies have shown poor and unreliable results9,10. Sowa et al. described a case in which a silicone radial head prosthesis was implanted for the treatment of wrist symptoms10. Proximal migration of the radius progressed, and it was concluded that a more rigid implant would be necessary. Sellman et al. reached a similar conclusion after performing a biomechanical study of this problem11. We report the case of a patient who had early progressive erosion of the capitellum after the insertion of a metal radial head prosthesis for the treatment of wrist pain following radial head resection after trauma. This complication has not been reported previously, to our knowledge. Our patient was informed that data concerning the case would be submitted for …

The effectiveness of diagnostic imaging methods for the assessment of soft tissue and articular disorders of the shoulder and elbow

There are no clear guidelines for diagnostic imaging of articular and soft tissue pathologies of the shoulder and elbow. Several methods are used, including magnetic resonance imaging (MRI), magnetic resonance arthrography (MRA) and ultrasound (US). Their cost-effectiveness is still unclear. We performed a meta-analysis of the relevant literature and discussed the role of MR imaging of the shoulder and elbow compared with other diagnostic imaging modalities. For the shoulder impingement syndrome and rotator cuff tears, MRI and US have a comparable accuracy for detection of full-thickness rotator cuff tears. MRA and US might be more accurate for the detection of partial-thickness tears than MRI. Given the large difference in cost of MR and US, ultrasound may be the most cost-effective diagnostic method for identification of full-thickness tears in a specialist hospital setting (Evidence level 3). Both MRA and CT arthrography (CTA) are effective methods for the detection of labrum tears. More recently, multidetector CTA has offered the advantages of thinner slices than with MRA in a shorter examination time. Still, MRA has the advantage towards CTA to directly visualize the affected structures with a better evaluation of extent and location and to detect associated capsuloligamentous injuries. For the elbow pathologies, plain MRI or MRA have the advantage towards CTA to detect occult bone injuries. CTA is better for the assessment of the thin cartilage of the elbow. Both US and MRI are reliable methods to detect chronic epicondylitis; US is more available and far more cost-effective (Evidence level 2). MRA can differentiate complete from partial tears of the medial collateral ligament. US or MRI can detect partial and complete biceps tendon tears and/or bursitis. MRI can provide important diagnostic information in lesions of the ulnar, radial, or median nerve.

Accuracy of MRI in characterization of soft tissue tumors and tumor-like lesions. A prospective study in 548 patients

The purpose of our study was to assess prospectively the value of MRI in characterization of soft tissue tumors (STT) and soft tissue tumor-like lesions in a multi-institutional setting by a group of experts. The material consisted of 548 untreated and proven STT or tumor-like lesions originating from a multi-institutional database of STT in which 930 consecutive patients with STT examined by MRI were registered between 1 January 2001 and 28 April 2003. Based on MRI findings, a suitably ordered differential diagnosis was made in consensus by two radiologists (J.L.M.A.G and A.M.D.S). MRI diagnoses were compared with histology results (455 cases, 83%) and/or 6-month follow-up (93 cases, 17%) as reference standards. The correlation between the MRI and histological diagnosis and between the radiological and histological phenotype were statistically determined. One hundred twenty-three patients presented with a malignant STT; 425 patients presented with a benign one. Concerning differentiation between malignant and benign lesions (dignity), a sensitivity of 93%, specificity of 82%, negative predictive value (NPV) of 98% and positive predictive value (PPV) of 60% with accuracy of 85% were obtained. Concerning phenotype characterization, if only the first MRI diagnosis was taken into account, a sensitivity of 67%, specificity of 98%, NPV of 98%, PPV of 70% and accuracy of 96% were obtained. For benign lesions, sensitivity of 75%, specificity of 98%, NPV of 98%, PPV of 76% and accuracy of 97% were obtained. The phenotype’s definition of malignant STT had a sensitivity of 37%, a specificity of 96%, NPV of 96%, PPV of 40% and an accuracy of 92%. A correct diagnosis compared with histological assessment was proposed in 227(50%) of the 455 histologically confirmed cases. Despite non-quantified MR parameter evaluation, the results of our prospective study were better than those reported in previous studies and demonstrated the need for a centralized approach to such rare pathology.

Three tesla magnetic resonance imaging of the anterior cruciate ligament of the knee: can we differentiate complete from partial tears?

PurposeTo determine the ability of 3.0T magnetic resonance (MR) imaging to identify partial tears of the anterior cruciate ligament (ACL) and to allow distinction of complete from partial ACL tears.Materials and methodsOne hundred seventy-two patients were prospectively studied by 3.0T MR imaging and arthroscopy in our institution. MR images were interpreted in consensus by two experienced reviewers, and the ACL was diagnosed as being normal, partially torn, or completely torn. Diagnostic accuracy of 3.0T MR for the detection of both complete and partial tears of the ACL was calculated using arthroscopy as the standard of reference.ResultsThere were 132 patients with an intact ACL, 17 had a partial, and 23 had a complete tear of the ACL seen at arthroscopy. Sensitivity, specificity, and accuracy of 3.0T MR for complete ACL tears were 83, 99, and 97%, respectively, and, for partial ACL tears, 77, 97, and 95%, respectively. Five of 40 ACL lesions (13%) could not correctly be identified as complete or partial ACL tears.ConclusionMR imaging at 3.0T represents a highly accurate method for identifying tears of the ACL. However, differentiation between complete and partial ACL tears and identification of partial tears of this ligament remains difficult, even at 3.0T.

Sports-related acute and chronic avulsion injuries in children and adolescents with special emphasis on tennis

Acute and chronic sports-related muscle and tendon injuries are not infrequent in youngsters. In particular, the physis is prone to trauma as it constitutes the weakest part of the immature skeleton. The type of sports activity determines the location of the lesion. Most commonly, apophyses of the hip and pelvis are subject to avulsion. The purpose of this paper is to give a short overview of the pathogenesis, location, prevalence and imaging characteristics of acute and chronic avulsion injuries in the immature skeleton, with special emphasis on tennis-related injuries. Tennis-related injuries particularly involve apophyses of the ischial tuberosity, the anterior inferior or superior iliac spine and the iliac crest.

Prospective Comparison of 1.5 and 3.0-T MRI for Evaluating the Knee Menisci and ACL

BACKGROUND MRI (magnetic resonance imaging) is widely used to diagnose meniscal pathology and ACL (anterior cruciate ligament) tears. Because of the enhanced signal-to-noise ratio and improved image quality at higher field strength, knee MRI equipment is shifting from 1.5 to 3.0 T. To date, objective evidence of improved diagnostic ability at 3.0 T is lacking. The purpose of this prospective study was to assess the accuracy of 1.5 and 3.0-T MRI of the knee, in the same individuals, for diagnosing meniscal pathology and ACL tears, utilizing arthroscopy as the reference standard. METHODS Two hundred patients underwent MRI of the knee at 1.5 and 3.0 T. All MRI examinations consisted of multiplanar turbo spin-echo sequences. One hundred patients underwent subsequent knee arthroscopy. Two blinded independent radiologists assessed all MRI studies to identify meniscal pathology and ACL tears. In patients with MRI results indicating the need for surgical treatment, the sensitivity and specificity of the 1.5 and 3.0-T protocols for detecting these lesions were determined, utilizing arthroscopy as the reference standard, and compared with use of the McNemar test. The kappa statistic for inter-reader agreement in the 200 patients was calculated. RESULTS For medial meniscal tears, the mean sensitivity and specificity for the two readers were 93% and 90%, respectively, at 1.5 T and 96% and 88%, respectively, at 3.0 T. For lateral meniscal tears, the mean sensitivity and specificity were 77% and 99%, respectively, at 1.5 T and 82% and 98%, respectively, at 3.0 T. For ACL tears, the mean sensitivity and specificity were 78% and 100%, respectively, at 1.5 T and 80% and 100%, respectively, at 3.0 T. None of the values for either reader differed significantly between the 1.5 and 3.0-T MRI protocols. Inter-reader agreement was almost perfect to perfect (kappa = 0.82 to 1.00). CONCLUSIONS Routine use of a 3.0-T MRI protocol did not significantly improve accuracy for evaluating the knee menisci and ACL compared with a similar 1.5-T protocol.

Stable or unstable tear of the anterior cruciate ligament of the knee: an MR diagnosis?

PurposeTo determine the usefulness of magnetic resonance (MR) imaging to distinguish stable from unstable tears of the anterior cruciate ligament (ACL) of the knee.Materials and methodsMR images of 97 patients with surgically confirmed ACL tear were retrospectively reviewed. According to arthroscopic and clinical examination, these patients had 36 stable and 61 unstable (9 partial and 52 complete) ACL tears. MR images were interpreted by two blinded reviewers and scored with respect to previously reported primary and secondary MR signs of ACL injury. Based on a comprehensive assessment of all the MR findings, ACLs were categorized as being stable or unstable. MR accuracy was calculated considering only primary MR signs and considering both primary and secondary MR signs of ACL injury, separately. Accuracy of each individual primary and secondary MR sign was calculated.ResultsConsidering only primary MR signs, sensitivity, specificity, and accuracy of MR were 77, 92, and 82%, respectively. Considering both primary and secondary MR signs, sensitivity, specificity, and accuracy of MR were 59, 81, and 67%, respectively. Of all MR signs, discontinuity and abnormal orientation had highest test accuracy (79 and 87%, respectively). Anterior tibial translation, uncovering of the posterior horn of the lateral meniscus, and hyperbuckled PCL were only seen in unstable ACLs (specificity 100%), but these secondary findings had low sensitivity (23%). Bone contusion around the lateral knee compartment was seen in both unstable and stable ACLs (accuracy 64%).ConclusionPreviously reported MR imaging signs do not allow accurate distinction between clinically stable and unstable ACL injuries. Anterior tibial translation, uncovering of the posterior horn of the lateral meniscus, and hyperbuckled PCL, if present, are helpful signs in the diagnosis of an unstable tear. The presence of bone marrow edema around the lateral knee compartment is not predictive of ACL insufficiency.

Does the location of a vascular loop in the cerebellopontine angle explain pulsatile and non-pulsatile tinnitus?

The purpose was to investigate patients with unexplained pulsatile and non-pulsatile tinnitus by means of MR imaging of the cerebellopontine angle (CPA) and to correlate the clinical subtype of tinnitus with the location of a blood vessel (in the internal auditory canal or at the cisternal part of the VIIIth cranial nerve). Clinical presentation of tinnitus and perceptive hearing loss were correlated. In 47 patients with unexplained tinnitus, an MR examination of the CPA was performed. Virtual endoscopy reconstructions were obtained using a 3D axial thin-section high-resolution heavily T2-weighted gradient echo constructive interference in steady state (CISS) data-set. High-resolution T2-weighted CISS images showed a significantly higher number of vascular loops in the internal auditory canal in patients with arterial pulsatile tinnitus compared to patients with non-pulsatile tinnitus (P<0.00001). Virtual endoscopy images were used to investigate vascular contacts at the cisternal part of the VIIIth cranial nerve in patients with low pitch and high pitch non-pulsatile tinnitus. A significantly different distribution of the vascular contacts (P=0.0320) was found. Furthermore, a correlation between the clinical presentation of non-pulsatile tinnitus (high pitch and low pitch) and the perceptive hearing loss was found (P=0.0235). High-resolution heavily T2-weighted CISS images and virtual endoscopy of the CPA can be used to evaluate whether a vascular contact is present in the internal auditory canal or at the cisternal part of the VIIIth cranial nerve and whether the location of the vascular contact correlates with the clinical subtype of tinnitus. Our findings suggest that there is a tonotopical structure of the cisternal part of the VIIIth cranial nerve. A correlation between the clinical presentation of tinnitus and hearing loss was found.

Imaging of orthopedic sports injuries

Relevant Basic Science and General Imaging Principles: The Clinicians Point of View.- Imaging Techniques and Procedures in Sports Injuries.- Cartilage Trauma .- Tendon and Ligamentous Trauma.- Bone Marrow Edema in Sports Injuries / General Concept.- Overuse Bone Trauma and Stress Fractures.-Pseudotumors in Sports.- Topografic Discussion: Shoulder Instability.- Rotator Cuff and Impingement.- Scapular, Clavicular, Acromioclavicular and Sternoclavicaular Joint Injuries.- Imaging of Sports Injuries of the Elbow .- Imaging of Wrist Injuries.-Finger and Hand.- Pelvis, Hip and Groin .- Sports-related Meniscal Injury.- Knee: Ligaments and Tendons.- Imaging of Anterior Knee Pain and Maltracking.- Injuries of the Ligaments and Tendons in the Ankle and Foot.- Ankle and Foot: Osteochondral Injuries.- Acute and Overuse Lesions of the Leg and Calf.- The Spine in Sports Injuries: Cervical Spine.- The Spine in Sports Injuries: Thoracic and Lumbar Spine.- Maxillofacial Injuries in Sports.- Thoracic and Abdominal Wall Injuries in Sports Injuries.- Special Considerations in the Immature Skeleton.- The Aging Athlete.- Monitoring of Sports Injury Repair: Natural History and Monitoring of Fractures and Microfractures.- Monitoring of Muscle, Tendon and Ligament Repair.- Sport-Specific Injuries: Sport-Specific Injuries.- Subject Index.- List of Contributors.