Biomedical subjects
Publications and source records attributed to D Resnick.
At the outset of this issue on MR imaging of the shoulder, one perspective of shoulder imaging is provided, that of a senior bone radiologist, perhaps to shed some light on the question: What is the precise role of MR imaging in the assessment of shoulder disorders?
The shoulder is a remarkable structure enjoying a greater range of motion than any other articulation in the human body. The shoulder is not a single joint but actually four separate articulations that act synergistically. The authors review the complex anatomy of the shoulder, presenting correlation between anatomic sections and MR arthrography.
OBJECTIVE: To evaluate the potential arthrographic effect of therapeutic ultrasound applied before magnetic resonance imaging (MRI) of the wrist. SUBJECTS AND METHODS: MRI of the wrist was performed in 6 asymptomatic volunteers before and after ultrasound therapy of the carpus. For each patient, ultrasound therapy was performed by a trained physiotherapist for 10 minutes, with doses titrated to the maximum tolerated without pain. The amount of fluid within the wrist joints before and after therapy was assessed subjectively by 2 reviewers, as well as objectively by digital analysis. RESULTS: Subjective appraisal of the images indicated that after ultrasound therapy there was an increase in joint fluid within the distal radioulnar joint in 4 volunteers, the midcarpal joint in 4 and the radiocarpal joint in 2. Computerized digital analysis of joint fluid confirmed an average volumetric increase in wrist joint fluid of 52.8% in 3 of the volunteers. The discomfort of the therapy was graded as 1/10 by 5 of the subjects and 4/10 by a single subject. CONCLUSIONS: Therapeutic ultrasound may be a useful adjuvant tool in the noninvasive induction of joint fluid before MRI of the wrist.
Structures of secreted forms of the human type I and II class A macrophage scavenger receptors were studied using biochemical and biophysical methods. Proteolytic analysis was used to determine the intramolecular disulfide bonds in the type I-specific scavenger receptor cysteine-rich (SRCR) domain: Cys2-Cys7, Cys3-Cys8, and Cys5-Cys6. This pattern is likely to be shared by the highly homologous domains in the many other members of the SRCR domain superfamily. Electron microscopy using rotary shadowing and negative staining showed that the type I and II receptors are extended molecules whose contour lengths are approximately 440 A. They comprised two adjacent fibrous segments, an alpha-helical coiled-coil ( approximately 230 A, including a contribution from the N-terminal spacer domain) and a collagenous triple helix ( approximately 210 A). The type I molecules also contained a C-terminal globular structure ( approximately 58 x 76 A) composed of three SRCR domains. The fibrous domains were joined by an extremely flexible hinge. The angle between these domains varied from 0 to 180 degrees and depended on the conditions of sample preparation. Unexpectedly, at physiologic pH, the prevalent angle seen using rotary shadowing was 0 degrees , resulting in a structure that is significantly more compact than previously suggested. The apparent juxtaposition of the fibrous domains at neutral pH provides a framework for future structure-function studies of these unusual multiligand receptors.
Glenoid hypoplasia, or dysplasia of the scapular neck, is usually a bilateral and symmetric finding. Associated findings include hypoplasia of the humeral head, elongation of the glenoid cavity, and alterations in the shape of the coracoid or clavicle. Glenoid hypoplasia has been reported sporadically in the radiologic literature, but the condition may be more frequent than previously thought. In this paper, we discuss the radiographic findings of glenoid hypoplasia and explore the possibility of an association between glenoid hypoplasia and shoulder instability.
The objective of this article was to offer a better characterization of the typical clinical presentation, radiologic findings, histology, treatment approaches, and differential diagnosis of cystic angiomatosis, a rare condition of which previous reports have been confusing because of unclear diagnostic criteria, different classifications, and variations in terminology. A case report using the improved imaging techniques of computed tomography scanning is presented in addition to an analysis and review of the previous literature, which relied heavily on plain film radiography, biopsy, and necropsy for diagnosis. A case report of a 26-year-old man initially symptomatic at age 12 is presented. Although a rare condition, cystic angiomatosis must be considered in pediatric and young adult patients presenting with diffuse, multifocal, cystic skeletal lesions, with or without visceral involvement.
Recently gout has been recognized as a cause of inflammation in patients with nodal osteoarthritis. We reviewed the clinical data and radiographs of four patients with known osteoarthritis of the interphalangeal joints of the hands who developed gout. Radiographic changes of osteoarthritis in the affected interphalangeal joint were present in all four patients. In our cases, radiographic findings were typical of gout in one patient, including the presence of large eccentric soft tissue masses and periarticular erosions. In three patients, radiographic findings were non-specific, including only a small eccentric nodule in one patient, diffuse soft tissue swelling in a second, and a large calcified soft tissue mass with bony erosions in a third. Whenever a patient with inter-phalangeal joint osteoarthritis presents with an acute episode of inflammation the possibility of gout should be considered. Recognition of gout will allow the timely initiation of appropriate therapy.
Osteolytic cystic lesions of the patella are rare lesions. A review of the literature revealed only one previously reported example. The pathogenesis and radiological and pathological features of intraosseous ganglion cysts are discussed. In addition, the differential diagnosis of lytic patellar lesions is discussed.
OBJECTIVE: Chondrocalcinosis of the knee is a common radiological finding in the elderly. However, visualization of chondrocalcinosis may be difficult in patients with advanced cartilage loss. The purpose of this study was to determine sensitivity, specificity, and accuracy of gastrocnemius tendon calcification that might serve as a radiographic marker of chondrocalcinosis in patients with painful knees. DESIGN AND PATIENTS: We prospectively evaluated 37 knee radiographs in 30 consecutive patients (29 men, 8 women; mean age 67 years, age range 37-90 years) with painful knees who had radiographic evidence of chondrocalcinosis. The frequency of fibrocartilage, hyaline cartilage, and gastrocnemius tendon calcification was determined. For a control group, we evaluated knee radiographs in 65 consecutive patients with knee pain (54 men, 11 women; mean age 59 years, age range 40-93 years) who had no radiological signs of chondrocalcinosis. The frequency of gastrocnemius tendon calcification in the control group was determined. RESULTS: Gastrocnemius tendon calcification was 41% sensitive, 100% specific, and 78% accurate in predicting chondrocalcinosis. The gastrocnemius tendon was calcified on 15 of 37 (41%) radiographs in the experimental group and on 0 of 67 radiographs in the control group. In the chondrocalcinosis group, 23 (62%) had posterior hyaline cartilage calcification, 14 (38%) had anterior hyaline cartilage calcification, 31 (84%) had medial meniscus calcification, and 36 (97%) had lateral meniscus calcification. CONCLUSIONS: Our results show that gastrocnemius tendon calcification is an accurate radiographic marker of chondrocalcinosis in patients with knee pain.
We present an unusual case of tophaceous pseudogout in the atlantoaxial joint with progressive cervical cord compression symptoms and lack of additional clinical manifestations of CPPD crystal deposition disease. This represents only the fourth reported case in the medical literature.
Various imaging methods have been applied to assessment of articular cartilage. These include standard radiography, arthrography, CT, CT arthrography, ultrasonography, and MR imaging. Radiography remains the initial musculoskeletal imaging method. However, it is insensitive to early stages of cartilage abnormalities. MR imaging has great potential in the assessment of articular cartilage, although high-quality scans are required because imaging signs of cartilage abnormalities may be subtle. The potential and limitations of various sequences and techniques are discussed, including MR arthrography. The role of the other imaging methods in assessment of articular cartilage appears to be limited.
OBJECTIVE: To assess hyaline cartilage of cadaveric ankles using different magnetic resonance (MR) imaging techniques and various methods of measurement. DESIGN AND PATIENTS: Cartilage thicknesses of the talus and tibia were measured in ten cadaveric ankles by naked eye and by digitized image analysis from MR images of fat-suppressed T1-weighted gradient recalled (FS-SPGR), sequences and pulsed transfer saturation sequences with (FS-STS) and without fat-suppression (STS); these measurements were compared with those derived from direct inspection of cadaveric sections. The accuracy and precision errors were evaluated statistically for each imaging technique as well as measuring method. Contrast-to-noise ratios of cartilage versus joint fluid and marrow were compared for each of the imaging sequences. RESULTS: Statistically, measurements from FS-SPGR images were associated with the smallest estimation error. Precision error of measurements derived from digitized image analysis was found to be smaller than that derived from naked eye measurements. Cartilage thickness measurements in images from STS and FS-STS sequences revealed larger errors in both accuracy and precision. Inter-observer variance was larger in naked eye assessment of the cartilage. Contrast-to-noise ratio of cartilage versus joint fluid and marrow was higher with FS-SPGR than with FS-STS or STS sequences. CONCLUSION: Of the sequences and measurement techniques studied, the FS-SPGR sequence combined with the use of digitized image analysis provides the most accurate method for the assessment of ankle hyaline cartilage.
We present a case of sarcoidosis with soft tissue masses and associated phalangeal erosive changes. Sarcoidosis of the musculoskeletal system presenting as a soft tissue mass has been described previously but is rare. To our knowledge, the combination of soft tissue masses and phalangeal erosions has never been described.
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RATIONALE AND OBJECTIVES: The ventral sacroiliac ligament (VSL), which bridges the sacroiliac (SI) joint anteriorly, has been described as an important stabilizing structure of the joint, but no data exist regarding its assessment with routine and advanced imaging methods. The authors determine the imaging appearance of the normal and abnormal VSL using close anatomic-histologic-imaging correlation. METHODS: Eight and 10 cadaveric SI joints were examined with magnetic resonance imaging in axial and coronal planes, respectively; and in four computed tomography scanning in both planes was obtained. Anatomic sectioning with histologic correlation at levels corresponding to those of imaging planes was performed. Representative examples of diseases that produce abnormalities of the VSL and connective tissue about the SI joint were reviewed. RESULTS: Magnetic resonance images showed the VSL-anterior capsular complex as a hypointense, linear, or minimally curved structure of approximately 2 mm thickness traversing the SI joint anteriorly. The VSL could not be separated from the anterior joint capsule by imaging studies, but such differentiation by histology could be determined based upon the orientation of its collagen fibers. Any disease process that affects the ligament or the site of ligamentous attachment to bone produces characteristic imaging alterations.
PURPOSE: To correlate magnetic resonance (MR) images of the sternoclavicular joint with anatomic sections. MATERIALS AND METHODS: MR imaging was performed on 14 sternoclavicular joints in seven specimens from cadavers (three men and four women 64-94 years of age at death; mean, 84 years). MR arthrography was performed in four specimens (eight joints), after injection of gadopentetate dimeglumine. After imaging, the specimens were frozen and cut into 3-mm-thick slices along the MR imaging planes. Images were correlated with the anatomic slices. RESULTS: MR imaging depicted the anatomy of the sternoclavicular joint and surrounding soft tissue. T2-weighted and proton-density-weighted images were superior to T1-weighted images in depiction of the intraarticular disk. MR arthrography depicted best the intraarticular disk and four of five perforations and delineated the joint capsule. All perforations also were depicted on T2-weighted images. CONCLUSION: MR imaging allows delineation of all structures of the sternoclavicular joint. MR arthrography allows delineation of perforations of the intraarticular disk.
PURPOSE: To determine if angling the coronal plane in magnetic resonance (MR) imaging of the knee increases the conspicuity of the posterolateral structures. MATERIALS AND METHODS: A coronal oblique MR imaging sequence performed parallel to the popliteal tendon proximally was added to our routine study in patient knee examinations. One hundred patients (age range, 12-72 years) underwent MR imaging. RESULTS: Coronal oblique images depicted the arcuate ligament in 46%, the fabellofibular ligament in 48%, and the fibular origin of the popliteal muscle in 53% of the patients, whereas standard coronal images depicted these in 10%, 34%, and 8% of the patients, respectively. Sagittal oblique images did not adequately depict these structures. CONCLUSION: Depiction of the structures in the posterolateral aspect of the knee was optimal on coronal oblique images. We advocate obtaining coronal oblique T2-weighted images in patients with either posterolateral knee pain or suspected injury to the posterolateral ligamentous structures.