Imaging Features of Soft-Tissue Calcifications and Related Diseases: A Systematic Approach

Soft-tissue calcification refers to a broad category of lesions. Calcifications are frequently identified by radiologists in daily practice. Using a simple algorithm based on the distribution pattern of the lesions and detailed clinical information, these calcified lesions can be systematically evaluated. The distribution pattern of the calcific deposits enables initial division into calcinosis circumscripta and calcinosis universalis. Using laboratory test results (serum calcium and phosphate levels) and clinical history, calcinosis circumscripta can be further categorized into four subtypes: dystrophic, iatrogenic, metastatic, and idiopathic calcification. This pictorial essay presents a systematic approach to the imaging features of soft-tissue calcifications and related diseases.

Desmoplastic Fibroma of Bone in a Toe: Radiographic and MRI Findings

Desmoplastic fibroma is a rare benign primary bone tumor that is histologically similar to the soft tissue desmoid tumor. It most often involves the mandible, large long bone or iliac bone. Desmoplastic fibroma in a toe has been extremely rarely reported. Authors report a rare case of desmoplastic fibroma of bone occurring in the distal phalanx of a foot, with descriptions of the radiographic and MRI findings, correlation of the radiologic and pathologic findings, and discussion on the differential diagnosis of the tumor.

Calcific Tendinitis of the Hand and Foot: A Report of Four Cases

Calcific tendinitis of hand and foot is rare and frequently misdiagnosed because of its rare incidence and its similar clinical presentation to other conditions such as infection. Awareness of the typical location as well as familiarity with the imaging findings is essential for making a correct diagnosis of this rare condition. We report four cases of calcific tendinitis of hand and foot, occurring in the flexor hallucis brevis, abductor digiti minimi, and abductor pollicis brevis.

Synovial Lesions with Low Signal Intensities on T2-Weighted MR Image

Pigmented villonodular synovitis, synovial chondromatosis, long-standing rheumatoid arthritis, hemophilic arthropathy, chronic tophaceous gout, amyloid arthropathy, tuberculous arthritis, and hemangioma are the synovial diseases showing low signal intensity on T2-weighted image. Synovial deposition of hemosiderin, urate, and amyloid and fibrosis or caseous necrosis of hypertrophied synovium are known as the pathologic causes of T2 signal intensity. Because of the low incidence of the synovial lesions showing T2 low signal intensity, recognition of these diseases would be helpful for the exact diagnosis.

Synovial Lesions with Low Signal Intensities on T2-Weighted MR Image

Pigmented villonodular synovitis, synovial chondromatosis, long-standing rheumatoid arthritis, hemophilic arthropathy, chronic tophaceous gout, amyloid arthropathy, tuberculous arthritis, and hemangioma are the synovial diseases showing low signal intensity on T2-weighted image. Synovial deposition of hemosiderin, urate, and amyloid and fibrosis or caseous necrosis of hypertrophied synovium are known as the pathologic causes of T2 signal intensity. Because of the low incidence of the synovial lesions showing T2 low signal intensity, recognition of these diseases would be helpful for the exact diagnosis.

Inferior Accessory Ossicle of the Anterior Arch of the Atlas / 대한정형외과학회잡지

An inferior accessory ossicle of the anterior arch of the atlas is quite rare and should not be confused with other pathological conditions such as a fracture. Here we report a case of an inferior accessory ossicle of the anterior arch of the atlas in a 29-year-old male and a review of literature.

Ultrasound Diagnosis of Either an Occult or Missed Fracture of an Extremity in Pediatric-Aged Children

OBJECTIVE: To report and assess the usefulness of ultrasound (US) findings for occult fractures of growing bones. MATERIALS AND METHODS: For six years, US scans were performed in children younger than 15 years who were referred with trauma-related local pain and swelling of the extremities. As a routine US examination, the soft tissue, bones, and adjacent joints were examined in the area of discomfort, in addition to the asymptomatic contralateral extremity for comparison. Twenty-five occult fractures in 25 children (age range, five months-15 years; average age, 7.7 years) were confirmed by initial and follow-up radiograms, additional imaging studies, and clinical observation longer than three weeks. RESULTS: The most common site of occult fractures was the elbow (n = 9, 36%), followed by the knee (n = 7, 28%), ischium (n = 4, 16%), distal fibula (n = 3, 12%), proximal femur (n = 1, 4%), and humeral shaft (n = 1, 4%). On the retrograde review of the routine radiographs, 13 out of the 25 cases showed no bone abnormalities except for various soft tissue swelling. For the US findings, cortical discontinuity (direct sign of a fracture) was clearly visualized in 23 cases (92%) and was questionable in two (8%). As auxiliary US findings (indirect signs of a fracture), step-off deformities, tiny avulsed bone fragments, double-line appearance of cortical margins, and diffuse irregularity of the bone surfaces were identified. CONCLUSION: Performing US for soft tissue and bone surfaces with pain and swelling, with or without trauma history in the extremities, is important for diagnosing occult or missed fractures of immature bones in pediatric-aged children.

Erosive Arthropathy with Osteolysis As a Typical Feature in Polyfibromatosis Syndrome: A Case Report and a Review of the Literature

Polyfibromatosis syndrome is a rare disease entity that is characterized by various clinical features such as palmar, plantar, and penile fibromatoses, keloid formations of the skin, and erosive arthropathy. Its precise pathophysiology or etiology remains unclear. In addition to distinctive diverse skin manifestations, patients with polyfibromatosis have been previously reported to show erosive arthropathy with significant limitation of movement at affected joints. However, the presence of erosive polyarthropathy in polyfibromatosis has not emphasized in previous cases. Here, we report a case of polyfibromatosis syndrome combined with painless massive structural destruction of hand and foot joints, and review the characteristics of erosive arthropathy in previous cases.

Usefulness of Coronal MR Image in Diagnosis of Foraminal and Extraforaminal Disc Herniation / 대한척추외과학회지

STUDY DESIGN: This is a retrospective study OBJECTIVES: The coronal MR images were carefully evaluated to document the efficacy of diagnosing foraminal and extraforaminal disc herniations. SUMMARY OF LITERATURE REVIEW: Extraforaminal disc herniations constitute 1~11.7% of all disc herniations. The diagnosis of it demands great caution because it must be distinguished from intraspinal canal disc herniation. Diagnosing extraforaminal disc herniations can be neglected with using ordinary diagnostic methods. MATERIALS AND METHODS: A retrospective analysis was performed on 24 patients, (26 cases) that underwent lumbar spine MRI, with the T2 coronal images, for the evaluation of disc herniations from March 2006 to March 2007. Every MRI image of each patient who had foraminal or extraforaminal disc herniations was graded according to the Pfirrmann's classification of diagnostic efficacy by two spinal surgery specialists and two radiology specialists. RESULTS: There were 13 cases of foraminal disc herniation and 13 cases of extraforaminal disc herniation in all 26 cases that were diagnosed by MRI. The coronal and axial images were more effective than the sagittal images for the discrimination of a compressed root. Especially, for the extraforaminal disc herniation, all of the coronal images were graded as grade 3; on the other hand, all of the sagittal images were not helpful for the assessment and the axial images were graded as grade 2 for 38.5% of the and as grade 3 for 61.5%. So, the coronal images were most effective for making the diagnosis of extraforaminal disc herniation and this was statistically significant (p<0.05). CONCLUSION: For the accurate discrimination of the location and the grading of foraminal and extraforaminal disc herniation, MRI, and especially the coronal images, is an effective and useful method in addition to conducting a physical examination.

Kimura's Disease in the Lower Extremity: A Case Report Mimicking the Malignant Soft Tissue Mass

We present a case of a 37-year-old woman who had Kimura's disease involving the lower extremity mimicking malignant soft tissue mass. The diagnosis of Kimura's disease would be considered if there is a subcutaneous solid mass showing the preservation of the nodal architecture with perinodal infiltrations and the laboratoryexaminations for peripheral eosinophilia and serum IgE level should be recommended although it occurs at the lower extremity.

Spindle Cell Lipoma of the Posterior Axilla: A Case Report

Spindle cell lipoma is characterized by different cell components, mature adiopocytes, spindle cells and collagen bundles, and it presents as a well-defined benign fatty mass on the posterior neck or upper back of middle aged men. As a result of the various ratios of non-adipose tissue, it is difficult to differentiate spindle cell lipoma from liposarcoma. To the best of our knowledge, the imaging features of spindle cell lipoma have not been reported in Korea. We report here on the imaging findings of a histologically confirmed spindle cell lipoma in the subcutaneous layer of the posterior axilla.

Osteosarcoma Arising in a Polyostotic Fibrous Dysplasia: A Case Report

Fibrous dysplasia is a skeletal developmental anomaly of the bone-forming mesenchyme that manifests as a defect in osteoblastic differentiation and maturation. It is a nonhereditary disorder of unknown cause. In fibrous dysplasia, the medullary bone is replaced by fibrous tissue, which appears various imaging findings. It is usually an incidental finding, generally not requiring further investigation. However, fibrous dysplasia may be complicated by pathologic fracture, and rarely by malignant degeneration. We present the image findings of a 44-year-old man who had a chondroblastic osteosarcoma arising from polyostotic fibrous dysplasia in the femur. Evidence of cortical destruction on plain radiography and soft tissue mass in the lesion on MR images suggested a tumor of malignant transformation.

A Case of Pedunculated Localized Nodular Synovitis of the Knee: MR Imaging Findings

Localized nodular synovitis of the knee joint is a rare benign tumorous condition, and should be differentially diagnosed with pigmented villonodular synovitis. We report a case of localized nodular synovitis in the knee that was noted to have a pedicle and characteristic findings on MR image.

Image Reconstruction of Eigenvalue of Diffusion Principal Axis Using Diffusion Tensor Imaging

PURPOSE: The objective of this work to construct eigenvalue maps that have information of magnitude of three primary diffusion directions using diffusion tensor images. MATERIALS AND METHODS: To construct eigenvalue maps, we used a 3.0T MRI scanner. We also compared the Moore-Penrose pseudo-inverse matrix method and the SVD (single value decomposition) method to calculate magnitude of three primary diffusion directions. Eigenvalue maps were constructed by calculating of magnitude of three primary diffusion directions. We did investigate the relationship between eigenvalue maps and fractional anisotropy map. RESULTS: Using Diffusion Tensor Images by diffusion tensor imaging sequence, we did construct eigenvalue maps of three primary diffusion directions. Comparison between eigenvalue maps and Fractional Anisotropy map shows what is difference of Fractional Anisotropy value in brain anatomy. Furthermore, through the simulation of variable eigenvalues, we confirmed changes of Fractional Anisotropy values by variable eigenvalues. And Fractional anisotropy was not determined by magnitude of each primary diffusion direction, but it was determined by combination of each primary diffusion direction. CONCLUSION: By construction of eigenvalue maps, we can confirm what is the reason of fractional anisotropy variation by measurement the magnitude of three primary diffusion directions on lesion of brain white matter, using eigenvalue maps and fractional anisotropy map.

Imaging of the Brachial Plexus

MR (magnetic resonance) imaging of the brachial plexus is challenging because of the complex and tangled anatomy of the brachial plexus and the multifariouness of pathologies that can put on it. Improvements in imaging techniques, including the availability of high resolution MR image systems and high channels multidetector computed tomography (CT), have led to more accurate diagnoses and improved serve for treatment planning. For the purpose of imaging and treatment of the brachioplexopathy, it is considerate to divide traumatic and nontraumatic diseases affecting the brachial plexus. MRI is the current gold standard imaging modality for nontraumatic brachial plexopathy. CT myelography is the preferred for the diagnosis of nerve root avulsions affecting the brachial plexus. Other modalities, such as CT, ultrasonography and positron emission tomography, have a limited role in the evaluation of brachial plexus pathology. High-quality, high-resolution MRI remains the main tool for imaging the brachial plexopathy.

MR Imaging Findings of Acute Gouty Arthritis

PURPOSE: The purpose of this study was to describe the clinical and MR imaging features of acute gouty arthritis and to define the characteristic findings that would be helpful for differentiating acute gouty arthritis from septic arthritis. MATERIALS AND METHODS: The authors retrospectively studied seven patients who suffered from acute gouty arthritis. The MR imaging findings were analyzed by two musculoskeletal radiologists who focused on joint effusion, subchondral bone erosion, bone marrow edema, synovial thickening (regular and even, or irregular and nodular), and the soft tissue changes (edema or abscess). The clinical records of the patients were reviewed with regard to age and gender, the clinical presentation and the laboratory findings (serum uric acid, WBC, erythrocyte sedimentation rate, C-reactive protein and synovial fluid culture). RESULTS: The patients consisted of six men and one woman whose mean age was 41 years (age range: 24-65 years). The joints involved were the knee (n=6), and ankle (n=1). Two patients had medical histories of gouty attacks that involved the first metatarsophalangeal joint. In six cases, the serum uric acid level during acute attacks was elevated. In all the patients, the affected joint became swollen, hot, erythematous and extremely tender, and this was accompanied by a high ESR and a high C-reactive protein level at the time of presentation. The results of Gram stain and culture of the synovial fluid were negative. In all patients, the MR images showed large amounts of joint effusion, thick irregular and nodular synovial thickening and soft tissue edema without subchondral bone erosions and soft tissue abscess. In one case, subchondral bone marrow edema of the medial femoral condyle was present. In five cases, there were multiple low signal foci in the joint on the spin-echo T2-weighted MR image. CONCLUSION: Even though the MR imaging findings of acute gouty arthritis are nonspecific, it should be considered as a possible diagnosis when a large amount of joint effusion, irregular and nodular synovial thickening and soft tissue edema without subchondral bone erosion, bone marrow edema or soft tissue abscess are seen in the knee or ankle joint, and especially if this is accompanied by the clinical and laboratory features of infection.

MR Findings of Hypoxic Brain Damage: Relation to Time Elapse and Prognosis of Patients

PURPOSE: To describe MR imaging features of hypoxic brain damage in relation to time elapse and prog-nosis of patients. MATERIALS AND METHODS: We reviewed 19 MR studies of 18 patients with hypoxic brain damage. MR imaging studies were performed between 1 to 20 days after the hypoxic insults (mean 8.6 days). MR images were analyzed with regard to the locations of abnormal signal intensities, the presence of brain edema. And imaging findings were correlated with the time elapse after the insults and the prognosis of patients. RESULTS: On 19 cases of MR studies, abnormal high intensities on T2-weighted images were found in the basal ganglia (15, 78.9%), cerebral cortex (13, 68.4%), white matter (9, 47.4%), thalamus (6, 31.6%), cerebellum (4, 21.1%) and brainstem (1, 5.3%), respectively. Cerebral cortical involvement was typically bilateral and diffuse, but sometimes limited to the parieto-occipital area. The brainstem and cerebellar involvement was rare and in all cases, cerebral cortical lesions accompanied. Most of the white matter lesions were accompanied with cortical and deep gray matter lesions and found in subacute period(>6 days). The cortical high signal intensity lesions on T1-weighted image were found mostly in subacute stage, but in some cases involvement was also found in acute stage (< or =6 days). The cortical edema is found on 11 cases in acute and subacute stages. In cases of recovered consciousness, cortical involvement and edema on MR were rare. CONCLUSION: MR findings of hypoxic brain damage were various, but diffuse bilateral involvement of cortex and/or deep gray matter was found in most of the cases. White matter involvement was rarely found in acute stage and usually found in subacute stage. In cases of good pronosis, cortical involvement and edema were rare.

A Case of Dialysis-related Amyloidosis of the Hip and Cervical Spine: Imaging Findings

Dialysis-related amyloidosis is a complication of long-term hemodialysis and it is characterized by the accumulation of beta2-microglobulin in the osteoarticular structures. We describe here the imaging findings of a case of dialysis-related amyloidosis involving the hip and cervical spine in a 62-year-old woman who received long-term dialysis. We focus here on the CT and MR imaging findings of the cervical spine and we include a review of the relevant literatures.

Sonographic Findings of Calcific Tendinitis around the Hip

PURPOSE: To evaluate the sonographic findings of calcific tendinitis around the hip. MATERIALS and METHODS: Ten patients (7 women and 3 men; mean age, 42 years; age range, 34-52 years) with a diagnosis of calcific tendinitis around the hip were evaluated. All the patients underwent radiography and sonography (color Doppler sonography in 6 patients). The sonographic findings were analyzed to determine the level of tendon thickening compared with the contralateral side as well as the shape and posterior acoustic shadowing of the calcification, and vascularity on color Doppler sonography. RESULTS: In all cases, sonography showed a thickening of the tendon compared with the contralateral normal tendon as well as hyperechoic calcific shadows within the thickened tendon. Intratendinous calcifications were mainly observed as a homogeneous ovoid hyperechoic shadow with or without acoustic shadowing. Color Doppler sonography showed increased vascularity within or around the thickened tendon in four of the six patients. CONCLUSION: Sonography is effective in detecting a thickening of the tendon as well as intratendinous calcification, and can be used to diagnose calcific tendinitis around the hip.

Metastatic Bone Tumors with Sunburst Periosteal Reaction

PURPOSE: The purpose of this study was to describe the clinical and imaging features of metastatic bone tumors with sunburst periosteal reaction and to define the characteristic findings which would be helpful for differentiating metastatic bone tumors from primary malignant bone tumors. MATERIALS AND METHODS: The authors retrospectively reviewed the cases of nine patients with pathologically confirmed metastatic bone tumors with sunburst periosteal reaction, for which imaging studies (plain radiographs [n=9], radioisotope [RI] scans [n=4], magnetic resonance [MR] images [n=6], and computed tomographic [CT] scans [n=4]) were performed. The imaging studies of each lesion were analyzed by two musculoskeletal radiologists focusing on the metastatic site, patterns of bone response, signal intensity characteristics and pattern of contrast enhancement on MR. The clinical records of the patients were reviewed with regard to the age and sex of the subjects, the clinical presentation, and the origin of the primary tumors. RESULTS: The cases consisted of six men and three women, whose mean age was 62 years (age range, 50-88 years). The primary tumors were adenocarcinoma of the stomach [n=4], adenocarcinoma of the lung [n=2], adenocarcinoma of the prostate [n=1], hepatocellular carcinoma of the liver [n=1], and adenocarcinoma of unknown origin [n=1]. The sites of metastatic involvement exhibiting sunburst periosteal reaction were the scapula [n=2], proximal humerus [n=2], rib [n=1], iliac bone [n=1], tibia [n=1], spine [n=1], and proximal phalanx [n=1]. In all patients, the imaging findings showed osteolytic [n=3] or osteoblastic [n=6] lesions with sunburst periosteal reaction. In six cases, the lesions were iso-intense on the T1-weighted images and heterogeneously hyperintense on the T2-weighted images. The gadolinium-enhanced T1-weighted images showed a nearly homogenous enhancement of the lesions without any central necrotic portion. CONCLUSION: Although metastatic bone tumor exhibiting sunburst periosteal reaction is rare, it should be included along with primary malignant bone tumors in the differential diagnosis of bone lesions with sunburst periosteal reaction, especially in older patients with or without a known primary malignancy.