Imaging Findings Of Desmoplastic Fibroma Rarely Involving The Clavicle: Case Report

Desmoplastic fibroma of bone is a rare locally aggressive, but non-metastatic tumor. In this case report, we present a desmoplastic fibroma in an unusual location, the clavicle. Desmoplastic fibroma involving the clavicle is extremely rare, with only 2 reported cases before 1985. We report the imaging findings of a desmoplastic fibroma of the clavicle with a review of the relevant literature.

Dual-Energy CT as a New Diagnostic Tool for Gout

Gout is the most common crystal-associated arthropathy. Gout is caused by deposition of monosodium urate crystals within the joints, and it is often associated with hyperuricemia. Acute gout involves the first metatarsophalangeal joint (podagra) in approximately 50% of cases and its peak incidence occurs in middle age. Although the clinical features can help with making the diagnosis of gout, many inflammatory diseases such as cellulitis, pseudogout and septic arthritis can mimic or coexist with it. The definitive diagnosis requires polarized light microscopy of the fluid aspirated from the involved joint and this shows needle-shaped, negative birefringent monosodium urate crystals. However, joint aspiration can be technically difficult, and none of the conventional imaging modalities for gout specifically identifies the chemical composition of uric acid. The advent of Dual-Energy CT (DECT) is a noninvasive method that has the potential to confirm gout and monitor the response to treatment. DECT scan can show monosodium urate deposition by using color coding. The authors performed DECT scans for detecting uric acid deposition and confirming the gout noninvasively.

Magnetic Resonance Imaging Diagnosis in Sports Injuries / 대한스포츠의학회지

MRI (magnetic resonance imaging) is widely applied to diagnose sport-related injuries including bone and soft-tissue injuries. Because the MR characteristics of hydrogen nuclei depend upon on their local tissue environment, soft tissue structures of similar density may exhibit difference in signal intensity (brightness on image). This enables MRI to get high soft-tissue contrast resolution superior to other imaging modalities such as computed tomography (CT). Advantages of MRI are its capacity to depict occult bone trauma or bone bruise and ligamentous or tendinous injuries that are not visible on conventional radiographs. MRI does not expose the patient to radiation dose, so it can be used safely for pediatric patients. In this review, we will discuss on the osseousand soft-tissue injuries of the extremities which could be helpful from MRI in various clinical situations.

Imaging Diagnosis of Osteoporotic Fracture

Osteoporotic vertebral fractures suspected at clinical evaluation require radiological confirmation. Most radiologists make the diagnosis of vertebral fracture on the basis of a qualitative impression. However, unlike other fractures, vertebral fractures are commonly found on radiographs obtained for other reasons in patients who do not show signs or symptoms suggestive of fractures. Radiologists qualitatively analyze radiographs of the thoracolumbar spine to identify vertebral fractures in patients whose clinical indications suggest trauma, osteoporosis, malignancy, or acute back pain. The accuracy of decision-making process can be enhanced by additional radiographic projections or by complementary examinations including DXA (Dual Energy X-ray Absorptiometry) morphometry, bone scan, CT, or MRI. The importance of imaging is highlighted by the fact that only about one in four vertebral fractures is recognized on the basis of clinical evaluations without radiographs. Radiographs may include lateral and AP (anterior/posterior) X-rays of the affected spinal segments. The physician may request bone scan and/or CT to help identify the location of the fracture, its status (stable versus unstable). Furthermore, an MRI scan may be performed if neurologic deficit, soft tissue trauma or hematoma are suspected.

Appropriate Position of the Forearm for the Measurement of BMD / 대한골다공증학회지

OBJECTIVES: The aim of this study was to evaluate the appropriate position of the forearm for measuring the BMD (Bone Mineral Density). MATERIAL & METHODS: CT scanning was performed in 21 men to determine the appropriate position for the forearm. Twenty one healthy volunteers who were without any history of operations, anomalies or trauma were enrolled. CT scanning was used to evaluate the cross sectional structures and the rotation angle on the horizontal plane of the distal radius. The rotation angle was measured by the m-view program on the PACS monitor. The DXA was used for measuring 20 dried radii of cadaveric specimens in pronation and supination with 3degrees, 5degrees, 7degrees and 10degrees of rotation respectively, including a neutral position (0degrees) to evaluate the changes of BMD according to the rotation. RESULTS: The mean rotation angle of the distal radius on the CT scan was 7degrees of supination (76%, n=16), 3.3degrees of pronation (15%, n=3), and 0degrees at the neutral position (9%, n=2), respectively. The total average rotation angle in the 21 people was 5.2degrees of supination. In the cadaveric study, the BMD of the distal radius was different according to the rotational angles. The lowest BMD was obtained in 1.4degrees of pronation. CONCLUSION: In the case of the measuring of the BMD in the forearm in a neutral position, the rotational angle of the distal radius is close to supination. Therefore, pronation is needed for the constant measurement of BMD in the forearm. We recommend measuring the lowest BMD of the distal radius at about five degrees of pronation.

Monostotic Fibrous Dysplasia in the Metacarpal Bone: A Case Report

Fibrous dysplasia is a slowly progressive, benign disorder characterized by fibrous tissue replacement of skeleton and may affect solitary or multiple bones. Monostotic fibrous dysplasia mainly occurrs in the rib, femur and tibia, however, rarely in the hand. We report a case of monostotic fibrous dysplasia confined to the 2nd metacarpal bone with findings of plain radiographs and MR imaging.

Primary Hepatic Choriocarcinoma: A Case Report

Choriocarcinoma is one of the most common malignancies associated with pregnancy. The characteristics of this malignancy include abnormal growth of the trophoblastic tissue, direct invasion of adjacent organs, and distant metastasis; however, it rarely presents extragonadally. Recently, we have experienced a case of primary hepatic choriocarcinoma in a middle-aged-man, which was characterized by a solitary large hepatic mass with central necrosis and hemorrhaging, as well as metastases to the lung and lymph nodes along the hepatoduodenal ligament. We report this case with a review of the literature.

MR Imaging of Intradural Extramedullary Tuberculoma of the Spinal Cord: Report of Two Cases

Intradural extramedullary tuberculoma of the spinal cord is a rare manifestation of the spinal tuberculosis, with a few cases described so far. Recently, we have experienced two cases of extensive intradural extramedullary tuberculoma at the thoracic spine. So, we report these cases with review of the literatures.

Peliosis Hepatis with Hemorrhagic Necrosis and Rupture: a Case Report with Emphasis on the Multi-Detector CT Findings

We report here on an uncommon case of peliosis hepatis with hemorrhagic necrosis that was complicated by massive intrahepatic bleeding and rupture, and treated by emergent right lobectomy. We demonstrate the imaging findings, with emphasis on the triphasic, contrast-enhanced multidetector CT findings, as well as reporting the clinical outcome in a case of peliosis hepatis with fatal hemorrhage.

16-Slice MDCT Arthrography of the Shoulder: Accuracy for Detection of Glenoid Labral and Rotator Cuff Tears

PURPOSE: We wanted to determine the diagnostic accuracy of 16-slice MDCT arthrography (CTA) for glenoid labral and rotator cuff tears of the shoulder. MATERIALS AND METHODS: We enrolled forty-five patients who underwent arthroscopy after CTA for pain or instability of the shoulder joint. The CTA images were analyzed for the existence, sites and types of glenoid labral tears and the presence and severity of rotator cuff tears. We determined the sensitivity, specificity and accuracy of CTA for detecting glenoid labral and rotator cuff tears on the basis of the arthroscopy findings. RESULTS: At arthroscopy, there were 33 SLAP lesions (9 type I, 23 type II and 1 type III), 6 Bankart lesions and 31 rotator cuff lesions (21 supraspinatus, 9 infraspinatus and 1 subscapularis). On CTA, the sensitivity, specificity and accuracy for detecting 24 SLAP lesions, excluding the type I lesions, were 83%, 100% and 91%, the total rotator cuff tears were 90%, 100% and 98%, the full thickness supraspinatus tendon tears were 100%, 94% and 96%, and the partial thickness supraspinatus tendon tears were 29%, 100% and 89%, respectively. CONCLUSION: 16-slice MDCT arthrography has high accuracy for the diagnosis of abnormality of the glenoid labrum or rotator cuff tears and it can be a useful alternative to MRI or US.

Diffusion-Weighted Imaging of Brain Injury Due to Neonatal Hypoglycemia: A Case Report

Profound hypoglycemia results in significant brain injury because glucose is essential for normal brain functioning. We present here a case of transient neonatal hypoglycemia with diffuse brain injury. Magnetic resonance imaging was performed 2 days after onset, and this revealed bilateral regions of restricted diffusion in the parietal, occipital, frontal and temporal lobes. On the T1-weighted images, the regions showed indistinct gray matter-white matter differentiation. There were subtle high signal intensity lesions along the corresponding regions of the FLAIR and T2-weighted images.

Mucoepidermoid Carcinoma of the Thymus: A Case Report

Mucoepidermoid carcinoma of the thymus is an extremely rare malignant mediastinal neoplasm, and to our knowledge, only 13 cases have been reported. We report a case of mucoepidermoid carcinoma of the thymus that was seen in a 53-yr-old man with right chest pain. Chest CT scan showed a huge, cystic mass having a focal solid portion with direct invasion of the adjacent anterior chest wall and pericardium in the anterior mediastinum. Mucoepidermoid carcinoma of the thymus should be included in the differential diagnosis for masses of the anterior mediastinum associated with extensive cystic changes, although the carcinoma is exceedingly rare.

Imaging Findings of Hepatic Paragonimiasis: A Case Report

Hepatic paragonimiasis is a rare form of ectopic infestation caused by Paragonimus. We experienced a case of hepatic paragonimiasis that showed characteristic imaging findings. CT and MR images showed a cluster of small cysts with rim enhancement in the subcapsular area of the liver. This finding seems to be characteristic for hepatic paragonimiasis, considering imaging findings in paragonimiasis involving other organs.

Focal Hepatic Lesions: Contrast-Enhancement Patterns at Pulse-Inversion Harmonic US using a Microbubble Contrast Agent

OBJECTIVE: To analyze the contrast-enhancement patterns obtained at pulseinversion harmonic imaging (PIHI) of focal hepatic lesions, and to thus determine tumor vascularity and the acoustic emission effect. MATERIALS AND METHODS: We reviewed pulse-inversion images in 90 consecutive patients with focal hepatic lesions, namely hepatocellular carcinoma (HCC) (n=43), metastases (n=30), and hemangioma (n=17). Vascular and delayed phase images were obtained immediately and five minutes following the injection of a microbubble contrast agent. Tumoral vascularity at vascular phase imaging and the acoustic emission effect at delayed phase imaging were each classified as one of four patterns. RESULTS: Vascular phase images depicted internal vessels in 93% of HCCs, marginal vessels in 83% of metastases, and peripheral nodular enhancement in 71% of hemangiomas. Delayed phase images showed inhomogeneous enhancement in 86% of HCCs; hypoechoic, decreased enhancement in 93% of metastases; and hypoechoic and reversed echogenicity in 65% of hemangiomas. Vascular and delayed phase enhancement patterns were associated with a specificity of 91% or greater, and 92% or greater, respectively, and with positive predictive values of 71% or greater, and 85% or greater, respectively. CONCLUSION: Contrast-enhancement patterns depicting tumoral vascularity and the acoustic emission effect at PIHI can help differentiate focal hepatic lesions.

A Case of Primary Pericardial Undifferentiated Sarcoma

Primary pericardial sarcomas are extremely rare. The authors report a case of a 46-yr-old woman in whom a large mediastinal mass was discovered. The patient presented with cough, dyspnea, and orthopnea. Diagnostic investigations, such as echocardiography, computed tomography, and exploratory thoracotomy provided the evidence of a large mass in the mediastinum, attached by a broad base to the superior portion of the pericardium. A excisional biopsy was performed, and histologic examination of a biopsy specimen showed undifferentiated sarcoma. However, the complete removal of the mass was impossible due to adhesion to the adjacent great vessels. After the completion of the chemotherapy the patient was completely asymptomatic. However, follow-up transesophageal echocardiography showed a residual 3x4 cm-sized mass. The patient received the radiotherapy with a total dose of 55 Gy over 6 weeks. At present, there is no evidence of disease progression.

Hip and Pelvis Diseases on Lumbar AP Radiographs Including Both Hip Joints

PURPOSE: To determine the frequency of diseases of the hip and pelvis, as seen of plain radiography of the lumbar spine in patients with suspicious lumbar disease, and to evaluate the methods used for lumbar spine radiography in Korea. MATERIALS AND METHDOS: Sixty university and training hospitals were randomly selected and asked to describe the projections, film size and radiographic techniques employed for routine radiography in patients with suspected disease of the lumbar spine. Plain radiographs of 1252 patients, taken using 14"x17"film and depicting both hip joints and the lumbar region, were analysed between March 1999 and February 2000. RESULTS: In 15 patients (1.2%), the radiographs revealed hip or pelvic lesions, confirmed as follows: avascular necrosis of the femoral head (n=11, with bilateral lesions in four cases); sustained ankylosing spondylitis (n=2); acetabular dysplasia (n=1); and insufficiency fracture of the pubic rami secondary to osteoporosis (n=1). In 11 of the 20 hospitals which responded, 14"x17"film was being used for lumbar radiography, while in the other nine, film size was smaller. CONCLUSION: Plain radiography of the lumbar spine including both hip joints, may be a useful way to simultaneously evaluate lesions not only of the lumbar spine but also of the hip and/or pelvis.

The Detectability of Hepatic Metastases in Candidates of Radiofrequency Ablation: Comparison for Helical CT Scanning and Late-Phase Pulse-Inversion Harmonic Imaging

PURPOSE: To compare dual-phase helical CT and pulse inversion harmonic US using microbubble contrast agents in the detection of hepatic metastases prior to radiofrequency (RF) ablation. MATERIALS AND METHODS: Twenty-one patients in whom hepatic metastases from colorectal cancer had been diagnosed by dual-phase CT scanning and who were considered to be candidates for RF ablation underwent pulse-inversion barmonic US examination. Images were obtained 5 minutes after the bolus injection of microbubble contrast agent SH U 508 A (4.0 g, 300 mg/mL). The number of metastatic tumors revealed by CT and US was determined, and the findings were statistically analysed. The influence of the results of US examination on treatment planning was also evaluated. RESULTS: In 21 patients, 48 metastatic lesions were detected by helical CT, and 56 lesions by US. These eight additional lesions revealed by US occurred in six patients (29%), and their diameter was 3-13 (mean, 7.2) mm. In three of these patients, RF ablation could not be performed, while in the other three, the additional lesions were ablated. CONCLUSION: Pulse-inversion harmonic US imaging using microbubble contrast agents may depict small hepatic metastatic tumors that were not apparent at CT. US-therefore appears to be useful in the planning of treatment prior to the RF ablation of hepatic metastases.

MR Imaging of the Meniscocapsular Tear of the Knee

PURPOSE: Meniscocapsular(MC) separation in knee joint can deteriorate joint function and must be repaired in arthroscopy. We investigated retrospectively MR imaging findings in order to find out its validity for accurate diagnosis & early treatment. MATERIALS AND METHODS: From Jan. 1998 to Dec. 1999, among the patients treated with MC tear under the arthroscopy, MRI findings was evaluated in 31 patients(18 cases: medial, 13 cases: lateral) at retrospectively. RESULTS: The important findings in medial meniscus were that fluid collection meniscus and MCL was 12 cases(67k) and increased distance between meniscus and capsule was 10 cases(56%), but in lateral meniscus, perimeniscal swelling was 10 cases(77%), and menisco-tibial extension rupture was 8 cases(62%). CONCLUSION: The important MR findings for the MC tear were the increasing distance or fluid between meniscus and joint capsule or MCL at medial meniscus, and perimeniscal swelling, menisco-tibial extension rupture at lateral meniscus.

Lumbar Spine Degenerative Disease: Effect on Bone Mineral Density Measurements in the Lumbar Spine and Femoral Neck

PURPOSE: To determine the effect of degenerative disease of the lumbar spine on bone mineral density in the lumbar spine and femoral neck. MATERIALS AND METHODS: We reviewed radiographs and dual energy x-ray absorptiometry scans of the lumbar spine and hip in 305 Caucasian women with suspected osteoporosis. One hundred and eighty-six patients remained after excluding women less than 40 years of age (n = 18) and those with hip osteoarthritis, scoliosis, lumbar spine fractures, lumbar spinal instrumentation, hip arthroplasty, metabolic bone disease other than osteoporosis, or medications known to influence bone metabolism (n = 101). On the basis of lumbar spine radiographs, those with absent/mild degenerative disease were assigned to the control group and those with moderate/severe degenerative disease to the degenerative group. Spine radiographs were evaluated for degenerative disease by two radiologists working independently; discrepant evaluations were resolved by consensus. Lumbar spine and femoral neck bone mineral density was compared between the two groups. RESULTS: Forty-five (24%) of 186 women were assigned to the degenerative group and 141 (76%) to the control group. In the degenerative group, mean bone mineral density measured 1.075 g/cm in the spine and 0.788 g/cm in the femoral neck, while for controls the corresponding figures were 0.989 g/cm and 0.765 g/cm Adjusted for age, weight and height by means of analysis of variance, degenerative disease of the lumbar spine was a significant predictor of increased bone mineral density in the spine (p = 0.0001) and femoral neck (p = 0.0287). CONCLUSION: Our results indicate a positive relationship between degenerative disease of the lumbar spine and bone mineral density in the lumbar spine and femoral neck, and suggest that degenerative disease in that region, which leads to an intrinsic increase in bone mineral density in the femoral neck, may be a good negative predictor of osteoporotic hip fractures.

Carcinoma Originating from Aberrant Breast Tissue of the Right Upper Anterior Chest Wall : A Case Report

Aberrant breast tissue is usually found in proximity to the normal breast, that is, in the axillary, sternal or clavicular regions. Carcinoma occurs more frequently in the aberrant tissue of the axilla than the extra-axillary site though the overall incidence of tumors of aberrant breast tissue is low. To our knowledge, studies regarding the carcinoma of aberrant breast tissue of the extra-axillary site have been reported rarely. Here we report a recent case of carcinoma originating from the extra-axillary aberrant breast tissue, presenting as a subcutaneous nodule on the right upper anterior chest wall. It is suggested that subcutaneous nodules of uncertain origin around the periphery of the breast should be suspected for breast carcinoma as a differential diagnosis and treated properly.