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.

Osseous Injury Associated With Ligamentous Tear of the Knee.

One of the most common knee injuries is ligament tear, which may initially manifest as an osseous injury in radiographs. Radiologists should therefore be able to recognize ligament tears of the knee as osseous abnormalities in images. This review focuses on the imaging features of knee ligament injuries and their related osseous injuries: anterior cruciate ligament (ACL) tear with Segond fracture; associated marrow contusion; ACL avulsion fracture; posterior cruciate ligament (PCL) tear with osseous avulsion of the ligament including arcuate sign; reverse Segond fracture; PCL avulsion fracture; medial collateral ligament tear with Pellegrini-Stieda disease; lateral collateral ligament tear with avulsion fracture of the fibular head; and patellar ligament injuries with Osgood-Schlatter and Sinding-Larsen-Johansson.

Validity of Intraoral Scans Compared with Plaster Models: An In-Vivo Comparison of Dental Measurements and 3D Surface Analysis.

PURPOSE: Dental measurements have been commonly taken from plaster dental models obtained from alginate impressions can. Through the use of an intraoral scanner, digital impressions now acquire the information directly from the mouth. The purpose of this study was to determine the validity of the intraoral scans compared to plaster models. MATERIALS AND METHODS: Two types of dental models (intraoral scan and plaster model) of 20 subjects were included in this study. The subjects had impressions taken of their teeth and made as plaster model. In addition, their mouths were scanned with the intraoral scanner and the scans were converted into digital models. Eight transverse and 16 anteroposterior measurements, 24 tooth heights and widths were recorded on the plaster models with a digital caliper and on the intraoral scan with 3D reverse engineering software. For 3D surface analysis, the two models were superimposed by using best-fit algorithm. The average differences between the two models at all points on the surfaces were computed. Paired t-test and Bland-Altman plot were used to determine the validity of measurements from the intraoral scan compared to those from the plaster model. RESULTS: There were no significant differences between the plaster models and intraoral scans, except for one measurement of lower intermolar width. The Bland-Altman plots of all measurements showed that differences between the two models were within the limits of agreement. The average surface difference between the two models was within 0.10 mm. CONCLUSIONS: The results of the present study indicate that the intraoral scans are clinically acceptable for diagnosis and treatment planning in dentistry and can be used in place of plaster models.

Lead-induced impairments in the neural processes related to working memory function.

BACKGROUND: It is well known that lead exposure induces neurotoxic effects, which can result in a variety of neurocognitive dysfunction. Especially, occupational lead exposures in adults are associated with decreases in cognitive performance including working memory. Despite recent advances in human neuroimaging techniques, the neural correlates of lead-exposed cognitive impairment remain unclear. Therefore, this study was aimed to compare the neural activations in relation to working memory function between the lead-exposed subjects and healthy controls. METHODOLOGY/PRINCIPAL FINDINGS: Thirty-one lead-exposed subjects and 34 healthy subjects performed an n-back memory task during MRI scan. We performed fMRI using the 1-back and 2-back memory tasks differing in cognitive demand. Functional MRI data were analyzed using within- and between-group analysis. We found that the lead-exposed subjects showed poorer working memory performance during high memory loading task than the healthy subjects. In addition, between-group analyses revealed that the lead-exposed subjects showed reduced activation in the dorsolateral prefrontal cortex, ventrolateral prefrontal cortex, pre supplementary motor areas, and inferior parietal cortex. CONCLUSIONS/SIGNIFICANCE: Our findings suggest that functional abnormalities in the frontoparietal working memory network might contribute to impairments in maintenance and manipulation of working memory in the lead-exposed subjects.

Spectrum of superficial nerve-related tumor and tumor-like lesions: MRI features.

Superficial soft-tissue masses arising from skin appendages, metastasis, and inflammatory lesions have been widely reported. However, nerve-related superficial mass-like lesions other than peripheral nerve sheath tumors are less commonly described. High resolution magnetic resonance imaging (MRI) is an excellent non-invasive tool for the evaluation of such lesions. In this article, the authors discuss the entire spectrum of these lesions and also outline a systemic diagnostic approach.

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.

Bone marrow edema pattern around the knee on magnetic resonance imaging excluding acute traumatic lesions.

Magnetic resonance imaging (MRI) is very sensitive for the detection of marrow abnormalities. Bone marrow edema on MRI has been defined as an area of low signal intensity on T1-weighted images, associated with intermediate or high signal intensity findings on T2-weighted images. The bone marrow edema pattern is a nonspecific finding with multiple etiologies. The knee is a common place for bone marrow signal abnormalities to appear on MRI. Besides contusions and fractures from acute trauma, there are a variety of other causes of the bone marrow edema pattern. It is important for the interpreter of the study to be aware of the different etiologies responsible for producing these changes and to be able to narrow the differential diagnosis without mistaking such a pattern for acute trauma or infiltrative tumor. This article concentrates on those entities that produce a bone marrow edema pattern not related to acute trauma including red marrow proliferation, stress, osteochondral lesions, osteonecrosis, bone marrow edema syndrome, arthropathy, infection, Paget's disease, and marrow replacement disorders.

MR imaging findings of high-voltage electrical burns in the upper extremities: correlation with angiographic findings.

BACKGROUND: A high-voltage electrical burn is often associated with deep muscle injuries. Hidden, undetected deep muscle injuries have a tendency for progressive tissue necrosis, and this can lead to major amputations or sepsis. MRI has excellent soft tissue contrast and it may aid in differentiating the areas of viable deep muscle from the areas of non-viable deep muscle. PURPOSE: To describe the MR imaging findings of a high-voltage electrical burn in the upper extremity with emphasis on the usefulness of the gadolinium-enhanced MRI and to compare the MR imaging findings with angiography. MATERIAL AND METHODS: We retrospectively reviewed the imaging studies of six patients with high-voltage electrical burns who underwent both MRI and angiography at the burn center of our hospital from January 2005 to December 2009. The imaging features were evaluated for the involved locations, the MR signal intensity of the affected muscles, the MR enhancement pattern, the involved arteries and the angiographic findings (classified as normal, sluggish flow, stenosis or occlusion) of the angiography of the upper extremity. We assessed the relationship between the MR imaging findings and the angiographic findings. RESULTS: The signal intensities of affected muscles were isointense or of slightly high signal intensity as compared with the adjacent unaffected skeletal muscle on the T1-weighted MR images. Affected muscles showed heterogenous high signal intensity relative to the adjacent unaffected skeletal muscle on the T2-weighted images. The gadolinium-enhanced T1-weighted images showed diffuse inhomogeneous enhancement or peripheral rim enhancement of the affected muscles. The angiographic findings of the arterial injuries showed complete occlusion in three patients, severe stenosis in two patients and sluggish flow in one patient. Of these, the five patients with complete occlusion or severe stenosis on angiography showed non-perfused and non-viable areas of edematous muscle on MRI. On the other hand, one patient with sluggish flow on angiography showed a perfused and viable area of edematous muscle on MRI. CONCLUSION: Gadolinium-enhanced MRI is a useful non-invasive imaging modality to detect the site and extent of hidden, undetected deep muscle injuries in a group of patients with high-voltage electrical burns of the upper extremities.

The differences in neural network activity between methamphetamine abusers and healthy subjects performing an emotion-matching task: functional MRI study.

Methamphetamine (MA) abusers commonly exhibit socially problematic behaviors, such as diminished empathy, decreased emotional regulation and interpersonal violence, which may be attributable to alterations in emotional experience. However, few studies have used functional MRI to examine directly the emotional experience of threatening or fearful non-face images in MA abusers. In this study, we investigated possible differences in neural correlates of negative emotional experiences between abstinent MA abusers and healthy subjects using complex visual scenes depicting fear or threat derived from the International Affective Picture System. In within-group analyses, healthy subjects and MA abusers activated a similarly distributed cortical network, prominently including the amygdala, fusiform gyrus, parahippocampal gyrus, ventrolateral prefrontal cortex and inferior frontal cortex. In between-group analyses, however, MA abusers showed a reduced activation in the bilateral dorsolateral prefrontal cortex and insula, and increased activation in the fusiform gyrus, hippocampus, parahippocampal gyrus and posterior cingulate cortex, relative to healthy subjects. Hypoactivation of the insula in MA abusers relative to healthy subjects suggests that the ability to have an emotional response to threatening scenes and empathy for another's pain could be compromised in MA abusers. Hyperactivity in the fusiform gyrus, parahippocampal gyrus and posterior cingulate cortex in MA abusers relative to healthy subjects indicates that threatening and fearful images from the International Affective Picture System may remind MA abusers of episodic memory related to similar experiences. Therefore, functional impairment of these neural networks in MA abusers may contribute to altered emotional experience in social interactions, which could lead to increased negative mood and stress in interpersonal communication.

Subungual tumors: clinicopathologic correlation with US and MR imaging findings.

Various types of tumors can affect the subungual space, including benign solid tumors (glomus tumor, subungual exostosis, soft-tissue chondroma, keratoacanthoma, hemangioma, lobular capillary hemangioma), benign cystic lesions (epidermal and mucoid cysts), and malignant tumors (squamous cell carcinoma, malignant melanoma). Imaging plays an important role in the detection and differentiation of subungual tumors because of their small size, nonspecific clinical manifestations, and functional significance. Ultrasonography (US)-in particular, high-resolution US with color Doppler studies-provides useful information regarding tumor size, location, shape, and internal characteristics (cystic, solid, or mixed), but it is limited in the further characterization of tissue. Magnetic resonance (MR) imaging has an important role in categorizing tumors according to their anatomic location, pathologic origin, and signal characteristics. There is some overlap between the US and MR imaging features of subungual tumors; however, certain features can allow accurate diagnosis and expedite management when correlated with clinical and pathologic findings.

Nuchal-type fibroma of the buttock: magnetic resonance imaging findings.

Nuchal-type fibroma, first described in 1988 by Enzinger and Weiss, is a rare fibrous growth occurring predominantly in the interscapular and paraspinous regions. It is typically located in the subcutaneous tissue of the posterior neck but may occur in extranuchal soft tissue sites such as the upper back, shoulder, and facial regions. In this article, we describe the magnetic resonance imaging findings of a nuchal-type fibroma that involved the buttock in a 45-year-old woman, and we review and discuss the literature on the subject.

Lobular capillary hemangioma in the soft tissue of the finger: sonographic findings.

OBJECTIVE: The purpose of this study was to describe the sonographic findings of pathologically confirmed subcutaneous lobular capillary hemangioma of the finger in six patients. MATERIALS AND METHODS: The clinical records were reviewed for data, including the patients' age and gender, the clinical presentation, a history of trauma, and the tumor site. The sonographic findings were retrospectively analyzed for the specific location within the superficial tissue, the tumor's size, shape, and margin, the internal echogenicity, the internal echo texture, the presence of calcification, the presence of a hypoechoic rim, and the internal vascularity. RESULTS: The study group consisted of three men and three women, and the six patients' mean age was 39 years (age range: 13-67 years). All the patients were admitted with a painful nodule or a painless protruding nodule in the finger with easy bleeding on contact. In all cases, there was no history of trauma. The mean size of the tumors was 0.85 cm. All the tumors were ill-defined, oval, subcutaneous nodules without calcifications or any hypoechoic rim. Color Doppler sonography showed marked internal vascularity in both the central and peripheral tumor regions in three cases and scanty vascularity in the peripheral region in three cases. CONCLUSIONS: Subcutaneous lobular capillary hemangioma should be considered when an ill-defined, oval, vascular subcutaneous nodule without calcifications or a hypoechoic rim is seen in the soft tissue of the finger, especially if this tumor is a painful small nodule or a painless protruding small nodule with easy bleeding on contact.

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.

Three-dimensional osseous micro-architecture of the distal humerus: implications for internal fixation of osteoporotic fracture.

BACKGROUND: The purpose of this study is to analyze 3-dimensional structural parameters of cortical and trabecular bone in the distal humerus using quantitative CT and to find regional variations and differences according to age. METHODS: We collected 14 cadaveric distal humeri with an average age of 58.4 years. The specimens were examined at 3 different levels: 1) distal trans-epicondylar section, 2) mid trans-olecranon fossa section, and 3) proximal supra-olecranon fossa section. RESULTS: In the distal section, bone volume was the greatest in the anterior part of the lateral condyle and the least in the posterior part of the lateral condyle. Cortical thickness in the distal section was the thickest in the posterior medial and the thinnest in the anterior aspect followed by lateral aspect. The changes in cortical thickness with aging were obvious in the posterior side and trabecular bone on the medial condyle. CONCLUSION: This study evaluated the differences in cortical and trabecular bone parameters in each different region of the distal humerus. We found a potential weakness of plate fixation in the posterolateral aspect of the distal condyle because of relative insufficient osseous micro-architecture, which may affect the treatment of osteoporotic distal humerus fractures especially in elderly patients.

CT and MRI findings of calcified spinal meningiomas: correlation with pathological findings.

OBJECTIVE: This study was designed to present characteristic CT and MR findings of calcified spinal meningiomas that correlate with pathological findings and to assess the efficacy of CT for the detection of calcifications within a mass in comparison to MRI. MATERIALS AND METHODS: Between 1998 and 2009, 10 out of 11 patients who had pathologically confirmed psammomatous meningiomas showed gross calcifications on CT images and were included in this study. On CT scans of the 10 patients, the distribution pattern, morphology and number of calcifications within masses were evaluated. MRI was performed in seven patients and signal intensities of masses were assessed. The pathological results analyzed semi-quantitatively were compared with the density or the size of calcifications within a mass as seen on a CT scan. RESULTS: Seven of 10 masses were located at the thoracic spine level. Eight masses had intradural locations. The other two masses had extradural locations. Four masses were completely calcified based on standard radiographs and CT. Symptoms duration, the size of the mass and size or number of calcifications within a mass had no correlation. The location, size, and distribution pattern of calcifications within masses were variable. On MR images, signal intensity of calcified tumor varied on all imaging sequences. All the masses enhanced after injection of intravenous contrast material. CONCLUSION: A calcified meningioma should be first suggested when extradural or intradural masses located in the spine contain calcifications regardless of the size or pattern as depicted on CT, especially in the presence of enhancement as seen on MR images.

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.

Intracortical lipoma of the femur.

Intracortical lipoma is an extremely rare benign primary bone tumor. We encountered a case of an intracortical lipoma found incidentally in the femur of a 31-year-old female. Magnetic resonance imaging and computed tomography of the femur demonstrated an intracortical fatty lesion in the posterolateral aspect of the diaphysis. The intracortical lesion showed some intramedullary extension, multiple septations, and dot-like calcifications. Intralesional curettage was performed. Histologically, the tumor consisted of mature, viable adipocytes without foci of fat necrosis or dystrophic calcification.

Non-infectious ischiogluteal bursitis: MRI findings.

OBJECTIVE: We wished to report on the MRI findings of non-infectious ischiogluteal bursitis. MATERIALS AND METHODS: The MRI findings of 17 confirmed cases of non-infectious ischiogluteal bursitis were analyzed: four out of the 17 cases were confirmed with surgery, and the remaining 13 cases were confirmed with MRI plus the clinical data. RESULTS: The enlarged bursae were located deep to the gluteus muscles and postero-inferior to the ischial tuberosity. The superior ends of the bursal sacs abutted to the infero-medial aspect of the ischial tuberosity. The signal intensity within the enlarged bursa on T1-weighted image (WI) was hypo-intense in three cases (3/17, 17.6%), iso-intense in 10 cases (10/17, 58.9%), and hyper-intense in four cases (4/17, 23.5%) in comparison to that of surrounding muscles. The bursal sac appeared homogeneous in 13 patients (13/17, 76.5%) and heterogeneous in the remaining four patients (4/17, 23.5%) on T1-WI. On T2-WI, the bursa was hyper-intense in all cases (17/17, 100%); it was heterogeneous in 10 cases and homogeneous in seven cases. The heterogeneity was variable depending on the degree of the blood-fluid levels and the septae within the bursae. With contrast enhancement, the inner wall of the bursae was smooth (5/17 cases), and irregular (12/17 cases) because of the synovial proliferation and septation. CONCLUSION: Ischiogluteal bursitis can be diagnosed with MRI by its characteristic location and cystic appearance.