Biomedical subjects
Publications and source records attributed to A Greenspan.
There are multiple conditions associated with the development of osteonecrosis including trauma, hemoglobinopathies, Caisson disease, local infiltrative lesions, hypercortisolism, alcohol consumption, chronic renal failure, and autoimmune disease.
A rare case of Gorham's disease affecting the radius in a 46-year-old woman is presented. It was studied by plain radiography, MRI, and scintigraphy, including three-phase radionuclide bone scan and thallium scan. Three-phase bone scan demonstrated slightly decreased activity in the affected portion of the forearm in the early phase, but showed increased activity on the blood pool and delayed imaging. A thallium scan revealed no abnormalities. Histopathologic examination revealed osteoclastic activity and scar tissue with minimal remaining vasculature.
The introduction of cross-sectional and multiplanar imaging techniques has not diminished the value of radionuclide bone scanning. Skeletal scintigraphy remains an extremely effective and relatively inexpensive tool for diagnosis of many disorders of bones and joints. The sensitivity of scintigraphy in detecting stress fractures approaches 100%, although it is less specific than plain film radiography. However, radionuclide bone scanning can reveal subtle early changes in bone metabolism. For evaluation of infections, particularly in patients with diabetic foot neuropathy, scintigraphy is the modality of choice, although a combination of imaging techniques may be necessary in previously damaged bone. Radionuclide bone scanning has retained its place in the evaluation of primary bone tumors and metastases, and in screening of patients with metabolic bone disease. The radiologist should be aware that although this modality is generally used as an ancillary technique in conjunction with plain radiography, conventional tomography, computed tomography (CT), and magnetic resonance imaging (MRI), at times it can be used as the primary modality not only for the identification of skeletal lesions but also to provide important information required to make a definite diagnosis.
BACKGROUND: Adapalene is a new chemical entity that exhibits tretinoin-like activities in the terminal differentiation process. OBJECTIVE: We evaluated a dose range effect of two concentrations of adapalene gel as acne treatment and compared adapalene 0.1% gel with tretinoin 0.025% gel in the treatment of acne patients in two large multicenter studies. METHODS: Multicenter, investigator-masked, parallel group studies including 89 acne patients in the dose range study and 591 patients in the concurrent controlled studies were conducted. RESULTS: Adapalene gel 0.1% was significantly more effective in treating acne lesions than 0.03% adapalene gel. Adapalene gel 0.1% was significantly more effective than 0.025% or tretinoin gel in one study and of the same effectiveness in the other study. Adapalene gel was always better tolerated than tretinoin gel. CONCLUSION: Adapalene 0.1% gel is a safe and effective treatment of acne vulgaris.
We present two patients with pathologically proven intraosseous lipoma of the os calcis. A review of the literature, the radiologic criteria, and the differential diagnosis are provided.
OBJECTIVE: The objective of this study was to describe the distribution and radiologic appearance of skeletal coccidioidomycosis in 19 documented cases. DESIGN AND PATIENTS: Medical records of 19 patients (17 men, 2 women; age range 17-62 years, mean age 34 years) with clinically confirmed skeletal coccidioidomycosis were retrospectively reviewed. The patients were studied with plain radiography (n = 19), skeletal scintigraphy (n = 6), computed tomography (CT) (n = 5), and magnetic resonance imaging (MRI) (n = 1). RESULTS: Multiple lesions were seen in 11 of 19 patients (58%). Of a total of 46 lesions, 27 (59%) were described as punched-out lytic, 10 (22%) as permeative/destructive, and 9 (17%) as involving a joint and/or disk space. Lesions were identified in almost every bone (with the exception of the facial bones, ulna, carpus, and fibula) and were most commonly found in the axial skeleton (20 of 46; 43%). CONCLUSION: Skeletal coccidioidomycosis is frequently multicentric and may involve almost any bone. The axial skeleton is the most common site of involvement. Lesions are usually well demarcated but may present with an ill-defined border and permeative type of bone destruction, especially in the spine. Joint involvement is not uncommon. Plain radiographs are effective in the initial evaluation of bones and joints, scintigraphic studies can identify disseminated disease, and CT and MRI are effective in determining soft tissue involvement and spinal abnormalities.
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BACKGROUND: Adapalene is a new synthetic retinoid analogue developed for the topical treatment of acne vulgaris. OBJECTIVE: The study was designed to compare the efficacy and safety and adapalene gel 0.1% with tretinoin gel 0.025% in the treatment of grade II to II facial acne vulgaris. METHODS: Three hundred twenty-three patients were enrolled in this investigator-masked, randomized, parallel group, multicenter trial. Patients applied the test materials to the entire facial area daily, for a period of 12 weeks. Efficacy and cutaneous tolerance were assessed at baseline and weeks 2,4,8, and 12. Efficacy was determined by investigator counts of noninflammatory open and closed comedones, and inflammatory papules and pustules, as well as global improvement. Cutaneous tolerance was evaluated by erythema, scaling, and dryness, along with burning and pruritus. RESULTS: Staring at weeks 2 and 4, adapalene gel produced numerically greater lesion reductions than did tretinoin gel for all lesion types. At week 12, the mean percent reduction in the different lesion counts was as follow: 49% versus 37% for total lesions (p<0.01); 46% versus 33% for noninflammatory lesions (p=0.02); 48% versus 38% for inflammatory lesions (p=0.06) in adapalene and tretinoin gel treatment groups, respectively. Cutaneous side effects were limited to a mild "retinoid dermatitis" occurring in both treatment groups; however, patients treated with adapalene gel tolerated this therapy significantly better than those treated with tretinoin gel. Laboratory test evaluations (hematology, blood chemistries, urinalysis) were performed in 54 patients before and after 3 months of treatment. No clinically significant changes were observed. CONCLUSION: Adapalene gel 0.1% applied once daily was significantly more effective in reducing acne lesions and was better tolerated than tretinoin gel 0.025% in the treatment of acne vulgaris.
An enostosis or bone island represents a focus of mature compact (cortical) bone within the cancellous bone (spongiosa). Thought by some to be a tumor-like condition and by others a hamartoma, this benign lesion is probably congenital or developmental in origin and reflects failure of resorption during endochondral ossification. A bone island can be virtually diagnosed based on its characteristic clinical and radiologic features. Typically asymptomatic, the lesion is usually an incidental finding, with a preference for the pelvis, femur, and other long bones, although it may be found anywhere in the skeleton, including the spine. Plain radiography reveals a homogeneously dense, sclerotic focus in the cancellous bone with distinctive radiating bony streaks ("thorny radiation") that blend with the trabeculae of the host bone, creating a feathered or brush-like border. On CT scan, a bone island appears as a low-attenuation focus, and on MRI sequences it shows low signal intensity like cortical bone. A distinguishing feature of bone islands is that they are usually "cold" on skeletal scintigraphy. Thus, bone scan has been and continues to be the means of differentiating bone islands from the more aggressive entities. However, reports of histologically confirmed bone islands that were scintigraphically active have raised a note of caution about relying on this modality in the differential consideration of lesions otherwise characteristic of bone islands. Guides to the correct diagnosis should be looked for in the individual clinical situation and in the morphological features of the lesion on plain radiography, CT, and MRI, without regard to the lesions activity on bone scan.(ABSTRACT TRUNCATED AT 250 WORDS)
PURPOSE: Objective of this study was to present the spectrum of early magnetic resonance imaging (MRI) findings following traumatic dislocation of the femoral head, and to identify any associated injuries that may have therapeutic or prognostic significance and be better delineated by MRI than by conventional radiography. PATIENTS AND METHODS: Prospective MRI of both hips was formed on 18 patients (14 male, 4 female; age range 14-54 years; average age 30.5 years) within 5 weeks of a traumatic femoral head dislocation. The interval between the time of injury and the time of injury and the imaging studies ranged from 2 to 35 days (average 13.2 days). Posterior dislocation was present in 14 patients and anterior dislocation in 4 patients. In the majority of cases, we performed axial T1, coronal T1, and coronal T2* (MPGR) sequences. Images were retrospectively evaluated by consensus of three radiologists for possible abnormalities of the bone and cartilage, joint space, and soft tissues. Because all patients were treated with closed reduction, surgical correlation was not obtained. RESULTS: All patients had a joint effusion or hemarthrosis. Of the 14 patients with posterior dislocation, isolated femoral head contusions (trabecular microfractures) were identified in 6 patients. Four patients had small femoral head fractures, and one had an osteochondral defect. Acetabular lip fractures were seen in six patients, and one patient had a labral tear. Four patients had intra-articular loose bodies and one had ligamentum teres entrapment. Twelve patients had iliofemoral ligament injury. All patients had muscle injury involving the gluteal region and medical fascial compartment, and 13 patients had anterior fascial compartment muscle injury. Seven patients with posterior dislocation had posterior fascial compartment injury. Of the four patients with anterior dislocation, two had bony contusion, two had cortical infraction, one had a labral tear, and all four had an iliofemoral ligament injury. All four patients in this group had muscle injury of the gluteal region and of the anterior and medial fascial compartments. CONCLUSIONS: MRI can effectively identify and quantify the muscle injury and joint effusion that invariably accompany traumatic hip dislocations. It is also useful for demonstrating trabecular bone contusion (trabecular injury) and iliofemoral ligament injury, which occur commonly with acute hip dislocation.
OBJECTIVE: This study was undertaken to describe the imaging characteristics of synovial hemangioma, with the goal of improving the disappointing rate (22%) of clinical diagnosis of this condition. A review of the literature and the differential diagnosis of intra-articular lesions, including synovial osteochondromatosis and pigmented villonodular synovitis, are also presented. PATIENTS: The subjects of the study were 8 patients (4 males, 4 females; age range: 5-47 years; mean age: 19 years) with histologically confirmed synovial hemangioma involving the knee (n = 7) or wrist (n = 1). We retrospectively examined the imaging studies performed in these patients, including plain radiography (n = 8), magnetic resonance imaging (MRI; n = 4), angiography (n = 3), arthrography (n = 2), and contrast-enhanced computed tomography (CT; n = 2). RESULTS: Plain radiographs showed a soft tissue density suggesting either joint effusion or a mass in all patients. Phleboliths and bone erosions on plain films in four patients with extra-articular soft tissue involvement pointed to the correct diagnosis. Angiography, showing fine-caliber, smooth-walled vessels, contrast pooling in dilated vascular spaces, and early visualization of venous structures, was diagnostic in two patients. Neither arthrography nor CT yielded specific enough findings. MRI was consistently effective in allowing the correct diagnosis to be made preoperatively, showing an intra-articular or juxta-articular mass of intermediate signal intensity on T1-weighted images and of high signal intensity of T2- or T2*-weighted images with low-signal channels or septa within it. A fluid-fluid level was found in two patients with a cavernous-type lesion. CONCLUSION: Despite the limited nature of this study, it shows clearly that MRI is the procedure of choice whenever an intra-articular vascular lesion such as synovial hemangioma is suspected. Nonetheless, phleboliths and evidence of extra-articular extension of plain radiographs point to angiography as an effective procedure of first resort because it can be combined with embolotherapy.
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RATIONALE AND OBJECTIVES: We compared the performance of fast spin-echo (FSE) with conventional spin-echo (CSE) magnetic resonance (MR) imaging sequences in the detection of meniscal tears. METHODS: Seventy-three patients underwent MR examination of the knee for suspected internal derangement. Each patient was scanned with a CSE sequence and one of two FSE sequences. The primary difference between the two FSE sequences consisted of the echo train length (ETL). Thirty-seven patients (group 1) were scanned with the FSE I sequence (ETL = 8), and 36 patients (group 2) were scanned with the FSE II sequence (ETL = 4). Menisci were graded as torn or not torn on the basis of their MR appearance. The sequences were compared with each other and with the surgical findings in 31 patients who underwent arthroscopy. RESULTS: In group 1, there was a significant discrepancy between the CSE and FSE I techniques (p = .006). The FSE I sequence detected only 11 of 19 surgically proven torn menisci as opposed to 18 of 19 detected with the CSE sequence. The FSE II sequence performed significantly better in group 2, with an accuracy equal to that of the CSE sequence. CONCLUSION: FSE sequences are extremely technique dependent with regard to detecting meniscal tears and should not replace CSE sequences in this setting until further studies are performed to optimize the technique.
Plain radiographs help establish the diagnosis and pattern of dislocation of the carpal scaphoid. Isolated dislocations can be treated with closed reduction, but dislocations in conjunction with axial carpal disruption must be treated with open reduction to fix the unstable radial half of the carpus to the stable ulnar half. Two case reports illustrate each type of carpal scaphoid dislocation.
A 75-year-old woman with histologically proven ovarian adenocarcinoma and no evidence of other malignant lesions was found to have disseminated blastic (sclerotic) metastases to bone without clinical evidence of gross peritoneal spread or lung involvement. The patient's survival for 28 months after the earliest evidence of bone involvement is noteworthy, because osseous metastasis in ovarian malignancy is usually a late manifestation of the disease.
PURPOSE: To evaluate bone islands that showed increased uptake of radiotracer on skeletal scintigraphy and to present an algorithm for examining such lesions to avoid misdiagnosis in difficult cases. PATIENTS AND METHODS: Over an 8-year period, 20 patients (10 men and 10 women ranging in age from 33 to 82 years) with bone islands that showed activity on skeletal scintigraphy were examined with plain radiography (all patients), computed tomography (CT; 5 patients) and magnetic resonance imaging (MRI; 4 patients). For six of the patients the clinical presentation and the radiologic studies suggested malignancy, which prompted biopsy and histopathologic examination. Histopathologic study was also performed for six other patients in whom the bone islands were found incidentally during evaluation for joint replacement surgery for osteoarthritis. In the last eight patients the lesions exhibited the characteristic radiologic features of enostosis, and these patients were followed for up to 3 years without biopsy. RESULTS: In all cases plain radiography showed the characteristic features of a bone island: a homogeneously dense, sclerotic focus in the cancellous bone with distinctive radiating bony streaks ("thorny radiation") that blended with the trabeculae of the host bone to create a feathered or brush-like border. Histopathologic examination of scintigraphically active bone islands showed increased osteoblastic activity, and the lesions were marked by a mixture of compact and trabecular bone. In the patients who did not undergo biopsy but were followed with radiologic examinations, there was no change in the size or appearance of the lesions. CONCLUSIONS: The key to the correct diagnosis of bone island lies in the distinctive radiographic features of enostosis. An asymptomatic, isolated sclerotic bone lesion showing feathered or brush borders is most likely an enostosis, regardless of its size or its activity on scintigraphy. Therefore, a practical algorithm for examining bone islands should flow from their morphologic features as observed on radiographs and CT and MRI scans, rather than from their activity on scintigraphy.