Intraosseous tumors of the skull. A pictorial review.

Radiologists often encounter intraosseous tumors of the calvarium. Compared with parenchymal lesions, information is limited. In this review, we list the calvarial tumors and correlate the radiologic appearance with the pathologic findings. We discuss primary intraosseous tumors and tumor secondary to systemic disease as well as metastatic malignant tumor. Differentiation between primary tumors and tumors secondary to systemic disease can be difficult. Physicians should explore the systematic disease. In the case of primary tumors, it is important to verify any soft-tissue component since this is an important differential diagnostic feature with the potential for malignant transformation.

Opportunities in IT Support of Workflow & Information Flow in the Emergency Department Digital Imaging Process.

The goal of this study is to examine workflow and information flow in the emergency department (ED) digital imaging process to identify features of an optimized system. Radiological imaging (x-rays, CT scans, etc) is unique in the ED setting, as the need for fast turn-around time and interactive communication between radiologists and emergency physicians is different than that of most other healthcare settings. The information technology systems which are used by both radiologists and emergency physicians to support these processes have been designed with a focus on the routine workflow of radiologists. We report the results of 14 hours of naturalistic observations of the use of digital imaging systems by a total of 22 ED and radiology staff. A hierarchical task analysis and an information process diagram are presented, and disparate theories that groups in the system have about other groups were discovered, particularly in the communication of clinical information.

Kyphoplasty and vertebroplasty produce the same degree of height restoration.

BACKGROUND AND PURPOSE: There are few comparative studies regarding morphologic changes after kyphoplasty and vertebroplasty. The purpose of this study was to compare restoration of vertebral body height and wedge angle and cement leakage with kyphoplasty and vertebroplasty in osteoporotic compression fractures. MATERIALS AND METHODS: Forty patients (57 vertebrae) were treated with kyphoplasty, and 66 patients (124 vertebrae) were treated with vertebroplasty. Cement leakage into the disk space and paravertebral soft tissues or veins was analyzed on immediate postoperative CT scans. The height and wedge angle were measured before and after treatment and analyzed with the Mann-Whitney U test and chi(2) test. RESULTS: Kyphoplasty and vertebroplasty both improved vertebral body height and the wedge angles (P < .05). However, these differences were not statistically significant when the 2 techniques were compared (P > .05). There were 18% of the kyphoplasty group and 49% of the vertebroplasty group that showed cement leakage into the paravertebral soft tissues or veins (P < .01). Cement leakage into the disk space occurred in 12% of the kyphoplasty group and in 25% of the vertebroplasty group (P < .01). However, no complications related to cement leakage were noted. CONCLUSIONS: Both kyphoplasty and vertebroplasty achieved the same degree of height restoration and improvement of the wedge angle. Kyphoplasty resulted in less cement leakage into the disk space and paravertebral soft tissues or veins than vertebroplasty.

Diffuse lipogranulomatosis involving soft tissues of the head and neck due to multiple self-injections of mineral oil.

We describe imaging findings of a 45-year-old man with a 6-month history of gradually increasing diffuse swelling of the neck. CT showed diffuse thickening and infiltration of the superficial and deep soft tissues bilaterally. On further investigation of his history, the patient stated that he had injected mineral oil into his neck to clean out his body from drugs. Biopsy results showed multinucleated giant cells and inflammatory infiltrates confirming the diagnosis of lipogranulomatosis.

Patients with osteoporosis on steroid medication tend to sustain subsequent fractures.

BACKGROUND AND PURPOSE: Repeat fractures after percutaneous vertebroplasty can be seen in patients with osteoporotic compression fractures. The purpose of this study was to identify characteristics of patients with new fractures after vertebroplasty. MATERIALS AND METHODS: Fifty-five consecutive patients were treated with vertebroplasty for painful osteoporotic compression fractures at our institution. The charts and radiographic studies of all patients were retrospectively reviewed. Special attention was paid to patient age and sex, imaging studies, long-term use of steroid medication, and treatment for osteoporosis. We used logistic regression analysis and the Fisher exact test for statistical evaluation. RESULTS: Thirty-five patients were treated with vertebroplasty at one time and did not develop new fractures, whereas 20 patients returned with new fractures. Sixteen of 55 patients had been on steroid medication. The incidence of subsequent vertebral compression fractures after vertebroplasty in patients on long-term steroid therapy was 69% (11/16), compared with 23% (9/39) in those with primary osteoporosis (ie, those who were not on steroid therapy). There was a statistically significant association between use of steroids and new fractures (P<.01). No statistically significant difference was noted in patient age, sex, and medication for osteoporosis. CONCLUSION: Patients who are on long-term steroid medication have an elevated risk of developing new fractures after vertebroplasty.

Vertebroplasty for osteoporotic fractures with spinal canal compromise.

BACKGROUND AND PURPOSE: Percutaneous vertebroplasty can aggravate spinal canal narrowing, especially in patients with preoperative retropulsion. The purpose of this study was to evaluate changes in spinal canal dimension during percutaneous vertebroplasty for osteoporotic fractures with retropulsion. MATERIALS AND METHODS: We reviewed all cases of osteoporotic vertebral fractures treated with vertebroplasty. Twenty-one patients (25 vertebrae) had a retropulsed fragment that compromised the dimension of the spinal canal on preoperative imaging. We measured the degree of retropulsion before and after vertebroplasty to evaluate changes in spinal canal dimension. We also evaluated pain, neurologic status, vertebral body height, and wedge angle. RESULTS: Mean retropulsion was 4.2 mm before and 4.4 mm after vertebroplasty. There was no statistically significant difference (P = .32). Mean increase in vertebral body height was 2.6 mm anteriorly, 1.7 mm centrally, and 0.3 mm posteriorly. Mean decrease in wedge angle was 4.7 degrees. There were statistically significant improvements in height and wedge angle (P < .01). None of our patients developed new symptoms during vertebroplasty or thereafter. Twenty of 21 patients (95%) showed partial or complete immediate pain relief, whereas 1 patient did not improve. CONCLUSION: Vertebroplasty can be performed safely in patients with spinal canal compromise. This procedure can reduce pain, increase vertebral body height, and decrease wedge angle without worsening of retropulsion.

MR images mimic disc after discectomy.

MRI of a 30-year-old woman 1 year after discectomy showed a residual disc-like tissue. The observation was initially confusing, but a close comparison of pre- and post-operative images suggested that the inferior wall of the anterior joint capsule had migrated superiorly after the removal of the disc and mimicked a residual disc on the follow-up MR images.

External validity of a randomised clinical trial of temporomandibular disorders: analysis of the patients who refused to participate in research.

PURPOSE: To assess the external validity of a randomised clinical trial (RCT) of a painful condition. METHOD: Consecutive patients with painful temporomandibular disorders (TMDs) were invited to participate in a clinical trial. Patients who refused to participate were compared to those who agreed to participate in this study with respect to degree of symptoms at time of presentation. RESULTS: The patients who refused to participate had more pain, and their condition interfered more with their daily life than those who accepted the invitation to participate. CONCLUSION: Selection bias in RCTs of painful conditions can skew the results, and external validity should be analysed before the results are generalised.

Acoustic characteristics of sounds from temporomandibular joints with and without effusion: an MRI study.

Joint effusion has been associated with temporomandibular joint (TMJ) pain but can only be diagnosed by magnetic resonance imaging (MRI). For screening of patients with suspected effusion a simple and less expensive method would be desirable. We recorded joint sounds during jaw opening and closing movement from 34 TMJs with internal derangement (ID). Seventeen joints had joint effusion seen on MRI. Spectrograms of the sounds were displayed as waterfall plots showing profiles of the consecutive Hamming windows. If the profiles were similar, as judged by initial evaluation, the displayed pattern was classified as stable. If some profiles were distinctly deviating in their pattern, this was classified as unstable. Joints with effusion showed unstable sound pattern more often than joints without effusion (P < 0.001). It was concluded that TMJ sound analyses have a potential to identify joints with effusion based on their unstable sound pattern.

MR grading of temporomandibular joint fluid: association with disk displacement categories, condyle marrow abnormalities and pain.

The purpose of this study was to investigate temporomandibular joint (TMJ) effusion on magnetic resonance (MR) images, and its association with specific categories of disk displacement, bone marrow abnormalities and pain. From a series of 523 consecutive TMJ MR imaging studies of patients referred to imaging because of pain and dysfunction, those with TMJ effusion, defined as an amount of fluid that exceeded the maximum amount seen in a control group of asymptomatic volunteers, were analysed. The selected patients were reassessed and the amount of TMJ fluid was graded bilaterally according to a set of reference films. Other parameters recorded included disk displacement categories and condyle marrow abnormalities. Pain self-records were obtained from the patients immediately before MR imaging. The association between the recorded parameters and TMJ pain was analysed with t-tests and regression analysis. Of the 523 patients, 70 (13%) had TMJ effusion, which was unilateral in 61%. Only 9% of the 70 patients had effusion bilaterally, whereas bilateral disk displacement was found in 80%. In the 76 joints with effusion, 83% showed two specific categories of disk displacement at closed mouth. Condyle marrow abnormalities were found in 31% of the 70 patients, mostly on one side, and in 24% of the 76 joints. An in-patient regression analysis of the side difference in TMJ pain showed that effusion and condyle marrow abnormalities were significant pain-increasing factors. In conclusion, patients with TMJ effusion represent a subgroup with pain and dysfunction with more severe intra-articular pathology than those with disk displacement but no other joint abnormalities.

MR evidence of temporomandibular joint fluid and condyle marrow alterations: occurrence in asymptomatic volunteers and symptomatic patients.

The purpose of this study was to estimate the frequency and amount of temporomandibular joint (TMJ) fluid, as well as the frequency and type of condyle marrow alterations in asymptomatic volunteers and compare to patients with TMJ pain and dysfunction. Proton-density and T2 weighted magnetic resonance (MR) images of the TMJs of 62 asymptomatic volunteers and 58 symptomatic patients were analysed for fluid and condyle marrow alterations as well as disk position. The amount of fluid (increased T2 signal) was characterized as none, minimal, moderate or marked and related to the disk position. The differentiation between moderate and marked fluid was based on the maximum amount of fluid seen in the volunteers; more than this amount was categorized as marked fluid. The marrow of the mandibular condyle was categorized as normal, edema (increased T2 signal) or sclerosis (decreased proton-density and T2 signal) and related to fluid and disk position. In the 62 asymptomatic volunteers, 50 (81%) had none or minimal and 12 (19%) had moderate TMJ fluid. In the 58 symptomatic patients, 40 (69%) had none or minimal and 18 (31%) had moderate or marked fluid. Both in volunteers and patients, moderate fluid could be seen in joints with normal disk position, but was significantly associated with disk displacement. In the 62 volunteers, no signal abnormalities in the condyle marrow were found. In the 58 patients, six (10%) had abnormal bone marrow. These six patients had disk displacement and two had moderate or marked fluid. Marked fluid and condyle marrow abnormalities were therefore not encountered in any of the asymptomatic volunteers but in about 10% of the patients.

Discectomy as an effective treatment for painful temporomandibular joint internal derangement: a 5-year clinical and radiographic follow-up.

PURPOSE: The purpose of this prospective study was to compare the preoperative and 5-year postoperative status of patients after unilateral discectomy for painful internal derangement of the temporomandibular joint. PATIENTS AND METHODS: The study was based on 64 patients. Fifty-six had disc displacement without reduction and 8 had disc displacement with reduction. The patients were examined clinically and radiographically before and 5 years after the operation according to a standardized protocol. RESULTS: Eighty-five percent of the patients (n = 52) had good results, 6% had acceptable results, and 9% had a poor outcome. Three patients (5%) were reoperated and 5 other patients (8%) needed a contralateral operation during the 5-year follow-up. The median increase in maximum mouth opening was 11 mm (range, -8 to +35 mm) and 83% of the patients had more than 40 mm maximal mouth opening postoperatively. Seventy-five percent of the patients had crepitation at 5-year follow-up compared with 27% before the operation. Postoperatively, the majority of the joints showed radiographic evidence of osteophytes, flattening, and sclerosis. The radiographic alterations did not correlate with the patients' symptoms. CONCLUSIONS: The results of this long-term follow-up after unilateral discectomy support the use of this operation in patients with painful internal derangement who show no improvement after prior nonsurgical treatment. The postoperative radiographic alterations should be interpreted as adaptive changes rather than progressive degenerative joint disease.

Ortho cubic super-high resolution computed tomography: a new radiographic technique with application to the temporomandibular joint.

OBJECTIVE: The purpose of this study was to present a newly developed ortho cubic super-high resolution computerized radiographic technique (Ortho-CT) and its application to the temporomandibular joint. METHOD AND PATIENTS: A prototype was assembled on a Scanora (Soredex Findent Co) with the use of a 4-inch image intensifier instead of film. Data were collected from a single 360 degrees scan and a cylinder 32 mm in height and 38 mm in diameter. Images were reconstructed with a software program on a personal computer. Imaging data consisted of 240 (height) x 280 (diameter) cubic voxels, each with a dimension of 0.136 mm. With this small voxel size, the image resolution was high and was the same in any direction. Three patients with temporomandibular joint disease (trauma, pain and dysfunction, fibroosseous ankylosis) were evaluated with Ortho-CT, and the images were compared to routine radiographic films. CONCLUSION: Preliminary clinical experience with Ortho-CT demonstrates subjectively superior image quality compared to panoramic and conventional tomographic images. The images were similar to conventional computed tomography, but this new radiographic technique is less expensive, takes less space, and gives a lesser patient dose.

Thickening of the glenoid fossa in osteoarthritis of the temporomandibular joint. An autopsy study.

OBJECTIVE: To evaluate the thickness of the roof of the glenoid fossa of the temporomandibular joint (TMJ) in relationship to the stage of internal derangement from autopsy material. MATERIAL AND METHODS: The minimum thickness of the roof of the glenoid fossa was measured with a caliper in 61 TMJ autopsy specimens. Based on macroscopic examination the joints were categorized as normal (30 joints), disk displacement (eight joints), disk displacement with osteoarthritis (12 joints) and osteoarthritis with perforation of the disk or posterior attachment (11 joints). The relationship between thickness of roof of the glenoid fossa and status of the joint was analysed. RESULTS: The roof of the glenoid fossa was on the average 0.6 mm in normal joints, 1.1 mm in joints both with disk displacement and disk displacement with osteoarthritis and 2.6 mm in joints with osteoarthritis and perforation. The difference between the normal joints and those with perforation was significant (P<0.01). CONCLUSION: Progressive remodeling with thickening of the roof of the glenoid fossa seems to be associated with perforation of the disk or posterior attachment.

The association of temporomandibular joint pain with abnormal bone marrow in the mandibular condyle.

PURPOSE: This study investigated the association between temporomandibular joint pain and bone marrow alterations in the mandibular condyle seen on magnetic resonance (MR) images. PATIENTS AND METHODS: The study was based on 112 temporomandibular joints in 112 patients with disc displacement without reduction. Thirty-four patients with abnormal bone marrow on MR images were compared with a control group of 78 patients with normal bone marrow. The analysis was based on proton density and T2-weighted MR images in the oblique sagittal and coronal planes. The degree of pain was correlated to the status of the bone marrow using statistical methods. RESULTS: The degree of pain in joints with abnormal bone marrow was higher than in joints with normal bone marrow signal on MR images (P = .0045). CONCLUSION: Because the stage of internal derangement was similar in both groups, more intensive pain appears to be associated with bone marrow alterations.

Decreased disk-eminence ratio is associated with advanced stages of temporomandibular joint internal derangement.

OBJECTIVE: To examine the possible correlation between the stage of internal derangement and the antero-posterior length of the disk in relation to the length of the articular eminence. STUDY DESIGN: Twenty asymptomatic volunteers with normal joints and 120 patients with TMJ dysfunction underwent MR imaging. The A-P length of the disk in relation to the length of the articular eminence (D/E ratio) was measured. RESULTS: The D/E ratio was 0.95 in the asymptomatic volunteers, 0.83 in patients with disk displacement with reduction, 0.74 in those with disk displacement without reduction and 0.57 in the patients with disk displacement and osteoarthritis. The relationship between the D/E ratio and the stage of internal derangement was statistically significant (P<0.01). CONCLUSION: The D/E ratio decreases with advancing internal derangement. We suggest that it is a reliable numerical method for staging the degree of the internal derangement.

Osteonecrosis of the temporomandibular joint: correlation of magnetic resonance imaging and histology.

PURPOSE: The aims of this study were to investigate whether osteonecrosis affects the mandibular condyle and to determine whether this condition could be diagnosed with magnetic resonance imaging (MRI). MATERIALS AND METHODS: The study was based on 50 temporomandibular joints in 44 patients in whom MRI and surgery were performed for painful internal derangements. At the time of surgery, a core biopsy specimen was obtained from the marrow of the mandibular condyles, and the histological observations were correlated to T1-(proton density) and T2-weighted MR images. RESULTS: Histological evidence of osteonecrosis was found in nine joints (18%). Bone marrow edema, which may be a precursor of osteonecrosis, was found in nine other joints. The MRI was 78% sensitive and 84% specific for the diagnosis of osteonecrosis of the mandibular condyle. However, the positive predictive value was only 54% because of a number of false-positive MRI diagnoses. CONCLUSION: Osteonecrosis can affect the mandibular condyle, and this condition can be diagnosed with MRI. A combination of edema and sclerosis of the bone marrow was the most reliable MRI sign of osteonecrosis. The cause, its clinical significance, and the need for treatment are unknown.