Diagnosis of medial temporomandibular joint disc displacement with dual space anteroposterior arthrotomography: correlation with cryosectional morphology.

This study was undertaken to determine if it is possible to identify medial disc displacement with dual space anteroposterior (AP) arthrotomography. Contrast medium was injected into the upper and lower joint spaces of 11 fresh temporomandibular joint (TMJ) autopsy specimens and arthrotomograms were obtained with an AP projection. The arthrotomograms of five joints showed an enlargement of the medial recess of the upper joint compartment with folding of the disc inferiorly. This was interpreted as an indication of medial disc displacement. Cryosections confirmed medial displacement of the disc in these five joints and showed a slight medial displacement of a disc in one additional joint. Retrospective evaluation of the arthrotomogram of this joint showed that the disc was slightly medially displaced, but without folding. The results of this study suggest that AP dual space arthrotomography can be useful for the diagnosis of medial disc displacement in cadaver material.     

Temporomandibular joint sounds: correlation to joint structure in fresh autopsy specimens.

In an attempt to better understand the cause of different types of temporomandibular joint (TMJ) sounds, we recorded joint sounds from 27 fresh autopsy specimens, displayed the time frequency distribution of the sound as a three-dimensional graph, and correlated the sound character to morphologic observations at subsequent dissection. Eleven joints elicited sounds, and 16 joints were silent. All joints with sounds had different degrees of intraarticular changes. These ranged from disk displacement with reduction to displacement without reduction and arthrosis of the articular surfaces. Reciprocal clicking occurred both in joints with disk displacement with and without reduction, as well as in joints with arthrotic changes. Crepitation only occurred in joints with arthrosis and perforation. The sample was too small to demonstrate any statistically significant association between the joint sound classified as clicking or crepitation and joint structure types of joint pathosis in this small sample. A high frequency component to the sound appeared to be associated with arthrosis of the articular surfaces. It was concluded that joint sounds indicate joint abnormality but that the absence of joint sound does not exclude intraarticular pathosis.     

Portal and peripheral plasma folates after ingestion of folic acid.

Folic acid in amounts of 2 mumol (0.88 mg) was given by mouth to four patients who had undergone portal vein catheterization. All had normal liver function. The increase in folates in plasma obtained from portal and peripheral veins was followed for three hours with the use of L. casei and S. faecalis as test organisms. The results lend support to the assumption that the liver is the main site of methylation of folic acid when given in physiological amounts.     

The hydrolysis and absorption of conjugated folates in man.

After ingestion of synthetic PteGlu3 in physiological doses, the folate forms were studied in plasma obtained from human vena portae blood. Plasma conjugase was inhibited by rapid heat-denaturation. The folate forms were assayed with L. casei and S. faecalis and identified by thin-layer chromatography (biautography). Mono- and diglutamic folate was demonstrated in the portal plasma, indicating that intestinal hydrolysis precedes the absorption of conjugated folates. The pteroylpolyglutamate hydrolase activity in the human gastrointestinal tract was investigated. The activity was demonstrated in gastric juice, pancreatic juice, and intestinal mucosa. The highest activity was found in the pancreatic juice with a pH-optimum of 4.5. In gastric juice the pH-optimum for the enzyme was 3 and the activity half of that found in pancreatic juice. However, in view of the volumes of these fluids produced every day, the activity at physiological pH might be enough to hydrolyse the daily intake of conjugated folates in amounts of about 500 mug.     

Temporomandibular joint disk displacement: comparison in asymptomatic volunteers and patients

PURPOSE: To compare the prevalence and type of temporomandibular joint (TMJ) disk displacement in asymptomatic volunteers with those in patients. MATERIALS AND METHODS: Bilateral oblique sagittal and oblique coronal intermediate-weighted magnetic resonance (MR) images of the TMJs in 58 patients with pain and dysfunction were analyzed and compared with corresponding MR images of 62 asymptomatic volunteers. RESULTS: Forty-five (78%) of 58 patients had disk displacement compared with 22 (35%) of 62 asymptomatic volunteers. Complete disk displacement was found in 46 (40%) of 115 joints in patients compared with three (2.4%) of 124 joints in asymptomatic volunteers, whereas partial disk displacement occurred in 26 (22.6%) and 27 (21.8%) joints, respectively. Two types of complete disk displacement, anterolateral and anterior, occurred frequently in patients, seldom in volunteers. Only minor differences were found between other types of disk displacement when prevalence in patients was compared with that of volunteers. The disk reduced to a normal position on open-mouth images in all joints in the volunteers compared with 76% of the joints in patients. CONCLUSION: TMJ disk displacement was less prevalent and was of a different type in asymptomatic volunteers compared with patients with pain and dysfunction.     

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.     

Improved diagnosis of actively bleeding aneurysm on CT angiography using delayed CT images

Computed tomographic angiography (CTA) is being increasingly utilized in the non-invasive diagnosis of aneurysmal subarachnoid hemorrhage (SAH). There are emerging reports of diagnosis of active aneurysmal bleeding on CTA, furthering our understanding of imaging features of active extravasation on cross-sectional studies. We demonstrate imaging characteristics of two such cases of active contrast extravasation from intracranial aneurysms. Additionally, we demonstrate that delayed CT images greatly improve the confidence of this diagnosis by demonstrating pooling of contrast in the subarachnoid space. Prompt recognition and management can improve prognosis of this potentially lethal condition.     

Abstracts and Posters

Abstract

Context/objective

Radiation exposure from medical imaging is an important patient safety consideration; however, patient exposure guidelines and information on cumulative inpatient exposure are lacking.

Design/setting

Trauma patients undergo numerous imaging studies, and spinal imaging confers a high effective dose; therefore, we examined cumulative effective radiation dose in patients hospitalized with spinal trauma. We hypothesized that people with spinal cord injury (SCI) would have higher exposures than those with spine fractures due to injury severity.

Particpants/interventions

Retrospective data were compiled for all patients with spine injuries admitted to a level I trauma center over a 2-year period.

Outcome measures

Injury severity score (ISS) and cumulative radiation exposure were then determined for these patients, including 406 patients with spinal fractures and 59 patients with SCI.

Results

Cumulative effective dose was 45 millisieverts (mSv) in SCI patients, compared to 38 mSv in spinal fracture patients (P = 0.01). Exposure was higher in patients with an ISS over 16 (P = 0.001). Mean exposure in both groups far exceeded the European annual occupational exposure maximum of 20 mSv. More than one-third of patients with SCI exceeded the US occupational maximum of 50 mSv.

Conclusion

Patients with SCI had significantly higher radiation exposure and ISS than those with spine fracture, but the effective dose was globally high. Dose did not correlate with injury severity for patients with SCI. While the benefits of imaging are clear, radiation exposure does involve risk and we urge practitioners to consider cumulative exposure when ordering diagnostic tests.     

Temporomandibular joint: improved MR image quality with decreased section thickness.

To determine if the quality of spin-echo magnetic resonance (MR) images of the temporomandibular joint (TMJ) could be improved by reducing section thickness, coronal and sagittal 3.0- and 1.5-mm MR images of the same joints were evaluated. Depiction of the disk, trabecular pattern, and cortex of the condyle was better on coronal 1.5-mm images than on 3.0-mm images (P less than .01), and 1.5-mm sagittal images were better for depiction of the trabecular pattern of the condyle than were 3.0-mm images (P less than .05). The ability of MR imaging with thinner sections to reveal more anatomic details should result in improved diagnostic accuracy.     

Double-contrast arthrotomography of the temporomandibular joint: Introduction of an arthrographic technique for visualization of the disc and articular surfaces

A technique for double-contrast arthrotomography of the temporomandibular joint was developed. Iodine contrast medium and air were injected into both joint compartments of 105 patients. Lateral tomography using a multi-film cassette was performed. The double-contrast arthrotomography depicted, with good definition, the configuration and position of the disc, its attachments, and the articular surfaces. Postarthrographically, the patients experienced transient discomfort, but there were no serious complications. Double-contrast arthrotomography facilitates the diagnosis of internal derangements by improving the radiographic image of the intra-articular anatomy.