Distinction of well-differentiated liposarcoma from lipoma in two patients with multiple well-differentiated fatty masses.

This case report describes the features of gadolinium-enhanced MRI in well-differentiated liposarcoma with histologic correlation and addresses the usefulness of this imaging technique in distinguishing well-differentiated liposarcoma from lipoma. Gadolinium-enhanced MRI revealed significantly enhanced signal in well-differentiated liposarcoma in a background of multiple well-differentiated benign fatty masses by showing the increased vascularity in the septa of well-differentiated liposarcoma. Although such signal enhancement can be seen in some types of benign lipomatous tumors with increased blood vessels, this technique is helpful in selection of biopsy site, especially in a clinical setting of multiple fatty masses.

Radiation doses to patients undergoing scoliosis radiography.

In this study we computed the radiation doses associated with scoliosis radiography and investigated how these radiation doses are influenced by the weight of the patient. We recorded the radiographic technique factors of 61 consecutive patients (46 females and 15 males) undergoing scoliosis radiography. A wedge-shaped aluminium filter attenuated the X-ray beam in the "chest region" relative to the "abdomen region". X-ray tube air kerma output factors (microGy mAs-1) and half value layers (HVLs) were determined experimentally for the "chest region" and "abdomen region". The energy imparted to each patient was computed from the air kerma area product, X-ray beam HVL and measured patient thickness. Values of patient effective dose were obtained using effective dose-to-energy conversion factors for specified radiographic projections, taking into account each patient's weight. The median patient age was 17 years, and the median patient weight was 53 kg. Entrance skin air kerma values in the "chest region" were approximately a factor of four lower than those in the "abdomen region". The air kerma values increased by a factor of two when the patient weight increased from 30 kg to 70 kg. Approximately 80% of the total energy imparted to a patient undergoing a scoliosis examination was in the "abdomen region", with the remaining 20% imparted to the "chest region". Energy imparted increased with patient weight, and was approximately 3 mJ for a 30 kg patient and approximately 8 mJ for a 70 kg adult patient. Effective doses showed little correlation with patient weight, with an average-sized patient (50 kg) receiving an effective dose of approximately 140 microSv. Patients undergoing scoliosis radiography receive effective doses that are low in comparison with other types of radiographic examination.

Cervical flexion, extension, protrusion, and retraction. A radiographic segmental analysis.

STUDY DESIGN: A lateral radiographic analysis of the cervical spine was performed on 20 asymptomatic volunteers. OBJECTIVES: To quantify the contribution of each cervical segment to each of four sagittal cervical end-range positions: full-length flexion, full-length extension, protrusion, and retraction. SUMMARY OF BACKGROUND DATA: Recent clinical research supports the relevance of cervical protrusion and retraction in symptomatic patients. Currently, few quantitative studies are available regarding cervical protrusion and retraction. METHODS: Lateral cervical radiographs of 20 asymptomatic volunteers for four test positions and a neutral position were collected. Mean angular measurements and available ranges of motion were calculated from the occiput to C7. RESULTS: Retraction consists of lower cervical extension and upper cervical flexion, whereas protrusion consists of lower cervical flexion and upper cervical extension. Full-length cervical flexion produced more flexion at lower segments than did protrusion, and full-length cervical extension produced more extension at lower segments than did retraction. With both full-length flexion and retraction, upper cervical segments are positioned in the flexion portion of their total range, but only retraction takes Occ-C1 and C1-C2 to their full end-range of flexion. Similarly, with both full-length extension and protrusion, upper cervical segments are positioned in the extension portion of their total range, but only protrusion takes Occ-C1 and C1-C2 to their end-range of extension. CONCLUSION: A greater range of motion at Occ-C1 and C1-C2 was found for the protruded and retracted positions compared with the full-length flexion and full-length extension positions. Effects on cervical symptoms reported to occur in response to flexion, extension, protrusion, and retraction test movements may correspond with the position of lower cervical segments.

Cervical sagittal range-of-motion analysis using three methods. Cervical range-of-motion device, 3space, and radiography.

STUDY DESIGN: Cervical flexion, extension, protrusion, and retraction were comparatively measured in volunteers using a cervical range-of-motion device (Performance Attainment Associates, Roseville, MN), a 3space system (Polhemus, Colchester, VT), and lateral radiographs. OBJECTIVES: To compare the outcomes of three methods of measurement of cervical flexion, extension, protrusion, and retraction. SUMMARY OF BACKGROUND DATA: Few studies compare cervical range-of-motion measurement devices with radiographic measurements, and no studies have compared methods of measurement for cervical protrusion and retraction measurement. METHODS: In 20 asymptomatic volunteers, four end-range sagittal cervical positions (flexion, extension, protrusion, and retraction) were measured simultaneously using a cervical range-of-motion device, a 3Space and lateral cervical radiographs. Measurements were compared, and differences were analyzed. RESULTS: There were no significant differences for flexion and extension measurements between the cervical range-of-motion device and that radiographic angle determined by an occipital line and the vertical, nor were there any between the 3Space and that radiographic angle between this same occipital line and C7. The cervical range-of-motion device and the 3Space measurements for flexion and extension, however, differed significantly from one another (P < 0.05). For protrusion and retraction, there was no significant difference between the 3Space and radiographic measurements, but these two both differed significantly from the cervical range-of-motion device (P < 0.05). CONCLUSIONS: Available methods of measurement differ as to whether the cervical spine is isolated or includes upper thoracic motion. Protrusion and retraction can be measured reliably with all three methods studied, but without measurement consistency between devices. Because end-range cervical flexion and extension-cannot occur in isolation from upper thoracic motion, true cervical motion can be measured only with an internally referenced, or landmark-based, methodology such as the 3Space. Even though the cervical range-of-motion device cannot measure isolated cervical flexion and extension, it is nevertheless a reliable clinical tool in measuring flexion and extension as well as protrusion and retraction as long as patient thoracic positioning is standardized to minimize the upper thoracic contribution.