Orbital decompression: postoperative computed tomography

Orbital decompression is an excellent surgical procedure to relieve acute increased intraorbital pressure. The most commonly used approach is via a Caldwell-Luc incision. Far less often a lateral orbitotomy is used. The postoperative CT findings of these procedures are described. It is important to recognize these changes so that they are not mistaken for primary sinus and orbital lesions.     

Orbital histiocytosis on computed tomography

Computed tomography (CT) findings in two patients with orbital histiocytosis are described. The main features are (a) replacement of bone by soft tissue, which has an absorption value of approximately 40 Hounsfield units (HU) and is not contrast-medium enhanced; (b) bone expansion at the rim of the lesion; (c) a large intraosseous component and a small extraosseous part; and (d) absence of calcification or periosteal reaction.     

Orbital trauma evaluation by computed tomography

Computed tomographic scans are useful for the evaluation of orbital trauma because they provide visualization of fractures, soft tissue damage, and embedded foreign bodies. Six cases are presented to demonstrate the usefulness of these studies in the evaluation of patients with a variety of injuries. By using both coronal and axial computed tomographic scans, orbital details can be studied with three-dimensional accuracy.     

Finger fractures imaging: accuracy of cone-beam computed tomography and multislice computed tomography

Objective  

To compare the diagnostic accuracy and radiation exposure of cone beam computed tomography (CBCT) and multislice computed tomography (MSCT) in the evaluation of finger fractures.     

Orbital computed tomography: calcific densities of the posterior globe.

Computed tomography's (CT) marked sensitivity to calcium increases its usefulness in the workup of certain ocular lesions. The CT findings in five calcific ocular lesions are described. The relatively limited differential diagnosis of such a finding is discussed.     

Multiplanar computed tomography of acetabular fractures

Following plain radiographic examination CT with multiplanar reformatting (CT/MPR) was used to assess 34 patients with pelvic trauma and definite (24 patients) or clinically suspected (10 patients) fractures. Computed tomography/MPR detected four fractures missed on conventional radiography. The findings on CT/MPR led to major alterations of patient management in seven cases. In four patients in whom the initial decision had been to use closed management with traction, information derived from CT/MPR led to open surgical reduction. In three patients in whom the initial impression had been that open management was dictated, CT/MPR contributed anatomical information that reserved that decision, leading to more conservative management. In all patients going to surgery the surgeons believed that surgical planning and execution had been significantly affected by the information provided by CT/MPR. Computed tomography/MPR was used postoperatively in 10 patients to confirm the status of reduction and fixation and to evaluate patients with unusual problems in the recovery period.     

Orbital metastasis: role of magnetic resonance imaging and computed tomography

Imaging of ocular and oral metastasis with CT and MRI is discussed. The relative advantages and disadvantages of the two techniques are presented. MRI seems to be particularly useful in discriminating intraocular tumor from retinal detachment. Both techniques depict orbital lesions well.     

X-ray computed tomography in fractures of the acetabulum

Radiographic assessment of these fractures remains difficult. Conventional techniques according to Letournel show the lesions but not to the best advantage, for instance the "congruency" of femoral head with acetabulum. 54 CT scan were performed (1982-1984) every time a doubt was persisting. Incarcerations of fragments, impactions of the acetabulum, sacro-iliac joint disjunctions, congruency and lesions of femoral head are much better seen with scanner. In planing the surgical therapy (or orthopedic), CT scan add a great deal to the information and dramatically improves the results.     

The diagnosis of hypertensive intracerebral hemorrhage: the contribution of computed tomography

Sixty-eight cases of hypertensive intracerebral hemorrhage were reviewed and the CT scans studied. The CT scan was accurate in localizing and measuring intracerebral hemorrhage. There were three cases of pontine hemorrhage which did not appear on the CT scan. Hemorrhages at other sites were always seen on the CT scan. The size of putaminal and thalamic hemorrhage as calculated from CT scan allowed accurate prognosis to be made at the onset. CT scanning has become the diagnostic test or first choice when intracerebral hemorrhage is suspected.     

Orbital tumors in children. Characterization by computed tomography

CT characteristics of orbital masses in 39 children were reviewed. Histological types and their relative frequencies differed considerably from reported adult cases. Analysis of seven separate CT characteristics for each type of mass indicated certain trends which may aid in the differential diagnosis.     

Orbital multiple myeloma: case report and review of computed tomography features

Orbital involvement at diagnosis in multiple myeloma is rare. Only a few a cases are reported with computed tomographic features. We report a case of orbital myeloma, and relevant medical reviews on computed tomography features are discussed.     

Multidetector computed tomography in acute joint fractures

Conventional radiography plays an essential diagnostic role in the primary evaluation of acute joint trauma. In complex fractures, however, computed tomography (CT) is an imaging modality often used second to radiography. As a result of technical breakthroughs in the field, multidetector CT (MDCT) allows faster imaging and better temporal, spatial, and contrast resolution compared with conventional single-slice spiral CT. MDCT with multiplanar reformation is helpful in disclosing fracture patterns, particularly in complex joint fractures, where they reveal occult fractures and show the exact number of fracture components and their degree of displacement.     

Under-reporting of osteoporotic vertebral fractures on computed tomography

Purpose

Osteoporotic vertebral fractures are frequently asymptomatic. They are often not diagnosed clinically or radiologically. Despite this, prevalent osteoporotic vertebral fractures predict future osteoporotic fractures and are associated with increased mortality and morbidity. Appropriate management of osteoporosis can reduce future fracture risk. Fractures on lateral chest radiographs taken for other conditions are frequently overlooked by radiologists. Our aim was to assess the value of computed tomography (CT) in the diagnosis of vertebral fracture and identify the frequency with which significant fractures are missed.

Materials and methods

The thoracic CT scans of 100 consecutive male and 100 consecutive female patients over 55 years were reviewed. CT images were acquired on General Electric Lightspeed multi-detector (MD) CT scanners (16 or 32 row) using 1.25 mm slice thickness. Midline sagittal images were reconstructed from the 3D volume images. The presence of moderate (25–40% height loss) or severe (>40% height loss) vertebral fractures between T1 and L1 was determined using an established semi-quantitative method and confirmed by morphological measurement. Results were compared with the formal CT report.

Results

Scans of 192 patients were analysed (95 female; 97 male); mean age 70.1 years. Thirty-eight (19.8%) patients had one or more moderate to severe vertebral fractures. Only 5 (13%) were correctly reported as having osteoporotic fractures in the official report. The sensitivity of axial CT images to vertebral fracture was 0.35.

Conclusion

Incidental osteoporotic vertebral fractures are under-reported on CT. The sensitivity of axial images in detecting these fractures is poor. Sagittal reformations are strongly recommended to improve the detection rate.     

Multidetector computed tomography of pediatric lateral condylar fractures

OBJECTIVE: The objective of this study was to compare lateral condylar fracture characterization using radiographs and multidetector computed tomography (MDCT) of the elbow and to evaluate outcomes in a group of children managed based on MDCT findings. METHODS: Unenhanced MDCT of the elbow with sagittal and coronal reformations was prospectively performed without sedation in 10 children between 1 and 16 years of age with lateral condylar fractures identified on frontal and lateral radiographs of the elbow. Two blinded readers reviewed all radiographs and MDCT images independently and in consensus. For the radiographs and MDCT images, readers graded the displacement of the lateral condyle fracture fragment and classified the fractures according to the Milch classification. Articular and epiphyseal cartilage integrity was assessed on MDCT. Patients were managed based on the consensus interpretation of the MDCT study. The frequency of interobserver agreement, discordant grading of fracture displacement and fracture classification between radiographs and MDCT images, and altered management based on the MDCT findings were determined. RESULTS: Individual readers agreed on fracture displacement in 9 patients (90%) on radiographs and in all 10 patients (100%) on MDCT. Individual readers agreed on fracture classification in 4 patients (40%) on radiographs and in 9 patients (90%) on MDCT. In 4 patients (40%), grading of fracture displacement differed between the consensus interpretation of the radiographs and MDCT images. In 6 patients (60%), fracture classification differed between the consensus interpretation of the radiographs and MDCT images. All 3 patients with fracture displacement greater than 5 mm and 1 patient with fracture displacement between 2 and 5 mm demonstrated disruption of the articular and epiphyseal cartilage on MDCT. Two patients (20%) with fracture displacement near the surgical threshold of 2 mm had altered management based on the MDCT findings. All patients progressed to complete fracture healing, with no delayed displacement or other complications. CONCLUSIONS: Multidetector computed tomography is a highly reproducible means of characterizing pediatric lateral condylar fractures and frequently demonstrates disruption of the epiphyseal and articular cartilage in patients with fracture displacement greater than 2 mm. The findings of MDCT may lead to altered treatment in patients with fracture displacement near the surgical threshold of 2 mm.