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Biomedical subjects

Georges Y El-Khoury

Publications and source records attributed to Georges Y El-Khoury.

17 recordsLinked to original sources

Peroneal tendon subluxation and dislocation: detection on volume-rendered images--initial experience.

Institutional review board approval was received and informed consent was not required for this Health Insurance Portability and Accountability Act-compliant study. The purpose of this study was to retrospectively assess the time efficiency of three-dimensional volume-rendered images obtained from multi-detector row computed tomographic data for the diagnosis of peroneal tendon subluxation or dislocation by using the consensus interpretation of multiplanar reformatted (MPR) images as the reference standard. The reference standard was provided by two musculoskeletal radiologists, and two less experienced readers evaluated 37 images in 32 patients (24 men, eight women; mean age, 41 years; age range, 18-75 years) with acute calcaneal fractures. An analysis of variance was used to compare interpretation time, and the Wilcoxon signed rank test was used to analyze diagnostic difficulty. The average time required for diagnosis was significantly shorter with volume-rendered images than with MPR images (reader 1: 42 vs 78 seconds, P<.001; reader 2: 50 vs 69 seconds, P<.01).

Adolescent↗

Imaging of cervical spine injuries of childhood.

Cervical spine injuries of children, though rare, have a high morbidity and mortality. The pediatric cervical spine is anatomically and biomechanically different from that of adults. Hence, the type, level and outcome of cervical spine injuries in children are different from those seen in adults. Normal developmental variants seen in children can make evaluation of the pediatric cervical spine challenging. This article reviews the epidemiology of pediatric cervical spine trauma, normal variants seen in children and specific injuries that are more common in the pediatric population. We also propose an evidence-based imaging protocol to avoid unnecessary imaging studies and minimize radiation exposure in children.

Adolescent↗

Interobserver agreement for Letournel acetabular fracture classification with multidetector CT: are standard Judet radiographs necessary?

PURPOSE: To retrospectively evaluate interobserver agreement for Letournel acetabular fracture classification with radiography alone and multidetector computed tomography (CT) alone and to retrospectively assess whether standard Judet views lead to a change in the classification. MATERIALS AND METHODS: Institutional review board approval was obtained; informed consent was not required for this HIPAA-compliant study, which included 101 imaging studies performed in 99 patients (78 male, 21 female; mean age, 43 years; age range, 15-86 years) with acetabular fractures. Two musculoskeletal radiologists independently classified the fractures with radiography alone and multidetector CT alone. Multiplanar reformatted and three-dimensional (3D) CT images were reviewed at a computer workstation. Readers were shown radiographs at the end of multidetector CT image reading to see if this would change the multidetector CT-based classification. kappa Values were calculated to assess interobserver agreement. For surgically treated patients, the McNemar test was used to compare the accuracy of readers' classifications. The reference standard was a combination of preoperative radiographic and multidetector CT image findings and intraoperative findings. RESULTS: Interobserver agreement was moderate (kappa = 0.42) with radiography and substantial (kappa = 0.70) with multidetector CT. Multidetector CT classification was changed in two cases (one case for each reader) after standard Judet views were added. In 73 surgically treated patients, agreement with the surgeons' classification was higher with multidetector CT than with radiography (P < .01 for one reader, P = .06 for the other reader). CONCLUSION: There is substantial interobserver agreement for Letournel acetabular fracture classification with multiplanar reformatted and 3D multidetector CT images. Standard Judet pelvic radiographs add little information for changing the multidetector CT classification.

Acetabulum↗

MDCT in the evaluation of skeletal trauma: principles, protocols, and clinical applications.

Multidetector computed tomography (MDCT) scanners have made volume imaging possible and are used extensively to study polytrauma patients, especially in the evaluation of the spine and peripheral skeleton. An MDCT scanner coupled with a modern workstation has become an essential diagnostic tool for any emergency department. Familiarity with the basic physical principles of MDCT such as projection data, section collimation, and beam collimation is important to achieve high-quality imaging while keeping unnecessary radiation to a minimum. After a polytrauma MDCT examination, images can be reconstructed to obtain different slice thickness, slice interval, fields of view, or reconstruction kernels. No additional scanning is needed for imaging the thoracolumbar spine or bony pelvis. High-quality multiplanar reformation (MPR) and three-dimensional (3-D) images can be created at the workstation using the volumetric data. However, MDCT is a high-dose examination, and care should be taken to use as low a dose as possible. In the musculoskeletal system, MDCT has long been used for evaluation of spinal and pelvic trauma; however, the frequency of its use in extremity trauma has been low. In the extremities, radiography seems to underestimate the extent and severity of injury, especially in complex areas such as the shoulder, elbow, wrist, knee, and ankle. MDCT in the extremities is helpful in fracture detection, evaluation, characterization, and treatment planning. The MPR images give excellent structural detail, and the 3-D images help in understanding the spatial relations, which is important for fracture classification and for preoperative planning. MDCT is also helpful in the follow-up of postoperative results, even in the presence of hardware. Tendon injuries can also be evaluated with MDCT.

Artificial Intelligence↗

Axial loading with hyperflexion injury to the atlas resulting in crushed lateral masses.

A 40-year-old man was involved in an ATV accident, in which he landed on the top of his head. There was no neurological deficit. A plain radiograph showed prevertebral soft tissue swelling at the atlas and axis level. Computed tomography (CT) demonstrated vertical fractures of the anterior aspects of both lateral masses of the atlas, extending to the junction of the lateral mass with the anterior arch bilaterally. There was no lateral offset of the lateral masses. The mechanism of injury is believed to be axial loading along with hyperflexion.

Accidents↗

Osteoblastomatosis of bone. A benign, multifocal osteoblastic lesion, distinct from osteoid osteoma and osteoblastoma, radiologically simulating a vascular tumor.

Two adult patients are described with multifocal osteolytic lesions radiologically simulating a vascular tumor. One patient had multiple bones involved. Histologically, the individual lesions had the features of the nidus of osteoid osteoma/osteoblastoma. A review of the English language medical literature yielded only one other reported case with similar features. The process is designated as osteoblastomatosis to indicate its bone-forming character, prominent osteoblast proliferation, and multiplicity. The cases are distinguished from multifocal/multicentric osteoid osteoma and osteoblastoma, and from benign and malignant vascular tumors.

Adult↗

Horizontal fracture of the anterior arch of the atlas associated with a congenital cleft of the anterior arch.

We report a rare combination of a horizontal fracture of the anterior arch of the atlas associated with a congenital cleft of the anterior arch. Sagittally reformatted computed tomography (CT) images demonstrated a fracture of the anterior arch of the atlas and a type II odontoid process fracture. There was also a smoothly marginated midline cleft of the anterior arch just above the fracture consistent with a congenital variant. 3D CT images were helpful in the evaluation of the fractures and the developmental variant. Magnetic resonance imaging showed a spinal cord injury. The patient underwent posterior C1-C2 fusion.

Accidental Falls↗

Acute traumatic spinal epidural hematoma: imaging and neurologic outcome.

The purpose of this study was to present MRI characteristics of traumatic spinal epidural hematomas (TSEHs) and to evaluate their effect on neurologic outcome. A retrospective analysis was performed of all 74 cases in which patients underwent emergent spinal MRI in the setting of acute trauma at our institution's Emergency Department between June 2002 and January 2003. MRI studies were evaluated for the presence of a TSEH. CT studies were evaluated for the presence of osseous trauma. Patient data were collected from medical records on the initial neurologic status at admission and at 6 months after injury. Twenty-seven of 74 patients had a spinal fracture and a TSEH. Twenty-five of 74 patients had a spinal fracture with no TSEH. Twenty-two of 74 patients had normal imaging studies. Six-month follow-up of neurologic status demonstrated no statistically significant difference in neurologic outcome between patients with spinal fractures and TSEH and those with spinal fractures but no TSEH. If a spinal fracture and abnormal neurologic exam are present, the neurologic outcome at 6 months is not worsened by the presence of a TSEH.

Adult↗

Orthopedic hardware complications diagnosed with multi-detector row CT.

PURPOSE: To retrospectively evaluate multi-detector row computed tomography (CT) for the depiction of orthopedic hardware complications in the spine and appendicular skeleton. MATERIALS AND METHODS: This HIPAA-compliant study had institutional review board approval; patient informed consent was not required. Results of 114 multi-detector row CT studies performed because of possible hardware complications in 109 patients (57 men, 52 women; mean age, 44 years; age range, 12-82 years) were available for analysis. The CT studies were retrospectively reviewed and compared with clinical or surgical outcomes, which were used as the reference standard. In another experiment, detection of hardware complications on radiographs and multi-detector row CT images was compared between two readers for selected cases (18 positive and 26 negative) by using receiver operating characteristic (ROC) methods. RESULTS: For 91 (80%) of 114 multi-detector row CT studies, the complication status could be determined on the basis of clinical or surgical outcomes. Twenty-three multi-detector row CT studies were confirmed to be positive (revealing 10 cases of nonunion, five cases of hardware malplacement, three cases of hardware loosening, three perihardware fractures, and two chronic infections), and 57 were confirmed to be negative. There were three false-positive and eight false-negative multi-detector row CT studies. With clinical or surgical outcomes as the reference standard, the sensitivity, specificity, and positive and negative predictive values of multi-detector row CT were 74% (23 of 31 studies), 95% (57 of 60 studies), 88% (23 of 26 studies), and 88% (57 of 65 studies), respectively. Results of ROC analysis indicated that detection of hardware complications was much lower with radiography than with multi-detector row CT (area under ROC curve, 0.84 vs 1.00; F = 4.69, df = 1, 43; P < .05). CONCLUSION: Multi-detector row CT is an effective tool for depicting orthopedic hardware complications.

Adolescent↗

Patellar fractures after total knee replacement.

OBJECTIVE: The objective of our study was to describe the patterns of patellar fracture after total knee replacement and assess their clinical significance. MATERIALS AND METHODS: A retrospective review of patellar fractures after total knee replacement was performed. Seventeen cases were identified over a 10-year period. Radiographs, radiology reports, medical records, and operative notes were reviewed and analyzed. The clinical analysis included the time to fracture, the patient's symptoms and signs, whether the extensor mechanism was disrupted, and the treatment administered for the fracture. The radiographic analysis included fracture pattern, displacement, patellar position, presence of patellar osteonecrosis, and presence of soft-tissue abnormality. RESULTS: The incidence of patellar fractures after total knee replacement was 1.14%. The mean time from total knee replacement to patellar fracture was 17.5 months. Nine fractures were asymptomatic and identified on routine follow-up radiographs. The patterns of fracture were diverse: Transverse (n = 6), comminuted (n = 2), vertical (n = 5), and avulsion (n =4) fractures were seen. Thirteen fractures were displaced. Patellar osteonecrosis was suspected in four fractures, and three fractures were associated with disruption of the quadriceps tendons. Thirteen fractures were treated nonoperatively, and four were treated surgically. CONCLUSION: Patellar fractures are an uncommon, but important, complication after total knee replacement. Radiologists should be familiar with the imaging features of these fractures and their clinical significance.

Aged↗

Cartilage thickness in cadaveric ankles: measurement with double-contrast multi-detector row CT arthrography versus MR imaging.

PURPOSE: To test the accuracy of double-contrast multi-detector row computed tomographic (CT) arthrography for measurement of cartilage thickness in cadaveric ankles and to compare this technique with three-dimensional (3D) fat-suppressed spoiled gradient-echo in the steady state (FS-SPGR) magnetic resonance (MR) imaging. MATERIALS AND METHODS: Five cadaveric ankles were used. In the ankle specimens, five to nine 1.5-mm-diameter holes were drilled across the joint traversing the tibial subchondral bone, tibial articular cartilage, talar dome cartilage, and talar subchondral bone. The ankle specimens were obtained and used according to institutional policies. Each ankle specimen was imaged first by using 3D FS-SPGR MR imaging with a 1.5-T magnet and then by using double-contrast arthrography followed by CT with a four-detector row scanner (ie, double-contrast multi-detector row CT arthrography). The section thickness used for CT scanning was 1.0 mm reconstructed in 0.5-mm intervals. The MR and CT images obtained in the five specimens were then downloaded to a workstation, where a measurement tool was used to measure the cartilage thickness at each hole. The physical measurement of cartilage thickness at each hole was used as the reference standard with which the MR imaging and CT measurements were compared. Linear regression and correlation analyses were performed by using a statistical computer program. RESULTS: Double-contrast arthrography followed by multi-detector row CT, as compared with 3D FS-SPGR MR imaging, enabled more accurate measurement of the physical cartilage thickness in the ankle (P < .001). CONCLUSION: In this study of five cadaveric ankles, multi-detector row CT arthrography was more accurate than 3D FS-SPGR MR imaging for measurement of articular cartilage thickness in the ankle.

Adult↗

Ball-thrower's fracture of the humerus.

A relatively rare case of ball-thrower's fracture of the humerus is presented. Severe muscular action is an uncommon cause of humeral fractures but has been well documented in the orthopedic literature. To our knowledge, this fracture has not been described in the radiology literature, and awareness of this entity could preclude further unnecessary workup. The mechanism of injury and its typical radiographic appearance is described.

Adult↗

Spondyloarthropathies: ankylosing spondylitis and psoriatic arthritis.

As advances in the treatment of ankylosing spondylitis continue, TNF-alpha blocking agents may eventually be used as a first-line treatment. MR imaging could then be used to aid in the early diagnosis of ankylosing spondylitis by identifying early sacroiliitis, followed by immediate initiation of treatment to prevent the progression of the disease with its accompanying morbidities. Currently, radiographic identification of sacroiliitis remains the mainstay in diagnosing ankylosing spondylitis. In ankylosing spondylitis and psoriasis, MR imaging can demonstrate areas that are undergoing active inflammatory changes and enthesitis, aiding in the diagnosis of a spondyloarthropathy.

Adult↗

Anterior rim tibial plateau fractures and posterolateral corner knee injury.

The aim of this study was to review MRI findings of clinically suspected posterolateral corner knee injuries and their associated internal derangements. Sixteen knees in 15 patients who had evidence of a posterolateral corner knee injury on the physical exam underwent MRI to evaluate the posterolateral corner of the knee and to look for associated injuries. Two musculoskeletal radiologists reviewed the scans. Surgery was performed on 10 of the knees. Tibial plateau fractures were present in 6 knees; 5 of the fractures were anteromedial rim tibial plateau fractures. The popliteus muscle was injured in 13 knees and the biceps femoris in 6 knees. The lateral collateral ligament was ruptured in 12 knees. The posterior cruciate ligament was completely ruptured in 7 knees and avulsed from its tibial attachment in 1 knee. Eleven knees had a complete anterior cruciate ligament rupture. The anterior cruciate ligament was edematous without complete disruption of all fibers in 3 knees. There was excellent correlation between the MRI results and operative results in regard to the presence of a posterolateral corner injury of the knee (9 of the 10 knees had a posterolateral corner injury). In our study MRI readily detected posterolateral corner injuries. Posterolateral corner injuries of the knee are frequently associated with a variety of significant injuries, including cruciate ligament tears, meniscus tears, and fractures. Fractures of the peripheral anteromedial tibial plateau are not common; however, given their relatively common occurrence in this study, they may be an indicator of a posterolateral corner injury to the knee.

Journal Article↗