A Novel Vector-Based Computer Tomography Alignment Measurement Protocol for Total Knee Arthroplasty.

Introduction: Component position and overall limb alignment following total knee arthroplasty (TKA) have been shown to influence implant survivorships and clinical outcomes. While most surgeons utilize standard x-ray imaging for preoperative joint assessments, computer tomography scans (CT), coupled with automated digital analyses have been shown to provide additional surgical and clinical benefits. However, to date, a postoperative CT measurement protocol has not been reported for robotic-arm assisted TKA (RATKA).

CT of the hip prosthesis: appearance of components, fixation, and complications.

Multidetector computed tomography (CT) is an excellent way to supplement the radiographic evaluation of problematic hip prostheses. Multidetector CT is well suited for assessing periprosthetic bone, determining precise acetabular cup position, and evaluating periprosthetic fluid collections or ossified masses. Metal implants pose a number of challenges in the performance and interpretation of CT examinations.

Normal tibiofibular relationships at the syndesmosis on axial CT imaging.

Objectives: Computed tomography (CT) is reported to be superior to plain radiography for imaging the syndesmosis, but CT criteria differentiating normal from abnormal tibiofibular relationships do not exist. The purpose of this study was to define normal tibiofibular relationships at the syndesmosis on axial CT imaging and to report the reliability of these measurements.

Methods: Thirty healthy volunteers underwent CT evaluation of bilateral ankles.

Total hip arthroplasty in patients with bone deficiency of the acetabulum.

Total hip replacement (THR) requires revision in only a minority of cases (approximately 17% of prosthetic hips fail), but when THR failures occur there may be significant acetabular bone deficiency. There is a variety of surgical hardware and strategies available to address this problem. The causes of primary THR revision include aseptic loosening or particle disease, infection, recurrent dislocation, implant failure, periprosthetic fracture, and leg length discrepancy.

Routine isotropic computed tomography scanning of chest: value of coronal and sagittal reformations.

Objective: We sought to evaluate the usefulness of coronal and sagittal reformations from isotropic chest computed tomography (CT) examinations.

Methods: A total of 30 chest CT examinations were reconstructed into 2 sets of axial source images: 0.9-mm slice width with 0.

Multichannel CT: evaluating the spine in postoperative patients with orthopedic hardware.

Evaluating the spine in patients with metal orthopedic hardware is challenging. Although the effectiveness of conventional computed tomography (CT) can be limited by severe beam-hardening artifacts, the evolution of multichannel CT in recent years has made available new techniques that can help minimize these artifacts. Multichannel CT allows faster scanning times, resulting in reduced motion artifacts; thinner sections, with which it is possible to create a scanned volume of isotropic voxels with equivalent image resolution in all planes; and the generation of a higher x-ray tube current, which may result in better penetration of metal hardware and reduction of artifacts.

Multichannel CT Imaging of Orthopedic Hardware and Implants.

The introduction of multichannel CT scanners provides both radiologists and surgeons with a new tool to image patients with orthopedic hardware. The key parameters that have made it possible to image the implants and the surrounding bone with multichannel CT are the higher available technical factors (kVp and mAs) coupled with the ability to acquire thin slices over a large scan region. These properties make it possible to produce high-quality multiplanar reformations that facilitate visualization of the orthopedic device and the surrounding bone.

Three-dimensional volume rendering of the tendons of the ankle and foot.

Three-dimensional (3D) rendering is the process of creating two-dimensional (2D) images that convey the 3D relationships of an object or objects. In the past 10 years, the use of volume-rendering (VR) images has become a commonly used method of 3D display. The improved data sets that result from spiral and multidetector computed tomography, improved software, and more powerful workstations significantly improve radiologists' ability to create these images.

CT with 3D rendering of the tendons of the foot and ankle: technique, normal anatomy, and disease.

Three-dimensional rendering of computed tomographic data with volume rendering (VR), shaded surface display (SSD), and maximum intensity projection has been performed for over 20 years. In the foot and ankle, no one image reformatting technique is satisfactory for displaying every anatomic relationship or disease process. Two-dimensional multiplanar reformatted (MPR) images are the basic images used for diagnosis.