Fluoroscopy

Background.  Thermal treatment of the lumbar intervertebral disc has been suggested for the treatment of chronic discogenic pain. Disc biacuplasty (D-BAC) is a novel procedure that uses two water-cooled radiofrequency electrodes in a bipolar configuration to heat a large volume of the posterior annulus fibrosus.Methods.  Seven porcine lumbar discs were treated with D-BAC to assess acute effects on the treated tissue in a “worst-case”in vivo model. Intradiscal and peridiscal temperatures were measured during treatment and histologic analysis was used to assess for evidence of acute thermal injury.Results.  Temperature monitoring at designated safety zones outside the disc demonstrated maintenance of near-physiologic conditions while temperature in the inner posterior annulus reached 65°C. Histologic sections of treated discs demonstrated no evidence of thermal damage to the dorsal root ganglia or spinal nerve roots when compared with controls. Increased coarseness of the fibrillar matrix and loss of cellular detail were noted in the nucleus pulposus of treated discs.Discussion.  Disc biacuplasty, in a porcine model, achieves suitable temperatures to induce thermal transition of collagen and thermoneurolysis while showing no evidence of damage to neural tissue in safety zones surrounding the disc.

Knee range of motion was determined in 60 patients to assess the effect of weight bearing on maximal knee flexion. Three patient subgroups were investigated: patients with normal knees, patients implanted with posterior cruciate-retaining (PCR) total knee arthroplasty (TKA), and patients implanted with posterior cruciate-substituting (PS) TKA. Maximal knee flexion was determined using videofluoroscopy both in a passive, non-weight-bearing mode and during active weight bearing. Flexion was diminished with weight bearing in all three subgroups (P < .045). Patients with normal knees exhibited significantly greater knee flexion than either TKA subgroup when measured either with or without weight bearing (P < .001). Knee flexion of both TKA subgroups was similar when measured passively without weight bearing. Patients with PS TKA demonstrated greater flexion than patients with PCR TKA when measured in weight bearing (P < .025), despite having less range of motion and lower clinical performance ratings preoperatively. Measurement of knee range of motion in a weight-bearing fashion may be a superior method of assessment of functional capabilities.

A nonfluoroscopic temporomandibular joint arthrographic technique is contrasted with a more widely employed fluoroscopically guided technique. The nonfluoroscopic technique uses a posterior approach to joint injection, as contrasted with the lateral injection approach of the fluoroscopically guided technique. The advantages of the nonfluoroscopic technique are less radiation dose to the patient, less expensive and less sophisticated imaging equipment, and less potential for neurovascular trauma. The fluoroscopic technique offers greater control of the procedure, less patient and operator time, and the capability for a dynamic videofluoroscopic study. Both techniques appear to be safe and efficacious. Differences in anatomy, imaging modalities, patient radiation exposure, and potential complications are also discussed as part of this comparison.

Study Objective: Quantify cervical spine range of motion during laryngoscopy via either direct laryngoscopy with a Miller blade or via video laryngoscopy with a CMAC system.
Design: Prospective case series
Setting: Interventional radiology suite at an academic medical center
Patients: Five adults requiring general anesthesia with tracheal intubation to facilitate interventional radiology procedures
Interventions: Fluoroscopic imaging of cervical spine anatomy prior to induction of general anesthesia and then during both direct laryngoscopy and video laryngoscopy
Measurements: Quantification of angles between skull base and prespecified cervical vertebrae and between the first cervical vertebrae and lower prespecified cervical vertebrae. These groups of  measurement either do or do not account for movement of the atlanto-occipital joint, respectively.
Main Results: There was a tendency toward reduced cervical extension both relative to skull base and intrinsicly within the cervical spine during laryngoscopy with the CMAC video laryngoscope as compared to direct laryngoscopy with a Miller blade.
Conclusions: We describe a novel technique to quantify cervical motion during laryngoscopy. Laryngoscopy with a CMAC video laryngoscope may reduce cervical extension as compared to direct laryngoscopy with a Miller blade. Video laryngoscopy may attenuate cervical extension during laryngoscopy, an effect that can be useful in patients with cervical spine disease or instability.

We describe a new method to cut a precise, high-quality femoral cavity in Revision Total Hip Replacement surgery (RTHR) using a surgical robot and an intra-operative C-arm fluoroscope. With respect to previous approaches, our method contains several new features. (1) We describe a novel checkerboard plate designed to correct the geometric distortion within fluoroscopic images. Unlike previous distortion correction devices, the plate does not completely obscure any part of the image, and the distortion correction algorithm works well even when there are some overlaid objects in the field of view. (2) Also included are a novel corkscrew fiducial object designed to be integrated with the robot end-effector, and a 6D pose estimation algorithm based on the two-dimensional (2D) projection of the corkscrew, used in robot-imager registration and imager co-registration. (3) In addition, we develop a cavity location algorithm, which utilizes image subtraction and 2D anatomy contour registration techniques. (4) Finally, we propose a progressive cut refinement strategy, which progressively improves the robot registration during the procedure. We have conducted several experiments, in both simulated and in vitro environments. The results indicate that our strategy is a promising method for precise orthopedic procedures like total hip replacement. Comp Aid Surg 5:373–390 (2000). © 2001 Wiley-Liss, Inc.

Wearing a spinal collar can cause dysphagia [1, 2]. The limited evidence on swallow function when wearing a spinal collar is exclusively in younger volunteers [3, 4]. The manufacturer of the Miami-J® collar, Ossur ® trains users to remove the sternal pad when a patient is eating or drinking.

Management of oropharyngeal swallowing dysfunction often requires both a clinical and an instrumental examination. A videofluoroscopic swallowing study is an instrumental examination that often could be a good option and a very useful tool for the swallowing clinician. At Skåne University Hospital, Malmö, Sweden, the name of such examination is therapeutic videoradiographic swallowing study (TVSS). A TVSS examination should always be performed in collaboration between a speech language pathologist and a radiologist. During the examination, the patient is seated in an upright position, but the examination can also be performed with the patient lying down. The TVSS examination can be performed both in frontal and lateral projection. Test material with varied consistencies as well as different therapeutic strategies can be tested during the examination. Any oral and/or pharyngeal dysfunction can be defined, for example a delay in the initiation of the pharyngeal swallow or an absent ph...

The use of lateral mass atlas screws is an important technique to achieve fusion and stability at the craniocervical region affected by different pathologies (degenerative, traumatic, inflammatory, neoplastic, or congenital). This paper describes the anatomy and techniques necessary for proper insertion of posterior C1 lateral mass screws, using anatomic dissection and intraoperative pictures. Knowledge of the anatomy and the surgical technique of insertion of C1 lateral mass screws are of paramount importance to have good surgical results.

The aim of this study was to report the characteristics of dysphagia in children with cerebral palsy (CP), related to gross motor function. Videofluoroscopic swallow study was performed in 29 children with CP, according to the manual of Logemann. Five questions about oromotor dysfunction were answered. Gross motor function level was classified by the Gross Motor Function Classification System Expanded and Revised. The results of the videofluoroscopic swallowing studies showed that reduced lip closure, inadequate bolus formation, residue in the oral cavity, delayed triggering of pharyngeal swallow, reduced larynx elevation, coating on the pharyngeal wall, delayed pharyngeal transit time, multiple swallow, and aspiration were significantly more common in the severe group (Gross Motor Function Classification System Expanded and Revised IV or V). As for aspiration, 50% of the children with severe CP had problems, but only 14.3% of them with moderate (Gross Motor Function Classification System Expanded and Revised III) CP and none of them with mild CP had abnormalities. In addition, five of the seven aspiration cases occurred silently. This study shows that dysphagia is closely related to gross motor function in children with CP. Silent aspiration was observed in the moderate to severe CP groups. Aspiration is an important cause of medical problems such as acute and chronic lung disease, and associated respiratory complications contribute significantly in increasing morbidity and mortality in these patient groups. Therefore, the authors suggest that early dysphagia evaluation including videofluoroscopic swallow study is necessary in managing feeding problems and may prevent chronic aspiration, malnutrition, and infections.

Digital radiography systems based on flat-panel detectors have been introduced into clinical practice in the past few years. The high detective quantum efficiency of these detectors allows the radiation dose to be reduced while maintaining image quality, an issue particularly significant for pediatric radiography. Another important aspect for dose optimization and monitoring is the integration of the detector into a computer-controlled x-ray examination system. This enables full control and complete reporting of all dose-relevant exposure parameters, including the determination of the exposure indicator and the patient dose (kerma-area product). In this paper the implementation of these principles in the Philips Digital Diagnost DR system is described and their relevance for pediatric applications is discussed.

Several studies have reported the asynchronous closure of normal bileaflet valves (NBVs), resulting in a split in its closing sound; however, the clinical significance of this split has never been studied in malfunctioning bileaflet valves (MBVs). The study comprised 218 valves in 184 patients, including normal monoleaflet valves (n = 10), NBVs (n = 198), and MBVs (n = 10). Valve function was confirmed by cinefluoroscopy prior to analysis of the valve sound by the Morlet continuous wavelet transform (CWT). The split interval (SI) for each heartbeat was measured, and the coefficient of variation (CV) of its mean (valve SI) was calculated as a parameter for the fluctuation of the SI. The CWT of monoleaflet valves showed a single spike, whereas NBVs exhibited a clear split. There was no significant difference in valve SI between the aortic and mitral positions; however, the mean of the CV was significantly greater in the mitral position (n = 90, 0.507 +/- 0.254) than in aortic position...