Facioscapulohumeral muscular dystrophy: a radiologic and manometric study of the pharynx and esophagus.

Facioscapulohumeral muscular dystrophy (FSHD) is not a recognized neuromuscular cause of dysphagia. However, a study of pharyngoesophageal function in FSHD has not been performed or reported. The aim of this study was to ascertain by relatively noninvasive techniques whether the dystrophic muscle disease that underlies FSHD involves the pharyngeal and/or the esophageal striated and smooth muscles. We used conventional cineradiography and intraluminal esophageal manometry on separate occasions to study pharyngeal and esophageal function in 20 patients with FSHD at various stages of disease, with or without complaints of deglutition. Age- and sex-matched control data were used for comparison of the manometric component of the study. Twelve men and eight women with FSHD were studied. The mean patient age was 38.1 years (41.9 years for controls), and the age range was 19-61 years (22-55 years for controls). The mean disease duration was 16.7 years (range = 4-39 years).Five patients admitted to having intermittent oropharyngeal dysphagia (difficulty to initiate swallowing, cough after swallowing, sensation of food stuck in throat, or nasal regurgitation), and three patients admitted to intermittent esophageal dysphagia (difficulty swallowing both liquids and solids). Chest roentgengrams showed a hiatal hernia in four patients, but no active cardiopulmonary disease. Abnormal instrumental results were documented in eight patients: Cineradiography detected ineffectual pharyngeal contractions (2 patients), pharyngeal diverticula but normal pharyngeal motility (2 patients), and decreased cricopharyngeal and upper esophageal relaxation (2 patients). The mean manometric pressure of the patient group was not significantly different from the control data. However, manometry detected motility abnormalities that were not reflected in the mean data and included increased lower esophageal sphincter resting pressure with normal or abnormal relaxation (2 patients) and inconsistent, high-amplitude, long-duration, primary peristaltic contractions (1 patient). Patients with FSHD did not spontaneously volunteer intermittent complaints of deglutition. This study did not definitely establish that the cause of abnormal pharyngeal and cervical esophageal function was related to the dystrophic process that underlies FSHD. Any esophageal dysmotility was nonspecific and insignificant and was caused by an undetermined, probably neuropathic, process unrelated to the muscular dystrophy.

Craniocervical motion during direct laryngoscopy and orotracheal intubation with the Macintosh and Miller blades: an in vivo cinefluoroscopic study.

BACKGROUND: Previous studies have characterized segmental craniocervical motion that occurs during direct laryngoscopy and intubation with a Macintosh laryngoscope blade. Comparable studies with the Miller blade have not been performed. The aim of this study was to compare maximal segmental craniocervical motion occurring during direct laryngoscopy and orotracheal intubation with Macintosh and Miller blades. METHODS: Eleven anesthetized and pharmacologically paralyzed patients underwent two sequential orotracheal intubations, one with a Macintosh blade and another with a Miller in random order. During each intubation, segmental craniocervical motion from the occiput to the fifth cervical vertebra (C5) was recorded using continuous lateral cinefluoroscopy. Single-frame images corresponding to the point of maximal cervical motion for both blade types were compared with a preintubation image. Using image analysis software, angular change in the sagittal plane at each of five intervertebral segments was compared between the Macintosh and Miller blades. RESULTS: Extension at occiput-C1 was greater with the Macintosh blade compared with the Miller (12.1 degrees +/- 4.9 degrees vs. 9.5 degrees +/- 3.8 degrees, respectively; mean difference = 2.7 degrees +/- 3.0 degrees; P = 0.012). Total craniocervical extension (occiput-C5) was also greater with the Macintosh blade compared with the Miller (28.1 degrees +/- 9.5 degrees vs. 23.2 degrees +/- 8.4 degrees, respectively; mean difference = 4.8 degrees +/- 4.4 degrees; P = 0.008). CONCLUSIONS: Compared with the Macintosh, the Miller blade was associated with a statistically significant, but quantitatively small, decrease in cervical extension. This difference is likely too small to be important in routine practice.

Do flat detector cardiac X-ray systems convey advantages over image-intensifier-based systems? Study comparing X-ray dose and image quality.

The recent introduction of "flat-panel detector" (FD)-based cardiac catheterisation laboratories should offer improvements in image quality and/or dose efficiency over X-ray systems of conventional design. We compared three X-ray systems, one image-intensifier (II)-based system (system A), and two FD-based designs (systems B and C), assessing their image quality and dose efficiency. Phantom measurements were performed to assess dose rates in fluoroscopy and cine acquisition. Phantom dose rates were broadly similar for all systems, with all systems classified as offering "low" dose rates in fluoroscopy on standard phantoms. Patient X-ray dose rate and subjective image quality was assessed for 90 patients. Dose area product (DAP) rates were similar for all systems, except system C, which had a lower DAP rate in fluoroscopy. In terms of subjective image quality, the order of preference was (best to worst): system C, system A, system B. This study indicates that the use of an FD detector does not infer an automatic improvement in image quality or dose efficiency over II based designs. Specification and configuration of all of the components in the X-ray system contribute to the dose levels used and image quality achieved.

High-dose fluoroscopy: the administrator's responsibilities.

During the past 15 years, developments in x-ray technologies have substantially improved the ability of practitioners to treat patients using fluoroscopically guided interventional techniques. Many of these procedures require a greater use of fluoroscopy and serial imaging (cine). This has increased the potential for radiation-induced dermatitis, epilation and severe radiation-induced burns to patients. Radiology administrators must realize that these high-dose procedures increase the risk for radiation injury and radiation-induced cancer in personnel as well as in patients. This article discusses particular clinical cases and describes positive, pro-active steps that practitioners and administrators can take to help prevent such injuries in their facilities. Unfortunately, with the exception of radiologists, a large proportion of physicians who use fluoroscopy have effectively no training or credentials in management of radiation or the biological effects associated with its use. In 1994, an FDA advisory warned that training of physicians for modern-day use of the fluoroscope was for the most part insufficient and needed to be expanded. Many prominent medical organizations such as the American College of Cardiology (14) and the American Heart Association (15) have published strongly worded position papers agreeing that there is an urgent need for such training. The consensus is that "rubber-stamp" privileges (16,17) to perform fluoroscopic procedures should no longer be granted. At present, the JCAHO is considering the implementation of a statement regarding JCAHO standards and privileges for practitioners to use fluoroscopic x-ray equipment. Whether or not the JCAHO becomes involved, it is becoming increasingly clear that all practitioners who use fluoroscopic radiation should be required to complete focused training in radiation physics, radiation biology and radiation safety. Training should include the pertinent aspects of radiation management in the clinical setting so that these physicians will be able to acceptably control risks to patients and personnel. The task of securing these materials and lecturers and documenting everything may fall on the shoulders of the radiology administrator or radiation safety staff. Completion of an approved educational program (with appropriate testing) provides the evidence needed by the facility to approve the practitioner's qualifications. In summary, it will take a concerted effort on the part of professional medical organizations and regulatory agencies to insure that the wealth of preventative information now available is disseminated to and put to use by these physicians who may fail to fully appreciate the potential for imparting serious injury to their patients. Even one radiation injury caused by lack of education is unacceptable.

Coronary artery motion in electron beam tomography.

PURPOSE: The purpose of this work was to evaluate coronary artery motion characteristics and determine optimal electron beam tomography (EBT) scan time during the cardiac cycle to image the coronary arteries. METHOD: This study evaluated the movement of coronary arteries in 20 EBT cine studies, at rest and during stress, obtained for evaluating coronary artery disease. The proximal, middle, and distal segments of each coronary artery were measured at multiple times during the cardiac cycle. The motion distance (mm) and velocity (mm/s) of each segment of the coronary arteries were then measured to establish the motion that occurs in the x and y axes during different times in the cardiac cycle. RESULTS: Coronary artery velocity ranged from 22.4 to 108.6 mm/s. The least motion (and slowest speed) occurred between 30-50 and 40-60% of the R-R interval at rest and stress, respectively. The right coronary artery moved the greatest in the x and y planes (highest speed and spatial change), followed in decreasing order by the circumflex, left main, and left anterior descending arteries. The phase of the cardiac cycle with the greatest coronary artery motion was between 0 and 20% of the R-R interval. CONCLUSION: Coronary artery motion varies greatly throughout the cardiac cycle. To minimize cardiac motion during tomographic imaging of the coronary arteries, we recommend 40-50% R-R interval as an electrocardiographic trigger time and avoiding the use of image acquisition times of >100 ms.

Proposed catheter standards for pharyngeal manofluorography (videomanometry)

With the recent introduction of commercially available pharyngeal manofluorography systems, catheter design should be standardized. Catheters of different designs can produce different data because of their design characteristics. A standard catheter design should make results between investigators comparable and facilitate acceptable normal values. The authors' combined laboratory experience with many catheter designs was reviewed and the literature consulted. For pharyngeal manofluorography, the proposed standard catheter should be 2 x 4 mm in diameter, ovoid, and 100 cm long. The catheter should be marked in centimeters with an anterior and posterior orientation. There should be a slightly malleable, 3- to 4-cm length without sensors beyond the most distal sensor. Solid state transducer sensors should be three or four in number and placed in the pharyngoesophageal segment, midhypopharynx, and tongue base (esophagus for fourth sensor). Sensor spacing should be 3 cm, except 2 cm between the midhypopharynx and tongue base. Unidirectional, in-line, posteriorly oriented sensors with the option of a single circumferential sensor in the cricopharyngeus are currently preferred over circumferential sensors because of their small diameter (patient comfort).

[Videocinematography of swallowing. Indications, methodology and findings]. / Videokinematographie des Schluckaktes. Indikation, Methodik und Befundung.

The purpose of this study was to given an introduction to the radiological evaluation of deglutition. The symptoms leading to videofluoroscopic investigation of swallowing are explained. The examination has to be tailored to the patient's symptoms. Each film scene depicts a characteristic patient position, a particular kind of contrast material and a certain amount. A systematic approach to analyze video films of deglutition and knowledge of the normal and abnormal swallowing functions are mandatory.

[Videocinematography and pre- and postoperative diagnosis of lip-maxillary-palatal clefts]. / Die Videokinematographie in der prä- und postoperativen Diagnostik der Lippen-Kiefer-Gaumen-Spalte.

Videocinematography is a valuable tool in the diagnostic workup and planning of functional surgery in cleft patients. The high resolution and depiction of the finest mucosal structures in motion allow objective and dynamic assessment of the individual velopharyngeal function. A total of 170 cleft patients were examined by videocinematography, and the results were compared to nasoendoscopy and to the clinical examination. The marked superiority of this radiological technique with regard to clearness of depiction and ease of use is shown. It can therefore be recommended without reservation for the pre- and postoperative assessment of cleft patients.

The mechanical characteristics of the human heel pad during foot strike in running: an in vivo cineradiographic study.

The compressive properties of the heel pad during the heel strike when running (barefoot and shod, two subjects, 4.5 m s-1) were studied by means of a high-speed two-dimensional cineradiographic registration (150 frames s-1) of an actual running step. Vertical ground reaction forces were measured with a force platform. In barefoot running the heel pad deforms to a maximal percentage deformation of 60.5 +/- 5.5%. In shod running the heel pad deforms only 35.5 +/- 2.5% and the nonlinear force-deformation relationship reflects an increasing stiffness when deformation rises. Although the amplitudes of the vertical ground reaction forces do not differ notably in both conditions, barefoot running implies a maximal deformation to the fatty heel tissue, reducing its functional role from shock reduction towards local protection of the heel bone. It is argued that embedding the foot in a well-fitting shoe increases the effective stiffness of the heel pad.

[High-frequency videocinematograpphy for the objective imaging of the velopharyngeal closure mechanism in cleft palate patients]. / Hochfrequenz-Videokinematographie zur objektiven Darstellung des velopharyngealen Verschlussmechanismus bei Gaumenspaltpatienten.

The use of high-frequency video cineradiography makes possible an objective and dynamic rendering of the individual velopharyngeal closer pattern. The high resolution and the depiction of the finest mucosal structures while in motion achieved by this technique opens up the possibility of exact and objective 3-dimensional evaluation of the velopharyngeal gap. Following secondary velopharyngoplasty on 80 cleft palate patients, the velopharyngeal closure was studied by means of high-frequency video cineradiography and this rendering was then compared to results obtained by nasoendoscopy and to the clinical findings. It became definitely apparent that the radiological technique is markedly superior in relation to clearness of depiction and ease of use, especially in young children. This imaging technique can be recommended without reservation for pre- and postoperative control of speech-improving procedures.

10 kHz microsecond pulsed X-ray generator utilising a hot-cathode triode with variable durations for biomedical radiography.

A 10 kHz pulsed X-ray generator utilising a hot-cathode triode in conjunction with a new type of grid control device for controlling X-ray duration is described. The energy-storage condenser was charged up to 70 kV by a power supply, and the electric charges in the condenser were discharged to the X-ray tube repetitively by the grid control device. The maximum values of the grid voltage (negative value), the tube voltage, and the tube current were -1.5 kV, 70 kV, and 0.4 A, respectively. The duration of the flash X-ray pulse was primarily determined by the time constant of the grid control device and the cut-off voltage of thermoelectrons. The X-ray duration was controlled within a region of less than 1 ms; the X-ray intensity with a pulse width of 0.27 ms, a charged voltage of 70 kV, and a peak tube current of 0.4 A was 0.92 microC kg-1 at 0.5 m per pulse. The maximum repetition rate was about 10 kHz, and the size of the focal spot was about 3.5 x 3.5 mm.

Measurement of right ventricular volume in human explanted hearts using ultrafast cine computed tomography.

The quantitative measurement of right ventricular (RV) volume has been attempted by a number of methods, including nuclear magnetic resonance imaging, contrast angiography, echocardiography, and radionuclide angiography. All of these methods have limitations. Ultrafast cine computed tomographic (CT) scan is a new technology that may have an important role in on-line ventricular volume measurements. Twelve human explanted hearts, fixed in formalin, were subjected to ultrafast cine CT scans to estimate RV volume. The volumes derived from the CT scans were compared with actual fluid volumes needed to fill the RV volume measurements. All measurements were conducted independently by two observers. Actual RV volumes in the 12 hearts ranged from 29.8 ml to 174.6 ml. A strongly significant correlation between actual volume and CT volume was seen (r = 0.99). Agreement between observers was also seen to be highly significant (r = 0.992). Limitations to accurate in vivo assessment due to bolus injection of contrast medium might include alterations in ventricular pressure change. Similarly, differentiation of the endocardial border with contrast may not be as sharp as that with an air-tissue interface. This study demonstrates that RV volumes can be reliably determined by ultrafast cine CT scans in explanted hearts. On-line systolic and diastolic volumes and thus stroke volume, ejection fraction, etc, can be accurately defined independent of cardiac orientation. This technique offers opportunities to study ventricular function under various conditions.

Radiation risk to patients from percutaneous transluminal coronary angioplasty.

OBJECTIVES: This retrospective study sought to estimate patient radiation exposure during percutaneous transluminal coronary angioplasty, the corresponding organ doses and the resulting cancer mortality risk. Patient demographic data were also examined. BACKGROUND: Coronary angioplasty is commonly used as an intervention for coronary atherosclerosis, and repeated application in the same patient is now common. The combined use of fluoroscopy and cineradiography in this complicated, delicate and, hence, lengthy procedure induced us to investigate the patient radiation exposures and resulting risks. METHODS: All complete records for angioplasty procedures performed over a 3-year period were entered into a data base. The data comprised 1,893 procedures performed in a total of 1,503 patients, of whom 21% had two or more procedures in the 3-year period. Fluoroscopy time was converted to entrance exposures, assuming a rate of 520 muC kg-1 min-1 (2.0 R min-1). Cineradiographic film lengths were determined for a smaller number of procedures (200) and converted to exposures at 7.7 muC kg-1 frame-1 (30 mR frame-1). In addition, fluoroscopy and cineradiographic times and, hence, exposures for 91 diagnostic angiograms performed in these patients were obtained. Exposures were converted to organ doses using the Monte Carlo results of the Rosenstein group and then to cancer mortality risks using the latest rates of the International Commission on Radiological Protection. RESULTS: The mean age was 56.0 years; men constituted 77.5% of the patients. Radiation doses varied considerably owing to a large spread in exposure times (e.g., fluoroscopy time per angioplasty case averaged 19 min but for some cases exceeded 1 h). The average patient skin entrance exposure per angioplasty procedure was 32.0 mC kg-1 (124 R), of which 69.7% was from cineradiography. The resulting cancer mortality risk per angioplasty procedure is approximately 8 x 10(-4). CONCLUSIONS: The skin exposures estimated for angioplasty are on average higher than for other X-ray procedures. The cancer mortality risk does not exceed the mortality risk of bypass surgery. Good professional practice requires maximization of the benefit/risk ratio through quality assurance in all aspects of the procedure.

A protocol for the videofluorographic swallowing study.

This paper presents a detailed protocol for performing the videofluorographic swallowing study (VFSS), and describes how it evolved from its antecedents. The objectives of the VFSS are both diagnostic and therapeutic. Preparing for the VFSS is described, including the equipment, food preparation, and a brief discussion of the clinical evaluation. The detailed description of the VFSS procedure covers the position of the patient, the foods presented, the views obtained, modifications of feeding and swallowing that are commonly employed, the standardized set of observations, and reporting the results. Criteria for deviating from the protocol or aborting the study are presented. The VFSS does not necessarily end when a patient aspirates. Indeed, the complete evaluation of aspiration, and the effects of maneuvers designed to reduce it, is a major purpose of the VFSS. Modifications of feeding and swallowing are tested empirically during the study. The modifications include therapeutic and compensatory techniques that may improve the safety and efficiency of swallowing. A rationale for deciding which modifications to test in a given patient is discussed. The protocol has been used successfully in more than 350 patients. It has improved the efficiency and quality of our videofluorographic examinations.

[Digital cineradiography (DCR) of the act of swallowing. The initial clinical experiences]. / Digitale Cine-Radiographie (DCR) des Schluckaktes. Erste klinische Erfahrungen.

Twenty-seven patients with different swallowing disorders were studied by employing digital cineradiography (DCR) for rapid imaging of the pharynx with a temporal resolution of up to 50 frames per second and a maximum spatial resolution of .8 per/mm. To facilitate therapy planning, the DCR study can be transferred to the otorhinolaryngologist via videotape. DCR is capable to substitute analog cine or video techniques in the pre- and postoperative examination of patients with swallowing disorders.