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T Bateman

Publications and source records attributed to T Bateman.

6 recordsLinked to original sources
PubMed1989

[Radiotherapy and cerebral stereotaxis. Examples of dosimetry with 3D reconstruction].

External stereotactic radiotherapy allows to irradiate a small and carefully delimited intracranial volume according to the spatial definition of the target. To determine the distribution of the dose in the volume irradiated, we developed a dosimetric programme adapted to our particular treatment conditions (arc therapy in the frontal and oblique planes converging onto the centre of the target volume with circular beams 8 to 20 mm in diameter using 18 MV X photons). The principle of the programme is a 3D reconstruction based on ten transverse CT slices. This reconstruction, related to the stereotactic coordinates defined during stereotactic localization, visualises the outline of each oblique frontal treatment plane and the outline of the three perpendicular reference planes passing through the centre of the target volume (i.e. transverse, sagittal, coronal). The isodose distribution is then calculated in the planes defined by these reconstructions. Under treatment conditions, we use the parameters measured for each beam with their additional collimation. We present an evaluation of this software performed on a phantom consisting of a skull containing a defined target.

Humans↗
PubMed1983

Clinical evaluation of seven-pinhole tomography for the detection and localization of coronary artery disease: comparison with planar imaging using quantitative analysis of myocardial thallium-201 distribution and washout after exercise.

The development of quantitative techniques to assist in the analysis of planar thallium-201 stress-redistribution scintigrams has led to improved abilities of this modality to detect the presence of and to localize significant coronary artery disease (CAD). This fact has encouraged the reevaluation of its capabilities relative to other types of scintigraphic data collection, including seven-pinhole tomography. We have undertaken a comparison of planar scintigraphy and seven-pinhole tomography to detect in 40 exercised patients (23 with angiographically demonstrated CAD, eight with normal coronary angiograms, and nine with less than or equal to 1% likelihood of having CAD) the presence of significant CAD and to localize it correctly to an individual coronary artery. Emphasis was placed on similar imaging conditions and on analysis of images by the same quantitative program of TI-201 distribution and washout. Both techniques were found to be highly sensitive and specific for disease detection and localization. Importantly, seven-pinhole tomography did not significantly improve results.

Coronary Disease↗
PubMed1983

Transient hemodynamic dysfunction after myocardial revascularization. Temperature dependence.

We studied hemodynamics and the effects of right atrial pacing (110 beats/min) following complete myocardial revascularization and hypothermic multidose potassium crystalloid cardioplegia in 12 patients with a normal preoperative left ventricular ejection fraction (LVEF). Measurements were made immediately preoperatively, postoperatively at specified temperatures during the rewarming period (90 degrees F, 94 degrees F, and 98 degrees F), and at 24 hours. No patient had a perioperative myocardial infarction. At 90 degrees F, hemodynamics were characterized by significant decreases in cardiac index, stroke volume index, and left ventricular stroke work index (LVSW) and an increase in systemic vascular resistance index (SVRI) compared to preoperative values (p less than 0.05). Right atrial pacing significantly increased cardiac index preoperatively and 24 hours postoperatively, but not during the rewarming period. Over the entire rewarming period (90 degrees F to 98 degrees F), each of the following variables correlated with temperature: cardiac index (r = 0.71 in sinus rhythm and r = 0.66 with right atrial pacing); stroke volume index (r = 0.33 and 0.66); SVRI (r = -0.80 and -0.64); LVSW (r = 0.37 and 0.73); and heart rate in sinus rhythm (r = 0.51). During the rewarming period, there was an inverse relationship between cardiac index and SVRI (r = -0.87). In conclusion, after myocardial revascularization: (1) transient hemodynamic dysfunction occurs during the rewarming period (90 degrees F to 98 degrees F); (2) this dysfunction is temperature-dependent; and (3) right atrial pacing at 110 beats/min does not improve hemodynamic function during the rewarming period. Temperature must be considered in the evaluation of left ventricular and hemodynamic function following myocardial revascularization.

Adult↗
PubMed1982

Right atrial tamponade complicating cardiac operation: clinical, hemodynamic, and scintigraphic correlates.

Persistent bleeding into the pericardial space in the early hours after cardiac operation not uncommonly results in cardiac tamponade. Single chamber tamponade also might be expected, since in this setting the pericardium frequently contains firm blood clots localized to the area of active bleeding. However, this complication has received very little attention in the surgical literature. We are therefore providing documentation that isolated right atrial tamponade can occur as a complication of cardiac operation and that there exists a potential for misdiagnosis and hence incorrect treatment of this condition. Right atrial tamponade may be recognized by a combination of low cardiac output, low blood pressure, prominent neck veins, right atrial pressure in excess of pulmonary capillary wedge pressure and right ventricular end-diastolic pressure, and a poor response to plasma volume expansion. Findings on chest roentgenogram and gated wall motion scintigraphy may be highly suggestive. This review should serve to increase awareness of this complication and to provide some helpful diagnostic clues.

Bioprosthesis↗