St Thomas' Hospital

About: St Thomas' Hospital is a healthcare organization based out in London, United Kingdom. It is known for research contribution in the topics: Population & Pregnancy. The organization has 12105 authors who have published 15596 publications receiving 624309 citations. The organization is also known as: St Thomas's Hospital & St. Thomas's.

The pathology of lymphangioma circumscriptum.

Abstract: A study of lymphangioma circumscriptum has been carried out over a number of years in an attempt to understand its nature and pathogenesis, with a view to improving treatment. It is postulated that the lesion consists essentially of a collection of large muscular-coated lymphatic cisterns, lying deep in the subcutaneous plane and communicating via dilated dermal lymphatics with the superficial vesicles. It seems that these cisterns do not communicate directly, if at all, with the general lymphatic system but represent a sequestrated part of it. They have been shown by cannulation to pulsate at a slow steady rate producing a rise and fall of pressure within them. It is believed that the vesicles are saccular dilatations of superficial lymphatics, secondary to raised pressure transmitted from the pulsating cisterns beneath. It is suggested that may be possible to treat these lesions more successfully and with better cosmetic results by excising the subcutaneous cisterns and leaving the overlying skin intact.

Anomalous origin of the left circumflex coronary artery. Recognition, antiographic demonstration and clinical significance.

Abstract: Anomalous origin of the circumflex coronary artery from the proximal right coronary artery or right sinus of Valsalva was recognized in 20 of 2996 patients undergoing selective coronary arteriography (0.67%). The relative frequency of this anomaly demands a high level of anticipation during the performance of selective coronary arteriography to assure that an adequate study has been obtained. Failure to recognize and properly demonstrate the anomaly can be hazardous to patient management. Two angiographic signs have proved reliable in recognizing the anomalous artery before its selective demonstration. These signs are a profile view of the artery behind the aortic root during left ventriculography (the "aortic root sign") and recognition of absent arterial inflow to a significant area of the posterior lateral left ventricle during selective injections of the main left coronary artery (the "sign of non-perfused myocardium"). These angiographic signs are described and the clinical implications of proper dem...

Experimental procedure for the manufacture and calibration of polyacrylamide gel (PAG) for magnetic resonance imaging (MRI) radiation dosimetry

Abstract: A simple methodology for the manufacture and calibration of polyacrylamide gel (PAG) for magnetic resonance imaging (MRI) radiation dosimetry is presented to enable individuals to undertake such work in a routine clinical environment. Samples of PAG were irradiated using a linear accelerator and imaged using a 0.5 T (22 MHz) Philips Gyroscan MRI scanner. The mean spin-lattice relaxation rate was measured using a `turbo-mixed' sequence, consisting of a series of pulses, each followed by acquisition of a train of spin echoes. The mean sensitivity for five different batches of PAG in the range up to 10 Gy was calculated to be for the mean spin-lattice relaxation rate with a percentage standard deviation of 1.25%. The overall reproducibility between batches was calculated to be 2.69%. This methodology, which introduces the novel use of pre-filled nitrogen vials for calibration, has been used to develop techniques for filling anatomically shaped anthropomorphic phantoms.