Motion artifact seen on slot-scanning direct digital mammography

OBJECTIVE: Our goal was to determine the appearance of motion artifact when imaging an anthropomorphic breast phantom using a digital slot-scanning system compared with a screen-film system. MATERIALS AND METHODS: Digital and screen-film images were obtained during both brief and continuous manually induced motion of an anthropomorphic phantom in four directions. Continuous motion was further characterized using a syringe pump to induce motion artifact. RESULTS: On screen-film images, brief motion caused degradation of the entire image, simulating a double exposure. Conversely, on digital images using a slot-scanning system, brief motion caused degradation of only a small portion of the image. Continuous motion resulted in smearing of phantom details with both systems, although the smearing was more strongly influenced by the direction of motion when the slot-scanning system was used. With the slot-scanning system, motion in the direction of the detector sweep resulted in elongated distortion, whereas motion in the opposite direction resulted in foreshortening; diagonal smearing was seen with perpendicular phantom motion. The magnitude of distortion for continuous motion at a set velocity was substantially less with the slot-scanning system. CONCLUSION: Motion artifact with a slot-scanning direct digital mammography unit differs significantly from that seen with a conventional screen-film unit and, despite a relatively long overall exposure, may prove to be less of a problem than with conventional units because any given part of an object is exposed only briefly.     

Bilateral recurrent nerve paralysis associated with multinodular substernal goiter: a case report

Substernal goiter is an infrequent occurrence and is found in two to five per cent of all patients undergoing thyroid surgery. These lesions are well known to cause respiratory symptoms and alterations in phonation due to direct compression of airway structures. Infrequently, unilateral recurrent nerve palsy has been reported in patients with substernal goiter. We report a case of bilateral recurrent nerve palsy associated with multinodular substernal goiter in an 89-year-old female who presented in respiratory distress.     

Surgical treatment of aortic arch hypoplasia in infants and children with biventricular hearts

Background. Results of aortic arch reconstruction in the setting of biventricular physiology are well documented in the adult population, however, in children, surgical outcome of this subgroup of patients is less clear.

Methods. We studied the clinical outcomes of 37 children aged 8 days to 15 years (median 26 months), who underwent aortic arch reconstruction for arch hypoplasia from 1982 to 1997. The children were divided into three groups: Group 1 (20 patients) had isolated aortic arch lesions, Group 2 (13 patients) had associated intra-cardiac pathology yet conserving a biventricular physiology, Group 3 (4 patients) had Williams Syndrome. Previous interventions for coarctation had been performed in 30 patients (81%). Arch repair consisted of a patch aortoplasty in the majority of patients (35 of 37 children).

Results. Operative mortality occurred in 5 children, 4 in Group 2 (31%), 1 in Group 3 (25%) and none in Group 1. Permanent neurological complications occurred in 2 children (5 %). During the follow-up, which ranged from 1 month to 8 years, balloon angioplasty for arch obstruction was required in 1 child. There was one late death, associated with a subsequent intra-cardiac repair.

Conclusions. Aortic arch surgery in children with isolated arch hypoplasia, is associated with excellent early and late survival in addition to a low reintervention rate. Alternative perfusion and operative strategies must be implemented in infants with associated intra-cardiac anomalies to improve results.     

Impact of graft ischemic time on outcomes after bilateral sequential single-lung transplantation

Background. Graft ischemic time (GIT) is a potential limiting factor in lung transplantation.

Methods. Seventy-four patients who underwent bilateral sequential single-lung transplantation were divided into three groups: group I, GIT less than 5 hours (n = 20); group II, GIT between 5 and 8 hours (n = 39); and group III, GIT more than 8 hours (n = 15). We compared early allograft function (ratio of arterial oxygen tension to inspired oxygen fraction and alveolar–arterial oxygen gradient), blood loss, the need for tracheostomy, the duration of ventilation, intensive care unit stay, and hospital stay. We also compared prevalences of acute and chronic rejection, airway complications, lung function test, and 2-year survival.

Results. Early allograft function in group III was significantly worse than those in groups I and II. However, there was no significant difference in any other variables of early and medium-term outcomes among the three groups. No significant correlation was detected between GIT and duration of intensive care unit stay or hospital stay.

Conclusions. The limitation of acceptable GIT could be extended from the traditionally approved 4 to 5 hours, to 5 to 8 hours or even longer.     

Preliminary results of a multicentre trial of the electrically stimulated gracilis neoanal sphincter

BACKGROUND: The electrically stimulated gracilis neoanal sphincter was initially developed to treat refractory incontinence. Good early results were reported from the two centres that pioneered the technique. The aim of this study was to assess the operation in a prospective multicentre setting. METHODS: The procedure was performed on 64 patients from seven centres worldwide and was performed in stages. All patients were evaluated clinically and manometrically before and after operation. RESULTS: There was a high incidence of infective and hardware-related complications. At a median of 10 months following closure of the defunctioning stoma 56 per cent had experienced a good functional result. The major functional problems comprised evacuatory difficulties experienced by 25 per cent. CONCLUSION: The technique is effective in treating otherwise refractory incontinence. It is, however, a complex procedure and the morbidity rate may be high, particularly during the learning curve, factors that necessitate careful patient selection. Presented to the Association of Surgeons of Great Britain and Ireland in Bournemouth, UK, April 1997 and the European Council of Coloproctology in Edinburgh, UK, June 1997; and published in abstract form as Br J Surg 1997; 88(Suppl): 39 and Int J Colorectal Dis 1997; 12: 144