How much can abbreviated protocols for breast MRI increase patient throughput? a multi-centric evaluation.

PURPOSE: To assess the impact of abbreviated breast MRI protocols on patient throughput considering non-scanning time and differences between in- and out-of-hospital settings. MATERIALS & METHODS: A total of 143 breast MRI exams from four study sites (hospital, three radiology centers) were included in this retrospective study. Total exam time (TET), Table Time (TT), Scan Time (ST), Table Switch Time (TST) and Planning Time (PT) were determined from consecutive breast MRI examinations. Possible number of scans and exams per hour were calculated. Four scan protocols were compared: full diagnostic protocol (n = 34, hospital), split dynamic protocol (n = 109, all sites) and two abbreviated protocols (n = 109, calculated, all sites). Data were described as median and interquartile range (IQR) and compared by Mann-Whitney-U-Test. RESULTS: Non-scanning time increased from 50% to 74% of the TET with a TST of 46% and a PT of 28% in the shortest abbreviated protocol. Number of possible scans per hour increased from 4.7 to 18.8 while number of possible exams per hour only increased from 2.3 to 5.1. Absolute TST (4.7 vs. 5.7 min, p = 0.46) and TET (18 min each, p = 0.35) did not differ significantly between in- and out-of-hospital exams. Absolute (4.4 vs. 2.8 min, p < 0.001) and relative (23 vs. 13%, p < 0.001) PT and TT (13.3 vs. 11.5 min, p = 0.004) was longer and relative TST (27% vs. 34%, p = 0.047) was shorter in hospital. CONCLUSION: TST and PT significantly contribute to TET and challenge the effectiveness of abbreviated protocols for increasing patient throughput. These findings show only low setting-dependent differences.

Combined texture analysis and machine learning in suspicious calcifications detected by mammography: Potential to avoid unnecessary stereotactical biopsies.

OBJECTIVES: To investigate whether combined texture analysis and machine learning can distinguish malignant from benign suspicious mammographic calcifications, to find an exploratory rule-out criterion to potentially avoid unnecessary benign biopsies. METHODS: Magnification views of 235 patients which underwent vacuum-assisted biopsy of suspicious calcifications (BI-RADS 4) during a two-year period were retrospectively analyzed using the texture analysis tool MaZda (Version 4.6). Microcalcifications were manually segmented and analyzed by two readers, resulting in 249 image features from gray-value histogram, gray-level co-occurrence and run-length matrices. After feature reduction with principal component analysis (PCA), a multilayer perceptron (MLP) artificial neural network was trained using histological results as the reference standard. For training and testing of this model, the dataset was split into 70 % and 30 %. ROC analysis was used to calculate diagnostic performance indices. RESULTS: 226 patients (150 benign, 76 malignant) were included in the final analysis due to missing data in 9 cases. Feature selection yielded nine image features for MLP training. Area under the ROC-curve in the testing dataset (n = 54) was 0.82 (95 %-CI: 0.70-0.94) and 0.832 (95 %-CI 0.72-0.94) for both readers, respectively. A high sensitivity threshold criterion was identified in the training dataset and successfully applied to the testing dataset, demonstrating the potential to avoid 37.1-45.7 % of unnecessary biopsies at the cost of one false-negative for each reader. CONCLUSION: Combined texture analysis and machine learning could be used for risk stratification in suspicious mammographic calcifications. At low costs in terms of false-negatives, unnecessary biopsies could be avoided.

Effect of dental correction on voluntary hay intake, apparent digestibility of feed and faecal particle size in horse.

In nine adult Warmblood horses with mild to moderate dental findings (no signs of discomfort during chewing), voluntary hay intake before and after dental correction was examined. In a second experiment, digestibility of feed and faecal particle size were determined (3 days of total faecal collection) before and after dental correction. During both digestion trials including a 3-day adaptation period, the amount of hay and concentrate (mixture of oats, barley and maize) was kept constant in each individual horse before and after dental correction. Voluntary hay intake in individual horses ranged from 11 to 22 g DM/kg BW/day and did not differ before and after dental treatment. Apparent digestibility of DM, energy, crude fibre and Nfe increased significantly after dental correction (energy digestibility before dental correction 46.8 ± 7.4%, after dental correction 51.5 ± 8.5%). Apparent digestibility of feed was higher in horses eating more concentrates than in those eating less concentrates. Improvement of digestibility was more marked in horses eating larger amounts of grain. There was no relationship between severity or type of dental alterations and improvement of apparent feed digestibility. Dental correction had no effect on faecal particle size.

Ten years of experience with the modified Ross procedure.

BACKGROUND: To assess the full root modification of the Ross procedure, we examined operative and long-term results. METHODS: We retrospectively reviewed 145 patients (118 men and 27 women) operated on from March 1987 through April 1997. Ages ranged from 17 to 68 years. Primary diagnosis was aortic stenosis in 43 patients (29.6%) and aortic regurgitation in 62 patients (42.8%). There was mixed disease (stenosis and regurgitation) in 40 patients (29.6%) of whom the vast majority had predominant stenosis. RESULTS: Early death was 7 of 145 patients (4.8%). Twelve patients had 14 significant complications (8.5%). There were four late deaths. Overall patient survival is 90.5% +/- 3.1% at 5 years and 84.5% +/- 14.1% at 7 years. Endocarditis occurred in three patients-two on the autograft and one on the pulmonary homograft. Three patients had cerebrovascular accidents. In 5 of 132 patients (3.8%) reoperations were required on the autograft. Freedom from autograft reoperation was 93.9% +/- 3.1% at 5 years and 88.6% +/- 6.4% at 7 years. Echocardiographic follow-up reveals more than mild aortic regurgitation in only nine patients, including the five patients in whom reoperations were required. Seven of 11 patients with active endocarditis at the time of the operation had adverse outcomes. CONCLUSIONS: Ten years' experience with the modified Ross procedure has shown excellent results with regard to short- and long-term morbidity and death. It is the procedure of choice for young patients who need aortic valve replacement but should be used with caution in the setting of active endocarditis.

Routine myocardial revascularization with the radial artery: a multicenter experience.

BACKGROUND: Current literature documents use of the radial artery (RA) for myocardial revascularization only as an alternative conduit in cases where the saphenous veins have been previously harvested or are unsuitable for use. Large-scale routine clinical use of the RA as the conduit of choice has not been reported. METHODS: This prospective study evaluated the harvest of the RA from 933 patients and the subsequent use of the conduit as a preferred coronary artery bypass graft second only to the left internal thoracic artery in 930 of these patients. RESULTS: Unilateral RA harvest was performed in 786 patients and 147 patients had bilateral RA harvest. A total of 1080 RAs were harvested; 214 (19.8%) originated from the dominant forearm. There was a mean of 3.30+/-0.93 grafts per patient of which 2.43+/-0.83 were arterial grafts. The mean number of RA grafts was 1.43+/-0.53. Operative mortality was 2.3% with none due to the RA graft(s). There was no ischemia nor motor dysfunction in the operated hands. Thirty-two (3.4%) patients experienced transient thenar dysesthesia that resolved in 1 day to 6 weeks. CONCLUSIONS: Our results demonstrate that routine total or near total arterial myocardial revascularization may be achieved safely and effectively with the use of one or both RAs in conjunction with the internal thoracic artery.

[Vulvar discharge before parturition and a risk factor for postpartum diseases of the sow and for early postnatal piglet losses]. / Scheidenausfluss ante partum als Risikofaktor für postpartale Erkrankungen der Sau und frühpostnatale Ferkelverluste.

Periparturient biotechniques with prednisolon are widely used in Europe for the prevention of perinatal losses in intensive pig production. However, the routinely applied 100 mg prednisolon on the 113th day of pregnancy to the sow are not without controversy. In four intensive pig production units altogether 2143 sows treated thus were subjected to the evaluation of the following parameters: A: the presence or absence of vulvar discharge at the 110th day of pregnancy B: postparturient disease of the sow C: early postnatal piglet losses The results showed that the sows having prepartal vulvar discharge developed after prednisolon application significantly (p < 0.001) higher incidence of postparturient disease (20.5% versus 9.3%) when compared to the sows having no prepartal vulvar discharge. The early postnatal losses were significantly higher (p < 0.05) in sows having prepartal vulvar discharge and consecutive postparturient disease when compared to the healthy sows. It is the opinion of the authors that prepartal biotechnique with prednisolon (in order to reduce perinatal losses) in sows showing the signs of prepartal vulvar discharge is contraindicated.

[Management of E. coli dependent factorial diseases in weaning piglets]. / Management der E. coli-bedingten Faktorenkrankheiten nach dem Absetzen der Ferkel.

The most important postweaning factorial diseases are at least partly caused by E. coli. The term postweaning coli complex can be subcategorized into the following manifestations: postweaning diarrhoea, edema disease, postweaning wasting and hemorrhagic gastroenteritis. In the presented study the effect of prophylactic zootechnique alone and zoo- and biotechnique in combination was evaluated during the first weeks postweaning. The results showed that combined zoo- and biotechnique is superior to simple zootechnique regarding food conversion (1.41 kg versus 1.73 kg), average daily weight gain (390 g versus 325 g) and postweaning piglet mortality (3.1% versus 4.9%). It is the opinion of the authors that combined postweaning zoo- and biotechnique should be performed in such pig production units where ETEC and/or SLTEC are present.

[The effect of timing of labor induction on the occurrence of congenital myofibrillar hypoplasia--short clinical report]. / Der Einfluss des Zeitpunktes der Partusinduktion auf das Auftreten der kongenitalen myofibrillären Hypoplasie--Kurzbericht aus der Praxis.

In an intensive pig production unit with routinely performed prostaglandin partus induction four groups of sows were formed shortly before parturition. The animals received 3 mg alfaprostol as a single intramuscular injection each. The sows of group 1 on the 112th, those of group 2 on the 113th and the animals of group 3 on the 114th day of pregnancy. Group 4 sows were not treated and formed the control group. We evaluated the number of live born piglets and the number of piglets born with congenital myofibrillar hypoplasia. The results showed no significant difference regarding live born piglets. As regards congenital myofibrillar hypoplasia the sows with early partus induction (group 1) showed significant higher incidence when compared to the other groups. It is likely that in cases of partus induction before the 113th day of pregnancy the fetus is still insufficiently protected by natural maturation, adaptation and tolerance ability against such congenital condition as CMH. Therefore it is the opinion of the authors that partus induction before the 113th day of pregnancy should not be performed.

Successful repair of combined septal and biventricular free wall rupture after acute myocardial infarction.

The following case is the first report of successful repair of combined left and right ventricular free wall and ventricular septal rupture. Reports of left ventricular free wall and septal rupture and reports of right ventricular free wall and septal rupture have been published both with and without successful surgical repair. This case demonstrates the presence of left and right ventricular free wall rupture along with septal rupture based upon cardiac catheterization and operative findings. In spite of her severe mechanical complications and prolonged hospital course, the patient is completely functional 1 year after surgical repair.

Hemodynamic compromise secondary to a mediastinal bronchogenic cyst.

Bronchogenic cysts are not commonly the cause of severe symptoms, and often present only as an abnormality on chest roentgenogram. We report an unusual patient with a mediastinal bronchogenic cyst associated with rapid hemodynamic deterioration secondary to compression of vital structures.

Homograft replacement of the aortic valve and root as a functional unit.

Homograft replacement of the aortic valve has inherent advantages for the patient in terms of decreased incidence of thromboembolism, endocarditis, and anticoagulation-related complications. Limitations in its use stem from a significant incidence of postoperative aortic regurgitation, related to difficulty with consistent commissural and sinotubular geometry when inserted in the subcoronary position. To minimize this complication, we used a homograft as a functional unit in 71 patients between 1986 and May 1993, either as a root replacement (n = 58) or as an intraaortic inclusion cylinder (n = 13). There were 4 pulmonary and 67 aortic homografts. Mean age of the 16 female and 55 male patients was 42 +/- 19 years (range, 0.6 to 84 years). Thirty patients had predominantly aortic regurgitation, 19 aortic stenosis, 18 mixed aortic valve disease, and 4 primary aneurysmal disease. Eighteen (25.4%) had infective endocarditis. Thirty-five patients (49%) had a previous operation on the aortic valve. Hospital mortality was 14.1% (10/71), 0% for inclusion cylinders and 17.2% (10/58) for root replacements (p = not significant). Recent follow-up was obtained in all hospital survivors. Mean follow-up period was 35 months (range, 1 to 81 months). There were six late deaths, 1/13 for inclusion cylinders and 5/48 for root replacements. Actuarial survival at 5 years was 74.9% +/- 5.6%. Reoperation was required in 3 patients (all with root replacements), 1 for postoperative endocarditis, 1 for left coronary ostial obstruction, and 1 for late onset of aortic dilatation and regurgitation (pulmonary homograft used as a root replacement). Two patients currently have asymptomatic greater than 2/4 aortic regurgitation. Freedom from significant aortic regurgitation was 88% +/- 7% at 6-year follow-up. More consistent maintenance of the sinotubular and commissural geometry of the aortic homograft may be achieved with the root replacement or the inclusion cylinder techniques. This may reduce the incidence of postoperative aortic regurgitation and further benefit the patient by reducing the need for reoperation in the future.

Pulmonary autograft replacement in children. The ideal solution?

Fifty-one children, aged 1.8 to 21 years (mean, 11.4) with aortic valve replacement using a pulmonary autograft are reviewed. Twenty-nine were intra-aortic implants and 22 were root replacements. There was one operative death, no late deaths, and two have required reoperation. Actuarial freedom from reoperation was 93% +/- 5.5 at 5.6 years. Freedom from progression of aortic insufficiency (AI) was 81% +/- 9 at 5.6 years in the intra-aortic implants and 86% +/- 10 in the root replacement. Enlargement of the pulmonary autograft was seen echocardiographically in both groups. This enlargement was consistent with somatic growth and not associated with progression of AI. Ten of 19 patients with aortic stenosis had an LV mass index suggestive of LV hypertrophy before operation. At 1 year, 18 of 25 had a normal LV mass index. Thirteen of 16 patients with AI had preoperative abnormal LV mass index. All but four returned to normal by 1 year. Low operative risk, excellent function, resolution of abnormal LV hemodynamics, and enlargement consistent with somatic growth suggest that the pulmonary autograft is the ideal replacement for the malfunctioning aortic valve.

Pulmonary autograft replacement of the aortic valve: an evolution of technique.

The use of the patient's pulmonary valve for replacement of the patient's diseased aortic valve was introduced and developed by Mr. Donald Ross. Its demonstrated durability, freedom from thromboembolism, and potential for growth has led to increased utilization of this technique. Modifications of the earlier techniques have led to a reproducible operation with low operative risk and excellent mid-term results.

Transcranial Doppler sonography monitoring of local intra-arterial thrombolysis in acute occlusion of the middle cerebral artery.

BACKGROUND AND PURPOSE: The aim of this study is to report on the use of transcranial Doppler ultrasonography as a noninvasive diagnostic monitoring tool during local intra-arterial thrombolysis in a patient with acute embolic occlusion of the middle cerebral artery. CASE DESCRIPTION: We describe a 41-year-old woman with mitral valve stenosis suffering from embolism of the middle cerebral artery. Local thrombolysis was performed with tissue plasminogen activator at a dosage of 0.05 mg/kg/hr. Progress of the thrombolysis was monitored by transcranial Doppler. The steps of recanalization could be ascertained by transcranial ultrasound showing a hemodynamically relevant residual stenosis after the first 120 minutes and complete patency of the M1 segment of the middle cerebral artery 180 minutes later. One branch of the middle cerebral artery still showed a filling defect. CONCLUSIONS: Our report demonstrates the potential usefulness of transcranial Doppler monitoring during thrombolysis of a proximal occlusion of the middle cerebral artery for guiding the treatment by assessing the reperfusion of the obstructed artery.

Normal left ventricular function following pulmonary autograft replacement of the aortic valve in children.

To assess growth potential and hemodynamic sequelae of pulmonary autograft valves implanted into aortic outflow tracts of children, we reviewed our experience with 37 patients (2-21 years) from August 1986 to December 1990. Twenty patients had predominantly aortic stenosis (AS), and 17 had aortic insufficiency (AI). Operative mortality was 3%. Two technical failures required reoperation. Of survivors, six (18%) have moderate AI. Pre- and postoperative echocardiograms were reviewed. The AS group showed increased left ventricular (LV) cavity size by greater than 1-year follow-up, and decreased LV wall and interventricular septal thickness. In the AI group, wall and septal thickness increased by 10 days and LV cavity decreased by 10 days, 60 days, and greater than 1 year. Root replacements (n = 14) showed mean increases of 4.3 mm and 5.3 mm, respectively, in diameters of the aortic annulus and aortic sinuses at greater than 1 year. Intraaortic implants increased 3.1 mm (annulus) and 3.9 mm (sinuses) at greater than 1 year. The pulmonary autograft procedure is safe, and successful implantation normalizes LV dimensions and function rapidly. The autograft valve shows evidence of growth at greater than 1 year postoperative. The pulmonary autograft may be the ideal valve replacement in children.

Replacement of the abdominal aorta with an aortic homograft in a patient with an aortic dissection.

The use of aortic and femoral homografts in early vascular surgery has been abandoned for the more successful and abundant synthetic substitutes. With the recent introduction of cryopreservation, homograft use has again met with improved success. A 40-year-old man who had a DeBakey Type I aortic dissection initially underwent replacement of the aortic root with a pulmonary homograft. Subsequently, in the presence of an intraabdominal infectious process, progressive mesenteric and lower limb ischemia was treated by replacing the abdominal aorta with an aortic homograft. Thirty-six months postoperative the patient has a functioning gastrointestinal tract and no vascular insufficiency of the lower extremities and no evidence of degeneration of the homograft. Further laboratory studies should be undertaken using the newer and improved cyropreserved homograft in the presence of, or potential for, an intraabdominal infectious process.

Aortic root replacement with pulmonary autograft.

Transfer of the pulmonary valve to the aortic position has been used successfully by Ross for more than 20 years and in our own institution since August 1986. To expand the use of this concept to patients with root disease and/or narrow annulus, we employed the main pulmonary artery with its valve as a conduit to replace the proximal ascending aorta, reimplanting the coronary ostia into the pulmonary trunk. Seventeen patients, aged 2-62 years, underwent the procedure with three deaths. Hemorrhage precipitated each death, and there was one reexploration for control of bleeding. Postoperative echocardiography showed excellent valvular function. No anticoagulants were used except daily aspirin in three patients who underwent concomitant procedures. There were no thromboembolic episodes. Right ventricular outflow tract reconstruction was accomplished with cryopreserved aortic (three) and pulmonary (14) allograft conduits. This operation has potential for superior long-term results in complex aortic valve disease.

Aortic valve and left ventricular outflow tract replacement using allograft and autograft valves: a preliminary report.

A comparison of allograft and autograft (pulmonary) replacement of the aortic valve has, to our knowledge, not been done in America. Fifty-seven patients (age range, 2 to 70 years; mean age, 30 years) underwent 59 operations for replacement of the aortic valve (20) or entire left ventricular outflow tract (39) using autograft (35) or allograft (24) valves. Many had undergone a previous operation (25) or had concomitant procedures (13). Postoperative mortality was 8.5% (5/59). Two deaths occurred in the allograft group and three in the more complex pulmonary autograft group. One late death occurred. One autograft was replaced with an allograft 7 months postoperatively for severe aortic regurgitation. There have been no episodes of either endocarditis or thromboembolism. Forty-nine of 51 survivors are in New York Heart Association class I. Preliminary results suggest that congenital or acquired disease of the left ventricular outflow tract and aortic valve can be safely and effectively treated with either allograft or autograft valve transplantation.