Volumetric rendering techniques: applications for three-dimensional imaging of the hip

Volumetric rendering is a new approach to three-dimensional (3D) imaging that overcomes many of the drawbacks of currently available surface-rendering systems. Its application on the Pixar Imaging System in two cases of acetabular fracture was assessed to illustrate the features of the technique. The fast-computing architecture and large memory of this system allow rapid generation of a series of high-quality 3D images in each plane of rotation (x or spinal axis, z or somersaulting axis) that can be viewed as independent static images or as an animated real-time video loop. Editing to remove the normal contralateral hemipelvis enhances appreciation of acetabular abnormalities. Every pixel of computed tomographic data is preserved, allowing representation of both soft tissue and bone as translucent overlap. The presentation of data also allows detection of subtle abnormalities and features and minimizes the artifact generation common in surface-rendered images.     

Radiologically guided balloon dilation of gastrointestinal strictures. Part I. Technique and factors influencing procedural success

Radiologically guided balloon catheters were used to dilate 94 gastrointestinal strictures in 92 patients over a 6-year period. Fifty strictures were esophageal and 44 nonesophageal (22 gastroenterostomies, 11 antral-pyloric strictures, four colorectal strictures, four enteroenterostomies, and three miscellaneous strictures). Factors influencing the success of stricture intubation included patient age, stricture location (esophageal vs. nonesophageal and proximal vs. distal esophageal), and association with a surgical anastomosis. Malignancy was associated with greater postdilation irregularity and a smaller increase in stricture diameter, as measured radiographically. Procedural failures occurred in 8% of cases (2% of esophageal and 30% of nonesophageal lesions). Two small, asymptomatic mucosal tears were seen after dilation (one esophageal and one colonic); no other procedural complications occurred. Following successful dilation, 16 patients (17%; six with esophageal and ten with non-esophageal strictures) had recurrence of symptoms during short-term (30-day) follow-up.     

Mucoid presentation of acute enterocolitis in children: a hospital-based case-control study

A hospital-based case-control study was carried out to clarify the characteristics of mucoid presentation of acute enterocolitis in children. One hundred sixty-eight cases of acute mucoid enterocolitis (study population) were compared with 200 cases of watery diarrhoea and 118 cases of blood dysentery (control groups) on the basis of clinical characteristics and findings on stool examination. Study and control groups were comparable with respect to age, body weight and nutritional status. There was no significant difference in clinical characteristics (duration of diarrhoea, stool frequency, presence of vomiting, fever and dehydration) between patients suffering from mucoid enterocolitis and blood dysentery. However, watery diarrhoea patients had significantly high frequencies of vomiting (p = 0.00001) and dehydration (p     

APOE, APOE promoter, and Tau genotypes and risk for concussion in college athletes.

OBJECTIVE: To investigate associations of APOE, APOE promoter (G-219T), and tau protein exon 6 polymorphisms (47 and 53) and a history of self-reported concussion in college athletes. DESIGN: Multi-center cross-sectional study. SETTING: Male football and male and female soccer programs at the University of South Carolina, Jacksonville University, Benedict College, and the College of Charleston. PARTICIPANTS: Active 18- to 30-year-old (n = 195) intercollegiate male football players and male and female soccer players during 2001 and 2002. ASSESSMENT OF RISK FACTORS: Written questionnaires and blood or mouthwash samples for DNA for genotyping by RFLP/PCR. MAIN OUTCOME MEASUREMENT: Self-reported history of concussions over the previous 8 years. RESULTS: A statistically significant, nearly 3-fold increase in risk of a history of concussion for those with the APOE promoter G-219T TT genotype relative to the GG genotype (OR, 2.8; 95% CI, 1.1 to 6.9) adjusted for age, sport, school, and years in their primary sport, a finding that was stronger for Cantu grade 2 and 3 concussions. CONCLUSIONS: These results suggest that college athletes with an APOE promoter G-219T TT genotype may be at increased risk for having a history of concussions, especially more severe concussions. Although there was some support for the possibility that the tau 53 polymorphism may be associated with increased risk of prior concussion (OR, 2.1; 95% CI, 0.3 to 14.5), there was no support for an association with APOE genotypes. The results of this cross-sectional study support the need for a prospective study of genetic factors, such as APOE promoter polymorphisms, and the incidence of and sequelae from concussions in college athletes.     

Utilization of screening mammography: comparison of different physician specialties

Data obtained on 426 consecutive patients referred to a breast center by 122 physicians, including family practitioners, general surgeons, and other specialists, showed that the obstetricians-gynecologists referred the greatest average number of patients per physician, with more than 50% of these referrals for screening mammography. Internists referred fewer patients by nearly a factor of ten, with only one-third of these patients referred for screening mammography. Internists may be the weakest link in the utilization of screening mammography.     

Accuracy of digital imaging interpretation on an 1K × 1K PC-based workstation in the emergency department

The purpose of this study was to evaluate the accuracy of interpretation of digital radiographs on 1K × 1K PC-based workstations and compare it to that of 2K × 2K workstations in our filmless emergency department. We reviewed 1013 studies, of which 404 were chest, 133 abdominal, and 476 musculoskeletal. All studies were interpreted prospectively on the 1K × 1K workstation, and the findings were compared to those on the 2K × 2K diagnostic workstation which served as the control. Among all the studies performed, 515 were negative (255 chest, 91 abdominal, and 169 musculoskeletal). Another 498 had positive findings (149 chest, 42 abdominal, and 307 musculoskeletal). When the cases were reviewed on the 1K × 1K monitor, the diagnosis was missed in 5 of the 149 positive chest cases (3.35 %), in 5 of the 307 positive musculoskeletal cases (1.63 %), and in none of the 42 positive abdominal cases (0 %). In total, we misinterpreted 10 of the 498 positive cases (2.01 %). The miss rate of the 1K × 1K clinicians' review station is low and acceptable for its stated purpose. However, we doubt that it can be used for primary diagnostic purposes.     

Colonoscopy in the patient requiring anticoagulation

PURPOSE: The aim of this study was to assess perioperative warfarin management and complications in patients requiring colonoscopy. METHODS: We retrospectively reviewed 109 cases of colonoscopies performed on 94 patients requiring anticoagulation with warfarin. Patients stopped their warfarin three days before colonoscopy. Coagulation profiles obtained just before the colonoscopy showed a median prothrombin time of 13.4 seconds with a range of 11.1 to 29.1 (normal range, 10.9–13) and a median international normalized ratio of 1.2 with a range of 0.9 to 2.6. Patients restarted warfarin the day after the examination. RESULTS: During the 109 colonoscopies, 47 percent of the patients underwent either hot biopsy or snare polypectomy. One examination that included several biopsies was associated with a hemorrhagic complication (0.92 percent) requiring hospitalization and transfusion. Subset analysis of the therapeutic (biopsy and snare polypectomy) group indicated a slightly higher complication rate (1.96 percent) with a median international normalized ratio of 1.3 (range, 1–2.3) and a median prothrombin time of 13.7 (range, 11.6–25.9). CONCLUSION: Patients taking warfarin for anticoagulation may safely undergo colonoscopy. The risk of hemorrhagic complications increases slightly with hot biopsy or snare procedures. Further studies are needed to refine guidelines for colonoscopy in the patient requiring anticoagulation.Poster presentation at The American Society of Colon and Rectal Surgeons' 100th Anniversary and Tripartite Meeting, Washington D.C., May 1 to 6, 1999.