Biphasic spiral CT of the liver: automatic bolus tracking or time delay?

The aim of this study was to evaluate the value of automatic bolus tracking for biphasic spiral CT of the liver in comparison with time delay examinations. Forty patients scheduled for a biphasic spiral CT of the liver randomly were examined either with time delay of 25 s for the arterial phase and 55 s for the portal-venous phase (n = 20), or with an automatic scan start triggered by contrast enhancement in the aorta (n = 20). Examinations were performed with 120 ml of contrast material and a flow rate of 4.0 ml/s. Density measurements of the aorta, of the liver parenchyma, and of the spleen were obtained by means of regions of interest (ROI). The end of the arterial phase was considered when hepatic parenchymal enhancement was greater than 20 HU. In all patients of the group with automatic bolus tracking arterial scanning was completed in the arterial phase of the liver. In 25 % of patients with fixed time delay, however, an enhancement of liver parenchyma during arterial phase greater than 20 HU was observed. During the portal-venous phase there was no significant difference in parenchymal enhancement between both groups. Automatic bolus tracking allows an individualized timing of the arterial phase in biphasic spiral CT of the liver. The timing is more accurate than in time delay scanning. Received: 18 February 2000 Revised: 13 July 2000 Accepted: 19 July 2000     

Optimization and Standardization of the “Comet Assay” for Analyzing the Repair of DNA Damage in Cells

BACKGROUND: The "comet assay" has become an interesting and a very useful tool for the analysis of the induction and amount of DNA damage in single cells thus offering the opportunity to measure the effectiveness of DNA repair. On the basis of the Ostling and Johanson protocol we have developed a modified method with increased sensitivity and high reproducibility. MATERIAL AND METHODS: Human tumor cells or isolated human peripheral blood lymphocytes were analyzed in the experiments. The amount of DNA damage and the effectiveness of DNA repair was measured after X-irradiation using the "comet assay" technique. RESULTS: In this presentation the influences of different methodological factors like agarose concentration, buffer pH, electrophoresis time, electric field strength on the applicability of the "comet assay" are described in detail and optimum conditions for "comet assay" experiments have been evaluated. Additionally the authors will show a comparison of different fluorescent DNA dyes pointing out their advantages or disadvantages for "comet" analysis. The usefulness of this technique and its capabilities are exemplified by showing DNA repair kinetics of human lymphocytes of different healthy or radiosensitive donors after in-vitro irradiation with 2 Gy X-rays. CONCLUSIONS: This paper presents data on the optimization and standardization of the original "comet assay" leading to an extremely fast and practicable protocol in the field of single cell gel electrophoresis. After irradiation with 0.1 Gy an increase in the amount of DNA damage can be measured with high statistical significance and the DNA repair capacity of individual cells after X-ray doses of 2 Gy can be analyzed with high reproducibility. The results comparing DNA repair capacities of different donors point out that the "comet assay" may have the potential for the estimation of individual radiosensitivity.     

Rotator Cuff Repair: Is there any role for acromioplasty?

Objectives: Acromioplasty has been one of the most common techniques amongst orthopedic surgeries in the past decade. However, its efficacy in arthroscopic surgeries of rotator cuff repair is still debatable. The purpose of this study is to compare the arthroscopic rotator cuff repair with or without acromioplasty in patients with complete rotator cuff tear.

Methods: In this prospective cohort study, patients with complete rotator cuff tear (acromion type II or III Bigliani) and a history of failure to the conservative treatment for at least 6 months were evaluated for eligibility. Patients, based on the time interval, were placed in one of two groups: arthroscopic rotator cuff repair with (RCR-A group) and without acromioplasty (RCR group). Patients were assessed for two years in term of pain intensity by VAS criteria and shoulder functional status by Quick-DASH, Constant score and simple shoulder test criteria.

Results: In the baseline assessment, RCR-A group (34 patients) and RCR group (33 patients) were similar. Comparing patients in two groups in relation to SST, Quick-DASH and VAS scores preoperatively showed there is no significant difference between the two groups. The SST, Quick-DASH and VAS scores improved significantly in both groups at both the 6-month and 2-year follow-ups (all P < 0.001). The extent of progress in the functional scores was similar in both groups (P > 0.05).

Conclusion: Arthroscopic rotator cuff repair without acromioplasty may be as reliable and useful as conventional rotator cuff repair with acromioplasty. Thus, acromioplasty cannot be recommended as a routine technique in every rotator cuff repair.     

Imaging for whom: patient or physician?

OBJECTIVE: Radiologic imaging examinations are being ordered beyond the margin of medical necessity. Radiologists can assess the value of imaging in a variety of clinical situations by gathering data regarding test ordering patterns and their effects on patient outcomes. CONCLUSION: Emerging information technologies have the potential to facilitate the collection of data and permit the dissemination of appropriate guidelines to limit the number of unnecessary and possibly harmful examinations.     

Maximum Diameter Measurements of Aortic Aneurysms on Axial CT Images After Endovascular Aneurysm Repair: Sufficient for Follow-up?

Purpose

To assess the accuracy of maximum diameter measurements of aortic aneurysms after endovascular aneurysm repair (EVAR) on axial computed tomographic (CT) images in comparison to maximum diameter measurements perpendicular to the intravascular centerline for follow-up by using three-dimensional (3D) volume measurements as the reference standard.

Materials and Methods

Forty-nine consecutive patients (73?±?7.5?years, range 51?C88?years), who underwent EVAR of an infrarenal aortic aneurysm were retrospectively included. Two blinded readers twice independently measured the maximum aneurysm diameter on axial CT images performed at discharge, and at 1 and 2?years after intervention. The maximum diameter perpendicular to the centerline was automatically measured. Volumes of the aortic aneurysms were calculated by dedicated semiautomated 3D segmentation software (3surgery, 3mensio, the Netherlands). Changes in diameter of 0.5?cm and in volume of 10% were considered clinically significant. Intra- and interobserver agreements were calculated by intraclass correlations (ICC) in a random effects analysis of variance. The two unidimensional measurement methods were correlated to the reference standard.

Results

Intra- and interobserver agreements for maximum aneurysm diameter measurements were excellent (ICC?=?0.98 and ICC?=?0.96, respectively). There was an excellent correlation between maximum aneurysm diameters measured on axial CT images and 3D volume measurements (r?=?0.93, P?r?=?0.93, P?Conclusion Measurements of maximum aneurysm diameters on axial CT images are an accurate, reliable, and robust method for follow-up after EVAR and can be used in daily routine.     

Assessment of abstracts submitted for the 1998 BNMS annual meeting: concordance or lottery?

The selection of abstracts for presentation at the Annual Meeting of the British Nuclear Medicine Society is an arduous task for the assessors. It is only to be expected that assessors' appreciation of an abstract will be biased by their interests and knowledge. This study assessed the concordance between the marks awarded by specialist and general assessors for the 173 abstracts submitted to the 1998 Spring BNMS meeting. The results showed considerable agreement among the markers for most comparisons. We conclude that the current combination of specialist assessors evaluating specific sections and three generalists assessing all abstracts appears to be working well.     

Dosimetry of yttrium-labelled radiopharmaceuticals for internal therapy: 86Y or 90Y imaging?

This paper reviews issues concerning (86)Y positron emission tomography (PET), (90)Y PET and (90)Y bremsstrahlung imaging. Specific methods and corrections developed for quantitative imaging, for application in preclinical and clinical studies, and to assess (90)Y dosimetry are discussed. The potential imaging capabilities with the radioisotopes (87)Y and (88)Y are also considered. Additional studies required to assess specific unaddressed issues are also identified.     

Survival of the fittest? The scientific basis for the Royal Navy pre-joining fitness test

The Royal Navy introduced a pre-joining fitness test to the selection procedures for RN Ratings from Summer 2003. The scientific basis for the test came from the present study to investigate if anthropometric and physical fitness measures predicted training failure. Fitness and anthropometric data from 1641 trainees were collected, together with their training outcome (i.e. pass or fail), during the period from September 2001 to March 2002. In addition, a retrospective interrogation of medical records identified those who reported any lower limb injuries. The overall rate of training attrition was 22%. Success in training was associated with: gender; age; physical fitness; and, in the case of females, Body Mass Index (BMI). The reported incidence of lower limb injury (LLI) was associated with: gender; physical fitness; and, for female trainees, BMI. The reported incidence of LLI was approximately 50% in the 'least-fit' female group compared to 10% in the 'most-fit' male group. 16% of females and 2% of males were considered 'unfit' (i.e. did not attain the prescribed run standards of 13 min 15 s and 11 min 13 s respectively). 3% of trainees were considered 'obese' (a BMI > 30 kg.m-2) whereas more than 25% were overweight (BMI > 25 kg.m-2). As a result of this work, selection candidates must now demonstrate a minimum standard of aerobic fitness prior to arrival at HMS Raleigh. The future impact of this selection measure on the reported incidence of lower limb injury and financial costs of training requires further investigation.