Coaxial cutting needle biopsies: how important is it to rotate the cutting needle between passes?

AIM: To use an in-vitro model to measure the effect of turning the notch of the cutting needle between passes on the mass of core biopsy material obtained from a typical coaxial biopsy system when multiple passes are performed. METHODS: A coaxial guide needle was placed within tissue-equivalent agar cylinders and a cutting biopsy needle was used to take core biopsies. Two, three, or four sequential biopsies were performed on the same cylinder with the notch of the cutting needle either inserted facing in the same direction (no rotation) or placed in a sequence of different directions (rotation). The mass of the tissue core obtained at each biopsy pass was measured. A post hoc telephone questionnaire of radiologists across Australia was also undertaken to analyse current practice in the context of these results. RESULTS: There were statistically significant increases in the mass of tissue obtained using rotation compared with no rotation. Using rotation, the total mass of tissue obtained from three passes was increased by 32.8% (95% CI 23.9-41.7%) and from four passes was increased by 45% (95% CI 37.2-52.9%). The mass of the second pass cores was statistically significantly greater (p<0.001). Fifty-nine percent of Australian radiologists surveyed do not currently change the rotation of the biopsy needle between passes. CONCLUSION: This in-vitro model confirms that the notch of the cutting needle should be placed into different directions at each pass whenever a coaxial cutting biopsy system is being used to maximize the mass of tissue obtained.     

Screening for cancer: when is it valid?--Lessons from the mammography experience

There is increasing interest in the development of imaging tests to screen for diseases such as cancer. Mammographic screening for breast cancer has undergone greater scrutiny than any other test. Many important lessons have been learned from the issues that have been raised with regard to mammographic screening. Those interested in developing new screening tests can learn from the mammography experience.     

Calcium scoring and chest pain: is it dead on arrival?

Coronary artery calcium (CAC) scoring has been shown to be a measure of overall coronary artery disease (CAD) burden and is a well-validated screening test that significantly improves cardiovascular risk prediction in asymptomatic adults beyond that provided with standard risk factors. The absence of coronary artery calcification identifies persons at very low cardiovascular risk. Among symptomatic patients, calcium scans have been shown to have high sensitivity for the presence of obstructive CAD among stable, low-intermediate risk middle-aged adults. This has prompted many to advocate for the expanded use of calcium scanning as a diagnostic test in symptomatic patients to rapidly identify patients without CAD, serving as a filter for invasive coronary angiography or hospital admission or both. However, recent studies suggest that the negative predictive value of CAC scoring to exclude obstructive CAD may be significantly decreased among patients at higher pretest likelihood for obstructive CAD, consistent with Bayesian reasoning. In a point-counterpoint format, this article discusses several considerations and potential limitations to the widespread use of CAC to exclude obstructive CAD in symptomatic patients which include (1) the effect of pretest disease prevalence on test accuracy, (2) limited clinical efficiency due to low specificity for obstructive CAD and myocardial ischemia and high background prevalence of CAC in adults, (3) occurrence of CAC relatively late in the atherosclerotic process, (4) lack of association of CAC with vulnerable and culprit coronary artery lesions, and (5) interindividual and racial heterogeneity in the process of atherosclerosis calcification.     

Proximal iliotibial band syndrome: what is it and where is it?

Objective  

To describe the clinical and MR imaging features of a unique strain at the iliac tubercle enthesis. While this strain appeared to correspond to the iliotibial band (IT band) enthesis, the literature regarding the IT band origin was discrepant. As such, our second goal was to prove that the IT band originated at the iliac tubercle, through cadaveric dissection.     

MRI in cystic pancreatic lesions,is it of value?

Introduction

Cystic pancreatic lesions are currently discovered at higher rate, hence adequate characterization of these lesions by the radiologist is important in guiding management.

Radon: is it a problem?

Radon gas is a major source of radiation exposure to the general public. Radon-222 is a product of uranium-238, present in varying concentrations in all soils. Radon enters buildings from soil, water, natural gas, and building materials. Its short-lived breakdown products, termed "radon daughters," include alpha-emitting solids that can deposit in the lungs. Firm evidence links lung cancer risk in miners with high exposure to radon daughters. The amount of risk associated with the much lower but chronic doses received in buildings is difficult to establish. By some extrapolations, radon daughters may be responsible for a significant number of lung cancer deaths. The existence or extent of synergism with smoking is unresolved. Local conditions can cause high levels of radon in some buildings, and measures that reduce indoor radon are of potential value.