When the diameter of the abdominal aorta should be considered as abnormal? A new ultrasonographic index using the wrist circumference as a body build reference.

PURPOSE: To use US to evaluate the normal values of aortic diameter (AD), stratifying the population by age, gender and body build, as measured using wrist circumference (WC). MATERIALS AND METHODS: Between April 2010 and February 2012, consecutive patients ≥ 30 years of age, without history of abdominal aortic aneurysm (AAA) were prospectively enrolled. They underwent an abdominal ultrasonography for reasons other than aorta evaluation. AD was measured at the infrarenal (AD1), intermediate (AD2), and iliac bifurcation (AD3) levels: a diameter ≥ 3 cm was considered as an aneurysm. The maximal aortic diameter (AD(max)) was measured for AAA patients. WC was measured; AD/WC ratio was calculated and presented in percentage: the range of normal values was obtained excluding AAA cases and calculated as mean ± 1.96 × standard deviation. Pearson correlation coefficient was used. RESULTS: We recruited 1200 patients, 15 (1.25%; age range=64-86 years) had AAA. AD ranges of the other patients were: AD1=0.74-1.84 cm, AD2=0.78-1.85 cm, and AD3=0.68-1.76 cm for females; AD1=0.86-2.02 cm, AD2=0.91-2.08 cm, and AD3=0.84-1.95 cm for males. AD2/WC ratio of non-AAA patients range was 4-15%, with only one outlier at 18%, while AD(max)/WC ratio of AAA patients range was 15-35% (p<0.001). ADs were significantly correlated with WC (r=0.253, p<0.001 for AD1, r=0.318, p<0.001 for AD2 and r=0.280, p<0.001 for AD3). CONCLUSION: The definition of normal AD should consider body build. An AD2/WC ratio of 15% may be regarded as a threshold to differentiate AAA- from non-AAA patients. Patients with AD2/WC values comprised between 12% and 15% may be at risk for AAA.

Performance assessment of four 64-slice computed tomographic devices for a typical clinical protocol.

OBJECTIVE: To compare the performances of four 64-slice CT devices, as regards radiation dose and image quality. METHODS: Effective dose was measured with thermoluminescent dosimeters in an Alderson Rando phantom (Alderson Research Laboratories, New York, NY). Quantitative image quality was evaluated in a Catphan 600 phantom (The Phantom Laboratory, New York, NY) using 3 parameters (modulation transfer function, contrast-to-noise ratio, and figure of merit). Effective and main organ doses were measured in 40 patients (10 for each CT device), who underwent an abdominal study with the same standard protocol; moreover, in these patients, clinical image quality, using a 5-grade quality score, was assessed. RESULTS: In-phantom measured doses and quantitative image quality showed some differences among the 4 devices. On the contrary, effective and organ doses provided to the patients were similar; no statistically significant differences were found also for clinical image quality. CONCLUSIONS: Some differences were found among the 4 devices from a physical point of view; on the other hand, the patient data were similar.

Screening mammography interpretation test: more frequent mistakes.

PURPOSE: To present the mammographic cases most commonly misinterpreted by the participants in the mammography self-test proposed by the Italian Society of Medical Radiology (SIRM) National Congress in Rimini, Italy, 2002, by analysing the findings responsible for errors, suggesting reasons for the errors, and assessing possible inadequacies in the format of the test. MATERIALS AND METHODS: The self-test was performed on the mammograms of 160 cases (32 positive and 128 negative for cancer as confirmed by histology). The mammograms had been taken in the four standard projections and placed on four multi-panel diaphanoscopes, each displaying a set of 40 cases comprising benign and malignant cases in equal proportions. The participants were given pre-printed forms on which to note down their diagnostic judgement. We evaluated a total of 134 fully-completed forms. Among these, we identified the 23 cases most frequently misread by over 15 participants in percentages varying between 40-90%. Of these cases, 10 were malignancies and 13 were negative mammograms. On review, we also assessed the diagnostic contribution of complementary investigations (not available the participants). RESULTS: The 134 fully-completed forms (all of the 40 cases) yielded a total of 5360 responses, 1180 of which (22.01%) were incorrect. Of these, 823 out of the 4288 cases expected to be negative (19.2%) were false positive, and 357 out of the 1072 cases expected to be positive (33.3%) were false negative. As regards the 23 most frequently misread cases, these were 10/32 (31.25%) mammograms positive for malignancy and 13/128 (10.15%) negative mammograms or mammograms showing benign disease. The 10 malignancies included 7 infiltrating ductal carcinomas, 1 infiltrating cribriform carcinoma, 1 infiltrating tubular carcinoma, and 1 carcinoma in situ. The 13 cases of benign disease--as established by histology or long-term follow-up--mistaken for malignancies by the test participants were fibrocystic breast disease in 5 cases, surgical scar in 1 case, ABBI scar in 1 case, radial scar in 2 cases, microcalcifications that had remained stable for years in 2 cases, focal sclero-adenosis in 1 case and sclero-elastosis in 1 case. CONCLUSIONS: The errors were due to microcalcifications, benign disease simulating a neoplasm, overlapping tissue, visibility of a lesion in one projection only, lesion site in relation to the corpus mammae, missed areas of asymmetry. Attention must be paid to these signs of focal breast disease since, if correctly evaluated, they enable the early diagnosis of low-grade carcinomas that frequently carry a favourable prognosis.

Quality assurance in diagnostic radiology: practical outcomes.

Over the last four years, our Health Physics Department has implemented a quality control programme focusing on the performance of the diagnostic X-ray machines in use at our hospital. The results of the tests performed (X-ray and light field alignment, tube voltage reproducibility and accuracy, ) were used to compare the 1999 and 2002 findings by means of the chi squared and Fischer statistical tests. The comparison has demonstrated that the decrease in the number of non-conformities, also emerging from a simple comparative analysis on the experimental data, was statistically significant with a p<0.05 for all of the X-ray machines examined. This finding confirms that our quality control programme had positive effects on the overall performance of the hospital diagnostic X-ray equipment, and appears to justify the resources employed for its implementation.