Feasibility of low-dose CT with model-based iterative image reconstruction in follow-up of patients with testicular cancer

PURPOSE

We examine the performance of pure model-based iterative reconstruction with reduced-dose CT in follow-up of patients with early-stage testicular cancer.

METHODS

Sixteen patients (mean age 35.6 ± 7.4 years) with stage I or II testicular cancer underwent conventional dose (CD) and low-dose (LD) CT acquisition during CT surveillance. LD data was reconstructed with model-based iterative reconstruction (LD-MBIR). Datasets were objectively and subjectively analysed at 8 anatomical levels. Two blinded clinical reads were compared to gold-standard assessment for diagnostic accuracy.

RESULTS

Mean radiation dose reduction of 67.1% was recorded. Mean dose measurements for LD-MBIR were: thorax - 66 ± 11 mGy cm (DLP), 1.0 ± 0.2 mSv (ED), 2.0 ± 0.4 mGy (SSDE); abdominopelvic - 128 ± 38 mGy cm (DLP), 1.9 ± 0.6 mSv (ED), 3.0 ± 0.6 mGy (SSDE). Objective noise and signal-to-noise ratio values were comparable between the CD and LD-MBIR images. LD-MBIR images were superior (p < 0.001) with regard to subjective noise, streak artefact, 2-plane contrast resolution, 2-plane spatial resolution and diagnostic acceptability. All patients were correctly categorised as positive, indeterminate or negative for metastatic disease by 2 readers on LD-MBIR and CD datasets.

CONCLUSIONS

MBIR facilitated a 67% reduction in radiation dose whilst producing images that were comparable or superior to conventional dose studies without loss of diagnostic utility.

The joint contribution of sex, age and type of myocardial infarction on hospital mortality following acute myocardial infarction

OBJECTIVE

Younger, but not older, women have a higher mortality than men of similar age after a myocardial infarction (MI). We sought to determine whether this relationship is true for both ST elevation MI (STEMI) and non-ST elevation MI (NSTEMI).

DESIGN

Retrospective cohort study.

SETTING

1057 USA hospitals participant in the National Registry of Myocardial Infarction between 2000 and 2006.

PATIENTS

126 172 STEMI and 235 257 NSTEMI patients.

MAIN OUTCOME MEASURE

Hospital death.

RESULTS

For both STEMI and NSTEMI, the younger the patient's age, the greater the excess mortality risk for women compared with men, while older women fared similarly (STEMI) or better (NSTEMI) than men (p<0.0001 for the age-sex interaction). In STEMI, the unadjusted women-to-men RR was 1.68 (95% CI 1.41 to 2.01), 1.78 (1.59 to 1.99), 1.45 (1.34 to 1.57), 1.08 (1.02 to 1.14) and 1.03 (0.98 to 1.07) for age <50 years, age 50-59, age 60-69, age 70-79 and age 80-89, respectively. For NSTEMI, corresponding unadjusted RRs were 1.56 (1.31 to 1.85), 1.42 (1.27 to 1.58), 1.17 (1.09 to 1.25), 0.92 (0.88 to 0.96) and 0.86 (0.83 to 0.89). After adjusting for risk status, the excess risk for younger women compared with men decreased to approximately 15-20%, while a better survival of older NSTEMI women compared with men persisted.

CONCLUSIONS

Sex-related differences in short-term mortality are age-dependent in both STEMI and NSTEMI patients.

A prototype sourceless kinematic-feedback based video game for movement based exercise

This paper presents a prototype kinematic and audio feedback based video game, availing of a scalable motion capture acquisition system, based around a number of orientation sensors. The orientation sensors used are USB based tri-axis magnetic and gravitational field transducers. The novel video-game is capable of incorporating the real time data from these sensors to control an on screen avatar, which in turn can be programmed to give appropriate instructions to the user i.e. play a sound file, once the user obtains a certain posture. The video game is designed to promote physical exercise and movement based relaxation, in particular; yoga. In addition, design considerations; implementation and performance of the system are analyzed, discussed and the accuracy qualitatively analyzed by comparing movement data obtained from it to that of a validated motion analysis technique, the CODA motion analysis system.