Scott analyzes whether whole-body screening MRIs are worth it by doing a detailed cost-benefit calculation, finding they cost about $108,000 per quality-adjusted life-year saved (right around the threshold of cost-effectiveness), and argues that while rich people immune to anxiety might benefit, most people claiming to be rational about medical decisions probably aren't. Longer summary

Scott performs a detailed cost-benefit analysis of whole-body screening MRIs in response to controversy over medical experts recommending against them. Using rough order-of-magnitude estimates, he calculates that screening 1,000 people saves about 32 quality-adjusted life-years (QALYs) at a cost of $2.7 million plus time and anxiety costs, working out to about $108,000 per QALY saved—right at the threshold of cost-effectiveness. He explores whether rich people who don't care about money should get screened, finding a plausible case but with many caveats about unknown factors that could swing the calculation either way. He then applies this analysis to Midjourney's proposed ultrasound scanner, finding it's unlikely to be clearly better than MRI. The post ends with a warning that people who think they're rational enough to ignore false positives are often the same people making irrational medical decisions based on contrarian appeals. Shorter summary

Scott explains why Midjourney's new ultrasound tomography scanner, despite being technologically interesting, faces major medical limitations and is unlikely to replace existing imaging methods or enable useful whole-body screening without significant future AI improvements. Longer summary

Scott analyzes Midjourney's announcement of a new medical scanner that uses ultrasound tomography to create 3D images of the body. He explains why, despite being technologically interesting, the scanner faces significant medical limitations: ultrasound cannot penetrate bone or air, limiting its usefulness compared to existing MRI and CT scans; it can't replace portable bedside ultrasound due to requiring patients to be submerged in water; and whole-body screening scans (even with existing superior MRI technology) are currently not recommended by medical consensus due to false positives causing more harm than benefit. Scott suggests the technology might become more viable if future AI advances dramatically improve ultrasound interpretation, wave dynamics for imaging through bone, and the ability to distinguish dangerous findings from harmless abnormalities. The post includes an appendix with Twitter responses from radiologists (universally negative) and other commenters (more optimistic), discussing potential applications like body composition measurement and the challenges of medical screening. Shorter summary