Will Morton, a staff writer for AuntMinnie.com, published an article about safety issues during magnetic resonance imaging. It begins
As the push toward stronger and faster MRI scanners continues, so does concern over magnet safety, according to Filiz Yetisir, who discussed the potential effects MRI has on patients at the…
In Chapter 14 of Intermediate Physics for Medicine and Biology, Russ Hobbie and I discuss photodynamic therapy.
Photodynamic therapy (PDT) uses a drug called a photosensitizer that is activated by light (Zhu and Finlay 2008; Wilson and Patterson 2008). PDT can treat accessible solid tumors such as basal cell carcinoma…
In Chapter 9 of Intermediate Physics for Medicine and Biology, Russ Hobbie and I mention electroporation.
Electrical burns, cardiac pacing, and nerve and muscle stimulation are produced by electric or rapidly changing magnetic fields. Even stronger electric fields increase membranepermeability. This is believed to be due to the transient formation…
A physicist working in medicine or biology needs to know some biochemistry. Not much, but enough to understand the structure and function of the most important biological molecules. For instance, one type of molecule that plays a key role in biology is protein. …
When discussing the biological effects of radiation in Intermediate Physics for Medicine and Biology, Russ Hobbie and I describe the bystander effect.
Ionization damage is not the entire story. The bystander effect in radiobiology refers to the “induction of biological effects in cells that are not directly traversed by a…
In Chapter 15 of Intermediate Physics for Medicine and Biology, Russ Hobbie and I discuss Compton Scattering. An incident photon scatters off a free electron, producing a scattered photon and a recoiling electron. We write
The inclusion of dynamics, which allows us to determine the relative number of photons scattered…
In Chapters 9 and 11 of Intermediate Physics for Medicine and Biology, Russ Hobbie and I discuss shot noise.
9.8.1 Shot Noise
The first (and smallest) limitation [on our ability to measure current] is called shot noise. …
The metric system is based on three fundamental units: the kilogram (kg, mass), the meter (m, distance), and the second (s, time). Often a combination of these three is given a name (called a derived unit), usually honoring a famous scientist. For example, a newton, the unit of force named…
Phys. Med. Biol.,
43:3083–3099.
Sometimes proponents of pseudoscience embrace nonsense, but other times they propose plausible-sounding ideas that are wrong because the numbers don’t add up. For example, suppose you are discussing with your friend about the biological effects of power-line magnetic fields. Your friend might say something like this:
The central slice theorem is key to understanding tomography. In Intermediate Physics for Medicine and Biology, Russ Hobbie and I ask the reader to prove the central slice theorem in a homework problem. Proofs are useful for their generality, but I often understand a theorem better by working an example…
