Radiology Key

(3.1) where N is the number of radioactive atoms present, and λ is referred to as the decay constant of the radionuclide . As can be seen from Eq. (3.1), it…

Fig. 12.1 Four slices of the heart in the short axis In nuclear medicine, two types of ECT have been in practice based on the type of radionuclides used: single…

(14.1) It should be noted that the roentgen applies only to air and to x- or γ-radiations. Because of practical limitations of the measuring instruments, the R unit is applicable…

Radionuclides Half-life Mode of decay (%) E β  + max(MeV) 11C 20.4 min β + (100) 0.970 13N 10 min β + (100) 1.2 15O 2 min β + (100) 1.74 18F 110 min β + (97) 0.64   EC (3)  68Ga 68 min β + (89)…

(10.1) The smaller numerical values of R o indicate better resolution and vice versa. Intrinsic Resolution Intrinsic resolution, R i , is the component of spatial resolution contributed by the…

Detectors Effective Atomic no (Z) Density (g/cm3) Scintillation decay time (ns) Photon yield (per keV) NaI(T1) 51 3.67 250 38 BGO 74 7.13 300 6 BaF2 54 4.89 0.6 2…

(1.1) where E is energy in ergs , m is the mass in grams, and c is the velocity of light in a vacuum given as 3 × 1010 cm/s. This relationship states…

Fig. 15.1 Structure of a typical mammalian cell. The nucleus contains chromosomes , which have a threadlike structure of two arms connected by a centromere (Fig. 15.2). Chromosomes are formed of…

Fig. 6.1 Illustration of Bragg ionization showing a peak near the end of the travel of the charged particle Linear Energy Transfer The linear energy transfer (LET) is the amount…

Fig. 2.1 Isometric transition of 99mTc. Ten percent of the decay follows internal conversion. Gamma (γ)-Ray Emission The common mode of an isomeric transition from an upper energy state of a…