Determination of surface areas, volumes, and lengths of cynomolgus monkey nasal cavities by ex vivo magnetic resonance imaging.

We have used high-resolution three-dimensional magnetic resonance imaging (MRI) to measure the surface area, volume, and length of the nasal cavities of cynomolgus monkeys (10 male, six female) over a range of body weights (1.9-5.3 kg, mean 2.9 kg) and ages (8-45 months, mean 30.0 months). The measurements were carried out ex vivo on formalin-fixed, decalcified nasal cavities filled with water. Mean (standard deviation) values were 30.2 (7.2) cm(2), 2.33 (0.65) cm(3), and 3.34 (0.44) cm, respectively. Linear regression least squares best fits provide the following empirical relationships: Nasal cavity surface area (SA, cm(2)) as a function of body weight (BW, kg): SA = 15.1 + 5.1(BW), R = 0.84 Nasal cavity volume (V, cm(3)) as a function of body weight: V = 1.15 + 0.4(BW), R = 0.74 Nasal cavity length (L, cm) as a function of body weight: L = 2.43 + 0.31(BW), R = 0.84 The left and right sides of the cavity were symmetrical in both males and females and showed little anatomical variation between individuals. The perimeter of the nasal cavity was maximal at about 60% of its extent from the nares. These data can aid in extrapolating nasal dosimetric exposure indices from cynomolgus monkeys (1.9-5.3 kg) to other species.