Automatic Detection of Fetal Nasal Bone in 2 Dimensional Ultrasound Image Using Map Matching

Recent study shows that fetal chromosomal abnormalities can be detected in early ultrasonic prenatal screening by identifying the absence of fetus nasal bone. The drawbacks of current method are operator dependent, observer variability and its inefficiency. In particular, accurate nasal bone detection requires highly trained sonographers and obstetrics and gynecology specialists since the ultrasound markers may easily confuse with noise and echogenic line in ultrasound image background. We present a computerized method of detecting the absent of nasal bone by using map matching computerized method. Image preprocessing is implemented prior map matching based on image correlation to assess the availability of nasal bone. The resultant threshold bordering the absent and present of nasal bone is set to value 0.35. The threshold can be further improved if a larger set of nasal bone ultrasound images applied. Key-Words: Chromosomal abnormalities, nasal bone, mapping matching, ultrasound image