Radiology Key

Figure. 2.1 Speed of sound . The speed of sound is constant for a specific material and does not vary with frequency. Speed of sound for various biological tissues is…

Thyroid gland Characteristic Size Measure sagittal × AP × transverse dimensions Unusual shape Note and measure extension of lobe(s) below clavicles, pyramidal lobe, and thyroglossal duct masses Echotexture Homogeneous or…

Figure 5.1 Goitrous thyroid in congenital hypothyroidism . Axial CT images (a–c) show a massively enlarged thyroid (arrows) in a 5-month-old with a TSH over 300. Full ultrasonic visualization of…

Figure 4.1 Ultrasound console units are manufactured in numerous versions. Shown here are the clinic- or radiology-based platform (a) and the portable, laptop-sized unit that can be mounted on a…

Figure 9.1 Superior parathyroid adenoma seen in longitudinal view. Indentation sign. (a) Upper PA, craniocaudal view, note indentation. (b) Upper PA, note indentation sign, and long pencil shape. (c) Small…

Figure. 3.1 Illustration of the Doppler shift . When a moving target reflects a sound, the frequency of the reflected sound wave is altered. The frequency is shifted up by…

Ultrasound pattern Estimated risk of malignancy (%) FNA size threshold High suspicion >70–90 ≥1 cm (repeat FNA within 12 months if initial cytology is benign) Intermediate suspicion 10–20 ≥1 cm…

Figure 13.1 Ultrasound image of a three-fiber thyroid nodule laser ablation in a transverse US B-mode scan. Laser marks are seen as anechoic spots surrounded by hyperechoic rims. These are…

  Median sensitivity (range) Median specificity (range) Hypoechoic c/w surrounding thyroid [6–12, 14, 15, 17–20] 81% (48–90%) 53% (36–92%) Marked hypoechogenicity c/w strap muscle [13, 18, 20] 41% (27–59%) 94%…

Figure 16.1 (a–d) Three dif ferent strain elastography images of a solid isoechoic right thyroid nodule measuring 37 × 17 × 18 mm; FNAB was positive for PTC. The result…