Table 1.

Medical image dimensions and bit depth for various image modalities [21]

Modality	Image dimension (pixels)	Gray level (bits)	Avg. size/exam (Mbytes)
Nuclear medicine (PET, SPECT)	128 × 128	12	1–2
Magnetic resonance imaging	256 × 256	12	8–20
Ultrasound	512 × 512	8	5–10
Computed tomography	512 × 512	12	20–40
Spiral or helical CT	512 × 512	12	80–160
Digitized electronic microscopy	512 × 512	8	Varies
Digitized color microscopy	512 × 512	24	Varies
Digital subtraction angiography (per run)	512 × 512 or 1024 × 1024	8	100–500
Digitized X-rays	2048 × 2048	12	8
Computed radiography	2048 × 2048	12	8
Digitized mammography	4096 × 4096	12	128 (4 images)