Table 2.

Different configurations of piezoelectric ultrasound transducer arrays that are used in clinical applications of photoacoustic imaging. BW: bandwidth.

Application	Element no.	Configuration	Center Frequency (MHz)	BW (%)	Ref
Breast cancer	588	Hemispherical	1	130	[87]
	512	Hemispherical	2	>100	[88]
	64	Arc	1.5	130	[89]
Dermatology	Single	Spherically focused	54.2	97	[90]
			102.8	105	[91]
Vascular	Single	Focused	50	70	[92]
	256	Linear	21	66	[93]
Carotid vessel	128	Linear	5	80	[94]
	Single	Spherically focused	100	80	[95]
Musculoskeletal	32	Unfocused	6.25	80	[96]
	128	Linear	11.25	75	[97]
Adipose tissue	256	Curved	5	60	[98,99]
Thyroid	192	Linear	5.8	82.7	[100]
	64	Arc	7.5	NA	[101]
Gynecology &Urology	128	Microconvex	6.5	NA	[102,103]

NA: not available.