Roentgen study of gross surgical specimens has been found to offer certain advantages under a variety of circumstances. Some of the information that can be obtained in this way will be considered here. After the superfluous blood and fluid are drained off, the specimen may be placed upon absorbent paper and carried to the department of roentgenology for immediate radiography. The hemostats may be left in place, especially for studies of the intestinal tract. A lead arrow will serve readily to indicate either the oral or caudal end of the specimen. Suitable identification similar to that used in routine roentgen examinations should be incorporated in the radiograph—the date, case number, and indication as to the side, left or right. The specimen, with clean absorbent paper, is placed upon a cassette of suitable size and the exposure is made. A brief résumé of the technical factors is given in Table I. All examinations should be made on the table top of the radiographic unit, with par-speed intensifying screens in the cassette. The cassette size depends on the size of the specimen; the usual dimensions are 6 1/2 × 8 1/2, 8 × 10, or 10 × 12 inches. All exposures are made at 30 inches, with a cone to cover the cassette. The films are developed like any other film, usually for three and a half to four minutes. The selection of kilovoltage is based upon the usual thickness of the part, on the assumption that moderate collapse and flattening of the specimen will occur. For every additional 1.0 cm. thickness of part 2.0 kv may be added. The only exception to this is Category 4, where an occlusal film may be used. A small calculus or chicken bone does not measure 1 cm. in thickness, but with the reduced milliampere-second ratio, increased kilovoltage is needed to obtain a satisfactory image. Since screens are not used in the small film holders employed for this type of exposure, a longer developing time may be needed. With practice, a skilled technician will readily become adept in this procedure. Cardiac and Vascular Lesions Frequently on acute fluoroscopic scrutiny a calcified plaque may be identified in the pericardium, a vascular orifice, or in one of the cardiac valvular cusps. The aortic and mitral valves are more commonly the site of such deposits, but accurate localization by radiographic or fluoroscopic study is difficult. A black and white photograph will not show to advantage the location of these plaques, but on a radiograph of the specimen they are readily localized as to chamber or vascular stem. Similarly, the identity of a cardiac or aortic aneurysm with or without calcification can definitely be determined. Coronary artery sclerosis is also easily demonstrated. Pulmonary Lesions Verification of partial pulmonary sequestration incident to a broncholith is readily accomplished by a radiograph of a segment of resected lung. The same is true for an hemangiomatous vascular anomaly.