Microdose mammography.

Tens of thousands of mammograms are performed daily in the United States. Accumulated radiation biologic data suggest that approximately 90-rad is the level of radition to the breast above which the incidence of cancer may be increase. A microdose system of roentgenography is described that provides better images at one-third to one-fifth the exposure of the commonly used low-dose system and about one-eight to one-tenth the dose of Xeromammography. This system should allow for repeated x-ray study in a patient as required, without exceeding the critical level.

Congenital absence of lumbar articular facets. Report of two cases.

X-ray evidence of an absent lumbar facet is usually considered to be indicative of the presence of an osteolytic bone lesion but on rate occasions may be due to a congenital anomaly. Two cases of the congenital absence of a lumbar superior articular facet suggest that this anomaly is not symptom-producing, and in one case was discovered incidentally in a patient without back pain yet led to the performance of a major surgical diagnostic operation. While, rare, a greater awareness of this condition, as clearly defined in the literature on the subject, might occasionally eliminate the need for a similar surgical procedure.