Adnexal torsion is characterized by partial or complete rotation of the suspensory ligament of the ovary and its corresponding vascular pedicle, resulting in vascular impairment that can culminate in hemorrhagic infarction, as well as necrosis of the ovary and fallopian tube. Because there are myriad causes of acute pelvic pain, the differential diagnosis of ovarian torsion is often challenging. Consequently, radiologists should be familiar with the main imaging findings. In this regard, there are typical signs of ovarian torsion on magnetic resonance imaging, including increased ovarian volume with stromal edema and peripheral distribution of the ovarian follicles, as well as thickening of the fallopian tube, an adnexal mass (causal factor) that shifts toward the midline, and the classic, pathognomonic “whirlpool sign”. The objective of this essay was to review and illustrate the various magnetic resonance imaging findings in ovarian torsion.

Epidemiological studies of Paget's disease of bone (PDB) have shown a remarkable geographical variation in the prevalence rates of the disease. In South America, the frequency is considered to be low, despite scant epidemiological data on this continent regarding the disease. The aim of this study was to evaluate the prevalence and incidence of PDB in one institution in the city of Recife, Northeast Brazil. All patients aged 45 years and over attending the Pernambuco Osteoporosis Centre at the Endocrine and Diabetes Department between January 2006 and December 2009 were assessed. Period prevalence and incidence density were calculated for each year for males and females separately, with confidence intervals and hypothesis test for difference between proportions. A total of 7,752 patients were assessed of which 53 presented with PDB. The total prevalence was 6.8 per 1,000 patients, and the incidence density for PDB was 50.3 per 10,000 person-years. Both prevalence and incidence increased during the period. Our data show that prevalence and incidence rates of PDB in Recife are comparable to those from Southern Europe. To our knowledge, this is the first epidemiological study of PDB in South America.