Ultrasonography (US) with a high-frequency (7.5-10-MHz) transducer has become the imaging modality of choice for examination of the scrotum. US examination can provide information valuable for the differential diagnosis of a variety of disease processes involving the scrotum that have similar clinical manifestations (eg, pain, swelling, or presence of mass). The pathologic condition that may be at the origin of such symptoms can vary from testicular torsion to infection to malignancy. The ability of color and power Doppler US to demonstrate testicular perfusion aids in reaching a specific diagnosis in patients with acute scrotal pain. This review covers the anatomy of the scrotum and the scanning protocol for scrotal US, as well as detailed descriptions of disease processes and their US appearances. Newly described conditions such as intratesticular varicoceles and other benign intratesticular cystic lesions are also discussed.

Ovarian torsion is defined as partial or complete rotation of the ovarian vascular pedicle and causes obstruction to venous outflow and arterial inflow. Ovarian torsion is usually associated with a cyst or tumor, which is typically benign; the most common is mature cystic teratoma. Ultrasonography (US) is the primary imaging modality for evaluation of ovarian torsion. US features of ovarian torsion include a unilateral enlarged ovary, uniform peripheral cystic structures, a coexistent mass within the affected ovary, free pelvic fluid, lack of arterial or venous flow, and a twisted vascular pedicle. The presence of flow at color Doppler imaging does not allow exclusion of torsion but instead suggests that the ovary may be viable, especially if flow is present centrally. Absence of flow in the twisted vascular pedicle may indicate that the ovary is not viable. The role of computed tomography (CT) has expanded, and it is increasingly used in evaluation of abdominal pain. Common CT features of ovarian torsion include an enlarged ovary, uterine deviation to the twisted side, smooth wall thickening of the twisted adnexal cystic mass, fallopian tube thickening, peripheral cystic structures, and ascites. Understanding the imaging appearance of ovarian torsion will lead to conservative, ovary-sparing treatment.

Ectopic pregnancy accounts for approximately 2% of all pregnancies and is the most common cause of pregnancy-related mortality in the first trimester. Initial evaluation consists of hormonal assays and pelvic ultrasonography (US). A history of pelvic pain along with an abnormal beta human chorionic gonadotropin level should trigger an evaluation for an ectopic pregnancy. The fallopian tube is the most common location for an ectopic pregnancy. An adnexal mass that is separate from the ovary and the tubal ring sign are the most common findings of a tubal pregnancy. Other types of ectopic pregnancy include interstitial, cornual, ovarian, cervical, scar, intraabdominal, and heterotopic pregnancy. Interstitial pregnancy occurs when the gestational sac implants in the myometrial segment of the fallopian tube. Cornual pregnancy refers to the implantation of a blastocyst within the cornua of a bicornuate or septate uterus. An ovarian pregnancy occurs when an ovum is fertilized and is retained within the ovary. Cervical pregnancy results from an implantation within the endocervical canal. In a scar pregnancy, implantation takes place within the scar of a prior cesarean section. In an intraabdominal pregnancy, implantation occurs within the intraperitoneal cavity. Heterotopic pregnancy occurs when an intrauterine and an extrauterine pregnancy occur simultaneously. A spectrum of intra- and extrauterine findings may be seen on US images. Although many of the US findings are nonspecific by themselves, when several of them are seen, the specificity of US in depicting an ectopic pregnancy substantially improves.

OBJECTIVE. The goal of this pictorial essay is to illustrate the multimodality imaging features of pleural and extrapleural solitary fibrous tumors.CONCLUSION. Solitary fibrous tumors tend to be well-defined, ovoid, heterogeneously enhancing lesions. MRI characteristically depicts areas of low signal intensity that correspond to dense collagen. The findings of lesion multiplicity and hypermetabolism on PET images should raise the suspicion of malignancy.

High-frequency ultrasonography (US) with a linear-array transducer is the modality of choice for the initial evaluation of patients with acute scrotal pain after trauma. Testicular trauma is the third most common cause of acute scrotal pain. US is useful in the triage of patients for medical or surgical management because it reliably depicts tunica albuginea rupture, intra- and extratesticular hematomas, and testicular contusions. Color Doppler US allows direct evaluation of testicular perfusion and detection of uncommon conditions, such as testicular torsion, that may be associated with scrotal trauma. In addition, 10% of testicular tumors are found incidentally at US performed for the evaluation of trauma. If a conservative approach is adopted for the management of an intratesticular abnormality after trauma, follow-up US should be performed until the images show a complete resolution of the abnormality, so that a tumor will not be missed.

Benign intratesticular lesions are rare, but recognition is important to avoid unnecessary surgical intervention. The ultrasonographic (US) features that help differentiate benign from malignant intratesticular lesions are emphasized by the authors. Benign lesions include intratesticular simple cysts, tubular ectasia, epidermoid cyst, tunica albuginea cyst, intratesticular varicocele, abscess, and hemorrhage (infarction). US features of cystic malignant neoplasms that help in differentiation of them from benign cystic lesions are also presented. The US appearance of epidermoid cysts varies with the maturation, compactness, and quantity of keratin present. Of the cystic malignant testicular tumors, which can occur anywhere in testicular parenchyma, teratomas are the most frequent to manifest as cystic masses. An abnormal rind of parenchyma with increased echogenicity usually surrounds these lesions. An intratesticular spermatocele communicates with the seminiferous tubules, whereas simple ectasia of the rete testis does not do so directly. These cysts contain spermatozoa and can be septate. The US findings of intratesticular varicocele are similar to those of extratesticular varicocele and include multiple anechoic, serpiginous, tubular structures of varying sizes. Improvements in gray-scale and Doppler US technology allow subtle distinctions between benign and malignant testicular lesions that were not possible a decade earlier.