Unique clinical manifestations, serum tumor markers, and imaging features at US, CT, and MR imaging can be used to differentiate benign from malignant ovarian tumors in children and adolescents, a population in which preserving future fertility and selecting appropriate surgical procedures are crucial. The incidence, histologic distribution, and clinical manifestations of ovarian tumors in the pediatric population are distinct from those in adults. Although ovarian neoplasms in childhood and adolescence are rare, the diagnosis should be considered in young girls with abdominal pain and a palpable mass. Differential diagnosis in children and adolescents with ovarian tumors should be conducted on the basis of unique clinical manifestations, elevated serum tumor marker levels, and distinctive imaging findings. Although the clinical manifestations are nonspecific and may overlap, they may assist in diagnosis of some types of ovarian tumors. Children who present with a palpable mass or symptoms of precocious puberty have a high likelihood of malignancy. Many ovarian tumors are associated with abnormal hormonal activity and/or abnormal sexual development. Elevated levels of serum tumor markers, including α-fetoprotein, the beta subunit of human chorionic gonadotropin, and CA-125, raise concern for ovarian mal...

Kim SH, et al. Korean J Radiol. 2009 Jan-Feb;10(1):63-70. https://doi.org/10.3348/kjr.2009.10.1.63

Although actinomycosis shows various radiologic findings while manifesting with nonspecific symptoms, several imaging features might be effectively used for making a correct diagnosis, including the highly aggressive nature beyond normal anatomic barriers, strong enhancement after contrast material administration, and suppurative necrosis within the mass. Actinomycosis is a chronic suppurative bacterial infection caused by Actinomyces species. Actinomyces israelii is the organism most commonly found in human disease. Actinomycosis usually manifests with abscess formation, dense fibrosis, and draining sinuses. The disease is further characterized by the tendency to extensively spread beyond normal fascial and connective tissue planes. Actinomycosis occurs most commonly in the cervicofacial region (50%–65%), followed by the thoracic (15%–30%) and abdominopelvic (20%) regions, but rarely involves the central nervous system. Most cases of cervicofacial actinomycosis are odontogenic in origin. In the acute form, cervicofacial disease can manifest with soft-tissue swelling, a painful pyogenic abscess, or a mass lesion. In the subacute to chronic form, a painless indurated mass can spread to the skin, leading to draining sinus tracts. Thoracic manifestations include parenchymal, bronchiectatic, and endobronchial actinomycosis. At computed tomography, pulmonary ac...

Purpose: To evaluate the efficacy of diffusion‐weighted imaging (DWI) on 3 Tesla (T) MR imaging to predict the tumor response to neoadjuvant chemoradiation therapy (CRT) in patients with locally advanced rectal cancer.Materials and Methods: Thirty‐five patients who underwent neoadjuvant CRT and subsequent surgical resection were included. Tumor volume was measured on T2‐weighted MR images before and after neoadjuvant CRT and the percentage of tumor volume reduction was calculated. The apparent diffusion coefficient (ADC) value was measured on the DWI before and after neoadjuvant CRT, and the change of ADC (Δ ADC) was calculated. The histopathologic response was categorized either as a responder to CRT or as a nonresponder. The relationship between the ADC parameters and the percentage of tumor volume reduction or histopathologic response was then evaluated.Results: There was a significant correlation between tumor volume reduction and pre‐CRT ADC and Δ ADC, respectively (r = −0.352, r = 0.615). Pre‐CRT ADC of the histopathologic responders was significantly lower than that of the histopathologic nonresponders (P = 0.034). Δ ADC of the histopathologic responders was significantly higher than that of the histopathologic nonresponders (P < 0.005).Conclusion: DWI on 3T MR imaging may be a promising technique for helping to predict and monitor the treatment response to neoadjuvant CRT in patients with locally advanced rectal cancer. J. Magn. Reson. Imaging 2012;35:110‐116.

Heo SH, et al. Korean J Radiol. 2010 May-Jun;11(3):295-303. https://doi.org/10.3348/kjr.2010.11.3.295