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Hydrosalpinx is a common adnexal lesion that may occur either in isolation or as a component of a complex pathologic process (eg, pelvic inflammatory disease, endometriosis, fallopian tube tumor, or tubal pregnancy) that leads to distal tubal occlusion. On magnetic resonance (MR) images, hydrosalpinx appears as a fluid-filled C- or S-shaped tubular structure that arises from the upper lateral margin of the uterus. Although hydrosalpinx is most often seen on ultrasonographic images, it also may be delineated on multiplanar MR images. MR imaging also may be useful for determining the cause of a hydrosalpinx or its associated adnexal process by characterizing the nature of the contents of the dilated tube. Tubal fluid with high signal intensity on T1-weighted images is suggestive of hematosalpinx associated with endometriosis and tubal pregnancy. A thickened wall of a dilated fallopian tube that displays variable or heterogeneous signal intensity may be indicative of pyosalpinx as a component of a tubo-ovarian abscess. The presence of an enhancing solid mass within a dilated tube is suggestive of fallopian tube carcinoma, whereas enhancement of the dilated tubal wall surrounding a saclike cystic mass may be indicative of a tubal pregnancy. Understanding the pathogenesis and clinical manifestations of conditions associated with hydrosalpinx may aid in the timely diagnosis of complex adnexal masses at MR imaging, enabling avoidance of unnecessary procedures., ((c) RSNA, 2009.)

Various pathologic conditions can occur in the renal sinus, primarily originating in the constituents of the renal sinus, and the renal sinus can be secondarily involved by surrounding renal parenchymal and adjacent retroperitoneal lesions. Lipomatosis and cysts are common renal sinus lesions with little clinical significance, but differentiation from other pathologic conditions is important. Renal vascular lesions such as renal artery aneurysm or arteriovenous fistula can mimic other parapelvic or peripelvic lesions at excretory urography, but their vascular nature is evident at color Doppler ultrasonography, contrast material-enhanced computed tomography (CT), and magnetic resonance (MR) imaging. Although most tumors originating in the renal pelvis are transitional cell carcinoma or squamous cell carcinoma, renal parenchymal tumors such as renal cell carcinoma or benign multilocular cystic nephroma have a tendency to grow into the renal sinus. Rare tumors of mesenchymal origin can develop in the renal sinus, but their imaging findings are nonspecific. The observation of renal sinus fat is important for detecting a small tumor located in that area and determining the exact tumor stage. Multiplanar CT or MR images can allow exact evaluation of the extent of complex renal sinus disease., (Copyright RSNA, 2004.)

Although radio-frequency (RF) ablation has been accepted as a promising and safe technique for treatment of unresectable hepatic tumors, investigation of its complications has been limited. According to the multicenter (1,139 patients in 11 institutions) survey data of the Korean Study Group of Radiofrequency Ablation, a spectrum of complications occurred after RF ablation of hepatic tumors. The prevalence of major complications was 2.43%. The most common complications were hepatic abscess (0.66%), peritoneal hemorrhage (0.46%), biloma (0.20%), ground pad burn (0.20%), pneumothorax (0.20%), and vasovagal reflex (0.13%). Other complications were biliary stricture, diaphragmatic injury, gastric ulcer, hemothorax, hepatic failure, hepatic infarction, renal infarction, sepsis, and transient ischemic attack. One procedure-related death (0.09%) occurred (due to peritoneal hemorrhage). Three important strategies for decreasing the rate of complications are prevention, early detection, and proper management. A physician who performs RF ablation of hepatic malignancies should be aware of the broad spectrum of major complications so that these strategies can be used., (Copyright RSNA, 2003.)

There is a broad spectrum of neurogenic tumors that involve the abdomen. These tumors can be classified as those of (a) ganglion cell origin (ganglioneuromas, ganglioneuroblastomas, neuroblastomas), (b) paraganglionic system origin (pheochromocytomas, paragangliomas), and (c) nerve sheath origin (neurilemmomas, neurofibromas, neurofibromatosis, malignant nerve sheath tumors). Abdominal neurogenic tumors are most commonly located in the retroperitoneum, especially in the paraspinal areas and adrenal glands. All of these tumors except neuroblastomas and ganglioneuroblastomas are seen in adult patients. Abdominal neurogenic tumor commonly manifests radiologically as a well-defined, smooth or lobulated mass. Calcification may be seen in all types of neurogenic tumors. The diagnosis of abdominal neurogenic tumor is suggested by the imaging appearance of the lesion, including its location, shape, and internal architecture. Benign and malignant neurogenic tumors are difficult to differentiate unless distant metastatic foci are seen. For malignant tumors, imaging modalities other than computed tomography (CT) and magnetic resonance (MR) imaging may be necessary for staging. However, because most neurogenic tumors in adults are benign, CT and MR imaging can be used to develop a differential diagnosis and help determine the immediate local extent of tumor., (Copyright RSNA, 2003.)

Ovarian tumors are classified on the basis of tumor origin as epithelial tumors (serous and mucinous tumors, endometrioid and clear cell carcinomas, Brenner tumor), germ cell tumors (mature and immature teratomas, dysgerminoma, endodermal sinus tumor, embryonal carcinoma), sex cord-stromal tumors (fibrothecoma; granulosa cell, sclerosing stromal, and Sertoli-Leydig cell tumors), and metastatic tumors. Epithelial tumors are primarily cystic and, when malignant, are associated with varying proportions of a solid component. Papillary projections are a distinctive feature of epithelial tumors. Profuse papillary projections are highly suggestive of borderline (low-malignant-potential) or malignant tumor. Ovarian teratomas demonstrate lipid material at computed tomography and magnetic resonance (MR) imaging. Malignant germ cell tumors manifest as a large, complex abdominal mass that contains both solid and cystic components. Tumor markers are helpful in diagnosis. The radiologic appearance of sex cord-stromal tumors varies from small solid masses to large multicystic masses. Granulosa cell tumors are usually large multicystic masses with solid components. Fibrothecoma, sclerosing stromal tumor, and Sertoli-Leydig cell tumors are usually solid masses. Fibromas have very low signal intensity on T2-weighted MR images. Certain radiologic findings predominate for each type of tumor. Knowledge of these key features of ovarian tumors provides the criteria for making a specific diagnosis or substantially narrowing the differential diagnosis., (Copyright RSNA, 2002)

In adnexal torsion, the ovary, ipsilateral fallopian tube, or both twist with the vascular pedicle, resulting in vascular compromise. Unrelieved torsion is likely to cause hemorrhagic infarction as the degree of arterial occlusion increases. Therefore, early diagnosis is important to preserve the affected ovary. Adnexal torsion commonly accompanies an ipsilateral ovarian neoplasm or cyst but can also occur in normal ovaries, usually in children. Although ultrasonography is typically the initial emergent examination, computed tomography (CT) and magnetic resonance (MR) imaging may also be useful diagnostic tools. Common CT and MR imaging features of adnexal torsion include fallopian tube thickening, smooth wall thickening of the twisted adnexal cystic mass, ascites, and uterine deviation to the twisted side. Uncommon imaging findings in adnexal torsion that are specific to hemorrhagic infarction include hemorrhage in the thickened fallopian tube, hemorrhage within the twisted ovarian mass, and hemoperitoneum. Additional imaging findings that can suggest hemorrhagic infarction include eccentric smooth wall thickening exceeding 10 mm in a cystic ovarian mass converging on the thickened fallopian tube and lack of contrast enhancement of the internal solid component or thickened wall of the twisted ovarian mass. Early diagnosis can help prevent irreversible structural damage and may allow conservative, ovary-sparing treatment., (Copyright RSNA, 2002)

Vasculitides can cause local or diffuse pathologic changes in the gastrointestinal tract, resulting in nonspecific paralytic ileus, mesenteric ischemia, submucosal edema and hemorrhage, or bowel perforation or stricture. The extent and clinical course of disease depend on the size and location of the affected vessel and the histologic characteristics of the lesion. Vasculitis may primarily involve large vessels (eg, giant cell arteritis, Takayasu arteritis), medium-sized vessels (eg, polyarteritis nodosa, Kawasaki disease, primary granulomatous central nervous system vasculitis), or small vessels (eg, Wegener granulomatosis, Churg-Strauss syndrome, microscopic polyangiitis, Henoch-Schönlein syndrome, systemic lupus erythematosus, rheumatoid vasculitis, Behçet syndrome). Radiologic findings in various types of vasculitis often overlap considerably and therefore have limited value in making a specific diagnosis. Nevertheless, the possibility of vasculitis should be considered whenever mesenteric ischemic changes occur in young patients, are noted at unusual sites (eg, stomach, duodenum, rectum), have a tendency to concomitantly involve the small and large intestine, and are associated with genitourinary involvement. Knowledge of systemic clinical manifestations in affected patients may suggest and even help establish the specific diagnosis.

Adenomyosis is a common gynecologic disorder that affects women during their menstrual life. Preoperative magnetic resonance (MR) images obtained in 45 patients with pathologically proved adenomyosis who underwent hysterectomy were retrospectively reviewed. Diffuse adenomyosis was seen in 30 cases (66.7%) and focal adenomyosis in 15 cases (33.3%). On T2-weighted MR images, diffuse adenomyosis usually manifested as diffuse thickening of the endometrial-myometrial junctional zone (7-37 mm; mean, 16 mm) with homogeneous low signal intensity. T2-weighted MR images were superior to contrast material-enhanced T1-weighted images in the evaluation of junctional zone thickening. High-signal-intensity foci were observed on T2-weighted images only in nine cases and on both T1- and T2-weighted images in three cases. Focal adenomyosis manifested on both T2-weighted and contrast-enhanced T1-weighted MR images as a localized, low-signal-intensity round or oval mass with a diameter of 2-7 cm (mean, 3.8 cm). All but one of the focal lesions had ill-defined margins. High-signal-intensity foci were noted in all cases of focal adenomyosis, either on T2-weighted images only (four cases) or on both T1- and T2-weighted images (11 cases). MR imaging is useful in diagnosing adenomyosis, differentiating adenomyosis from uterine myoma, and planning appropriate treatment.

This study evaluated the usefulness of T2-weighted and gadolinium-enhanced T1-weighted magnetic resonance (MR) images correlated with patients' menopausal status in assessing the depth of myometrial invasion in stage I endometrial carcinoma. MR images of 46 patients with stage I endometrial carcinoma were retrospectively reviewed. Twenty-five patients were premenopausal, and 21 were postmenopausal. The staging accuracy without regard to menopausal status was 59% for T2-weighted images and 61% for gadolinium-enhanced T1-weighted images. However, when staging accuracy was evaluated separately in the premenopausal and postmenopausal patient groups, T2-weighted imaging had an accuracy of 80% in the premenopausal group and gadolinium-enhanced T1-weighted imaging had an accuracy of 81% in the postmenopausal group. Therefore, T2-weighted imaging was more accurate in premenopausal patients and gadolinium-enhanced T1-weighted imaging was more accurate in postmenopausal patients. The overall accuracy of staging with MR imaging improved to 80% when patients' menopausal status was considered. Therefore, menopausal status should be considered when T2-weighted and gadolinium-enhanced T1-weighted MR images are used to stage early endometrial carcinoma.