Müllerian duct anomalies: MR imaging evaluation

Twenty-nine patients underwent magnetic resonance (MR) imaging for investigation of müllerian duct anomalies (MDAs). The anomalies evaluated were uterine agenesis (n = 2), uterine hypoplasia (n = 5), unicornuate uterus (n = 5), uterus didelphys (n = 5), bicornuate uterus (n = 10), and septate uterus (n = 2). The MR imaging interpretation was correlated with results of laparotomy (n = 18), hysterosalpingography (HSG) (n = 5), laparoscopy (n = 2), hysteroscopy (n = 1), HSG and laparotomy (n = 2), and HSG and laparoscopy (n = 1). MR imaging enabled correct classification of the anomaly in each patient and identification of coincidental gynecologic disease in 10 patients (34%). MR imaging results influenced clinical treatment in six (24%) of 25 patients referred prospectively. Of particular value was the ability to characterize septal tissue (myometrium versus fibrous tissue), identify the patients in whom the septum of bicornuate uteri had both fibrous and myometrial components, and establish that suspected adnexal lesions were actually components of obstructed MDAs.     

Gadolinium-enhanced MR imaging in the evaluation of uterine fibroids treated with uterine artery embolization.

OBJECTIVE: The purpose of this study was to determine whether tumor volume reduction can be predicted by the infarction rate of uterine fibroids as seen on gadolinium-enhanced MR images obtained immediately after uterine artery embolization. MATERIALS AND METHODS: In our study, 36 women with symptomatic uterine fibroids successfully underwent uterine artery embolization. Unenhanced and enhanced MR imaging was performed before the procedure and repeated at 1 week, 4 months, and 1 year after the procedure. We retrospectively reviewed enhanced MR images of uterine fibroids after uterine artery embolization. At 4 months after uterine artery embolization, we compared the rate of tumor volume reduction in patients with completely infarcted dominant fibroids with the rate of tumor volume reduction in patients with partially infarcted fibroids. RESULTS: Enhanced MR images obtained 1 week after uterine artery embolization revealed that 100% infarction rates of the dominant uterine fibroids were achieved in 33 women (92%), and 70--90% infarction rates were seen in the remaining three (8%). They also revealed that of a total of 204 fibroids in these patients, 100% infarction was achieved in 199 fibroids (98%). Enhanced MR images obtained 4 months after uterine artery embolization showed that tumor volume reduction of the completely infarcted dominant fibroids (n = 23) was 60% +/- 18%, whereas that of the partially infarcted fibroids (n = 5) was 35% +/- 27% (p = 0.0367). CONCLUSION: Gadolinium-enhanced MR imaging is a useful diagnostic technique for uterine fibroids after uterine artery embolization because it assesses the degree of infarction in the embolized fibroids, which corresponds to the subsequent tumor volume reduction.     

Corpus callosum and limbic system: neuroanatomic MR evaluation of developmental anomalies

Agenesis of the corpus callosum is a complex malformation of the brain that has been associated with varying degrees of limbic system maldevelopment. We retrospectively reviewed the records of 11 patients with callosal agenesis (seven total, four partial) who underwent magnetic resonance (MR) imaging, with particular attention to the associated malformations of the limbic system. Comparison was made with selected images from MR examinations of healthy volunteers and with necropsy specimens from other patients with callosal agenesis. Ten of 11 patients demonstrated limbic anomalies (severe motion artifact precluded evaluation of these structures in one patient). MR depicted not only the abnormalities intrinsic to callosal agenesis but also the frequently associated malformations of the limbic system.     

MR imaging of fetal anomalies

MR imaging can be used to confirm the presence of most gross fetal anomalies detected by sonography in the second and third trimesters. The MR imaging findings in 25 cases of fetal anomalies first identified on sonography are illustrated.     

MR of neuronal migration anomalies

Migration anomalies are congenital malformations caused by insults to migrating neuroblasts during the third to fifth gestational months. Included in this group are agyria, pachygyria, polymicrogyria, unilateral megalencephaly, schizencephaly, and gray matter heterotopias. Patients who have these conditions present clinically with developmental delay and seizures, and abnormal motor skills are noted in the more severely affected infants. To determine the utility of MR as a method for imaging in these patients, we used MR to evaluate 13 patients who had the full spectrum of migration anomalies. MR was more sensitive than CT in detecting these anomalies because of its better contrast between gray and white matter. We found that MR was particularly more sensitive in detecting schizencephaly, where recognizing the presence of gray matter lining the cleft is critical to distinguishing that disease from porencephaly, and in detecting polymicrogyria, where critical details of cortical architecture are obscured on CT by the overlying bone. Multiplanar capabilities were also found to be essential, since narrow clefts may not be detected when the imaging plane is parallel to the cleft. MR should be the primary imaging method for infants who have seizures or developmental delay.     

Congenital thoracic vascular anomalies: evaluation with state-of-the-art MR imaging and MDCT

Congenital thoracic vascular anomalies include embryologic developmental disorders of the thoracic aorta, aortic arch branch arteries, pulmonary arteries, thoracic systemic veins, and pulmonary veins. Diagnostic evaluation of these anomalies in pediatric patients has evolved with innovations in diagnostic imaging technology. State-of-the-art magnetic resonance (MR) imaging, MR angiography multidetector-row computed tomographic (MDCT) angiography, and advanced postprocessing visualization techniques offer accurate and reliable high-resolution two-dimensional and three-dimensional noninvasive anatomic displays for interpretation and clinical management of congenital thoracic vascular anomalies. This article reviews vascular MR imaging, MR angiography, MDCT angiography, and advanced visualization techniques and applications for the assessment of congenital thoracic vascular anomalies, emphasizing clinical embryology and the characteristic imaging findings.     

Clinical utility of susceptibility-weighted MR sequence for the evaluation of uterine sarcomas

PurposeHigh intensity intra-tumoral hemorrhagic necrosis on T1-weighted images is a suggestive finding for uterine sarcomas, however, the reported prevalence varies. The purpose of this study is to evaluate the capability of susceptibility-weighted MR sequences (SWS) for the diagnosis of uterine sarcomas.Materials and methodsMR imaging of surgically proven 10 uterine sarcomas and 24 benign leiomyomas were retrospectively evaluated for the presence of high intensity areas on T1-weighted images and signal voids on SWS (T2 star-weighted angiography: SWAN).ResultsHigh intensity areas on T1-weighted images and signal voids on SWS were observed in 40% and 100% of sarcomas, whereas 0% and 4% of leiomyomas, respectively. The accuracy, sensitivity, and specificity for T1-weighted images were 82%, 40%, and 100%, and for SWS were 97%, 100%, and 96%, respectively.ConclusionThe demonstration of intra-tumoral hemorrhage in patients suspected with uterine sarcomas by SWS may provide valuable diagnostic findings.     

MR evaluation of vestibulocochlear anomalies associated with large endolymphatic duct and sac.

BACKGROUND AND PURPOSE: Large endolymphatic duct and sac (LEDS) is one of the most common anomalies seen in patients with congenital sensorineural hearing loss (SNHL), and is known to occur with other inner ear findings. Our purpose was to use high-resolution T2-weighted fast spin-echo (FSE) MR imaging to describe the features and prevalence of specific anomalies that occur in association with LEDS. METHODS: We retrospectively reviewed MR images of the inner ear obtained in 63 patients with LEDS and in 60 control subjects. We evaluated each image for features of cochlear and vestibular dysplasia, including deficiency of the cochlear modiolus, gross cochlear dysmorphism, asymmetry of the cochlear scalar chambers, enlargement of the membranous vestibule, gross vestibular dysmorphism, and abnormality of the semicircular canals (SCC). RESULTS: Cochlear anomalies were present in 76% of ears with LEDS. Modiolar deficiency, gross dysmorphism, and scalar asymmetry were seen in 94%, 71%, and 65% of abnormal cochleas, respectively. Vestibular abnormalities were present in 40% of ears with LEDS. Simple enlargement, gross dysmorphism, and distortion of the lateral SCC were seen in 84%, 16%, and 32% of abnormal vestibules, respectively. CONCLUSION: Coexistent cochlear anomalies, vestibular anomalies, or both are present in most ears with LEDS, and appear as a spectrum of lesions, ranging from subtle dymorphism to overt dysplasia. The presence of coexistent anomalies in LEDS affects treatment decisions and prognosis. Newer techniques of high-resolution FSE MR imaging provide a means of exquisite characterization of LEDS, as well as more sensitive detection of associated vestibulocochlear anomalies.     

Diagnosis of uterine anomalies: relative accuracy of MR imaging, endovaginal sonography, and hysterosalpingography.

The purpose of this study was to compare the relative accuracy of magnetic resonance (MR) imaging (n = 26), endovaginal sonography (EVS) (n = 14), and hysterosalpingography (HSG) (n = 20) in the classification of müllerian duct anomalies in 26 patients. There were 24 cases of surgically proved anomaly, and two patients had normal uteri (one with a vaginal septum). MR imaging allowed diagnosis of 24 of 24 cases (accuracy, 100%), and EVS was correct in 11 of 12 cases (accuracy, 92%). HSG was correct in only four cases. In the diagnosis of septate uterus, MR imaging demonstrated a sensitivity and specificity of 100% and EVS demonstrated a sensitivity of 100% and a specificity of 80%. Both MR imaging and EVS demonstrated a sensitivity and specificity of 100% in distinguishing those anomalies that did not require surgery. The high accuracy of MR imaging and EVS permit noninvasive differentiation of uterine anomalies and can spare women diagnostic laparoscopy, promoting cost-effective diagnosis.     

MR evaluation of developmental venous anomalies: medullary venous anatomy of venous angiomas.

PURPOSETo present characteristic MR findings of developmental venous anomalies (DVAs) in terms of location of caput and draining veins, to correlate these findings with normal medullary venous anatomy, and to suggest an approach to the evaluation of DVAs by means of MR imaging.METHODSWe reviewed the contrast-enhanced MR examinations of 61 patients with DVA, which were selected from 4624 consecutive cranial MR examinations. Site of the DVA and size and direction of draining veins were recorded.RESULTSSeventy-two DVAs with 78 draining veins were located: 18 were juxtacortical, 13 were subcortical, and 41 were periventricular or deep. Twenty-six of the DVA caputs were frontal, 16 were parietal, 13 were in the brachium pontis/dentate, seven were in the temporal lobe, three were in the cerebellar hemisphere, three were in the occipital lobe, three were in the basal ganglia, and one was in the pons. The draining veins were superficial in 29 cases and deep in 49. Of the 36 supratentorial deep draining veins, 16 were in the trigone/occipital horn, 11 were in the mid-body of the lateral ventricle, seven were in the frontal horn, and two were in the temporal horn. Among the 14 infratentorial deep draining veins, five were in the lateral recess of the fourth ventricle, four were anterior transpontine veins, three were lateral transpontine veins, and two were precentral cerebellar veins.CONCLUSIONThe DVA caputs and their draining veins occurred in typical locations that could be predicted from the normal medullary venous anatomy, with the frontal, parietal, and brachium pontis/dentate being the most common locations. Drainage can occur in superficial cortical veins or sinuses or in deep ventricular veins or in both, no matter where the caput is located. Whether drainage was superficial or deep could not be predicted on the basis of the site of the DVA caput. Contrast-enhanced T1-weighted MR images showed the DVAs best, but diagnosis could be made from T2-weighted MR images.     

子宫肿块的MRI诊断

目的：分析子宫肿块的MRI表现，探讨MRI的诊断价值及其诊断能力。方法：对经手术理证实的38例（69个病灶）子宫肿块的MRI表现进行回顾性分析，并与超声检查相对比。结果：良性病变26例，分别为子宫平滑肌瘤、腺肌病、慢性血肿。恶性病变15例，分别为子宫内膜癌、宫颈癌、子宫平滑肌肉瘤、滋养细胞肿瘤和转移瘤。有3例良恶性肿瘤同时并存。所有病例均于T2WI显示较好，T1WI对于判断肿瘤是否宫外侵犯较有帮助。MRI对子宫肿块的检出率和诊断的正确率分别为94．2％、89．8％，均高于B超（82．6％、75．3％）。结论：MRI能较准确地显示病灶数目、大小、范围、内部结构及与周围的关系，对于判断肿瘤的良恶性及肿瘤的分期有很大价值。     

MR imaging of uterine inversion

Inversion of the uterus is a postpartum complication that is an obstetric emergency. This report describes a case of inversion of the uterus in which clinical evaluation was inconclusive, and magnetic resonance (MR) of the pelvis revealed findings virtually pathognomonic of incomplete inversion of the uterus with far greater conspicuity than on corresponding ultrasound. The MR findings directly resulted in earlier therapeutic intervention with a possible decrease in morbidity.     

Congenital anorectal anomalies: MR imaging

Twenty-one patients with anorectal anomalies were evaluated with magnetic resonance (MR) imaging. In seven preoperative patients, MR imaging demonstrated the level of atresia correctly by showing the rectal pouch and sphincter muscles. The exact location and development of the sphincter muscles were estimated and associated anomalies involving the kidneys and the spine and its contents were evaluated. In 14 postoperative patients, the location of the pulled-through intestine was examined in relation to the sphincter muscles. MR imaging demonstrated operative complications affecting rectal continence--such as a misplaced neorectum, inadvertently pulled-through mesenteric fat, and an implantation mucous retention cyst--and provided objective data for individuals with persistent incontinence after surgery who were under consideration for repeat surgery. The authors recommend MR imaging in all patients being considered for repeat procedures and in any patient without prior surgery who is suspected of having a high anomaly; any degree of sacral agenesis; or spinal, genito-urinary tract, or cloacal anomalies.     

Clinical failure after uterine artery embolization: evaluation of patient and MR imaging characteristics

PURPOSE: To investigate the patient and magnetic resonance (MR) imaging characteristics associated with clinical failure after uterine artery embolization (UAE). MATERIALS AND METHODS: Seventy-eight consecutive patients who underwent UAE were examined. Contrast-enhanced MR imaging was performed before and 4 months after the procedure, and clinical follow-up was performed at 15 months. Patients were divided into success and failure groups strictly on the basis of their clinical outcomes. Clinical follow-up included evaluation of fibroid symptoms and the need for further treatment after UAE. Findings at pre- and postprocedural MR imaging were compared, and data collected included changes in uterine and fibroid volumes, fibroid location, and fibroid perfusion. RESULTS: Fifty-eight patients were placed into the success group and 20 into the failure group. There were no differences between the baseline characteristics of the two groups. The reduction in uterine and dominant fibroid volumes was greater in the success group compared with the failure group; however, the difference was not statistically significant (success group: [295/845] 34.9% vs [80/282.5] 28.3%, respectively, P=.18; failure group: [317/733] 43.2% vs [114/337.6] 33.9%, P=.32). The reduction in total fibroid volume was greater in the success group than the failure group ([189.6/393.5] 48.2% vs [148.7/439.9] 33.8%, respectively; P=.02) despite the fact that the percentage of fibroids completely infarcted was similar between the two groups ([136/172] 79% vs [41/50] 82%, P=.77). Pedunculated subserosal fibroids were more common in the failure group than in the success group (P<.03) and did not reduce in volume as significantly (53.8% vs 14.7%, respectively; P=.02). CONCLUSIONS: In general, the reduction in total fibroid volume after embolization is smaller in patients with poor clinical improvement. In addition, these patients have a higher number of pedunculated subserosal fibroids, and these fibroids tend to reduce in volume to a lesser extent.     

MR imaging of unilateral pulmonary artery anomalies

Magnetic resonance (MR) imaging of the pulmonary arteries was performed in seven children with unilateral pulmonary artery abnormalities. Five had congenital absence or interruption of a pulmonary artery; two had postsurgical occlusion or narrowing of a pulmonary artery. A small patent hilar pulmonary artery was identified in one of the five cases of congenital pulmonary artery interruption or absence. Occluding thrombus was identified in the right pulmonary artery of one child following pulmonary artery banding. In another case marked narrowing of the right pulmonary artery was identified secondary to migration of a pulmonary artery band. The MR findings were confirmed by angiography in all cases. Magnetic resonance appears to be a useful noninvasive modality for accurate anatomic depiction of unilateral pulmonary artery abnormalities in childhood. It may be especially valuable for diagnosis of pulmonary artery stenosis or occlusion following surgical treatment of congenital heart disease.     

MR imaging of uterine cervical carcinoma

We retrospectively analyzed the magnetic resonance (MR) imaging findings of 20 consecutive patients with primary untreated carcinoma of the cervix who underwent surgery and one patient who underwent percutaneous needle biopsy of enlarged pelvic lymph nodes. Most of the patients were clinical Stage IB. The clinical assessment of the parametria in these patients was more accurate than the MR assessment of the parametria (95 versus 79%). Magnetic resonance was valuable for detecting metastatic pelvic lymphadenopathy. Enlarged pelvic lymph nodes (greater than 1.5 cm in diameter) were demonstrated by MR in all three patients with histologic verification of metastatic lymphadenopathy. In summary, the major therapeutic value of MR in patients with untreated cervical carcinoma is in assessing the pelvic lymph nodes. In patients with clinical Stage IB disease, MR assessment of the parametria does not add useful additional information.     

MR imaging of uterine sarcomas.

OBJECTIVE: The MR imaging appearances of uterine sarcomas are not well described in the literature. We describe the MR imaging features of uterine sarcomas. MATERIALS AND METHODS: MR images from all patients with histologically proven uterine sarcomas scanned between 1993 and 2000 were reviewed. Tumor size, its relationship to the uterus, signal characteristics, and enhancement pattern after IV injection of gadolinium were noted. RESULTS: Twenty-five scans from 22 patients were reviewed. Findings from the scans included 11 leiomyosarcomas, five mixed müllerian tumors, two rhabdosarcomas, and four endometrial stromal sarcomas. Two patterns of disease were observed, including a characteristic large heterogenous pelvic mass (n = 17) and an endometrial mass indistinguishable from endometrial carcinoma (n = 8). On T2-weighted images, the large masses were characteristically of low or intermediate background signal intensity with pockets of very high T2 signal. The areas of high T2 signal corresponded to cystic necrosis in the tumor. Pockets of high T1-weighted signal corresponded to hemorrhage. Gadolinium enhancement was present in the solid components of all tumors. This pattern was observed in all recurrent sarcomas. Some correlation was shown between the histologic subtypes and the MR imaging appearances. CONCLUSION: Uterine sarcomas show two patterns on MR imaging. The most common presentation is a large heterogenous mass. However, sarcomas can mimic endometrial carcinoma.