April Bailey

Strengthening the Argument for Rapid Brain MR Imaging: Estimation of Reduction in Lifetime Attributable Risk of Developing Fatal Cancer in Children with Shunted Hydrocephalus by Instituting a Rapid Brain MR Imaging Protocol in Lieu of Head CT

BACKGROUND AND PURPOSE: Children with shunted hydrocephalus have been undergoing surveillance neuroimaging, generally in the form of head CT, for evaluation of ventricular size. As the life expectancy of these children has improved due to better shunt technology and medical care, risks related to the ionizing radiation incurred during multiple head CT examinations that they are expected to undergo throughout their lifetime have become a concern. The purpose of this study is to estimate the LAR of developing fatal cancer due to head CT for ventricular size assessment in children with shunted hydrocephalus and to assess the impact of instituting a rapid brain MR imaging protocol in reducing radiation exposure. MATERIALS AND METHODS: Retrospective review of medical records yielded 182 patients who underwent neuroimaging for assessment of ventricular size. Available neuroimaging studies (head CT and rapid brain MR) were counted and annual neuroimaging frequency was calculated. It was assumed that these patients undergo a similar number of neuroimaging studies annually through 20 years of age. A risk estimate was calculated based on the BEIR VII report and effective doses obtained using the International Commission on Radiologic Protection Report 103 organ weighting factors. RESULTS: The mean annual neuroimaging study frequency was 2.1. Based on the average age of 1.89 years, it was assumed neuroimaging surveillance commences in the second year of life. LAR was calculated assuming that a patient undergoes neuroimaging in the form of head CT at this frequency (2/year) through 20 years of age. Assuming 2 scans are performed per year and the low-dose head CT protocol is used, approximately 1 excess lifetime fatal cancer would be generated per 230 patients; with standard head CT, there would be 1 excess lifetime fatal cancer per 97 patients. CONCLUSIONS: Children with shunted hydrocephalus are at increased risk of developing fatal cancer if they are to undergo surveillance using head CT. Implementation of a rapid brain MR imaging protocol with no radiation detriment will reduce this risk.

Postoperative Imaging after Surgical Repair for Pelvic Floor Dysfunction

Pelvic floor dysfunction encompasses an extremely common set of conditions, with various surgical and nonsurgical treatment options. Surgical options include injection of urethral bulking agents, native tissue repair with or without bioabsorbable or synthetic graft material, placement of synthetic midurethral slings or use of vaginal mesh kits, and mesh sacrocolpopexy procedures. Numerous different synthetic products with varied imaging appearances exist, and some of these products may be difficult to identify at imaging. Patients often present with recurrent or new symptoms after surgery; and depending on the presenting complaint and the nature of the initial intervention, imaging with ultrasonography (US), magnetic resonance (MR) imaging, voiding cystourethrography, or computed tomography (CT) may be indicated. US and MR imaging can both be used to image urethral bulking agents; US is often used to follow potential changes in bulking agent volume with time. Compared with MR imaging, US depicts midurethral slings better in the urethrovaginal space, and MR imaging is better than US for depiction of the arms in the retropubic space and obturator foramen. Mesh along the vaginal wall may be depicted with both US and MR imaging; however, the distal arms of the mesh traversing the sacrospinous ligaments or within the ischiorectal fossae (ischioanal fossae) are better depicted with MR imaging. Scarring can mimic slings and mesh at both US and MR imaging. MR imaging is superior to US for depiction of sacrocolpopexy mesh and associated complications. Voiding cystourethrography and CT are used less commonly because they rarely allow direct depiction of implanted material. Online supplemental material is available for this article. (©)RSNA, 2016.

Fetal MR imaging of gastrointestinal abnormalities

Fetal magnetic resonance (MR) imaging plays an increasing and valuable role in antenatal diagnosis and perinatal management of fetal gastrointestinal (GI) abnormalities. Advances in MR imaging data acquisition and use of motion-insensitive techniques have established MR imaging as an important adjunct to obstetric ultrasonography (US) for fetal diagnosis. In this regard, MR imaging provides high diagnostic accuracy for antenatal diagnosis of common and uncommon GI pathologic conditions. In the setting of fetal GI disease, T1-weighted images demonstrate the amount and distribution of meconium, which is crucial to the diagnostic capability of fetal MR imaging. Specifically, knowledge of the T1 signal intensity characteristics of fetal meconium, the normal pattern of meconium with advancing gestational age, and the expected caliber of small and large bowel in the fetus is key to diagnosis of abnormalities of the GI tract. Use of ultrafast T2-weighted sequences for evaluation of the expected location and morphology of fluid-containing structures, including the stomach and small bowel, in the fetal abdomen further aids in diagnostic confidence. Uncommonly encountered fetal GI pathologic conditions, especially cloacal dysmorphology, may demonstrate characteristic MR imaging patterns, which may add additional information to that from fetal US, allowing improved fetal and neonatal management. This article discusses common indications for fetal MR imaging of the GI tract, imaging protocols for fetal GI MR imaging, the normal appearance of the fetal GI tract with advancing gestational age, and the imaging appearances of common fetal GI abnormalities, as well as uncommon fetal GI conditions with characteristic appearances. (©)RSNA, 2016.

Ovarian involvement in endometrioid adenocarcinoma of uterus

OBJECTIVE Ovarian preservation is an option for some premenopausal patients with early stage endometrial cancer. Studies have shown that ovarian preservation in selected patients does not negatively impact survival outcomes. The objective of this study is to determine the frequency and characteristics of ovarian involvement when endometrial cancer is clinically confined to the uterus. METHODS Patients with endometrioid adenocarcinoma of uterus treated at our institution between 2000 and 2013 were identified. Patients with ovarian metastasis or synchronous primary ovarian cancer were included. Patients were excluded if there was gross extrapelvic disease on examination or imaging. RESULTS Seven hundred and fifty-nine patients were found to have endometrial cancer with the disease confined to the pelvis (stages I, II, and III). Fifteen patients (2%) had ovarian metastasis. Twenty-three patients (3%) had synchronous uterine and ovarian cancer. Most ovarian lesions (32 out of 38) were either enlarged or had abnormal appearing surface involvement. Six patients had microscopic ovarian involvement, accounting for 0.8% of the endometrial cancer patients with pelvis-confined disease. All of the patients were greater than 50 years of age. For those patients with microscopic ovarian metastasis, all had FIGO grade 3 disease, deep myometrial invasion, and extrauterine involvement of either cervix or lymph nodes. CONCLUSIONS Microscopic ovarian involvement occurred in 0.8% of patients with endometrial cancer. For premenopausal patients with endometrial cancer, normal appearing ovaries may be considered for preservation in the absence of extrauterine spread, grade 3 disease and deep myometrial invasion.

Influence of rectal gel volume on defecation during dynamic pelvic floor magnetic resonance imaging

PURPOSE To evaluate effects of altering rectal contrast volume on defecatory effort during magnetic resonance defecography (MRD). METHODS We assessed defecation qualitatively and quantitatively as a function of rectal distention (group A: 180 cc, n=31; group B: 120 cc, n=31). Quantitative evaluation comprised measuring rectal area on midline sagittal images pre- and post-defecation. RESULTS Resting rectal area was significantly higher for group A than for group B (35.2 vs. 28.3 cm(2), P<.0001). Post-defecation rectal area and change in area (pre- to post-defecation) were not significantly different. Subjective evaluation showed no significant difference. CONCLUSION Decreasing rectal gel volume from 180 to 120 cc did not compromise defecation performance during MRD.

Para-aortic nodal metastases in cervical cancer: a blind spot in the International Federation of Gynecology and Obstetrics staging system: current diagnosis and management

In cervical cancer, para-aortic nodal (PALN) metastases at presentation is a strong indicator of poor prognosis. Despite this, International Federation of Gynecology and Obstetrics staging system does not require evaluation of lymph node involvement and does not incorporate clinically detected PALN into the staging system. In the USA, despite screening, a significant number of women still present at an advanced stage often with nodal metastases. While the presence of PALN metastases often indicates occult systemic disease, it is possible with modern therapies to provide long-term control of disease in a percentage of patients. We review the epidemiology, diagnosis and treatment of PALN metastases in cervical cancer outlining advances in modern imaging and combined modality therapies (surgery, chemotherapy and radiation therapy).

Assessment of acute thermal damage volumes in muscle using magnetization‐prepared 3D T2‐weighted imaging following MRI‐guided high‐intensity focused ultrasound therapy

To evaluate magnetization‐prepared 3D T2‐weighted magnetic resonance imaging (MRI) measurements of acute tissue changes produced during ablative MR high‐intensity focused ultrasound (MR‐HIFU) exposures.

Magnetic resonance imaging of acute abdominal and pelvic pain in pregnancy

Abstract Evaluation of acute abdominal and pelvic pain in pregnancy presents a diagnostic challenge for clinicians and radiologists alike. The differential diagnosis includes obstetric and nonobstetric conditions unique to pregnancy, in addition to causes of acute abdominal and pelvic pain unrelated to the pregnancy. The clinical presentation and course of disease may be altered in pregnancy, and several pathologies are exacerbated by pregnancy. Discriminating clinical features in the diagnosis of abdominal and pelvic pain are often confounded by expected anatomic and physiologic changes in pregnancy. Moreover, while diagnostic pathways may be altered in pregnancy, the necessity for a timely and accurate diagnosis must be underscored, as delay in treatment may result in an undesirable increase in morbidity and/or mortality for both the patient and fetus. Advances in magnetic resonance imaging (MRI) through faster acquisition and motion-insensitive techniques, coupled with increased awareness and education regarding the value of MRI in diagnosing a wide range of pathology, have established MRI as a valuable strategy in the investigation of acute abdominal and pelvic pain in the pregnant patient. This review presents a practical approach to common obstetric and nonobstetric causes of acute abdominal and pelvic pain during pregnancy, as well as safety considerations for performing MRI in this patient population.

Comparison of saline infusion sonography (SIS) versus SIS-guided endometrial sampling in the diagnosis of endometrial pathology

To compare saline infusion sonography (SIS) to tissue obtained from SIS‐guided endometrial sampling (SISES) to determine sensitivity and specificity for benign and malignant conditions of the endometrium.

MR imaging of the fetal cerebellar vermis: Biometric predictors of adverse neurologic outcome.

To provide normal biometry of the cerebellar vermis using fetal MR and determine threshold values associated with abnormal neurologic outcome.