Nyree Griffin

Small bowel MR enterography: problem solving in Crohn’s disease

AbstractMagnetic resonance enterography (MRE) is fast becoming the first-line radiological investigation to evaluate the small bowel in patients with Crohn’s disease. It can demonstrate both mural and extramural complications. The lack of ionizing radiation, together with high-contrast resolution, multiplanar capability and cine-imaging make it an attractive imaging modality in such patients who need prolonged follow-up. A key question in the management of such patients is the assessment of disease activity. Clinical indices, endoscopic and histological findings have traditionally been used as surrogate markers but all have limitations. MRE can help address this question. The purpose of this pictorial review is to (1) detail the MRE protocol used at our institution; (2) describe the rationale for the MR sequences used and their limitations; (3) compare MRE with other small bowel imaging techniques; (4) discuss how MRE can help distinguish between inflammatory, stricturing and penetrating disease, and thus facilitate management of this difficult condition. Main Messages • MR enterography (MRE) is the preferred imaging investigation to assess Crohn’s disease. T2-weighted, post-contrast and diffusion-weighted imaging (DWI) can be used.• MRE offers no radiation exposure, high-contrast resolution, multiplanar ability and cine imaging.• MRE can help define disease activity, a key question in the management of Crohn’s disease.• MRE can help distinguish between inflammatory, stricturing and penetrating disease.• MRE can demonstrate both mural and extramural complications.

Magnetic resonance imaging of vaginal and vulval pathology

There are a number of conditions affecting the vagina and vulva that can be optimally assessed with the use of high-resolution magnetic resonance imaging (MRI). This paper gives a suggested protocol for MRI technique and sequences for imaging the pelvis and perineum and reviews the MRI appearances of many of the common pathologies affecting the vagina and vulva. Congenital anomalies, inflammatory and neoplastic entities such as vaginal and vulval carcinoma are discussed, with rarer malignancies also reviewed.

Magnetic resonance cholangiopancreatography: the ABC of MRCP

Magnetic resonance cholangiopancreatography (MRCP) is a technique that has evolved over the past two decades. It continues to have a fundamental role in the non-invasive investigation of many pancreatico-biliary disorders. The purpose of this review is to summarise the key concepts behind MRCP, the different techniques that are currently employed (including functional and secretin-stimulated MRCP), the pitfalls the reader should be aware of, and the main clinical indications for its use.

Magnetic Resonance Imaging for the Evaluation of Acute Abdominal Pain in Pregnancy

The investigation of acute abdominal pain in pregnancy is challenging. The use of ultrasound may be limited due to the patients change in body habitus and computed tomography is not desirable due to fetal irradiation. Magnetic resonance imaging (MRI) has thus become increasingly popular in the evaluation of such patients, due to its lack of ionizing radiation, multiplanar capability and high contrast resolution. This review will detail the MRI technique required to image the pregnant abdomen and describe the MRI features of common causes of acute abdominal pain in pregnancy.

Anal carcinomas: the role of endoanal ultrasound and magnetic resonance imaging in staging, response evaluation and follow-up.

Anal carcinoma is an important but rare condition, managed in specialist centres. Both endoanal ultrasound and magnetic resonance imaging (MRI) can be used in the locoregional staging and follow-up of patients with anal cancer, and both may assist in treatment planning and prognosis. Recent guidelines published by the European Society for Medical Oncology have recommended MRI as the technique of choice for assessment of locoregional disease. This paper describes the techniques for both endoanal ultrasound and MRI, and compares the relative merits and disadvantages of each in the local assessment of anal carcinoma.

Cysts, cavities, and honeycombing in multisystem disorders: differential diagnosis and findings on thin-section CT

Pulmonary cysts, cavities, and honeycombing are seen in a number of systemic disorders. The purpose of this review is to discuss the findings on thin-section computed tomography (CT) in both congenital and acquired multisystem conditions that give rise to multiple cystic spaces in the lungs. Conditions discussed include lymphangioleiomyomatosis, Langerhans cell histiocytosis, lymphocytic interstitial pneumonia, and Birt-Hogg-Dubé syndrome, with reference to specific features that may be helpful in the differentiation of these conditions on CT.

Magnetic Resonance Elastography in the Diagnosis of Hepatic Fibrosis

Liver fibrosis is a common feature of many chronic liver diseases, and can ultimately progress to cirrhosis. Conventional imaging is insensitive to liver fibrosis, necessitating a liver biopsy for diagnosis and monitoring of progression. However, liver biopsy risks complications, and is an imperfect gold standard in view of sampling error and intraobserver or interobserver variation. Magnetic resonance elastography (MRE) is a noninvasive method for assessing the mechanical properties of tissues and is gaining credence as a method of assessment for hepatic fibrosis. The aim of this review is to describe how MRE is performed, to review the present literature on the subject, to compare MRE with other noninvasive techniques used to assess for liver fibrosis, and to highlight areas of future research.

Adnexal Masses: Characterization and Imaging Strategies

The differential diagnosis for adnexal masses is wide, encompassing a range of benign, borderline, and malignant entities. Stratification of risk is made on age, menopausal status, imaging features, and tumor markers. This review outlines the different imaging modalities available to characterize adnexal masses, describes the typical ultrasound and magnetic resonance imaging features of the most commonly encountered adnexal lesions, and provides a suggested imaging algorithm in the management of such patients.

The role of hepatocyte-specific contrast agents in hepatobiliary magnetic resonance imaging

Hepatocyte-specific contrast agents have been made available in the last 15 years for magnetic resonance imaging of the liver. These agents are differentially taken up by functioning hepatocytes and excreted in the biliary system. They can help distinguish focal liver lesions of hepatocellular origin from lesions of nonhepatocellular origin, and can also be used in the evaluation of the biliary tree. The purpose of this review is to summarize the different types of hepatocyte-specific contrast agents presently available, their use in the characterization of focal liver lesions, their role in the evaluation of biliary pathology, and their potential future applications.

Hidradenitis suppurativa: MRI features in anogenital disease

BACKGROUND: Hidradenitis suppurativa is a rare chronic inflammatory disorder of apocrine gland-bearing skin, which commonly affects the anogenital region. There has been very little literature to date on the MRI appearances of anogenital hidradenitis suppurativa. OBJECTIVE: The aim of this study was to assess the MRI features of anogenital hidradenitis suppurativa in the largest cohort of patients to be published to date. DESIGN: After an institutional review board waiver, patients with hidradenitis suppurativa who were undergoing MRI for anogenital disease between 2005 and 2012 were identified from our institutional database. The MRI appearances were recorded by 2 radiologists in consensus, blinded to clinical details. Location of disease, number of tracts, presence of anal fistula, and supralevator involvement were recorded. Patient demographics were also noted. SETTINGS: This study was conducted at the Department of Radiology, Guy’s and St Thomas’ National Health Service Foundation Trust. PATIENTS: Patients included were those undergoing MRI for anogenital disease in hidradenitis suppurativa between 2005 and 2012. MAIN OUTCOME MEASURES: The distribution of sinus tracts in anogenital hidradenitis suppurativa on MRI was measured. RESULTS: Thirty-one MRIs were performed in 18 patients (15 men; mean age, 46 years). On the baseline MRI, multiple tracts were seen in the natal cleft (16/18; 83%), the perianal (12/18; 61%), the perineal (13/18; 56%), and the gluteal (8/18; 44%) regions. A communication with the anal canal was present in only 4 patients. Three patients had supralevator extension. Seven patients had follow-up MRIs with variable response to interval treatment: 3 of 7 showed responding disease, 3 of 7 showed stable disease, and 1 of 7 showed progressive disease. LIMITATIONS: This study was limited by its relatively small cohort of patients. CONCLUSIONS: In hidradenitis suppurativa, anogenital disease is usually subcutaneous but extensive, with only a minority of patients demonstrating deeper involvement. MRI may help define the extent of anogenital disease and assess response to treatment.