MR defecography in patients with fecal incontinence: imaging findings and their effect on surgical management

PURPOSE: To retrospectively evaluate magnetic resonance (MR) defecography findings in patients with fecal incontinence who were evaluated for surgical treatment and to assess the influence of MR defecography on surgical therapy. MATERIALS AND METHODS: Institutional review board approval was obtained. Informed consent was waived; however, written informed consent for imaging was obtained. Fifty patients (44 women, six men; mean age, 61 years) with fecal incontinence were placed in a sitting position and underwent MR defecography performed with an open-configuration MR system. Midsagittal T1-weighted MR images were obtained at rest, at maximal contraction of the sphincter, and at defecation. Images were prospectively and retrospectively reviewed by two independent observers for a variety of findings. Interobserver agreement was analyzed by calculating kappa statistics. Prospective interpretation of MR defecography findings was used to influence surgical therapy, and retrospective interpretation was used for concomitant pelvic floor disorders. RESULTS: MR defecography revealed rectal descent of more than 6 cm (relative to the pubococcygeal line) in 47 (94%) of 50 patients. A bladder descent of more than 3 cm was present in 20 (40%) of 50 patients, and a vaginal vault descent of more than 3 cm was present in 19 (43%) of 44 women. Moreover, 17 (34%) anterior proctoceles, 16 (32%) enteroceles, and 10 (20%) rectal prolapses were noted. Interobserver agreement was good to excellent (kappa = 0.6-0.91) for image analysis results. MR defecography findings led to changes in the surgical approach in 22 (67%) of 33 patients who underwent surgery. CONCLUSION: MR defecography may demonstrate a variety of abnormal findings in patients who are considered candidates for surgical therapy for fecal incontinence, and the findings may influence the surgical treatment that is subsequently chosen. Supplemental material: http://radiology.rsnajnls.org/cgi/content/full/2402050648/DC1     

Anorectal function in patients with defecation disorders and asymptomatic subjects: evaluation with defecography

A controlled radiologic study of anorectal function was performed with the use of defecography in 19 patients with constipation and 13 with incontinence. All patients were age and sex matched to control subjects who were referred for barium enema study and who had no defecation disorder. There were no statistically significant differences between either patient group and the control group in anorectal angle and excursion of the anorectal junction. In the 32 patients and 155 consecutive patients referred for defecography because of a variety of defecation disturbances, approximately twice as many rectal wall abnormalities were seen compared with findings in the control group. These findings included intussusception, rectal prolapse, rectocele, mucosal prolapse, spastic pelvic floor, descending perineum syndrome, and solitary rectal ulcer syndrome. In conclusion, the main role of defecography is to document rectal wall changes during defecation straining as possible causes of evacuation difficulties. Clinical symptoms should also be taken into account when treatment is contemplated.     

排粪造影诊断排粪功能障碍的应用

本文报道对便秘的病因、影像表现及排粪造影对直肠前突的诊断应用价值进行探讨,现总结如下。1材料与方法1.1临床资料收集我院2011年～2012年3月间共87例病例,男性10例,女性77例,年龄16～72岁。病程1～30年。将本组87例分为对照组和异常组。对照组:10例,均无排粪障碍,其中男6例,女4例,年龄24～64岁。异常组:77例,男4例,女     

Ovarian carcinoma in patients with endometriosis: MR imaging findings

OBJECTIVE: Various types of malignancy can develop in patients with endometriosis. Enhancing mural nodules have been reported as an imaging characteristic of malignant transformations. We evaluated contrast-enhanced MR imaging to determine the optimum sequence to reveal mural nodules and other characteristics of malignant transformations. MATERIALS AND METHODS: We examined 10 patients with pathologically proven ovarian adenocarcinoma in endometriosis and 10 patients (the control group) with ovarian endometrioma suggestive of malignant transformation on the basis of sonographic findings. We analyzed the size and nature of the endometriomas in each patient. We compared four types of contrast-enhanced MR imaging to determine which sequence best revealed mural nodules. RESULTS: In the malignant and control groups, 80% of the cysts with findings suggestive of malignant transformation showed unilateral disease or larger endometrial cysts on the suggestive side than on the contralateral side. High signal intensity on T1-weighted images and low signal intensity on T2-weighted images relative to the myometrium were observed only in two of 10 malignant endometrial cysts and in all control cysts. All malignant endometriomas had small mural nodules with low signal intensity on T1-weighted contrast-enhanced images. Only three benign endometriomas had mural nodules and none of them enhanced. The enhancement of mural nodules was easily seen on dynamic subtraction imaging. CONCLUSION: On the basis of our findings, endometrial cysts with malignant transformation rarely show low signal intensity on T2-weighted images and usually have enhancing mural nodules. Because the enhancement of mural nodules is often difficult to evaluate on conventional T1-weighted images, dynamic subtraction imaging can be valuable.     

MR imaging of the brain in pediatric patients: diagnostic value of HASTE sequences

OBJECTIVE: The objective of this study was to determine the diagnostic value of half-Fourier single-shot turbo spin-echo (HASTE) sequences in MR imaging of the brain in pediatric patients. SUBJECTS AND METHODS: HASTE sequences were performed in 80 infants and children. Two radiologists who were unaware of the patients' medical histories independently reviewed the images for the presence of nine findings: defects of the parenchyma, hypoplasia or agenesis of the corpus callosum, edema, signs of increased intracranial pressure, myelination disorders, migration disorders, malformations, tumors, and widening of spaces of the cerebrospinal fluid. A conventional MR imaging examination that served as the reference examination was evaluated by the same two radiologists in a final consensus interpretation. The findings detected on the HASTE images were compared with the findings seen on the conventional MR images. The sensitivity and specificity of HASTE sequences were calculated, and Cohen's kappa statistic was used to determine interobserver agreement. RESULTS: Both radiologists correctly diagnosed all 20 defects of the parenchyma that were present in the patients. Radiologist 1 correctly identified 20 and radiologist 2 correctly identified 21 of the 22 patients with hypoplasia or agenesis of the corpus callosum. Both radiologists correctly diagnosed edema in eight of the nine patients in whom edema was present, and both correctly identified signs of increased intracranial pressure in eight of the nine children who had this condition. Radiologist 1 correctly diagnosed seven and radiologist 2 correctly identified nine of the 11 cases of myelination disorders. Both radiologists correctly diagnosed six of the 14 cases with migration disorders. All 13 brain malformations present in the patients were correctly identified by both reviewers. Both radiologists correctly identified all 11 patients with tumors, and both correctly identified all 35 patients with widening of spaces of the cerebrospinal fluid. CONCLUSION: HASTE images are highly sensitive for excluding the presence of brain tumor, hydrocephalus, or malformations of the brain. HASTE images are not reliable for evaluating patients with suspected myelination disorders or migration disorders.     

MR imaging findings in patients with bone-chip allografts

Increasing use of MR to evaluate primary bone neoplasms has stimulated numerous articles on the initial assessment of these lesions. However, scant MR literature has been written about the postoperative MR appearance. We studied the MR appearance of lesions treated by curettage followed by packing with cancellous bone-chip allograft. We retrospectively reviewed the MR scans of 18 consecutive patients treated in this way. Pathologic diagnoses of these lesions were confirmed according to commonly accepted criteria. The allograft sites showed a distinctive pattern of speckled bright signal on T1-weighted images in eight cases. Thirteen of 18 grafts showed a whorled or speckled pattern of increased signal on the T2-weighted images. Only four allograft regions had predominantly low signal on both T1- and T2-weighted images. Two of 18 patients had recurrent tumor proved by open biopsy. MR images in these cases showed areas of homogeneous signal that replaced areas of speckled hyperintensity on both T1- and T2-weighted images. In both these recurrences the tumor had signal intensity similar to that seen on the preoperative MR study. We conclude that knowledge of the MR appearance of cancellous bone chip allografts is important to avoid misinterpreting areas of high signal on T1- or T2-weighted images as areas of recurrence of tumor and/or hemorrhage.     

Inconclusive findings at mammography: the value of MR imaging

Summary Purpose: To evaluate the usefulness of magnetic resonance (MR) imaging in the assessment of inconclusive findings at mammography, such as indeterminate focal or diffuse breast abnormalities, post-treatment breasts with extensive scarring, dense breasts, and findings suggesting multifocal or multicentric breast cancer. Material and Methods: 254 patients underwent mammography, sonography, and MRI of the breast. Dynamic MR imaging was done using a thin-section three-dimensional gradient-echo sequence (FLASH, TR = 11.8 ms; TE = 5 ms; flip angle = 25 °) which was applied in a dynamic fashion before and every 90 seconds after injection of gadopentetate dimeglumine. Diagnoses were confirmed at biopsy (n = 165) or by follow-up (n = 89). Results: Among various breast anomalies, the highest proportion of breast cancers was associated with dense breast tissue (27.8 %), architectural distortion (26.9 %), and irregular scars (15.8 %). Sensitivity of dynamic MR imaging was 93.7 %, and specificity was 83.3 %. As compared to mammography and sonography, MR detected 6 occult carcinomas, and showed additional malignant lesions in 19/63 women (30.2 %) with biopsy-proven breast cancer. Conclusion: MR imaging of the breast may provide valuable additional information in indeterminate breast anomalies. However, because of its inherent limitations, it should not replace core needle biopsy in all lesions which are amenable to biopsy. Because of its high sensitivity in the detection of invasive carcinomas in any type of breast tissue, MR imaging is considered the modality of choice in the evaluation of dense breasts in high-risk patients or in patients with clinical suspicion of occult breast cancer, and for preoperative tumor staging.      

Muscle infarction in patients with diabetes mellitus: MR imaging findings

PURPOSE: To describe the magnetic resonance (MR) imaging findings in diabetic patients with muscle infarction and to describe commonly associated clinical features. MATERIALS AND METHODS: The MR imaging studies of 21 patients with diabetic muscle infarction were reviewed retrospectively. Of the 21 patients, 12 were women, and nine were men; the mean age was 48 years (range, 30-77 years). RESULTS: Eight patients had bilateral lower-extremity involvement; six had involvement confined to the right lower extremity and seven to the left. The thigh was involved in 17 patients (81%). One or more of the musculi vastus, the most frequently affected muscle group, were affected in 16 patients (76%). Four patients (19%) had isolated calf involvement. MR imaging studies showed diffuse enlargement of involved muscle groups and partial loss of normal fatty intermuscular septa. MR imaging also allowed identification of areas of subfascial fluid in 16 patients (76%) and subcutaneous edema in 19 patients (90%). MR imaging showed involved muscle groups best with T2-weighted, inversion-recovery, and gadolinium-enhanced sequences, where the infarcted muscles appeared diffusely hyperintense compared with adjacent muscles. Comparison of T2-weighted and gadolinium-enhanced MR images of nine patients showed enlarged, enhancing muscles in all patients and small, focal, rim-enhancing fluid collections in six of nine patients (66%). CONCLUSION: Diabetic muscle infarction is suggested in diabetic patients with sudden onset of severe pain in the thigh or calf muscles who have MR imaging findings of diffuse edema and swelling of multiple thigh and calf muscles (often in more than one compartment).     

胼胝体梗死的MRI表现及其诊断价值

目的：探讨胼胝体梗死的MRI表现特征及其诊断价值。方法：在连续2年颅脑MRI检查中搜集569例脑梗死病例．对其中有胼胝体梗死的36例进行回顾性分析。全部病例均行sE与TSE序列T1WI、T2wI扫描，15例加FLAIR序列扫描，l3例行钆喷替酸葡甲胺(GdDTPA)增强扫描。结果：569例脑梗死中36例(6．3％)MRI确诊为胼胝体梗死。其中3例为单纯胼胝体梗死，33例同时伴其它部位脑梗死。36例共45个梗死灶，位于胼胝体膝部19个，体部15个，压部10个，膝体部1个。T1WI呈略低信号26个，低信号19个，T2wI均呈高信号；15例FLAIR序列11例呈高信号，4例呈低信号；13例增强扫描9例强化。结论：胼胝体梗死少见。MRI可清楚显示胼胝体梗死的存在、部位与范围，但缺乏特征性，结合临床及脑内其它部位梗死灶并存可确定诊断。     

Urgent MRI with MR cholangiopancreatography (MRCP) of acute cholecystitis and related complications: diagnostic role and spectrum of imaging findings

Acute cholecystitis, which is usually associated with gallstones, is one of the commonest surgical causes of emergency hospital admission and may be further complicated by mural necrosis, perforation, and abscess formation. Magnetic resonance imaging (MRI) is increasingly available in the emergency setting. Technically improved equipment and faster acquisition protocols allow excellent tissue contrast and MRI is now an attractive modality for imaging acute abdominal disorders. The use of MRI with MR cholangiopancreatography in the emergency setting provides rapid, noninvasive, and confident diagnosis or exclusion of acute cholecystitis and of coexistent choledocholithiasis. To familiarize the reader with these cross-sectional imaging appearances, this paper reviews MRI findings consistent with uncomplicated cholecystitis. These include gallbladder distension, intraluminal sludge and gallstones, impacted stones obstructing the gallbladder neck or cystic duct, thickening of the gallbladder wall, abnormal signal intensity and edematous stratification, and pericholecystic and perihepatic fluid, plus increased enhancement of the gallbladder wall and adjacent liver parenchyma when intravenous paramagnetic contrast is used. Furthermore, MRI allows prompt detection and comprehensive visualization and characterization of cholecystitis-related complications such as gangrene, perforation, pericholecystic abscess, and intrahepatic fistulization. Some previous literature reports, and our experience, suggest that, when available, MRI should be recommended to provide prompt and efficient triage of patients with suspected cholecystitis and inconclusive clinical, laboratory, and sonographic findings. It facilitates appropriate therapeutic planning, including the timing of surgery (emergency or delayed), approach (laparoscopic or laparotomic), and need for preoperative or intraoperative removal of stone(s) in the common bile duct.     

Dropped gallstones: spectrum of imaging findings,complications and diagnostic pitfalls

Spillage of gallstones into the abdominal cavity, referred to as “dropped gallstones” (DGs), occurs commonly during laparoscopic cholecystectomy. The majority of these spilled stones remain clinically silent; however, if uncomplicated DGs are not correctly identified on subsequent imaging, they may mimic peritoneal implants and cause unduly concern. A small percentage of DGs cause complications, including abscess and fistula formation. Recognising the DG within the abscess is critical for definitive treatment. This pictorial review illustrates the imaging appearances and complications of DGs on CT, MRI and ultrasound and emphasises pitfalls in diagnosis.Laparoscopic cholecystectomy (LC) is the procedure of choice for routine gallbladder removal and is the most common major abdominal procedure performed in Western countries [1]. The use of laparoscopic technique has resulted in an increased incidence of spillage of stones into the intraperitoneal space (∼30%) owing to perforation of the gallbladder during cholecystectomy [1,2]. Spilled gallstones, “dropped gallstones” (DGs), were initially considered to be harmless; however, it is now well recognized that DGs can result in complications, mainly abscess and fistula formation [2]. The purpose of this essay is to illustrate the spectrum of CT, sonographic and MRI findings of DGs, describe associated complications, and present diagnostic mimics and pitfalls.     

Radiation myelopathy in over-irradiated patients: MR imaging findings

The objective of this work is to report the MRI findings in patients with radiation myelopathy due to accidental local over-irradiation syndrome. Eight patients (seven males and one female) were suffering from over-irradiation syndrome as a result of treatments from a malfunctioning linear electron accelerator. The mean accidental estimated dose was 136 Gy delivered to the “open-neck” (seven cases) and to the thoracic wall (one case), during a mean of 5.4 sessions (range 1–9 sessions). Paresthesia and weakness in the upper extremities were the earliest symptoms (87.5 %), with evolution to paralysis in all patients. No patient is alive (mean survival time 64 days). In all cases MRI was negative for neurologic lesions in the acute phase ( < 90 days from irradiation; Radiation Therapy Oncology Group scoring system). Late signs of radiation myelitis manifested as high-intensity signals on T2-weighted images in three patients, and as Gd-DTPA enhancement of T1-weighted images in one case. Autopsies performed on four patients who died in acute phase showed morphologic alterations in white matter: edema in 75 %, and necrosis and glial reaction as well as obliterative vasculitis in all cases. In cases of over-irradiation, MRI may be normal in acute phase even if the patients have severe neurologic deficit, as positive MRI findings appear only in delayed radiation myelitis. Received 25 March 1996; Revision received 3 July 1996; Accepted 4 September 1996     

MR imaging findings of parotid tumors with pathologic diagnostic clues: a pictorial essay

This pictorial essay depicts MR features of benign and malignant parotid tumors. Increased T2 signal intensity is suggestive of pleomorphic adenoma. Tumors with relatively low signal intensity on T2-weighted images are more likely to be malignant even when they are well-demarcated. Fat suppression technique improves the ability to define the boundaries of neoplatic or inflammatory lesions.     

MR imaging of nontraumatic brachial plexopathies: frequency and spectrum of findings.

Magnetic resonance imaging is the method of choice for evaluating patients with a nontraumatic brachial plexopathy. Although there is a wide range of disease processes that may cause a brachial plexopathy, radiation fibrosis, primary and metastatic lung cancer, and metastatic breast cancer account for almost three-fourths of the causes. Radiation fibrosis, the most common cause in our series, may occur several months to years after the completion of therapy. Findings of radiation fibrosis include (a) thickening and diffuse enhancement of the brachial plexus without a focal mass and (b) soft-tissue changes with low signal intensity on both T1- and T2-weighted images. Lung cancer arising in the lung apex may invade the lower portion of the brachial plexus. Many tumors may metastasize to the brachial plexus, causing a brachial plexopathy. Breast cancer is the most likely to metastasize because major lymphatic drainage routes for the breast course through the apex of the axilla.     

Intraocular lesions in patients with systemic disease: findings on MR imaging

Twenty-one intraocular lesions associated with various systemic diseases in 15 patients were studied by MR imaging. The disorders included diabetes mellitus, cardiovascular disease, Beh?et disease, sarcoidosis, and ankylosing spondylitis. MR was performed on a 0.5-T system using a surface-coil technique. Ophthalmoscopic visualization of the fundus was precluded by the presence of opaque media in all cases. MR was found to be effective in demonstrating intraocular bleeding, vitreous opacity, detached lesions of the posterior pole, and eyeball deformity. Surface-coil MR is a useful adjunct in the evaluation of the eyes affected by systemic diseases, especially in patients with opaque media.