Magnetic Resonance Imaging of Renal Mass Lesions

1987 ◽  
pp. 115-131
Author(s):  
J. V. Kaude ◽  
R. E. Kinard
2004 ◽  
Vol 128 (7) ◽  
pp. 749-758 ◽  
Author(s):  
Teresa Ribalta ◽  
Ian E. McCutcheon ◽  
Antonio G. Neto ◽  
Deepali Gupta ◽  
A. J. Kumar ◽  
...  

Abstract Context.—Resorbable substances used to achieve hemostasis during neurosurgical procedures comprise 3 principal classes based on chemical composition: (1) gelatin sponge, (2) oxidized cellulose, and (3) microfibrillar collagen. Nonresorbable hemostatic aides include various forms of cotton and rayon-based hemostats (cottonoids and kites). Resorbable and nonresorbable hemostatic agents have been reported to cause symptomatic mass lesions, most commonly following intra-abdominal surgery. Histologic examination typically shows a core of degenerating hemostatic agent surrounded by an inflammatory reaction. Each agent exhibits distinctive morphologic features that often permit specific identification. Hemostat-associated mass lesions have been variously referred to as textilomas, gossypibomas, gauzomas, or muslinomas. Objectives.—The aims of this study were to (1) identify cases of histologically proven cases of textiloma in neurosurgical operations, (2) characterize the specific hemostatic agent associated with textiloma formation, and (3) characterize the preoperative magnetic resonance imaging appearance of textiloma. Design.—Cases in which a textiloma constituted the sole finding on repeat surgery for recurrent brain tumor, or was a clinically significant component of a radiologically identified mass lesion together with residual tumor, constituted the study set. Results.—Five textilomas were identified and evaluated. The primary neoplasm was different in each case and included pituitary adenoma, tanycytic ependymoma, anaplastic astrocytoma, gliosarcoma, and oligodendroglioma. In all cases, preoperative magnetic resonance imaging suggested recurrent tumor. Textilomas included all categories of resorbable hemostatic agent. Other foreign bodies were present in some cases; the origin of these foreign bodies was traced to fibers shed from nonresorbable hemostatic material placed temporarily during surgery and removed before closure (cottonoids and kites). Inflammatory reactions included giant cells, granulomas, and fibroblastic proliferation. Microfibrillar collagen (Avitene) textilomas were associated with a striking eosinophil infiltration that was not seen with any other hemostatic agent. Conclusions.—Hemostatic agents may produce clinically symptomatic, radiologically apparent mass lesions. When considering a mass lesion arising after intracranial surgery, the differential diagnosis should include textiloma along with recurrent tumor and radiation necrosis.


2007 ◽  
Vol 22 (6) ◽  
pp. 1-10 ◽  
Author(s):  
Tarvinder Singh ◽  
Michel Kliot

Recent advancements in the field of imaging, particularly magnetic resonance imaging, have improved the way peripheral nerve tumors are diagnosed, monitored, and treated both medically and surgically. When combined with the all-important clinical evaluation and electrodiagnostic studies, imaging permits a clinician to accomplish the following: identify the size, shape, location, and distribution of mass lesions; infer the risks in resecting a mass lesion by displaying its relationship to nearby nerve fascicles; determine growth rates when serial imaging studies are available; suggest the nature of the pathological entity; and visualize muscle denervation associated with nerve damage. The authors describe some of the commonly used imaging modalities and discuss their use in evaluating and treating peripheral nerve tumors and other mass lesions.


1986 ◽  
Vol 136 (3) ◽  
pp. 566-570 ◽  
Author(s):  
Nolan Karstaedt ◽  
David L. McCullough ◽  
Neil T. Wolfman ◽  
Raymond B. Dyer

Neurosurgery ◽  
1986 ◽  
Vol 18 (5) ◽  
pp. 625-627
Author(s):  
Michael N. Bucci ◽  
Keith L. Black ◽  
Joan L. Venes ◽  
Joseph T. Latack

Abstract Computed tomography has proven invaluable in the assessment of intracranial mass lesions. Low attenuation lesions can, however, present diagnostic difficulties. We report three cases where magnetic resonance imaging was beneficial in clarifying solid versus cystic intracranial lesions.


Author(s):  
Roberto Jose Diaz ◽  
Gregory W. Basil ◽  
Ricardo J. Komotar

Central nervous system (CNS) lymphoma must be considered in the differential diagnosis of any immunocompromised patient with a solid brain lesion. In such patients, diagnosis can be made via a careful review of important signs, symptoms, and classic radiologic findings. While there is no single physical exam finding classic for lymphoma, the clinician must carefully evaluate patients for the presence or absence of findings that may suggest an alternative diagnosis. Such findings include the stigmata of endocarditis, symptoms suggestive of pneumonia, or additional non-CNS mass lesions. Additionally, several imaging modalities including magnetic resonance imaging, diffusion-weighted magnetic resonance imaging, susceptibility weighted imaging, and dynamic contrast-enhanced imaging can be useful in identifying this condition. While steroids can be helpful in reducing the disease burden and decreasing edema, they may also hinder diagnosis. Surgery may be indicated for either diagnostic or decompressive purposes; however, the mainstay of treatment is chemotherapeutic and immunotherapeutic agents with radiation reserved for refractory cases.


2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Yu Ji ◽  
Hui Li ◽  
Alexandra V. Edwards ◽  
John Papaioannou ◽  
Wenjuan Ma ◽  
...  

Abstract Background As artificial intelligence methods for the diagnosis of disease advance, we aimed to evaluate machine learning in the predictive task of distinguishing between malignant and benign breast lesions on an independent clinical magnetic resonance imaging (MRI) dataset within a single institution for subsequent use as a computer aid for radiologists. Methods Computer analysis was conducted on consecutive dynamic contrast-enhanced MRI (DCE-MRI) studies from 1483 breast cancer and 496 benign patients who underwent MRI examinations between February 2015 and October 2017; with the age ranges of the cancer and benign patients being 19 to 77 and 16 to 76 years old, respectively. Cases were separated into a training dataset (years 2015 & 2016; 1444 cases) and an independent testing dataset (year 2017; 535 cases) based solely on MRI examination date. After radiologist indication of the lesion, the computer automatically segmented and extracted radiomic features, which were subsequently merged with a support-vector machine (SVM) to yield a lesion signature. Area under the receiving operating characteristic (ROC) curve (AUC) with 95% confidence intervals (CI) served as the primary figure of merit in the statistical evaluation for this clinical classification task. Results In the task of distinguishing malignant and benign breast lesions DCE-MRI, the trained predictive model yielded an AUC value of 0.89 (95% CI: 0.858, 0.922) on the independent image set. AUC values of 0.88 (95% CI: 0.845, 0.926) and 0.90 (95% CI: 0.837, 0.940) were obtained for mass lesions only and non-mass lesions only, respectively. Compared with actual clinical management decisions, the predictive model achieved 99.5% sensitivity with 9.6% fewer recommended biopsies. Conclusion On an independent, consecutive clinical dataset within a single institution, a trained machine learning system yielded promising performance in distinguishing between malignant and benign breast lesions.


2013 ◽  
Vol 119 (6) ◽  
pp. 1461-1466 ◽  
Author(s):  
Charles H. Cho ◽  
Garni Barkhoudarian ◽  
Liangge Hsu ◽  
Wenya Linda Bi ◽  
Amir A. Zamani ◽  
...  

Object Identification of the normal pituitary gland is an important component of presurgical planning, defining many aspects of the surgical approach and facilitating normal gland preservation. Magnetic resonance imaging is a proven imaging modality for optimal soft-tissue contrast discrimination in the brain. This study is designed to validate the accuracy of localization of the normal pituitary gland with MRI in a cohort of surgical patients with pituitary mass lesions, and to evaluate for correlation between presurgical pituitary hormone values and pituitary gland characteristics on neuroimaging. Methods Fifty-eight consecutive patients with pituitary mass lesions were included in the study. Anterior pituitary hormone levels were measured preoperatively in all patients. Video recordings from the endoscopic or microscopic surgical procedures were available for evaluation in 47 cases. Intraoperative identification of the normal gland was possible in 43 of 58 cases. Retrospective MR images were reviewed in a blinded fashion for the 43 cases, emphasizing the position of the normal gland and the extent of compression and displacement by the lesion. Results There was excellent agreement between imaging and surgery in 84% of the cases for normal gland localization, and in 70% for compression or noncompression of the normal gland. There was no consistent correlation between preoperative pituitary dysfunction and pituitary gland localization on imaging, gland identification during surgery, or pituitary gland compression. Conclusions Magnetic resonance imaging proved to be accurate in identifying the normal gland in patients with pituitary mass lesions, and was useful for preoperative surgical planning.


Neurosurgery ◽  
1990 ◽  
Vol 27 (5) ◽  
pp. 789-798 ◽  
Author(s):  
Dan S. Heffez ◽  
James S. Zinreich ◽  
Donlin M. Long

Abstract A major limitation to the effective treatment of intrinsic mass lesions of the brain stem has been the inability to clearly define the pathological anatomy radiographically. The improved soft tissue resolution offered by magnetic resonance imaging, as compared with axial computed tomography, now makes it possible not only to accurately distinguish anatomical relationships, but also to predict the pathological nature of the lesion. Accordingly, we have been encouraged to pursue a more aggressive approach to intrinsic lesions of the brain stem that appear well circumscribed on magnetic resonance imaging scan. The object of this paper is to report the successfuly treatment of four intrinsic lesions of the brain stem and to present an overview of the relevant published experience.


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