ABSTRACT
Primary retroperitoneal masses are a rare but diverse group of benign and malignant processes. Magnetic resonance (MR) imaging is playing an increasing role in evaluating retroperitoneal soft-tissue masses. Since the MR imaging features of most retroperitoneal soft-tissue masses are nonspecific, prediction of a specific histologic diagnosis remains a challenge for the radiologist. However, there are certain specific MR imaging appearances that are helpful. Dynamic enhancement patterns can reflect the vascularity of masses, differentiating benign from malignant soft-tissue masses. This article pictorially illustrates the MR imaging features of various common and uncommon retroperitoneal masses.
Subject(s)
Magnetic Resonance Imaging , Retroperitoneal Fibrosis/diagnosis , Retroperitoneal Neoplasms/diagnosis , Retroperitoneal Neoplasms/pathology , Histiocytoma, Benign Fibrous/diagnosis , Humans , Lipoma/diagnosis , Liposarcoma/diagnosis , Lymphangioma/diagnosis , Lymphangioma/pathology , Lymphatic Diseases/diagnosis , Lymphatic Metastasis , Nerve Sheath Neoplasms/diagnosis , Paraganglioma/diagnosisABSTRACT
OBJECTIVE: Our objective was to detail peritoneal anatomy, techniques for optimizing peritoneal MRI, and the MRI characteristics of several disease processes that frequently involve the peritoneum. CONCLUSION: Homogeneous fat suppression and dynamic contrast-enhanced imaging, including delayed imaging, are critical technical factors for successful lesion detection and characterization on peritoneal MRI.
Subject(s)
Magnetic Resonance Imaging , Peritoneal Diseases/diagnosis , Peritoneal Neoplasms/diagnosis , Peritoneum/pathology , Adult , Female , Humans , Male , Middle Aged , Peritoneum/anatomy & histologyABSTRACT
Clinical evaluation of neuromuscular disorders typically consists of obtaining a detailed clinical history, physical examination, and electrophysiologic examinations. Electrodiagnostic examinations significantly aid in distinguishing between myopathy, neuropathy, and neuromuscular disorders. Electrodiagnostic examinations also assist in determining the severity and extent of disease. Progress can also be monitored on follow-up testing. The benefit of magnetic resonance imaging (MRI) in neuromuscular disease evaluation lies primarily in identifying a specific underlying gross pathologic cause and its location in the neuraxis as well as in identifying associated secondary findings. In some cases, MRI is particularly helpful when a solitary, small, deep muscle is affected. Imaging can be useful in assessing clinical progress in some cases. Causes of muscle denervation include mass lesions and trauma as well as infectious, autoimmune, and idiopathic causes. This article illustrates the common denervation syndromes that involve the shoulder girdle: Parsonage-Turner syndrome, quadrilateral space syndrome, and suprascapular neuropathy. By demonstrating the exact muscles involved and spared, MRI noninvasively identifies the level of nerve insult in the neuraxis. Furthermore, in cases in which a mass is responsible for denervation, MRI can directly show the cause and aid in treatment planning.
