Helena Gabriel

CT Diagnosis of Chyluria After Partial Nephrectomy

OBJECTIVE The purpose of this study was to describe the CT diagnosis of chyluria after partial nephrectomy. CONCLUSION Fat in the bladder can be identified on CT after partial nephrectomy. This finding is caused by chyluria secondary to lymphatic injury and should not be mistaken for other abnormalities. Our study population did not need treatment of chyluria.

Adrenal lesions with heterogeneous suppression on chemical shift imaging: Clinical implications

To investigate the frequency and significance of adrenal lesions that demonstrate heterogeneous suppression on chemical shift magnetic resonance imaging (MRI).

Thyroid and parathyroid ultrasound examination

These guidelines are an educational tool designed to assist practitioners in providing appropriate radiologic care for patients. They are not inflexible rules or requirements of practice and are not intended, nor should they be used, to establish a legal standard of care. For these reasons and those set forth below, the American College of Radiology cautions against the use of these guidelines in litigation in which the clinical decisions of a practitioner are called into question.

Subcentimeter Thyroid Nodules: Utility of Sonographic Characterization and Ultrasound-Guided Needle Biopsy

OBJECTIVE The purpose of this study is to examine subcentimeter thyroid nodules to determine their rate of malignancy, the accuracy of various ultrasound features in prediction of malignancy, and the utility of ultrasound-guided biopsy of these nodules. MATERIALS AND METHODS Included in this retrospective study were 104 patients in whom 108 thyroid nodules smaller than 1 cm had been biopsied. Diagnostic ultrasound examinations were reviewed, and nodules were evaluated for the following ultrasound features: internal echogenicity, margins, height-to-width ratio, presence of calcifications, posterior acoustic features, solid-to-cystic ratio, presence of a halo, and color Doppler characteristics. In addition, a subjective assessment of level of suspicion was assigned to each nodule. Each feature was correlated with the pathologic results to determine the accuracy of the feature for predicting malignancy. RESULTS Adequate cytologic specimens were obtained in 97 of the 108 subcentimeter biopsies (90%) performed. The average size of malignant nodules was significantly smaller than the average size of benign nodules (6.4 ± 2.1 vs 7.7 ± 1.4 mm, p = 0.041). The rate of carcinoma among nodules with a final diagnosis was 19% (16/85). The most accurate features significantly associated with malignancy were posterior acoustic shadowing (87%), many diffuse calcifications (82%), rim calcifications (81%), and taller than wide shape (79%). The subjective level of suspicion correlated well with the presence of malignancy (76%). CONCLUSION Subcentimeter nodules are significantly associated with the risk of malignancy and can be accurately and safely biopsied with a very high diagnostic rate. Certain ultrasound features can be used to accurately stratify risk of malignancy, although no single feature replaces the clinicians overall impression.

Sonographic appearance of nodular fasciitis

First described in 1955, nodular fasciitis, or pseudosarcomatous fibromatosis, is a benign, self-limiting reactive process composed of proliferating fibroblasts in a myxoid stroma. 1 - 6 A rich cellular array of spindle-shaped fibroblasts, micro-hemorrhages, and numerous mitotic figures are characteristic features on low-magnification light microscopy. 3 Nodular fasciitis most commonly appears in the third and fourth decades with a solitary, rapidly growing, sometimes painful nodule arising in the upper extremity,4-6 which can be clinically confused with a sarcoma. Although a relatively common lesion, nodular fasciitis is underreported in the radiology literature. Typical magnetic resonance imaging (MRI) findings include low signal intensity on Tl-weighted images and high signal intensity on T2-weighted images, although they vary in homogeneity and patterns of enhancement. 4 , 5 On sonography, nodular fasciitis has been described as oval or lobulated, isoechoic, or with mixed areas of isoechogenicity and hypoechogenicity 7 As described below, we report a case of a patient with nodular fasciitis who underwent extensive imaging including sonography and MRI and describe the imaging features of this disease process. In this case, the lesion was well defined and slightly hypoechoic yet mildly heterogeneous and showed posterior acoustic enhancement.

Chemical Shift MR Imaging of the Adrenal Gland: Principles, Pitfalls, and Applications

Adrenal lesions are a common imaging finding. The vast majority of adrenal lesions are adenomas, which contain intracytoplasmic (microscopic) fat. It is important to distinguish between adenomas and malignant tumors, and chemical shift magnetic resonance (MR) imaging can be used to accomplish this distinction by depicting the fat in adenomas. Chemical shift imaging is based on the difference in precession frequencies of water and fat molecules, which causes them to be in different relative phases during the acquisition sequence and allows in-phase and opposed-phase images to be obtained. It is important to acquire these images by using the earliest possible echo times, with the opposed-phase echo before the in-phase echo, and by using a single breath hold to preserve diagnostic accuracy. Intracytoplasmic fat is depicted as signal drop on opposed-phase images when compared with in-phase images. Both qualitative and quantitative methods for assessing signal drop are detailed. The appearances of adrenal adenomas and other adrenal tumors on chemical shift MR images are described, and discriminatory ability at chemical shift MR imaging compared with that at adrenal computed tomography (CT) is explained. Other adrenal-related conditions in which chemical shift MR imaging is helpful are also discussed. Chemical shift MR imaging is a robust tool for evaluating adrenal lesions that are indeterminate at nonenhanced CT. However, it is important to know the advantages and disadvantages, including several potential imaging pitfalls. The characterization of adrenal lesions by using chemical shift MR imaging and adrenal CT should always occur in the appropriate clinical setting.

Computed Tomography and Magnetic Resonance Imaging Features of Lesions of the Renal Medulla and Sinus

The kidneys can harbor a wide variety of lesions, many of which can be visualized by computed tomography and magnetic resonance imaging. In this article, the pertinent renal anatomic relationships as well as the histologic composition and function of the renal medulla and sinus are reviewed. Additionally, computed tomography and magnetic resonance imaging features of renal sinus and medullary lesions in adult patients are presented. This article reviews the salient imaging features of various malignant, benign neoplastic, and nonneoplastic lesions of the sinus and medulla.

Compound Versus Fundamental Imaging in the Detection of Subdermal Contraceptive Implants

The purpose of this study was to compare the use of fundamental versus compound sonographic imaging in the localization of nonpalpable subdermal contraceptive implants.

Cystadenoma of the Rete Testis: Sonographic Appearance

WEB This is a Web exclusive article. he rete testis is an anastomotic network of ducts that is often a site of benign cystic change. In rare instances, neoplasms such as benign cystadenoma and malignant cystadenocarcinoma occur in the rete testis. Cystadenoma of the rete testis has been described in the urology and pathology literature. To our knowledge, however, the radiologic findings have not been described [1–3]. We present a case of cystadenoma of the rete testis and describe the sonographic appearance.

Role of Imaging in Surveillance and Diagnosis of Hepatocellular Carcinoma

The prognosis for hepatocellular carcinoma (HCC) is dependent on tumor stage at diagnosis, with curative treatment options more available to early-detected HCCs. Professional organizations have produced HCC screening guidelines in at-risk groups, with ultrasound the most commonly used screening tool and increased interest in MRI in specific populations. HCC may be diagnosed by imaging features alone and have been universally incorporated into management guidelines. The radiology community has standardized imaging criteria for HCC with the development of the Liver Imaging Reporting and Data System, which has expanded to incorporate computed tomography, MR, and contrast-enhanced ultrasound for diagnostic purposes.