Resumen:

Abstract

Evaluation of diagnostic underestimation and incidence in BI-RADS 3, 4 and 5 nodules studied by ultrasound-guided core biopsy.

Objectives: To retrospectively determine the false negatives rate and the extent of underestimation of ultrasound-guided core biopsy of breast nodules, and to determine the incidence of the various lesions presenting as breast nodules.

Materials and Methods: We studied core biopsies of breast nodules from January 2000 to September 2010, performed by a radiologist with 10 years experience in breast imaging, using 14-gauge and 10-cm needles. For ultrasound guidance, two ultrasound machines with a 5-12 MHz linear transducer were used. Biopsied lesions had a moderate or high suspicion of malignancy (BI-RADS 4 and 5) and some were probably benign lesions (BI-RADS 3). Histological findings of core-biopsy were correlated with those of surgery for each lesion. Cases of benign lesions which had not been operated on underwent a 1- to 10-year clinical and radiological follow-up.

Results: A total of 190 biopsies were performed. The false negative rate was 3%, sensitivity was 95% and specificity was 100% (PPV 100% and NPV 95%).

Discussion: There was 94% consistency between core biopsy results and surgery. The false negative rate is acceptable as compared to other reports, where it ranges from 0 to 8%.

Conclusions: This study indicates that ultrasound-guided core biopsy is a valid method, with a high degree of accuracy and a low rate of false negatives and underestimation, in the diagnosis malignant and benign of breast nodules. This has been confirmed by surgical excision and / or clinical and imaging follow-up of different lesions.

Keywords: Breast. Breast nodule. Core-biopsy.

Resumen:

Abstract:

3T MRI neurography: preliminary experience.

Purpose: Demonstrate the advantages of the IDEAL (Iterative Decomposition of water and fat with Echo Asymmetry and Least-squares estimation) sequence in the evaluation of peripheral nerves, brachial plexus and lumbar plexus, for the diagnosis of compression or entrapment neuropathies, non-entrapment neuropathies, and the underlying conditions. The IDEAL sequence provides 4 types of images from a single acquisition, allowing uniform fat or water suppression and in phase/out of phase images of water, fat or a combination of both.

Materials and Methods: This is a retrospective study, from January 2011 to June 2011. Eleven neurographies were performed on 3T MRI (HDX 3T, GE Healthcare, USA), with 8-channel phased array coils on sagittal and coronal planes, with 1.2-0 mm slices with no gap, axial 3D spoiled gradient recalled (SPGR) T , with 1-0-mm slice thickness with and without gadolinium injection and variable field of view (FOV) according to the nerve or plexus to explore. Results. We found 2 schwannomas (brachial plexus and sciatic nerve), 1 neuritis (compression to median nerve), 2 cases of multiple neurofibromas (lumbosacral plexus, sciatic nerve, brachial plexus), 3 traumatic neuromas (peroneal nerve) and 1 pseudomeningocele avulsion (brachial plexus), and 2 with no structural alterations (lumbosacral plexus and peroneal nerve).

Conclusion: In this preliminary experience, the use of highresolution sequences in magnetic resonance imaging neurography studies provided excellent signal homogeneity, improving the recognition of the nerve structure and signal, the identification of anatomical variations, and causes of neuropathy, as well as the characterization of denervation changes of the affected muscle groups.

Keywords: Neurography. Peripheral nerves. Plexus. Neuropathy. Magnetic resonance.

Introducción:

Introduction:

Cystic lesions affecting the pancreas are a frequent finding in clinical practice. They pose differential diagnoses which should be known and interpreted by radiologists, determining doubts concerning their etiology in many cases.
Pancreatic Pseudocysts are the most frequent cystic lesions of the pancreas. Other lesions, which include cystic pancreatic neoplasms are not frequent, they represent only the 10%-15% of all pancreatic cysts.
The increase in the use of diagnostic imaging methods like Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) has increased the recognition of such lesions and with that, the number of resections.
Among lesions that are not Pseudocysts, Serous Cystadenoma, Mucinous Cystic Neoplasm and Intraductal Papillary Mucinous Neoplasm (IPMN) are the most frequent, representing the 90% of cystic pancreatic lesions.
The initial evaluation must be oriented to exclude pancreatic Pseudocysts, which are found in patients with a history of acute or chronic pancreatitis or abdominal trauma. Cystic tumors do not have these antecedents.
Even though the morphology of the cystic lesions contributes to the interpretation of the images and the approximation to a diagnosis of the lesions, sometimes the precise characterization can be very difficult due to the great variety of cell types.
Images are essential in the evaluation of patients with cystic pancreatic lesions, being the CT the preferred imaging modality for the initial detection and the characterization of pancreatic cysts. 5 The MRI with Cholangioresonance precisely shows the morphologic characteristics of the cysts and has the advantage to show the relationship of the cysts with the pancreatic duct.
The objective of this paper is to analyze cystic lesions of the pancreas diagnosed with CT, MRI and ultrasound, in order to determine its imaging characteristics, typification and classification, trying to identify signs which allow for the differentiation between benign and malign lesions, correlating the findings with the histopathology results of percutaneous puncture biopsy, surgery or clinical evolution.

Resumen:

Abstract:

Neurocysticercosis is a major parasitic disease of the central nervous system, affecting endemic areas worldwide. It spreads through intermediary hosts, pigs and eventually men to his definitive host: humans. It causes lesions in the CNS which have different evolutive stages and can be asymptomatic or clinically evident. Imaging studies play an important role in the diagnosis of the disease and in its appropriate control.

Key Words: Neurocysticercosis, Computed Tomography, Magnetic Resonance, Imaging

Resumo:

Abstract

Objective: To identify and evaluate the prevalence of congenital central nervous system (CNS) malformations and associated defects diagnosed by obstetric ultrasonography.

Materials and Methods: Observational, descriptive, crosssectional study developed in an institution of reference for high-risk pregnancies.

Results: Congenital CNS malformations without other associated defects were present in 65.78% of cases, as follows: hydrocephalus (37.5%), myelomeningocele (15%), encephalocele (12.5%), corpus callosum agenesis (12.5%), anencephaly (12.5%), holoprosencephaly (7.5%), Dandy-Walker (7.5%), Arnold-Chiari (5.0%), hydranencephaly (5.0%), meningocele (5.0%), arachnoid cyst (2.5%). Congenital malformations of other systems were associated with such malformations, as follows: craniofacial (73.9%), orthopedic (65.2%), cardiovascular (34.8%), genitourinary (30.4%), gastrointestinal (30.4%), respiratory (8.7%), syndromic (8.7%), ophthalmologic (4.3%). The sonographic sensitivity in the study of CNS malformations was 79.4%. The rate of false-negative results was 20.5%. Oligohydramnios, present in 25% of false-negative studies, stands out among the quantifiable limitations.

Conclusion: Obstetric ultrasonography presents good sensitivity in the screening for fetal CNS malformations, specially with the constant improvement and control of specialized methods such as Doppler and volumetric ultrasonography (3D/4D), contributing to consolidate its role as a modality of choice in this routine. Magnetic resonance imaging may play a supplementary role, providing information for an even better perinatal care.

Keywords: Congenital malformations; Central nervous system malformations; Associated malformations; Ultrasonography.

Resumo:

Abstract:

The present study was aimed at describing key computed tomography and magnetic resonance imaging findings in patients with acute abdominal pain derived from pelvic inflammatory disease. Two radiologists consensually selected and analyzed computed tomography and magnetic resonance imaging studies performed between January 2010 and December 2011 in patients with proven pelvic inflammatory disease leading to presentation of acute abdomen. Main findings included presence of intracavitary fluid collections, anomalous enhancement of the pelvic excavation and densification of adnexal fat planes. Pelvic inflammatory disease is one of the leading causes of abdominal pain in women of childbearing age and it has been increasingly been diagnosed by means of computed tomography and magnetic resonance imaging supplementing the role of ultrasonography. It is crucial that radiologists become familiar with the main sectional imaging findings in the diagnosis of this common cause of acute abdomen.

Keywords: Acute abdomen; Pelvic inflammatory disease; X-ray computed tomography; Magnetic resonance imaging

Resumen:

Triple receptor-negative breast cancer. How is it seen on imaging findings?

Abstract:

In HIV-infected patients, liver and biliary tract may be affected by different entities, such as AIDScholangiopathy, which is usually associated with CD4+T lymphocytes count below 100 cells/mm3 along with non-specific symptoms. Although imaging studies play a major diagnostic role they should always be evaluated according to patients clinical context. While ultrasound and CT scans provide relevant diagnostic information, specialized studies such as MRI and MRCP have become increasingly valuable due to their ability to demonstrate parietal as well as stenotic biliary changes. Despite ERCP remaining the gold-standard for diagnosis of AIDSrelated cholangiopathy, currently it is usually reserved to clearly exclude the presence of malignancy, or as a specific invasive therapeutic procedure, when indicated.

Key words: AIDS, Biliary tract diseases, Endoscopic retrograde cholangiopancreatography (ERCP), HIV, Magnetic resonance imaging (MRI), Sclerosing cholangitis.

Abstract:

Endometriosis is the presence of endometrial tissue outside the uterine cavity(1-3). This endometrial tissue may be located in the ovaries as endometriomas and/or as extraperitoneal/subperitoneal implants(3,4) . When implant depth is greater than 5 mm, condition is referred to as deep endometriosis(3,4). It represents a common cause of pelvic pain and infertility in young women(1-3). Surgery remains the best treatment option, so pre-operative evaluation to assess the extent of disease is essential(3,4) . Magnetic resonance imaging (MRI) is a non-invasive, non-ionizing radiation method, offering high contrast resolution,which allows multiplanar evaluation of endometriosis, thus facilitating a correct diagnosis and appropriate treatment(2-4). Radiologists have to be familiar with MR imaging appearance of endometriosis, in order to guide clinicians and provide adequate information to assure accurate diagnosis and timely treatment of this entity.

Key words: Endometriosis, MRI.

Resumen:

Abstract

Summary: The diaphragmatic hernia is defined as a defect in the continuity of muscular fibers which allow communication among abdominal and thoracic cavities. Diaphragmatic hernias can have a congenital origin as a result of the alteration in the fusion of pleuroperitoneal membranes or in the formation of the transverse septum during development, which origin can be traumatic as a consequence of a muscle tear due to penetrating, iatrogenic injuries or due to blunt abdominal trauma. The traumatic diaphragmatic hernia diagnosis is based on images studies. Conventional chest x-rays remains as the initial evaluation method in patients with a suspicion of a traumatic tear of the diaphragm. Sensitivity between 27 and 73% has been described. Multiple detector computed tomography (MDCT) has become the diagnosis method for patients with traumatic diaphragmatic hernia suspicion. Studies have proven that the sensitivity of this method ranges between 71 - 90% and a specificity between 98 and 100%. We present a series of 10 patients with traumatic diaphragmatic hernia diagnosed through MDCT, with a manifestation checkup carried out by the conventional radiology and the MDCT of this entity

Resumen:

Abstract

Summary: Colonic transit time with radiopaque markers (CTTRm) is a test which evaluates colonic motility in a simple and effective manner. It was first described in 1969 and it is still used as a complementary method of studying patients with constipation. We present 9 patients who underwent this study as part of their clinical constipation diagnosis in 2010; moreover, the technique, diagnostic contributions and indications of the test are reviewed. The exam technique has not been adequately standardized in literature. however, the fact that it helps determine the role of the colon as the cause of constipation in a patient has led to its inclusion in the study guidelines of constipation, which makes the standardization of the study technique and presentation even more important.

Resumen:

Abstract:
Brain connectivity is a key concept for understanding brain function. Current methods to detect and quantify different types of connectivity with neuroimaging techniques are fundamental for understanding the pathophysiology of many neurologic and psychiatric disorders. This article aims to present a critical review of the magnetic resonance imaging techniques used to measure brain connectivity within the context of the Human Connectome Project. We review techniques used to measure: a) structural connectivity b) functional connectivity (main component analysis, independent component analysis, seed voxel, meta-analysis), and c) effective connectivity (psychophysiological interactions, causal dynamic models, multivariate autoregressive models, and structural equation models). These three approaches make it possible to combine and use different statistical techniques to elaborate mathematical models in the attempt to understand the functioning of the brain. The fi ndings obtained with these techniques must be validated by other techniques for analyzing structural and functional connectivity. This information is integrated in the Human Connectome Project where all these approaches converge to provide a representation of all the different models of connectivity.

Keywords: Brain connectivity; Functional connectivity; Effective connectivity; Connectome; Magnetic resonance imaging; Methods; fMRI; Independent component analysis; Meta-analysis

Resumen:

Abstract:

Breast imaging plays a signifi cant role in treatment. Ultrasonography to drain fl uid collections, vacuum-assisted biopsy to excise papillomas and fi broadenomas, and stereotactic excisional biopsy are a few examples of interventional procedures performed by radiologists in patients with breast disease. Moreover, there is a growing interest in the minimally invasive treatment of invasive tumors, which aims to achieve the same efficacy while minimizing morbidity and improving the esthetic outcome. Especially noteworthy are thermal ablation techniques, which involve destroying tumors with heat or cold. The most widely studied thermal ablation techniques are radiofrequency, high intensity focused ultrasound, laser therapy, microwaves, and cryoablation.
After a review of the literature, we conclude that the development of these treatment approaches will depend largely on the capacity of imaging techniques to plan the destruction of the tumor. Ultrasonography and magnetic resonance imaging are the current techniques of choice for this purpose.
The evidence suggests that small invasive carcinomas can be efficaciously treated with thermal ablation, especially by radiofrequency ablation; however, before this technique can be validated, phase III clinical trials must compare it with conservative surgery in terms of local progression and overall survival

Key Words: Radiofrequency; Ablation; Laser therapy; Focused ultrasound

Resumen:

Abstract

Soft tissue foreign bodies due to penetrating injuries are a common reason for emergency department visits. We present a series of six cases in which ultrasound was used successfully not only as a diagnostic tool but also as a real-time guidance for their removal.

Key words: ultrasound, sonography, foreign body, penetrating wounds.

Resumen:

Abstract:

Purpose: In this review, a brief discussion of the important events of pancreatic embryology is followed by presentation of congenital anomalies and normal variants. For each variant, the appearance at different radiologic modalities including computed tomography, magnetic resonance (MR) imaging, endoscopic retrograde cholangiopancreatography, MR cholangiopancreatography, and fluoroscopy will be demonstrated.

Abstract:

Abstract:

Giant cell tumor (GCT) of bone is generally a benign tumor composed of mononuclear stromal cells and characteristic multinucleated giant cells that exhibit osteoclastic activity. It usually develops in long bones but can occur in unusual locations. The typical appearance is a lytic lesion with a well-defined but nonsclerotic margin that is eccentric in location, extends near the articular surface, and occurs in patients with closed physes. However, GCT may have aggressive features, including cortical expansion or destruction with a soft-tissue component. Fluid-fluid levels, consistent with secondary formation of aneurysmal bone cysts, are seen in 14% of cases. GCT can mimic or be mimicked by other benign or malignant lesions at both radiologic evaluation and histologic analysis. Rarely, GCT is associated with histologically benign lung metastases or undergoes malignant degeneration. In the past, the mainstay of treatment was surgical, primarily consisting of curettage with cement placement, with recurrence rates of 15%–25%. Recurrence is suggested by development of progressive lucency at the cement-bone interface. Other complications include pathologic fracture and postoperative infection. Denosumab, a monoclonal antibody that targets the osteoclastic activity of GCT, has produced 90% tumor necrosis in early studies, results indicative of promise as a potential adjuvant therapy.