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Biomedical subjects

Larissa Braga

Publications and source records attributed to Larissa Braga.

At least 19 recordsLinked to original sources
PubMed2006

Validation of the NHANES ADL scale in a sample of patients with report of cervical pain: factor analysis, item response theory analysis, and line item validity.

BACKGROUND: Few functional outcomes scales have used Item Response Theory (IRT) for validation. IRT allows individual line item validations and offers substantial advantages over classic methods of scale validation or the simplest from of IRT known as Rasch. Rasch analysis reduces data to dichotomous variables thus decreasing the sensitivity of Likert-type data responses. PURPOSE: The purpose of this study was to create an outcome scale associated with the latent trait of functioning and disability, validated using IRT, in a population with report of cervical pain. METHODS: Using the NHANES database, a recently created scale (NHANES ADL scale) was analysed using factor analysis, internal analyses of consistency, IRT, and comparison with internal measures of functioning and disability. RESULTS: The newly created NHANES ADL scale demonstrated uni-dimensionality, was internally reliable, and was correlated to internal measures of functioning and disability. Additionally, the majority of the scale items demonstrate strong discrimination and suitable thresholds. DISCUSSION: The NHANES ADL scale effectively measures physical, social, and emotional disability in patients with a cervical impairment, and may be an efficient measure of perceived limitations from working and generalized daily physical activity. CONCLUSION: The newly created NHANES ADL scale demonstrates internal consistency, unidimensionality, and line item validity. The NHANES ADL scale appears to be a useful instrument in measurement of functioning and disability in patients with report of cervical pain.

Activities of Daily Living↗
PubMed2006

Cross-cultural adaptation and validation of the Brazilian Portuguese version of the Neck Disability Index and Neck Pain and Disability Scale.

STUDY DESIGN: This study's design was a cross-cultural validation of the Neck Disability Index and Neck Pain and Disability Scale. OBJECTIVES: This study's objective was to translate, culturally adapt, and validate a Brazilian Portuguese version of the Neck Disability Index (NDI-BR) and the Neck Pain and Disability Scale (NPDS-BR). SUMMARY OF BACKGROUND DATA: Although several valid measures exist for measurement of neck pain and functional impairment, these measures have yet been validated in Brazilian Portuguese. Successful linguistic and cultural translation may allow appropriate cross-cultural comparison for clinical and laboratory research analysis. METHODS: The NDI-BR and NPAD-BR were culturally and linguistically translated from English into Brazilian Portuguese. The translated version of the instrument was administered to 203 patients at a midsize hospital in southern Brazil. Psychometric evaluation included factor analysis, internal reliability measures, test-retest reliability at 1 and 7 days, and criterion validity comparison with the Brazilian version of the SF-36. RESULTS: Factor analyses demonstrated a single-factor subscale for the NDI-BR and three subscales for the NPDS-BR. An item analysis showed a high degree of internal consistency for the NDI-BR (r = 0.74) and the three subscales of the NPDS-BR (subscale 1, r = 0.89; subscale 2, r = 0.81; subscale 3, r = 0.72). Test-retest reliability was also acceptable at for the NDI-BR (0.98 at baseline and 0.48 at 7 days) and subset one (0.96 at baseline and 0.91 at 7 days), subset 2 (0.96 at baseline and 0.62 at 7 days), and subset 3 (0.52 at baseline and 0.45 at 7 days) of the NPDS-BR. Construct validity was established during comparison of the Brazilian version of the SF-36. Only items associated with physical role, bodily pain, and emotional role failed significant correlation. CONCLUSIONS: A reliable and valid Portuguese version of the Neck Disability Index and Neck Pain and DisabilityScale was developed, which will facilitate the examination of functional performance within a large patient population, as well as cross-cultural comparisons.

Adult↗
PubMed2006

Hepatocellular carcinoma missed on gadolinium enhanced MR imaging, discovered in liver explants: retrospective evaluation.

The main purpose of this study was to determine if hepatocellular carcinomas (HCCs) missed on prospective magnetic resonance (MR) study could be identified on retrospective MR analysis, and to determine the cause for misdiagnosis. Among 555 patients who underwent liver transplantation between 1993 and 2004, 279 were imaged with MR imaging and four of these revealed HCCs in explanted livers that were not reported on prospective MR reading. The main cause of missed lesions were suboptimal image quality due to inability of patients to suspend respiration; other causes were HCC misinterpreted as high-grade dysplastic nodule and isoenhancement of HCC on early phase images.

Adult↗
PubMed2006

Adult celiac disease: what is the role of MRI?

PURPOSE: To evaluate the ability of MRI to identify intra- and extraintestinal findings of celiac disease in an adult population. MATERIALS AND METHODS: Forty-one subjects (18 men and 23 women; mean age = 41.3 years; 31 with biopsy-proven celiac disease, and 10 healthy volunteers) underwent MRI of the small bowel. MR studies were performed on a 1.5-T magnet using T2-weighted half-Fourier single-shot turbo spin-echo (HASTE) and true fast imaging in steady-state precession (True-FISP) sequences. The MR features and sensitivity, and the specificity and accuracy of some of these features are described. RESULTS: In the 31 celiac patients, MRI showed bowel dilatation in 61.3% (N = 19), increased number of ileal folds in 48.4% (N = 15), reversed fold pattern abnormality in 38.7% (N = 12), increased wall thickness in 16.1% (N = 5), duodenal stenosis in 6.5% (N = 2), intussusception in 12.9% (N = 4), mesenteric lymphadenopathy in 41.9% (N = 13), mesenteric vascular changes in 22.6% (N = 7), ascites in 6.5% (N = 2), and no abnormalities in 12.9% (N = 4). The volunteers had unremarkable exams. The overall specificity and accuracy were 100%, and sensitivity was 79% and 75% for increased number of ileal folders and reversed fold pattern abnormality, respectively. CONCLUSION: MRI is able to demonstrate intra- and extraintestinal features that may lead to the diagnosis of celiac disease in adults.

Adult↗
PubMed2006

Influence of acetabular coverage on hip survival after free vascularized fibular grafting for femoral head osteonecrosis.

BACKGROUND: Osteonecrosis of the femoral head frequently results in collapse of the head and subsequent arthrosis of the joint. Surgical treatment has been based entirely on the evaluation of the femoral side of the hip joint, with little consideration given to the possible influence on outcome of the orientation of the acetabulum. METHODS: We retrospectively reviewed a consecutive series of 200 hips in 160 patients with osteonecrosis of the femoral head who had undergone free vascularized fibular grafting between 1997 and 1998. The mean duration of clinical follow-up was 7.5 years. Ninety-one hips in seventy-one patients were evaluated radiographically for evidence of progression of femoral head collapse at a minimum of two years, and a mean of three years, postoperatively. We defined conversion to a total hip arthroplasty and progression of femoral head collapse as the failure end points, and we analyzed the association of the acetabular center-edge angle of Wiberg, the area and laterality of the lesion, the amount of preoperative collapse of the femoral head, and the etiology of the osteonecrosis with the likelihood of failure. RESULTS: Forty-eight (24%) of the 200 hips had undergone conversion to a total hip arthroplasty at the time of the final clinical follow-up. In addition, 15% (fourteen) of the ninety-one hips with sufficient radiographic follow-up demonstrated progression of femoral head collapse at the time of the final radiographic examination. Of the hips with a center-edge angle of </=30 degrees , 55% (of those with sufficient radiographic follow-up) demonstrated progressive collapse and 45% were converted to a total hip arthroplasty. In contrast, of the hips with a center-edge angle of >30 degrees , 10% had progressive collapse (p = 0.002) and 6% were converted to a total hip arthroplasty (p < 0.001). Neither the etiology nor the size of the lesion was significantly correlated with progression of collapse or conversion to a total hip arthroplasty. CONCLUSIONS: Patients with osteonecrosis of the femoral head and a suboptimal center-edge angle of the hip are at substantial risk for progression of femoral head collapse and conversion to a total hip arthroplasty following free vascularized fibular grafting. An estimation of the degree of hip dysplasia should be included in the preoperative assessment of patients with osteonecrosis of the femoral head for prognostic and possibly surgical planning purposes.

Acetabulum↗
PubMed2005

Hepatic nodules in liver transplantation candidates: MR imaging and underlying hepatic disease.

OBJECTIVE: To assess by MR imaging the frequency of hepatic nodules in patients waiting on the liver transplant list and to determine whether certain underlying hepatic diseases were more often associated with the development of such hepatic nodules. MATERIAL AND METHODS: We reviewed the MR and clinical records in all patients seen by the liver transplant service at our center since its inception in January 1998 until September 2002. A total of 371 patients (207 men and 164 women, age range 18-68 years, mean 45 years) were included in the study. The presence of hepatic nodules, size, number and underlying hepatic diseases were determined in all patients. Magnetic resonance imaging was performed on a 1.5-T MR imager using T1-weighted, T2-weighted and multi-phase gadolinium-enhanced sequences. Odds ratio (OR) and 95% confidence intervals (CIs) were computed to evaluate the association between the underlying hepatic disease and the development of hepatic nodule. RESULTS: Among 371 liver transplantation candidates, the most common underlying hepatic disease was hepatitis C virus (HCV) infection, either alone (n=93; 25%) or associated with other hepatic diseases (n=40; 10.8%). Of all patients, 33 (8.9%) had regenerative nodules (RNs), 40 (10.7%) dysplastic nodules (DNs) and 57 (15.3%) hepatocellular carcinomas (HCCs). Hepatocellular carcinoma was observed in 35.3% of patients with HCV infection and alcohol abuse combined, 24.5% with cryptogenic cirrhosis, 25% with hemochromatosis and 19% with alcohol abuse. Patients who had either DNs or HCC were 2.5 times more likely to have either alcohol abuse or HCV, alone or combined, as the substrate of their liver disease (OR 2.54, 95% CI 1.56-4.13). Our data suggest a supra-additive interaction between HCV infection and ethanol in their association with MR imaging detected lesions. CONCLUSION: Patients with cryptogenic cirrhosis, alcohol abuse, HCV infection (alone or combined) and hemochromatosis had the greatest likelihood of having HCC, with the combination of HCV infection and alcohol abuse having the highest of all.

Adolescent↗
PubMed2005

Pre-, peri-, and posttreatment imaging of liver lesions.

This article provides an overview of current treatment approaches in patients with primary or secondary liver diseases. Emphasis is placed on MR imaging prior, during, and after various treatments, including liver resection, systemic chemotherapy, transcatheter arterial chemoembolization, ablative therapies, and liver transplantation. Findings described for MR imaging are directly applicable to findings for CT and potentially contrast-enhanced ultrasound. The authors' description, however, will deal mainly with MR imaging as this is the their preferred approach due to diagnostic accuracy and patient safety, and the findings are most demonstrative on MR imaging.

Diagnostic Imaging↗
PubMed2005

Magnetic resonance imaging features of focal liver lesions after intervention.

The aim of this article is to provide an overview of MRI features of primary and secondary liver lesions after intervention. Emphasis is given to T2- and T1-weighted pre and post intravenous gadolinium chelates appearance of successfully treated lesions and, from residual/recurrent tumors after therapy. In addition, complications after procedures are briefly cited. Liver resection, radiation therapy, systemic chemotherapy, transcatheter arterial chemoembolization, ablative therapies and liver transplantation are the methods discussed in this review. Among these methods, special attention is given to MRI findings after ablative therapies since radiofrequency ablation is commonly performed in our institution.

Humans↗
PubMed2004

Early heterogeneous enhancement of the liver: magnetic resonance imaging findings and clinical significance.

PURPOSE: To investigate and assess the radiologic, serological, and histopathologic findings in patients who presented with early heterogeneous enhancement (EHE) on gadolinium-enhanced early-phase magnetic resonance imaging (MRI) of the liver. MATERIALS AND METHODS: We searched our radiologic records of MRI of the liver from July 1999 to April 2002 to identify patients with EHE. Three investigators retrospectively evaluated in consensus the MR images in each patient for intensity and characteristic of EHE blinded to clinical information. Serological laboratory values and clinical information were obtained in all patients, and histologic findings were available in 19. RESULTS: We identified 67 patients with EHE. Of them, 62 patients (93%) had underlying chronic liver disease. Twenty-seven patients had viral hepatitis, 13 had alcohol abuse, 6 had primary sclerosing cholangitis, and the others had miscellaneous etiologies. The five patients without chronic liver disease had the following clinical histories: concurrent chemotherapy for extrahepatic malignancy (two patients), concurrent intraabdominal infection (one), and no known associated disease (two). Intensity of EHE was intense in 6 (9%), moderate in 22 (33%), and mild in 39 (58%). Pattern of EHE was geographic in 15 patients (22%), patchy in 37 (55%), and miliary in 15 (22%). All EHE showed rapid fading on postcontrast late-phase images. EHE showed mild to moderate hyperintensity on T2-weighted images in 30 patients (45%). In the 19 patients with histological correlation, 19 (100%) had hepatocellular necrosis, 19 (100%) had fibrosis, 18 (95%) had inflammatory cell infiltration, 17 (89%) had capillary-size vessels within fibrous septa, and 16 (84%) had ductal proliferation. No statistical correlation was found between the intensity or pattern of EHE on MR images and the extent of elevation of serological laboratory values or severity of histologic findings. CONCLUSION: Several different types of underlying chronic liver disease were observed in most of the patients with EHE. Hepatocyte necrosis, fibrosis, or inflammatory processes were found in all patients with EHE who had histopathological correlation.

Adolescent↗
PubMed2004

Cavernous hemangiomas in patients with chronic liver disease: MR imaging findings.

The purpose of our study was to assess the difference in magnetic resonance imaging (MRI) features of cavernous hemangiomas in patients with chronic liver disease compared them with hemangiomas in normal livers. We retrospectively searched our records of MRI of the liver between October 1998 and June 2002, and identified 76 hemangiomas in 49 patients (18 men and 31 women; age range 29-81 years [mean, 57 years]). Hemangiomas were classified into 3 groups: patients with cirrhosis [group 1, 8 lesions in 8 patients], patients with chronic hepatitis [group 2, 6 lesions in 5 patients], and patients without underlying liver disease [group 3, 62 lesions in 36 patients]. Four radiologists, blinded to clinical information, retrospectively reviewed in consensus the MRI findings of hemangiomas for number, size, signal intensities on T1- and T2-weighted images, and enhancement patterns on early- and late-phase postcontrast images. The mean lesion numbers and sizes were 1.0 and 16.2 +/- 9.6 mm, 1.2 and 15.3 +/- 7.1 mm, and 1.7 and 26.1 +/- 24.7 mm in groups 1-3, respectively. There was a correlation (p < 0.05, coefficient: 0.35) between lesion number and severity of liver disease. Although there was no significant difference in lesion size among the 3 groups, all of 11 lesions larger than 4 cm in diameter belonged to group 3. Almost all lesions appeared moderately hypointense on T1-weighted images and moderately hyperintense on T2-weighted images. Twenty-seven lesions showed immediate homogeneous enhancement (pattern 1), and 49 showed peripheral nodular enhancement with centripetal enhancement progression (pattern 2). There was no difference in frequency of enhancement patterns among the 3 groups. Hemangiomas were more often solitary in livers with chronic liver disease, large lesions were exclusively seen in livers without chronic liver disease, and there was a trend for small lesions in patients with chronic liver disease.

Adult↗
PubMed2004

Modern hepatic imaging.

This article provides a brief overview of the current status of commonly employed diagnostic techniques--US, CT, MR, and PET--for the evaluation of liver metastases and HCC as well as a description of imaging in RF ablation and liver transplantation. The various advantages and limitations of the techniques have been outlined. At the present time, at our center, MRI is used most often to evaluate these liver pathologies, due to its high accuracy for lesion detection and characterization.

Carcinoma, Hepatocellular↗
PubMed2004

Does hypervascularity of liver metastases as detected on MRI predict disease progression in breast cancer patients?

OBJECTIVE: The aim of our study was to evaluate the association of the vascularity of liver metastases, as characterized by MRI, and disease progression in breast cancer patients. MATERIALS AND METHODS: Sixteen breast cancer patients with liver metastases who underwent MRI before and after systemic therapy were retrospectively identified. On the basis of comparison of each MRI examination with the previous examination, disease status of the patients was classified as complete response, partial response, stable disease, or progressive disease. Liver metastases were characterized as hyper- or hypovascular on the basis of the degree of enhancement in the arterial, portal, and interstitial phases of imaging after administration of a contrast agent. Fisher's exact test and ordinal logistic regression models, including the type of systemic therapy, presence of multiple metastases, and hormone receptor status, were used to estimate the unadjusted and risk-adjusted association between the presence of hypervascular liver metastases and disease progression. RESULTS: All patients in our sample (n = 16) were women and most (12/16, 75%) were white. Their median age was 51.5 years. In unadjusted analyses, the association between the presence of hypervascular liver metastases and disease progression was statistically significant (p < 0.0001). In multiple logistic regression analyses, hypervascular liver metastases were found to be an independent predictor of disease progression. Patients with hypervascular liver lesions were 20.5 times more likely to experience disease progression than patients without hypervascular metastases (odds ratio, 20.5; 95% confidence interval, 5.1-83.5; p < 0.0001). CONCLUSION: Our analysis provides suggestive evidence that disease progression can be predicted through MRI assessment of the vascularity of liver metastases in patients with breast cancer.

Adult↗
PubMed2003

Inflammatory myofibroblastic tumor of the hepatobiliary system: report of MR imaging appearance in four patients.

The purpose of this report is to describe the magnetic resonance (MR) imaging features of hepatic inflammatory myofibroblastic tumor (IMT). Two observers retrospectively analyzed images from six MR imaging examinations in four consecutive patients. Tumor location, size, extent, morphology, and number; signal intensity on nonenhanced images; enhancement pattern on serial gadolinium-enhanced images; duct wall thickness; and presence of biliary dilatation, vascular invasion, and lymphadenopathy were assessed. MR imaging findings were compared with histologic findings. On MR images, hepatic IMT manifested as a mass-like lesion in two patients and an area of periportal soft-tissue infiltration in three; one patient had both patterns. Because periportal infiltration is a common feature in both IMT and other malignant tumors of the porta hepatis, histologic examination should be considered before diagnosis and treatment.

Adult↗
PubMed2003

Assessment of aorto-iliac disease with magnetic resonance angiography using arterial phase 3-D gradient-echo and interstitial phase 2-D fat-suppressed spoiled gradient-echo sequences.

PURPOSE: To evaluate magnetic resonance angiography (MRA) of the pelvis for the examination of the aorto-iliac system using arterial phase 3-D gradient echo and interstitial phase 2-D fat-suppressed spoiled gradient-echo (SGE), with comparison to surgery and angiography. MATERIALS AND METHODS: Ninety MR angiograms performed on 79 consecutive patients were analyzed, retrospectively, for the presence of narrowing, aneurysm, and dissection. Comparisons were made with angiography and surgery in 50 examinations, and a weighted kappa statistic test was applied to assess agreement. MR examinations were performed at 1.5T 3-D fast imaging in steady state precession (FISP) acquired immediately, and fat-suppressed SGE in the interstitial phase following gadolinium administration. RESULTS: MRA had overall sensitivities of 100% at aortic segments, 100% at common iliac, 93.8% at external, and 95.7% at internal iliac, and specificities of 100% at aortic segments, 89.7% at common iliac, 95.2% at external iliac, and 88.7% at internal iliac in detection of vascular disease. The agreement of MRA with the angiography and surgery yielded a weighted kappa statistic of 0.97 at the aortic, 0.94 at the common, 0.85 at the external, and 0.82 at the internal iliac segments. CONCLUSION: This study demonstrates an excellent performance of MRA in the evaluation of aorto-iliac arterial system and almost perfect agreement with angiography and surgery at all vascular levels.

Adult↗
PubMed2003

Giant hemangioma of the liver: MR imaging characteristics in 24 patients.

We retrospectively reviewed the magnetic resonance imaging (MRI) of giant hemangiomas in 24 patients. MRI studies comprised T1-weighted, T2-weighted and serial gadolinium-enhanced spoiled gradient echo (SGE) images. Morphologic features, signal characteristics and enhancement patterns were assessed. Histopathologic evaluation was obtained in nine patients. On T2-weighted images all lesions (size 5.7-24 cm) were hyperintense relative to the spleen and two dominant patterns of heterogeneity were demonstrated: a central heterogeneous area of either bright, dark, or mixed signal intensity, and a network of multiple fibrous septa of low signal intensity. Histopathologic evaluation of two lesions with a central bright area demonstrated the presence of hypocellular myxoid tissue. Central enhancement (9 lesions) and an irregular flame-shaped peripheral pattern of enhancement (12 lesions) were present in lesions with a mean diameter greater than 10 cm. Although giant hemangiomas show greater variability in their MR imaging appearance, an accurate diagnosis can be made through still characteristic features of high signal intensity on T2-weighted images and discontinuous peripheral enhancement.

Adult↗
PubMed2003

Liver metastases from unknown primary site: demonstration on MR images.

To demonstrate the MR imaging features of liver metastases in patients with the clinical and histologic diagnosis of tumors of unknown primary tumors, a retrospective 7-year study was performed that included a total of 14 consecutive patients (7 men and 7 women; age range, 39-82 years; mean age, 60.6 years) with liver metastases from unknown primary site who had undergone MR imaging. The following lesion features were evaluated: a) number, b) diameter, c) signal intensity on T1 and T(2)-weighted images, and d) pattern of enhancement on immediate, 45 s and 90 s post gadolinium images. Lesions were classified as hypovascular, hypervascular and nearly isovascular relative to liver parenchyma as shown on immediate post gadolinium images. Patients were separated into four major groups, related to the histologic diagnosis of the lesions: (I) poorly differentiated neoplasms; (II) well-differentiated and moderately differentiated adenocarcinoma; (III) squamous cell carcinoma; (IV) combined poorly differentiated carcinoma and poorly differentiated adenocarcinoma. MRI findings were correlated with histologic information obtained by chart review and confirmed by retrospective histopathology review. All patients had the histologic diagnosis of adenocarcinoma: 8 patients belonged to group II (1 patient with the subtype well-differentiated and 7 patients with the subtype moderately differentiated) and 6 patients to group IV. Eleven patients (79%) presented with multiple lesions distributed throughout both hepatic lobes; 3 patients exhibited solitary lesions. All solitary metastases possessed a diameter equal or larger than 5 cm. Patients with multiple metastases demonstrated a wide range of diameter, ranging from less than 1.5 cm to more than 5 cm. Regarding lesion vascularity, 4 of 13 of the patients had hypovascular metastases and 9 of 13 of the patients had hypervascular lesions. One patient demonstrated both types of lesions. Five of six patients with the histopathologic diagnosis of poorly differentiated adenocarcinoma demonstrated hypervascular metastases. Solitary metastases were most often hypovascular (2 of 3); however no correlation with the histologic subtype was possible. Liver metastases from unknown primary site are often multiple and often hypervascular. Poorly differentiated tumors are the most common histologic type. Metastases are not uncommonly hypovascular, and these are often solitary.

Adenocarcinoma↗
PubMed2003

Primary malignant mesothelioma of the liver: MR imaging findings.

We report the MR imaging findings of a primary malignant mesothelioma of the liver arising from Glisson's capsule. A 54-year-old woman, presenting with acute abdominal pain and a large liver mass previously shown on CT, underwent MR imaging to characterize the lesion. The tumor was a greater than 12 cm tumor located in the right lobe of the liver, which was sharply marginated, with heterogeneous internal signal, septations and central necrosis. The tumor was considered a hepatocellular carcinoma. The diagnosis of malignant mesothelioma was established by immunohistochemical staining and electron microscopy of the resected tumor.

Abdominal Pain↗