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Dive into the research topics where Ravi Menezes is active.

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Featured researches published by Ravi Menezes.


Radiology | 2011

Analysis of Gadobenate Dimeglumine–enhanced MR Findings for Characterizing Small (1–2-cm) Hepatic Nodules in Patients at High Risk for Hepatocellular Carcinoma

Tae Kyoung Kim; Kyoung Ho Lee; H.-J. Jang; Masoom A. Haider; Lindsay M. Jacks; Ravi Menezes; Seong Ho Park; Leyla Kochak Yazdi; Morris Sherman; Korosh Khalili

PURPOSE To retrospectively identify magnetic resonance (MR) imaging findings that are associated with hepatocellular carcinoma (HCC) in 1-2-cm nodules detected at surveillance ultrasonography (US) and to propose newer MR imaging diagnostic criteria. MATERIALS AND METHODS Institutional research ethics board approval was obtained, and informed patient consent was waived. Among 145 consecutive patients who had 1-2-cm nodules that were newly detected at surveillance US, 108 patients underwent gadobenate dimeglumine-enhanced MR imaging. After excluding hemangiomas and unconfirmed nodules, the study sample comprised 96 patients with 116 nodules, including 43 HCCs and 73 benign nodules. MR imaging findings were assessed for signal intensity at each sequence. On the basis of the results of univariate and multivariable logistic regression analyses, several diagnostic criteria were developed by using combinations of MR imaging findings, which were then compared with the American Association for the Study of Liver Diseases (AASLD) practice guideline. RESULTS Univariate analysis revealed four imaging findings associated with HCC, including arterial phase hyperintensity, portal or delayed phase hypointensity (washout), hyperintensity on T2-weighted images, and hepatobiliary phase hypointensity (P < .001 for each). In the multivariable analysis, arterial phase hyperintensity (adjusted odds ratio [OR], 17.1; P = .003) and washout (adjusted OR, 11.7; P = .007) were associated with HCC. Of the developed criteria, the criteria including nodules fitting the AASLD practice guideline (arterial phase hyperintensity and washout) or nodules having three or more findings were considered most reasonable, showing improved sensitivity (77% [33 of 43] versus 67% [29 of 43], P = .048) and comparable specificity (95% [69 of 73] versus 99% [72 of 73], P = .09), as compared with AASLD practice guideline. CONCLUSION Alternative MR imaging criteria for diagnosing HCC in 1-2-cm nodules detected at surveillance US that can improve sensitivity compared with the AASLD practice guideline were proposed. A larger study is needed to verify the preliminary criteria in this study. SUPPLEMENTAL MATERIAL http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.11101549/-/DC1.


Lung Cancer | 2010

Lung cancer screening using low-dose computed tomography in at-risk individuals: The Toronto experience

Ravi Menezes; H. Roberts; Narinder Paul; Maureen McGregor; Tae Bong Chung; Demetris Patsios; Gordon Weisbrod; Stephen J. Herman; Andre Pereira; Alexander McGregor; Zhi Dong; Igor Sitartchouk; Scott L. Boerner; Ming-Sound Tsao; Shaf Keshavjee; Frances A. Shepherd

OBJECTIVE The Department of Medical Imaging at the University Health Network in Toronto is performing a lung cancer screening study, utilizing low-dose computed tomography (LDCT) as the modality. Baseline and annual repeat results are reported on the first 3352 participants, enrolled between June 2003 and May 2007. METHODS Enrollment was limited to those aged 50 years or older, with a smoking history of at least 10 pack-years, no previous cancer and general good health. A helical low-dose CT (LDCT) of the chest was performed using 120kVp, 40-60mA, images were reconstructed with 1-1.25mm overlapping slices. The primary objectives were the detection of parenchymal nodules and diagnosis of early stage lung cancer. Baseline LDCTs were termed positive if at least one indeterminate non-calcified nodule 5mm or larger in size, or non-solid nodule 8mm or larger in size was identified. Follow up periods for individuals with a positive baseline LDCT were determined by nodule characteristics. RESULTS The median age at baseline was 60 years (range 50-83), with a median of 30 pack-years of cigarette smoking (range 10-189). Baseline CT evaluations were positive in 600 (18%) participants. To date, 2686 (80%) of the participants have returned for at least one annual repeat screening LDCT. Biopsies have been recommended for 82 participants since the study began, and 64 have been diagnosed with screen-detected cancer (62 lung, two plasmacytoma of the rib). A total of 65 lung cancers have been diagnosed (62 screen-detected, 3 interim), 57 are NSCLC (82% with known stage are stage I or II) and the rate of surgical resection was 80%. Sensitivity and specificity of the protocol in successfully diagnosing early stage lung cancers were 87.7% and 99.3%, respectively. CONCLUSIONS Data indicate that LDCT can identify small lung cancers in an at-risk population. The diagnostic algorithm results in few false-positive invasive procedures. Most cancers are detected at an early stage, where the cancer is resectable with a greater potential for cure. Long-term follow up of lung cancer cases will be carried out to determine survival.


Journal of Cardiovascular Magnetic Resonance | 2011

3D Echo systematically underestimates right ventricular volumes compared to cardiovascular magnetic resonance in adult congenital heart disease patients with moderate or severe RV dilatation

Andrew M. Crean; Neil Maredia; George Ballard; Ravi Menezes; Gill Wharton; Jan Forster; John P. Greenwood; John Thomson

BackgroundThree dimensional echo is a relatively new technique which may offer a rapid alternative for the examination of the right heart. However its role in patients with non-standard ventricular size or anatomy is unclear. This study compared volumetric measurements of the right ventricle in 25 patients with adult congenital heart disease using both cardiovascular magnetic resonance (CMR) and three dimensional echocardiography.MethodsPatients were grouped by diagnosis into those expected to have normal or near-normal RV size (patients with repaired coarctation of the aorta) and patients expected to have moderate or worse RV enlargement (patients with repaired tetralogy of Fallot or transposition of the great arteries). Right ventricular end diastolic volume, end systolic volume and ejection fraction were compared using both methods with CMR regarded as the reference standardResultsBland-Altman analysis of the 25 patients demonstrated that for both RV EDV and RV ESV, there was a significant and systematic under-estimation of volume by 3D echo compared to CMR. This bias led to a mean underestimation of RV EDV by -34% (95%CI: -91% to + 23%). The degree of underestimation was more marked for RV ESV with a bias of -42% (95%CI: -117% to + 32%). There was also a tendency to overestimate RV EF by 3D echo with a bias of approximately 13% (95% CI -52% to +27%).ConclusionsStatistically significant and clinically meaningful differences in volumetric measurements were observed between the two techniques. Three dimensional echocardiography does not appear ready for routine clinical use in RV assessment in congenital heart disease patients with more than mild RV dilatation at the current time.


Cancer Epidemiology, Biomarkers & Prevention | 2008

Vitamin D Receptor Expression in Normal, Premalignant, and Malignant Human Lung Tissue

Ravi Menezes; Richard T. Cheney; Aliya N. Husain; Maria Tretiakova; Gregory M. Loewen; Candace S. Johnson; Vijay Jayaprakash; Kirsten B. Moysich; Ravi Salgia; Mary E. Reid

Background: There is a strong interest in identifying chemopreventive agents that might help decrease the burden of lung cancer. The active metabolite of vitamin D, 1,25-dihydroxycholecalciferol (calcitriol), has been shown to have antiproliferative effects in several tumor types, mediated by the vitamin D receptor (VDR). This is the first comprehensive survey of VDR expression in a series of human lung tissues, including normal and premalignant central airway biopsies and lung tumors. Methods: Immunohistochemical expression of nuclear and cytoplasmic VDR was examined in 180 premalignant or malignant bronchial biopsies from bronchoscopy of 78 high-risk individuals at the Roswell Park Cancer Institute and also in 63 tumor samples from 35 lung cancer patients from the University of Chicago Hospitals. Associations between clinicopathologic data and VDR expression were examined. Results: VDR expression was present in many samples. In biopsies, VDR was commonly detected throughout the full epithelial layer. Most histologically normal (60%, 53 of 88) and metaplastic (61%, 39 of 64) samples had moderate to high nuclear intensity; dysplastic samples mostly had low nuclear intensity (10 of 18, 55%). In tumor samples, 62% (38 of 61) were lacking cytoplasmic VDR, with nuclear expression present in 79%(49 of 62). Analysis of all samples revealed a positive linear trend between proportion of samples with greater nuclear than cytoplasmic intensity and increasing histologic grade (P < 0.01). Conclusions: VDR expression spanned the lung carcinogenesis spectrum. Nuclear expression was similar across various histologies, whereas cytoplasmic expression decreased with increasing histologic grade. These results indicate that there is potential for the use of calcitriol as a chemopreventive agent against the development of lung cancer. (Cancer Epidemiol Biomarkers Prev 2008;17(5):1104–10)


Ultrasound in Obstetrics & Gynecology | 2011

Retrospective review of diagnostic performance of intracranial translucency in detection of open spina bifida at the 11–13‐week scan

Katherine Fong; Ants Toi; Nan Okun; E. Al-Shami; Ravi Menezes

To evaluate diagnostic performance of intracranial translucency (IT) for detection of open spina bifida and interobserver agreement for visualization of IT during the 11–13‐week scan.


Canadian Association of Radiologists Journal-journal De L Association Canadienne Des Radiologistes | 2011

Assessing the impact of incidental findings in a lung cancer screening study by using low-dose computed tomography.

Michael J. Kucharczyk; Ravi Menezes; Alexander McGregor; Narinder S. Paul; Heidi C. Roberts

Purpose To assess the prevalence and nature of incidental findings (IF) seen in low-dose computed tomographies (LDCT) from a lung cancer screening study for at-risk individuals. Materials and Methods Radiology reports from LDCTs of 4073 participants of a lung cancer screening study were retrospectively reviewed for findings other than lung nodules, that is, IFs, which were regarded as actionable. The frequency, nature, and expected cost of these IFs, and their anticipated follow-up were estimated. Results There were 880 IFs described in 782 study participants (19%); the median age of the participants was 62 years (range, 46–80 years). More IFs were found in men (55%) than in women. The majority of these findings were noncardiovascular (76%), for which imaging was suggested for 74%. There were 7 severe IFs (0.8%) that merited immediate attention. Seven known cancers were diagnosed from follow-ups of the IFs. The majority of IFs (n = 486 [55%]) would require imaging follow-up if clinically indicated, with an estimated total a cost of CAN


Reviews on environmental health | 2002

Environmental exposure to polychlorinated biphenyls and breast cancer risk.

Kirsten B. Moysich; Ravi Menezes; Julie A. Baker; Karen L. Falkner

45,500 to CAN


American Journal of Roentgenology | 2014

Comparative MRI Analysis of Morphologic Patterns of Bile Duct Disease in IgG4-Related Systemic Disease Versus Primary Sclerosing Cholangitis

Ajay Tokala; Korosh Khalili; Ravi Menezes; Gideon M. Hirschfield; Kartik S. Jhaveri

51,000 to provide initial diagnostic workup. Conclusion IFs on lung cancer screening studies are not uncommon and frequently require imaging or other follow-up for definitive diagnoses and to assess their clinical relevance. The implication of IFs has to be considered when determining a cost-effective and ethical protocol for the utilisation of LDCT in a high-risk population.


American Journal of Roentgenology | 2012

CT Screening for Lung Cancer: Implication of Lung Biopsy Recommendations

Ute Wagnetz; Ravi Menezes; Scott L. Boerner; Narinder Paul; Dirk Wagnetz; Shaf Keshavjee; Heidi C. Roberts

Breast cancer is a major public health problem in the United States and in most industrialized countries. Although epidemiologic studies have identified a number of established risk factors for this disease, these factors explain only a small proportion of breast cancer incidence. Environmental exposure has been implicated in breast cancer etiology because of the vast geographic variation in breast cancer incidence rates across countries and regions within countries. Further, the steady increase in breast cancer rates over the past decades points to a potential role of environmental exposure in its development. One suspected environmental factor is the polychlorinated biphenyls (PCBs), which were manufactured commercially for a variety of industrial applications from the 1930s until the 1970s. PCBs have been associated with estrogenic, tumor promoting, and immunosuppressive activities, all of which are relevant in the development of breast cancer. The purpose of this review is to summarize the growing body of epidemiological evidence on the association between environmental PCB exposure and breast cancer risk. Three major types of study design have been used to investigate such a relation: clinic-based case-control studies, retrospective case-control studies, and nested case-control studies. Although findings from clinic-based case-control studies tend to point to an adverse effect of high PCB body burden on risk, the results from the more methodologically sound retrospective and nested studies do not provide strong support for a role of PCBs in breast cancer development. The association between PCB exposure and risk among racially and genetically susceptible subgroups may warrant further investigation. Methodological challenges in the design and analysis of epidemiologic studies on PCBs and breast cancer risk are discussed.


Cancer | 2013

Added cancer yield of breast magnetic resonance imaging screening in women with a prior history of chest radiation therapy

Vivianne Freitas; Anabel M. Scaranelo; Ravi Menezes; Supriya Kulkarni; David C. Hodgson; Pavel Crystal

OBJECTIVE The purpose of this study was to perform a retrospective MRI-based comparative analysis of the morphologic patterns of bile duct disease in IgG4-related systemic disease (ISD, also called autoimmune pancreatitis) compared with primary sclerosing cholangitis (PSC) and the autoimmune liver diseases autoimmune hepatitis and primary biliary cirrhosis. MATERIALS AND METHODS This study included 162 consecutively registered patients (47 with ISD, 73 with PSC, and 42 with autoimmune liver diseases). Two abdominal radiologists retrospectively reviewed MR images in consensus. Imaging findings on the bile ducts, liver, pancreas, and other organs were analyzed to establish disease patterns. RESULTS ISD was associated with contiguous thickening of intrahepatic and extrahepatic bile ducts (p<0.001), pancreatic parenchymal abnormalities (p<0.001), renal abnormalities (p<0.001), and gallbladder wall thickening (p<0.03). The severity of common bile duct wall thickness was significantly different in ISD (p<0.001). The mean single wall thickness in the ISD group was 3.00 (SD, 1.47) mm, in the PSC group was 1.89 (SD, 0.73) mm, and in the autoimmune liver disease group was 1.80 (SD, 0.67) mm. PSC was associated with liver parenchymal abnormalities (p<0.001). We did not find statistical significance between the three groups in location (p=0.220) or length (p=0.703) of extrahepatic bile duct strictures, enhancement of bile duct stricture (p=0.033), upper abdominal lymphadenopathy, or retroperitoneal fibrosis. Although presence of intrahepatic bile duct stricture was statistically significant when all three groups were compared, it was not useful for differentiating ISD from PSC. CONCLUSION The presence of continuous as opposed to skip disease in the bile ducts, gallbladder involvement, and single-wall common bile duct thickness greater than 2.5 mm supports a diagnosis of ISD over PSC. ISD and PSC could not be differentiated on the basis of location and length of common bile duct stricture.

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Korosh Khalili

University Health Network

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Narinder Paul

Toronto General Hospital

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Sandra Fischer

University Health Network

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Kirsten B. Moysich

Roswell Park Cancer Institute

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Mary E. Reid

Roswell Park Cancer Institute

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Vijayvel Jayaprakash

Roswell Park Cancer Institute

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Andrew M. Crean

University Health Network

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Ants Toi

University of Toronto

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