Citations

Showing 10 of 108048 citations.

Diagnostic disagreement between tests of evacuatory function: a prospective study of 100 constipated patients
Palit, Somnath, Thin, N , Knowles, Charles H. , Lunniss, Peter J., Bharucha, Adil E. , Scott, S. Mark

Mayo Clinic

Neurogastroenterology & Motility | May 7, 2016 | Volume: 28 | Issue: 10 | Pages: 1589-1598

10.1111/nmo.12859 | PMID 27154577 Get It

AbstractBackgroundEvacuatory dysfunction (ED) is a common cause of constipation and may be sub‐classified on the basis of specialist tests. Such tests may guide treatment e.g., biofeedback therapy for ‘functional’ defecatory disorders (FDD). However, there is no gold standard, and prior studies have not prospectively and systematically compared all tests that are used to diagnose forms of ED.MethodsOne hundred consecutive patients fulfilling Rome III criteria for functional constipation underwent four tests: expulsion of a rectal balloon distended to 50 mL (BE50) or until patients experienced the desire to defecate (BEDDV), evacuation proctography (EP) and anorectal manometry. Yields and agreements between tests for the diagnosis of ED and FDD were assessed.Key ResultsPositive diagnostic yields for ED were: BEDDV 18%, BE50 31%, EP 38% and anorectal manometry (ARM) 68%. Agreement was substantial between the two balloon tests (k = 0.66), only fair between proctography and BE50 (k = 0.27), poor between manometry and proctography (k = 0.01), and there was no agreement between the balloon tests and manometry (k = −0.07 for both BE50 and BEDDV). For the diagnosis of FDD, there was only fair agreement between ARM and EP (k = 0.23), ARM ± BE50 and EP (k = 0.18), ARM and EP ± BE50 (k = 0.30) and ARM ± BE50 and EP ± BE50 (k = 0.23).Conclusions & InferencesThere is considerable disagreement between the results of various tests used to diagnose ED and FDD. This highlights the need for a reappraisal of both diagnostic criteria, and what represents the ‘gold standard’ investigation.
Mapping Reentry
Asirvatham, Samuel J. , Stevenson, William G. , Asirvatham, Samuel J

Mayo Clinic

Circulation: Arrhythmia and Electrophysiology | May 7, 2016 | Volume: 9 | Issue: 5 | Pages: No page available

10.1161/circep.116.003609 | PMID 27153878 Get It

Fixed…Or Needs Fixing?
Newman, Darrell B. , Miranda, William R. , Connolly, Heidi M. , Newman, D Brian

Mayo Clinic

Circulation: Cardiovascular Imaging | May 7, 2016 | Volume: 9 | Issue: 5 | Pages: No page available

10.1161/circimaging.116.004877 | PMID 27154075 Get It

Chronic Recreational Physical Inactivity and Epithelial Ovarian Cancer Risk: Evidence from the Ovarian Cancer Association Consortium
Cannioto, Rikki , LaMonte, Michael J. , Sucheston‐Campbell, Lara, Eng, Kevin H., Szender, J. Brian, Chang‐Claude, Jenny, Schmalfeldt, Barbara , Klapdor, R, Gower, Emily, Minlikeeva, Albina N. , Zirpoli, Gary , Edwards, Robert P., Goode, Ellen L. , Goodman, Marc T. , Høgdall, Estrid , Hosono, Satoyo , Jensen, Allan , Jordan, Susan J. , Group, on behalf of The Australian Ovarian Cancer Study, Matsuo, Keitaro , Ness, Roberta B., Olsen, Catherine M. , Olson, Sara H. , Pearce, Celeste Leigh , Pike, Malcolm C. , Rossing, Mary Anne, Szamreta, Elizabeth A. , Thompson, Pamela J., Tseng, Chiu-Chen , Vierkant, Robert A. , Webb, Penelope M. , Wentzensen, Nicolas , Wicklund, Kristine G. , Winham, Stacey J. , Wu, Anna H. , Schildkraut, Joellen M. , Terry, Kathryn L. , Kelemen, Linda E. , Moysich, Kirsten B. , Risch, Harvey A. , Hong, Chi‐Chen , Bandera, Elisa V. , Berchuck, Andrew , Cramer, Daniel W. , Doherty, Jennifer A. , Fridley, Brooke L. , Group, on behalf of The Australian Ovarian Cancer Study, Kjær, Susanne K. , Modugno, Francesmary , Winham, Stacey J , Webb, Penelope M , Jensen, Allan , Vierkant, Robert A , Moysich, Kirsten , Matsuo, Keitaro , Høgdall, Estrid , Zirpoli, Gary , Goodman, Marc T

Mayo Clinic

Cancer Epidemiology, Biomarkers & Prevention | May 7, 2016 | Volume: 25 | Issue: 7 | Pages: 1114-1124

10.1158/1055-9965.epi-15-1330 | PMID 27197285 Get It

Abstract Background: Despite a large body of literature evaluating the association between recreational physical activity and epithelial ovarian cancer (EOC) risk, the extant evidence is inconclusive, and little is known about the independent association between recreational physical inactivity and EOC risk. We conducted a pooled analysis of nine studies from the Ovarian Cancer Association Consortium to investigate the association between chronic recreational physical inactivity and EOC risk. Methods: In accordance with the 2008 Physical Activity Guidelines for Americans, women reporting no regular, weekly recreational physical activity were classified as inactive. Multivariable logistic regression was utilized to estimate the ORs and 95% confidence intervals (CI) for the association between inactivity and EOC risk overall and by subgroups based upon histotype, menopausal status, race, and body mass index. Results: The current analysis included data from 8,309 EOC patients and 12,612 controls. We observed a significant positive association between inactivity and EOC risk (OR = 1.34; 95% CI, 1.14–1.57), and similar associations were observed for each histotype. Conclusions: In this large pooled analysis examining the association between recreational physical inactivity and EOC risk, we observed consistent evidence of an association between chronic inactivity and all EOC histotypes. Impact: These data add to the growing body of evidence suggesting that inactivity is an independent risk factor for cancer. If the apparent association between inactivity and EOC risk is substantiated, additional work via targeted interventions should be pursued to characterize the dose of activity required to mitigate the risk of this highly fatal disease. Cancer Epidemiol Biomarkers Prev; 25(7); 1114–24. ©2016 AACR.
Pilot study of sphenopalatine injection of onabotulinumtoxinA for the treatment of intractable chronic migraine
Bratbak, Daniel Fossum , Nordgård, Ståle, Stovner, Lars Jacob , Linde, Mattias , Aschehoug, Irina, Folvik, Mari, Dodick, David W. , Tronvik, Erling

Mayo Clinic

Cephalalgia | May 7, 2016 | Volume: 37 | Issue: 4 | Pages: 356-364

10.1177/0333102416648328 | PMID 27154997 Get It

Objective The main objective of this pilot study was to investigate the safety of administering onabotulinumtoxinA towards the sphenopalatine ganglion in 10 patients with intractable chronic migraine with an open, uncontrolled design. We also collected efficacy data to provide an indication as to whether future placebo-controlled studies should be performed. Method In a prospective, open-label, uncontrolled study after one-month baseline, we performed bilateral injections of 25 IU onabotulinumtoxinA (total dose 50 IU) toward the sphenopalatine ganglion in a single outpatient session in 10 patients with intractable migraine with a follow-up of 12 weeks. The primary outcome was adverse events and the main efficacy outcome was frequency of moderate and severe headache days in month 2 post-treatment compared to baseline. Results All 10 patients experienced a total of 25 adverse events. The majority of these were different types of local discomfort in the face and jaw, and none were classified as serious. In an intention-to-treat analysis of the main efficacy outcome, a statistically significant reduction of moderate and severe headache days in baseline versus month 2 was observed (16.3 ± 6.2 days baseline versus 7.6 ± 7.6 days month 2, p = 0.009). Eight out of 10 patients experienced an at least 50% reduction of moderate and severe headache days compared to baseline. Conclusion The result warrants randomised, placebo-controlled studies to establish both safety and efficacy of this potential novel treatment of chronic migraine.
Clinical results of ultrasound bladder vibrometry for assessment of bladder compliance
Cheong, Mathew , Denis, Max , Gregory, Adriana , Nenadic, Ivan , Husmann, Douglas A. , Mynderse, Lance A. , Bayat, Mahdi , Kumar, Viksit , Mehrmohammadi, Mohammad , Alizad, Azra , Fatemi, Mostafa

Mayo Clinic

Journal of the Acoustical Society of America | May 6, 2016 | Volume: 139 | Issue: 4_Supplement | Pages: 2176-2176

10.1121/1.4950464 Get It

Healthy human bladder is a viscoelastic shell capable of expanding to allow storage of urine at low pressures. The ability to maintain low pressures as the urine volume increases is called bladder compliance. Compliance is a key in proper functioning of urinary system. Spinal cord injuries and other neurogenic diseases can cause deterioration in bladder expansion capability (e.g., through excessive growth of fibrotic tissue), which in turn can increase the rigidity of the wall and reduce bladder compliance. Urodynamic study (UDS) is the clinical standard for evaluation of the bladder compliance through observation of bladder pressure-volume behavior. However, this method is costly and invasive. Ultrasound bladder vibrometry (UBV) has been introduced as noninvasive technique for evaluation of bladder viscoelasticity through excitation of the bladder using ultrasound radiation force and tracking the resulting Lamb waves. Here, we present the results of UBV from 44 patients undergoing concurrent UDS and UBV studies. Our results show that elasticity parameters obtained from the UBV closely correlate with the UDS pressure-volume data with a median Pearson’s correlation value of more than 0.8. These results prove the potential utility of UBV as an alternative noninvasive method for bladder compliance assessment. [Work supported by NIH grant DK99231.]
Differentiation of breast lesions based on viscoelasticity response at sub-Hertz frequencies
Nabavizadeh, Alireza , Gregory, Adriana , Bayat, Mahdi , Kumar, Viksit , Alizad, Azra , Fatemi, Mostafa

Mayo Clinic

Journal of the Acoustical Society of America | May 6, 2016 | Volume: 139 | Issue: 4_Supplement | Pages: 2028-2028

10.1121/1.4949985 Get It

There is an urgent need for a noninvasive but more accurate method to assess breast masses before referring the patient to biopsy. In this study, we use the slow viscoelastic creep response to evaluate breast masses at low (<1 Hz) frequencies. This method uses an automated ramp-and-hold compression device and a high-frame-rate ultrasound imaging to track tissue strain. The study cohort included 30 pre-biopsy patients with suspicious masses. Sequential high-frame-rate images were recorded during the ramp-and-hold process. The data were used to calculate the creep response at each point. Then, using a classic linear model, the retardation-time map was created within the field of view. The resulting retardation-time maps exhibited clear distinction of the mass margins. The results showed that benign breast lesions appear with an increase in creep retardation-time compared to surrounding breast glandular tissue, and the opposite trend was true for the malignant lesions. Statistical analysis of the viscoelasticity features revealed that a contrast feature based on the retardation-time is an accurate classifier of malignant and benign masses (P<0.0003). It is concluded that the retardation time is a promising biomarker for differentiation of breast masses. [Work supported by NIH Grant CA168575.]
A generalized reconstruction framework for transient elastography
Aquino, Wilkins , Bayat, Mahdi , Ghosh, Susanta , Alizad, Azra , Fatemi, Mostafa

Mayo Clinic

Journal of the Acoustical Society of America | May 6, 2016 | Volume: 139 | Issue: 4_Supplement | Pages: 2028-2028

10.1121/1.4949984 Get It

Ultrasound transient elastography has emerged as a promising imaging modality for noninvasive evaluation of tissue mechanical properties. Most of the established techniques, however, rely on a pointwise measurement of the induced shear wave speed based on a localized planar wave propagation assumption. This assumption is not always true as most tissues exhibit heterogamous characteristics. Complex interaction of different geometries, boundary conditions, and tissue composition limit the ability of these techniques such that additional spatial-temporal filtering and signal truncations are required. These signal conditionings might lead to improvement in elasticity estimation for some cases (e.g. certain geometries, material properties) but the fact that they do not stem from a comprehensive framework can lead to unrealistic mechanical properties in more complex scenarios. We present a generalized framework based on inverse solution of the elasto-dynamic equations which can simultaneously solve for material properties and geometries without requiring any prior knowledge of the wave types. The method is based on a modified error in constitutive equation (MECE) without requiring additional filtering. We present the results of standard phantom studies based on acoustic radiation force excitation and fast ultrasound tracking where MECE technique successfully estimated the elastic moduli and geometry. [Work supported by NIH grant CA174723.]
Bone demineralization assessment using acoustic radiation force
Denis, Max , Wan, Leighton , Cheong, Mathew , Fatemi, Mostafa , Alizad, Azra

Mayo Clinic

Journal of the Acoustical Society of America | May 6, 2016 | Volume: 139 | Issue: 4_Supplement | Pages: 2028-2028

10.1121/1.4949983 Get It

In this work, an ultrasound-guided remote measurement technique is proposed for bone demineralization assessment. Utilizing an acoustic radiation force (ARF) beam as our excitation source and a receiving hydrophone, the mechanical properties of a bone can be noninvasively assessed. Focusing the ARF beam on the bone surface acts as point force generating vibrational waves. Coupling the bone surface and hydrophone, the ensuing radiating acoustic pressure from these vibrational waves are captured for analysis. Of particular interest, are the features best related to the bone’s mechanical properties. Conducting ex-vivo experiments demonstrated that the velocity feature best delineates intact and demineralized bones. The typical velocity of an intact bone (3000 m/s) is higher in comparison to a 72 h demineralized bone (1600 m/s). According to the receiver operating characteristic (ROC) curve, the optimal velocity cut-off value of 3096 m/s yields 80% sensitivity and 82.61% specificity between the intact and demineralized bones. Other features, such as the spectra of the demineralized bones’ acoustic response, exhibited higher attenuation for frequencies below 200 kHz in comparison to the intact bones. A time-frequency analysis demonstrated a frequency shift with demineralization. These results demonstrate the potential application of our proposed technique for monitoring bone demineralization.
Medicaid Expansion and Implications for Cancer Disparities
Barwise, Amelia , Barwise, Amelia K

Mayo Clinic

American Journal of Public Health | May 6, 2016 | Volume: 106 | Issue: 6 | Pages: e8-e8

10.2105/ajph.2016.303105 | PMID 27153035 Get It