The Experts below are selected from a list of 8985 Experts worldwide ranked by ideXlab platform
M Alaopas - One of the best experts on this subject based on the ideXlab platform.
-
mr urography in evaluation of acute flank pain
American Journal of Roentgenology, 2012Co-Authors: M Sudah, Ritva Vanninen, Kaarina Partanen, A Heino, Petri Vainio, M AlaopasAbstract:OBJECTIVE. The aim of this study was to compare the usefulness of breath-hold heavily T2-weighted sequences with gadolinium-enhanced three-dimensional fast low-angle shot (3D FLASH) MR urography in the evaluation of patients with acute flank pain.SUBJECTS AND METHODS. Forty consecutive patients with symptoms of acute flank pain underwent MR urography followed immediately by excretory urography. Heavily T2-weighted (combined thin-slice half-Fourier acquisition single-shot turbo spin-echo [HASTE] and thick-slab single-shot turbo spin-echo) and 3D FLASH sequences were evaluated separately and independently by two experienced radiologists for the presence, cause, level, and degree of obstruction. Interobserver agreement was calculated using the kappa statistic. Excretory urography and the final clinical diagnosis were used as reference.RESULTS. Twenty-six patients were found to have unilateral obstruction caused by ureteral stones. Both MR urography methods were excellent for detecting obstruction. In the det...
-
patients with acute flank pain comparison of mr urography with unenhanced helical ct
Radiology, 2002Co-Authors: M Sudah, Ritva Vanninen, Kaarina Partanen, A Heino, Sakari Kainulainen, Auli Malinen, M AlaopasAbstract:PURPOSE: To compare unenhanced helical computed tomography (CT) and magnetic resonance (MR) urography, by using T2-weighted and contrast material–enhanced T1-weighted imaging to examine patients with acute flank pain, with reference to excretory urography and final clinical diagnosis. MATERIALS AND METHODS: Forty-nine patients underwent CT, MR urography (with T2-weighted and gadopentetate dimeglumine–enhanced T1-weighted sequences), and excretory urography. CT and MR urographic findings were evaluated separately and independently by two radiologists each (CT, observers A and B; MR urography, observers C and D) for the presence, cause, level, and degree of obstruction. The final conclusive diagnosis was based on the combination of excretory urographic, clinical, and interventional results. RESULTS: At final diagnosis, 32 (65%) patients were found to have ureteral stones causing unilateral obstruction. In ureteral stone detection, the sensitivity and specificity of CT were 90.6% (29 of 32 patients) and 100....
-
mr urography in evaluation of acute flank pain t2 weighted sequences and gadolinium enhanced three dimensional flash compared with urography
American Journal of Roentgenology, 2001Co-Authors: M Sudah, Ritva Vanninen, Kaarina Partanen, A Heino, Petri Vainio, M AlaopasAbstract:OBJECTIVE The aim of this study was to compare the usefulness of breath-hold heavily T2-weighted sequences with gadolinium-enhanced three-dimensional fast low-angle shot (3D FLASH) MR urography in the evaluation of patients with acute flank pain. SUBJECTS AND METHODS Forty consecutive patients with symptoms of acute flank pain underwent MR urography followed immediately by excretory urography. Heavily T2-weighted (combined thin-slice half-Fourier acquisition single-shot turbo spin-echo [HASTE] and thick-slab single-shot turbo spin-echo) and 3D FLASH sequences were evaluated separately and independently by two experienced radiologists for the presence, cause, level, and degree of obstruction. Interobserver agreement was calculated using the kappa statistic. Excretory urography and the final clinical diagnosis were used as reference. RESULTS Twenty-six patients were found to have unilateral obstruction caused by ureteral stones. Both MR urography methods were excellent for detecting obstruction. In the detection of stones 3D FLASH was superior, with a sensitivity of 96.2% and 100% and specificity of 100% and 100% for observers A and B, respectively, compared with a sensitivity of 57.7% and 53.8% and a specificity of 100% and 100%, respectively, for T2-weighted sequences. The best degree of obstruction was seen with 3D FLASH, and the interobserver agreement was excellent for stone detection (kappa = 0.97). CONCLUSION T2-weighted sequences alone are not sufficient for examining patients with acute flank pain. However, the combined use of both T2-weighted and 3D FLASH sequences will ensure better confidence in the evaluation of acute suspected renal colic. MR urography can replace conventional excretory urography when the latter is contraindicated or undesirable.
-
mr urography in evaluation of acute flank pain t2 weighted sequences and gadolinium enhanced three dimensional flash compared with urography fast low angle shot
American Journal of Roentgenology, 2001Co-Authors: M Sudah, Ritva Vanninen, Kaarina Partanen, A Heino, Petri Vainio, M AlaopasAbstract:OBJECTIVE. The aim of this study was to compare the usefulness of breath-hold heavily T2-weighted sequences with gadolinium-enhanced three-dimensional fast low-angle shot (3D FLASH) MR urography in the evaluation of patients with acute flank pain.SUBJECTS AND METHODS. Forty consecutive patients with symptoms of acute flank pain underwent MR urography followed immediately by excretory urography. Heavily T2-weighted (combined thin-slice half-Fourier acquisition single-shot turbo spin-echo [HASTE] and thick-slab single-shot turbo spin-echo) and 3D FLASH sequences were evaluated separately and independently by two experienced radiologists for the presence, cause, level, and degree of obstruction. Interobserver agreement was calculated using the kappa statistic. Excretory urography and the final clinical diagnosis were used as reference.RESULTS. Twenty-six patients were found to have unilateral obstruction caused by ureteral stones. Both MR urography methods were excellent for detecting obstruction. In the det...
M Sudah - One of the best experts on this subject based on the ideXlab platform.
-
mr urography in evaluation of acute flank pain
American Journal of Roentgenology, 2012Co-Authors: M Sudah, Ritva Vanninen, Kaarina Partanen, A Heino, Petri Vainio, M AlaopasAbstract:OBJECTIVE. The aim of this study was to compare the usefulness of breath-hold heavily T2-weighted sequences with gadolinium-enhanced three-dimensional fast low-angle shot (3D FLASH) MR urography in the evaluation of patients with acute flank pain.SUBJECTS AND METHODS. Forty consecutive patients with symptoms of acute flank pain underwent MR urography followed immediately by excretory urography. Heavily T2-weighted (combined thin-slice half-Fourier acquisition single-shot turbo spin-echo [HASTE] and thick-slab single-shot turbo spin-echo) and 3D FLASH sequences were evaluated separately and independently by two experienced radiologists for the presence, cause, level, and degree of obstruction. Interobserver agreement was calculated using the kappa statistic. Excretory urography and the final clinical diagnosis were used as reference.RESULTS. Twenty-six patients were found to have unilateral obstruction caused by ureteral stones. Both MR urography methods were excellent for detecting obstruction. In the det...
-
patients with acute flank pain comparison of mr urography with unenhanced helical ct
Radiology, 2002Co-Authors: M Sudah, Ritva Vanninen, Kaarina Partanen, A Heino, Sakari Kainulainen, Auli Malinen, M AlaopasAbstract:PURPOSE: To compare unenhanced helical computed tomography (CT) and magnetic resonance (MR) urography, by using T2-weighted and contrast material–enhanced T1-weighted imaging to examine patients with acute flank pain, with reference to excretory urography and final clinical diagnosis. MATERIALS AND METHODS: Forty-nine patients underwent CT, MR urography (with T2-weighted and gadopentetate dimeglumine–enhanced T1-weighted sequences), and excretory urography. CT and MR urographic findings were evaluated separately and independently by two radiologists each (CT, observers A and B; MR urography, observers C and D) for the presence, cause, level, and degree of obstruction. The final conclusive diagnosis was based on the combination of excretory urographic, clinical, and interventional results. RESULTS: At final diagnosis, 32 (65%) patients were found to have ureteral stones causing unilateral obstruction. In ureteral stone detection, the sensitivity and specificity of CT were 90.6% (29 of 32 patients) and 100....
-
mr urography in evaluation of acute flank pain t2 weighted sequences and gadolinium enhanced three dimensional flash compared with urography
American Journal of Roentgenology, 2001Co-Authors: M Sudah, Ritva Vanninen, Kaarina Partanen, A Heino, Petri Vainio, M AlaopasAbstract:OBJECTIVE The aim of this study was to compare the usefulness of breath-hold heavily T2-weighted sequences with gadolinium-enhanced three-dimensional fast low-angle shot (3D FLASH) MR urography in the evaluation of patients with acute flank pain. SUBJECTS AND METHODS Forty consecutive patients with symptoms of acute flank pain underwent MR urography followed immediately by excretory urography. Heavily T2-weighted (combined thin-slice half-Fourier acquisition single-shot turbo spin-echo [HASTE] and thick-slab single-shot turbo spin-echo) and 3D FLASH sequences were evaluated separately and independently by two experienced radiologists for the presence, cause, level, and degree of obstruction. Interobserver agreement was calculated using the kappa statistic. Excretory urography and the final clinical diagnosis were used as reference. RESULTS Twenty-six patients were found to have unilateral obstruction caused by ureteral stones. Both MR urography methods were excellent for detecting obstruction. In the detection of stones 3D FLASH was superior, with a sensitivity of 96.2% and 100% and specificity of 100% and 100% for observers A and B, respectively, compared with a sensitivity of 57.7% and 53.8% and a specificity of 100% and 100%, respectively, for T2-weighted sequences. The best degree of obstruction was seen with 3D FLASH, and the interobserver agreement was excellent for stone detection (kappa = 0.97). CONCLUSION T2-weighted sequences alone are not sufficient for examining patients with acute flank pain. However, the combined use of both T2-weighted and 3D FLASH sequences will ensure better confidence in the evaluation of acute suspected renal colic. MR urography can replace conventional excretory urography when the latter is contraindicated or undesirable.
-
mr urography in evaluation of acute flank pain t2 weighted sequences and gadolinium enhanced three dimensional flash compared with urography fast low angle shot
American Journal of Roentgenology, 2001Co-Authors: M Sudah, Ritva Vanninen, Kaarina Partanen, A Heino, Petri Vainio, M AlaopasAbstract:OBJECTIVE. The aim of this study was to compare the usefulness of breath-hold heavily T2-weighted sequences with gadolinium-enhanced three-dimensional fast low-angle shot (3D FLASH) MR urography in the evaluation of patients with acute flank pain.SUBJECTS AND METHODS. Forty consecutive patients with symptoms of acute flank pain underwent MR urography followed immediately by excretory urography. Heavily T2-weighted (combined thin-slice half-Fourier acquisition single-shot turbo spin-echo [HASTE] and thick-slab single-shot turbo spin-echo) and 3D FLASH sequences were evaluated separately and independently by two experienced radiologists for the presence, cause, level, and degree of obstruction. Interobserver agreement was calculated using the kappa statistic. Excretory urography and the final clinical diagnosis were used as reference.RESULTS. Twenty-six patients were found to have unilateral obstruction caused by ureteral stones. Both MR urography methods were excellent for detecting obstruction. In the det...
J Srinivasan - One of the best experts on this subject based on the ideXlab platform.
-
impact of african Orography and the indian summer monsoon on the low level somali jet
International Journal of Climatology, 2009Co-Authors: Arindam Chakraborty, Ravi S Nanjundiah, J SrinivasanAbstract:The low-level jet (LLJ) over the Indian region, which is most prominent during the monsoon (June-September) season, has been studied with a general circulation model (GCM). The role of African Orography in modulating this jet is the focus of this article. The presence of African Orography intensifies the cross-equatorial flow. Contrary to previous modelling studies we find that cross-equatorial flow occurs even in the absence of African Orography, though this flow is much weaker even when the Indian monsoon rainfall is high. However, the location of the meridional jet near the equator in the Somali region is linked to the Indian monsoon rainfall rather than to the land-sea contrast over Somalia. Also, the presence of African Orography, and not the strength of the Indian monsoon, controls the vertical extent of the equatorial meridional wind. In an aqua-planet simulation, the cross-equatorial flow occurs about 30° to the west of the rainfall maximum. Thus, the longitudinal location of the equatorial Somali jet depends upon the occurrence of monsoon heating, but the vertical structure of the jet is on account of the western boundary current in the atmosphere due to the East African highlands under the influence of monsoonal heat source.
-
theoretical aspects of the onset of indian summer monsoon from perturbed Orography simulations in a gcm
Annales Geophysicae, 2006Co-Authors: Arindam Chakraborty, Ravi S Nanjundiah, J SrinivasanAbstract:A theory is proposed to determine the onset of the Indian Summer Monsoon (ISM) in an Atmospheric General Circulation Model (AGCM). The onset of ISM is delayed substantially in the absence of global Orography. The impact of Orography over different parts of the Earth on the onset of ISM has also been investigated using five additional perturbed simulations. The large difference in the date of onset of ISM in these simulations has been explained by a new theory based on the Surface Moist Static Energy (SMSE) and vertical velocity at the mid-troposphere. It is found that onset occurs only after SMSE crosses a threshold value and the large-scale vertical motion in the middle troposphere becomes upward. This study shows that both dynamics and thermodynamics play profound roles in the onset of the monsoon.
-
role of asian and african Orography in indian summer monsoon
Geophysical Research Letters, 2002Co-Authors: Arindam Chakraborty, Ravi S Nanjundiah, J SrinivasanAbstract:Role of Asian and African Orography in the Indian summer monsoon has been investigated using a general circulation model. Orography of Asian region west of 80°E appears to have more impact on the Indian summer monsoon rainfall than the Orography to the east of 80°E. It has been found that removal of the African Orography increases the seasonal precipitation over the Indian sub-continent by 28%, whereas removal of Orography over the entire globe reduces it by 25%. Moreover, there was a substantial delay in all-India monsoon onset in the experiment in which mountains were removed globally, mainly due to the intrusion of midlatitude dry air west of 80°E. The increase in precipitation in which Orography over Africa was removed was due to the positive feedback between the wind over the East African coast/Arabian Sea and precipitation over Bay of Bengal, with the latter leading the former by about 2 days.
Daniel Eastwood - One of the best experts on this subject based on the ideXlab platform.
-
multidetector computerized tomography urography as the primary imaging modality for detecting urinary tract neoplasms in patients with asymptomatic hematuria
The Journal of Urology, 2008Co-Authors: Gary S. Sudakoff, Michael L Guralnick, R S Hellman, Dell P Dunn, Daniel EastwoodAbstract:Purpose: We determined whether multidetector computerized tomography urography is sensitive and specific for detecting urinary tract neoplasms when used as the primary imaging modality for evaluating patients with hematuria.Materials and Methods: A retrospective review was performed of the radiological, urological and pathological records of 468 patients without a history of urinary neoplasms who presented with hematuria. All patients underwent multidetector computerized tomography urography and complete urological evaluation, including cystoscopy. Laboratory urinalysis and cytology were done in 350 and 318 of the 468 patients, respectively. Multivariate logistic regression analysis was performed using the variables multidetector computerized tomography urography diagnosis, worst urine cytology, number of red blood cells per high power field, gross hematuria, age and gender to predict urinary tract neoplasm.Results: A total of 50 urinary neoplasms were diagnosed in 468 patients. Multidetector computerized...
-
opacification of the genitourinary collecting system during mdct urography with enhanced ct digital radiography nonsaline versus saline bolus
American Journal of Roentgenology, 2006Co-Authors: Gary S. Sudakoff, R S Hellman, Dell P Dunn, Mario A Laguna, Charles R Wilson, Robert W Prost, Daniel EastwoodAbstract:OBJECTIVE: The purpose of this study was to determine whether a saline bolus during CT urography improves urinary collecting system opacification and whether the addition of enhanced CT digital radiography (CTDR) improves urinary collecting system visualization with or without a saline bolus. MATERIALS AND METHODS: One hundred eight CT urography and enhanced CTDR examinations were reviewed. Fifty-four patients were given a saline bolus during CT urography, and 54 patients underwent CT urography without a saline bolus. Urinary collecting system opacification was evaluated by group (saline vs nonsaline), imaging technique (CT urography alone vs CT urography plus enhanced CTDR), number of enhanced CTDR images, and site of nonopacified urinary segments. Using a multivariate logistic regression model, we determined significance of variables and odds of complete opacification. RESULTS: In the saline group, 248 nonopacified sites were identified on CT urography alone and 95 sites with CT urography plus enhanced CTDR. In the nonsaline group, 185 nonopacified sites were identified on CT urography alone and 59 sites with CT urography plus enhanced CTDR. Combining both groups, 433 nonopacified sites were identified with CT urography alone and 154 sites with CT urography plus enhanced CTDR. Multivariate logistic regression showed significance for group (p = 0.010), imaging method (p < 0.0001), number of enhanced CTDR images (p = 0.048), and site of segment opacification (p < 0.0001). The renal pelvis shows the greatest odds and the distal ureter the lowest odds for complete opacification by group or imaging method. CONCLUSION: The addition of a saline bolus offers no improvement, whereas the addition of enhanced CTDR offers significant improvement in collecting system opacification during CT urography.
A Heino - One of the best experts on this subject based on the ideXlab platform.
-
mr urography in evaluation of acute flank pain
American Journal of Roentgenology, 2012Co-Authors: M Sudah, Ritva Vanninen, Kaarina Partanen, A Heino, Petri Vainio, M AlaopasAbstract:OBJECTIVE. The aim of this study was to compare the usefulness of breath-hold heavily T2-weighted sequences with gadolinium-enhanced three-dimensional fast low-angle shot (3D FLASH) MR urography in the evaluation of patients with acute flank pain.SUBJECTS AND METHODS. Forty consecutive patients with symptoms of acute flank pain underwent MR urography followed immediately by excretory urography. Heavily T2-weighted (combined thin-slice half-Fourier acquisition single-shot turbo spin-echo [HASTE] and thick-slab single-shot turbo spin-echo) and 3D FLASH sequences were evaluated separately and independently by two experienced radiologists for the presence, cause, level, and degree of obstruction. Interobserver agreement was calculated using the kappa statistic. Excretory urography and the final clinical diagnosis were used as reference.RESULTS. Twenty-six patients were found to have unilateral obstruction caused by ureteral stones. Both MR urography methods were excellent for detecting obstruction. In the det...
-
patients with acute flank pain comparison of mr urography with unenhanced helical ct
Radiology, 2002Co-Authors: M Sudah, Ritva Vanninen, Kaarina Partanen, A Heino, Sakari Kainulainen, Auli Malinen, M AlaopasAbstract:PURPOSE: To compare unenhanced helical computed tomography (CT) and magnetic resonance (MR) urography, by using T2-weighted and contrast material–enhanced T1-weighted imaging to examine patients with acute flank pain, with reference to excretory urography and final clinical diagnosis. MATERIALS AND METHODS: Forty-nine patients underwent CT, MR urography (with T2-weighted and gadopentetate dimeglumine–enhanced T1-weighted sequences), and excretory urography. CT and MR urographic findings were evaluated separately and independently by two radiologists each (CT, observers A and B; MR urography, observers C and D) for the presence, cause, level, and degree of obstruction. The final conclusive diagnosis was based on the combination of excretory urographic, clinical, and interventional results. RESULTS: At final diagnosis, 32 (65%) patients were found to have ureteral stones causing unilateral obstruction. In ureteral stone detection, the sensitivity and specificity of CT were 90.6% (29 of 32 patients) and 100....
-
mr urography in evaluation of acute flank pain t2 weighted sequences and gadolinium enhanced three dimensional flash compared with urography
American Journal of Roentgenology, 2001Co-Authors: M Sudah, Ritva Vanninen, Kaarina Partanen, A Heino, Petri Vainio, M AlaopasAbstract:OBJECTIVE The aim of this study was to compare the usefulness of breath-hold heavily T2-weighted sequences with gadolinium-enhanced three-dimensional fast low-angle shot (3D FLASH) MR urography in the evaluation of patients with acute flank pain. SUBJECTS AND METHODS Forty consecutive patients with symptoms of acute flank pain underwent MR urography followed immediately by excretory urography. Heavily T2-weighted (combined thin-slice half-Fourier acquisition single-shot turbo spin-echo [HASTE] and thick-slab single-shot turbo spin-echo) and 3D FLASH sequences were evaluated separately and independently by two experienced radiologists for the presence, cause, level, and degree of obstruction. Interobserver agreement was calculated using the kappa statistic. Excretory urography and the final clinical diagnosis were used as reference. RESULTS Twenty-six patients were found to have unilateral obstruction caused by ureteral stones. Both MR urography methods were excellent for detecting obstruction. In the detection of stones 3D FLASH was superior, with a sensitivity of 96.2% and 100% and specificity of 100% and 100% for observers A and B, respectively, compared with a sensitivity of 57.7% and 53.8% and a specificity of 100% and 100%, respectively, for T2-weighted sequences. The best degree of obstruction was seen with 3D FLASH, and the interobserver agreement was excellent for stone detection (kappa = 0.97). CONCLUSION T2-weighted sequences alone are not sufficient for examining patients with acute flank pain. However, the combined use of both T2-weighted and 3D FLASH sequences will ensure better confidence in the evaluation of acute suspected renal colic. MR urography can replace conventional excretory urography when the latter is contraindicated or undesirable.
-
mr urography in evaluation of acute flank pain t2 weighted sequences and gadolinium enhanced three dimensional flash compared with urography fast low angle shot
American Journal of Roentgenology, 2001Co-Authors: M Sudah, Ritva Vanninen, Kaarina Partanen, A Heino, Petri Vainio, M AlaopasAbstract:OBJECTIVE. The aim of this study was to compare the usefulness of breath-hold heavily T2-weighted sequences with gadolinium-enhanced three-dimensional fast low-angle shot (3D FLASH) MR urography in the evaluation of patients with acute flank pain.SUBJECTS AND METHODS. Forty consecutive patients with symptoms of acute flank pain underwent MR urography followed immediately by excretory urography. Heavily T2-weighted (combined thin-slice half-Fourier acquisition single-shot turbo spin-echo [HASTE] and thick-slab single-shot turbo spin-echo) and 3D FLASH sequences were evaluated separately and independently by two experienced radiologists for the presence, cause, level, and degree of obstruction. Interobserver agreement was calculated using the kappa statistic. Excretory urography and the final clinical diagnosis were used as reference.RESULTS. Twenty-six patients were found to have unilateral obstruction caused by ureteral stones. Both MR urography methods were excellent for detecting obstruction. In the det...