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Assessment of the ability of CT urography with low-dose multi-phasic excretory phases for opacification of the urinary system

View Article: PubMed Central - PubMed

ABSTRACT

Objective: To prospectively evaluate the ability of CT urography with a low-dose multi-phasic excretory phase for opacification of the urinary system.

Materials and methods: Thirty-two patients underwent CT urography with low-dose multi-phasic s using adaptive iterative dose reduction 3D acquired at 5-, 10-, and 15-minute delays. Opacification scores of the upper urinary tracts and the urinary bladder were assigned for each excretory phase by two radiologists, who recorded whether adequate (>75%) or complete (100%) opacification of the upper urinary tract and urinary bladder was achieved in each patient. Adequate and complete opacification rates of the upper urinary tracts and the urinary bladder were compared among three excretory phases and among combined multi-phasic excretory phases using Cochran's Q test.

Results: There was no significant difference among three excretory phases with 5-, 10-, and 15-minute delays in adequate (56.3, 43.8, and 63.5%, respectively; P = 0.174) and complete opacification rates (9.3, 15.6, and 18.7%, respectively; P = 0.417) of the upper urinary tracts. Combined tri-phasic excretory phases significantly improved adequate and complete opacification rates to 84.4% and 43.8%, respectively (P = 0.002). In contrast, there were significant differences among three excretory phases for the rate of adequate (31.3, 84.4, and 93.8%, respectively; P<0.001) and complete opacification (21.9, 53.1, and 81.3%, respectively; P<0.001) of the urinary bladder. Multi-phasic excretory phases did not improve these rates because opacification was always better with a longer delay.

Conclusion: Although multi-phasic acquisition of excretory phases is effective at improving opacification of the upper urinary tracts, complete opacification is difficult even with tri-phasic acquisition.

No MeSH data available.


Maximum intensity projection images show the upper urinary tracts obtained in the three excretory phases in a 44-year-old man.A, Excretory phase with a 5-minute delay. B, Excretory phase with a 10-minute delay. C, Excretory phase with a 15-minute delay. With a 5-minute delay, non-opacification was noted in the right ureter, but with a 10- or 15-minute delay, the non-opacified segments were delineated. On the other hand, just a 5-minute delay was sufficient for complete opacification of the left ureter. The numbers of completely opacified segments were 5, 4, 6, 6, 7, 7, and 8 with the 5-, 10-, 15-, 5 + 10-, 5 + 15-, 10 + 15-, and 5 + 10 + 15-minute delays, respectively. Multi-phasic acquisition was thus able to delineate more segments.
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pone.0174800.g003: Maximum intensity projection images show the upper urinary tracts obtained in the three excretory phases in a 44-year-old man.A, Excretory phase with a 5-minute delay. B, Excretory phase with a 10-minute delay. C, Excretory phase with a 15-minute delay. With a 5-minute delay, non-opacification was noted in the right ureter, but with a 10- or 15-minute delay, the non-opacified segments were delineated. On the other hand, just a 5-minute delay was sufficient for complete opacification of the left ureter. The numbers of completely opacified segments were 5, 4, 6, 6, 7, 7, and 8 with the 5-, 10-, 15-, 5 + 10-, 5 + 15-, 10 + 15-, and 5 + 10 + 15-minute delays, respectively. Multi-phasic acquisition was thus able to delineate more segments.

Mentions: The numbers of patients with complete and adequate opacification of the upper urinary tracts in the three obtained EPs are shown in Table 2. Although complete and adequate opacification of the upper urinary tracts were achieved more often on the EP with a 15-minute delay, there was no significant difference among the three EPs (p = 0.417, and 0.174, respectively). Complete opacification was achieved only with a 5- or 10-minute delay in three patients. On bi-phasic EPs, complete opacification of the upper urinary tracts was achieved in 6 (18.7%), 9 (28.1%), and 12 (37.5%) patients with 5+10-, 5+15-, and 10+15-minute delays, respectively, and adequate opacification of the upper urinary tracts was achieved in 26 (81.3%), 26 (81.3%), and 24 (75.0%) patients, respectively. On tri-phasic EPs, 14 (43.8%) and 27 (84.4%) patients showed complete and adequate opacification, respectively. There were significant differences for the rate of complete and adequate opacification among single- (15-minute delay), bi- (10+15-minute delays for complete opacification, 5+15-minute delays for adequate opacification), and tri-phasic acquisitions (5+10+15-minute delays) (p = 0.002 for both, Table 3, Fig 3). In pairwise comparisons, a significant difference in the rate of complete and adequate opacification was found only between single- and tri-phasic acquisition (p = 0.008, and 0.016, respectively).


Assessment of the ability of CT urography with low-dose multi-phasic excretory phases for opacification of the urinary system
Maximum intensity projection images show the upper urinary tracts obtained in the three excretory phases in a 44-year-old man.A, Excretory phase with a 5-minute delay. B, Excretory phase with a 10-minute delay. C, Excretory phase with a 15-minute delay. With a 5-minute delay, non-opacification was noted in the right ureter, but with a 10- or 15-minute delay, the non-opacified segments were delineated. On the other hand, just a 5-minute delay was sufficient for complete opacification of the left ureter. The numbers of completely opacified segments were 5, 4, 6, 6, 7, 7, and 8 with the 5-, 10-, 15-, 5 + 10-, 5 + 15-, 10 + 15-, and 5 + 10 + 15-minute delays, respectively. Multi-phasic acquisition was thus able to delineate more segments.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5383231&req=5

pone.0174800.g003: Maximum intensity projection images show the upper urinary tracts obtained in the three excretory phases in a 44-year-old man.A, Excretory phase with a 5-minute delay. B, Excretory phase with a 10-minute delay. C, Excretory phase with a 15-minute delay. With a 5-minute delay, non-opacification was noted in the right ureter, but with a 10- or 15-minute delay, the non-opacified segments were delineated. On the other hand, just a 5-minute delay was sufficient for complete opacification of the left ureter. The numbers of completely opacified segments were 5, 4, 6, 6, 7, 7, and 8 with the 5-, 10-, 15-, 5 + 10-, 5 + 15-, 10 + 15-, and 5 + 10 + 15-minute delays, respectively. Multi-phasic acquisition was thus able to delineate more segments.
Mentions: The numbers of patients with complete and adequate opacification of the upper urinary tracts in the three obtained EPs are shown in Table 2. Although complete and adequate opacification of the upper urinary tracts were achieved more often on the EP with a 15-minute delay, there was no significant difference among the three EPs (p = 0.417, and 0.174, respectively). Complete opacification was achieved only with a 5- or 10-minute delay in three patients. On bi-phasic EPs, complete opacification of the upper urinary tracts was achieved in 6 (18.7%), 9 (28.1%), and 12 (37.5%) patients with 5+10-, 5+15-, and 10+15-minute delays, respectively, and adequate opacification of the upper urinary tracts was achieved in 26 (81.3%), 26 (81.3%), and 24 (75.0%) patients, respectively. On tri-phasic EPs, 14 (43.8%) and 27 (84.4%) patients showed complete and adequate opacification, respectively. There were significant differences for the rate of complete and adequate opacification among single- (15-minute delay), bi- (10+15-minute delays for complete opacification, 5+15-minute delays for adequate opacification), and tri-phasic acquisitions (5+10+15-minute delays) (p = 0.002 for both, Table 3, Fig 3). In pairwise comparisons, a significant difference in the rate of complete and adequate opacification was found only between single- and tri-phasic acquisition (p = 0.008, and 0.016, respectively).

View Article: PubMed Central - PubMed

ABSTRACT

Objective: To prospectively evaluate the ability of CT urography with a low-dose multi-phasic excretory phase for opacification of the urinary system.

Materials and methods: Thirty-two patients underwent CT urography with low-dose multi-phasic s using adaptive iterative dose reduction 3D acquired at 5-, 10-, and 15-minute delays. Opacification scores of the upper urinary tracts and the urinary bladder were assigned for each excretory phase by two radiologists, who recorded whether adequate (>75%) or complete (100%) opacification of the upper urinary tract and urinary bladder was achieved in each patient. Adequate and complete opacification rates of the upper urinary tracts and the urinary bladder were compared among three excretory phases and among combined multi-phasic excretory phases using Cochran's Q test.

Results: There was no significant difference among three excretory phases with 5-, 10-, and 15-minute delays in adequate (56.3, 43.8, and 63.5%, respectively; P = 0.174) and complete opacification rates (9.3, 15.6, and 18.7%, respectively; P = 0.417) of the upper urinary tracts. Combined tri-phasic excretory phases significantly improved adequate and complete opacification rates to 84.4% and 43.8%, respectively (P = 0.002). In contrast, there were significant differences among three excretory phases for the rate of adequate (31.3, 84.4, and 93.8%, respectively; P<0.001) and complete opacification (21.9, 53.1, and 81.3%, respectively; P<0.001) of the urinary bladder. Multi-phasic excretory phases did not improve these rates because opacification was always better with a longer delay.

Conclusion: Although multi-phasic acquisition of excretory phases is effective at improving opacification of the upper urinary tracts, complete opacification is difficult even with tri-phasic acquisition.

No MeSH data available.