RoFo : Fortschritte auf dem Gebiete der Rontgenstrahlen und der Nuklearmedizin · 2026
The Impact of TE and TR on Apparent Diffusion Coefficient and Diffusion-derived Vessel Density Quantification: Studies of Healthy Liver and Spleen.
СтатьяНазвание и аннотация: Перевод пока не подготовлен
Обработка статьи · этапы, ошибки и управление
Загрузка состояния…
Ошибки и ограничения
История · было → стало
Состояние обновляется каждые 5 секунд, пока блок открыт. Процент показывается только там, где известен объём работы. Пауза останавливает продолжение этапа; текущий запрос к источнику может завершиться.
Xu Fan-Yi, Wáng Yì Xiáng J
Аннотация
PURPOSE: This study investigates the impact of echo time (TE) and repetition time (TR) on apparent diffusion coefficient (ADC) and diffusion-derived vessel density (DDVD) values. Spleen has longer T1 and T2 than the liver, and spleen has a T2 similar to most hepatocellular carcinomas.
MATERIALS AND METHODS: Liver and spleen diffusion MRI was conducted with six volunteers at 3.0 T with multiple sessions. When TE was changed with steps of TE=46 ms, 52 ms, 60 ms, 70 ms, and 80 ms, TR was fixed at 2000 ms. When TR was changed with steps of TR=200 ms, 300 ms, 500 ms, 1000 ms, and 2000 ms, TE was fixed at 46 ms. The b-values included 0, 1, 2, 10, and 600 s/mm². ADC was calculated with b=0 and b=600 s/mm² images. DDVD was the signal difference between on b=0 image and a very low b-value image (b=1, 2, 10 s/mm2). Thirty-five scans for each ADC data point and 23 scans for each DDVD data point were included.
RESULTS: Following the increase in TE from 46ms to 80ms, the ADC value increased by 23.9% (median) for the liver and 18.2% (median) for the spleen, while the ADCspleen/ADCliver ratio was smaller when TE was longer. Following the increase in TR from 200ms to 2000 ms, the ADC value decreased by 4.8% (median) for the liver and 14.6% (median) for the spleen, while the ADCspleen/ADCliver ratio was smaller when TR was longer. Following the increase in TE from 46ms to 80ms, there was a decrease in the DDVD value. DDVDspleen/DDVDliver ratios were greater when TE was long. Following the increase in TR from 200ms to 2000ms, there was a biphasic change in the DDVD value. The DDVD values were highest when TR was 500ms, and DDVDspleen/DDVDliver ratios followed a mono-phasic decrease.
CONCLUSION: TR and TE have very notable impact on the ADC and DDVD values of the liver and spleen.
KEY POINTS: · An increase of TE and an increase of TR are both associated with a decreasing ADCspleen/ADCliver ratio.. · Longer TE is associated with an increased DDVDspleen/DDVDliver ratio.. · The lesion detectability and lesion-to-tissue contrast by ADC and DDVD maps may be amplified by optimizing TE and TR values..
CITATION FORMAT: · Xu FY, Wáng YXJ. The Impact of TE and TR on Apparent Diffusion Coefficient and Diffusion-derived Vessel Density Quantification: Studies of Healthy Liver and Spleen. Rofo 2026; DOI 10.1055/a-2777-6695.
MATERIALS AND METHODS: Liver and spleen diffusion MRI was conducted with six volunteers at 3.0 T with multiple sessions. When TE was changed with steps of TE=46 ms, 52 ms, 60 ms, 70 ms, and 80 ms, TR was fixed at 2000 ms. When TR was changed with steps of TR=200 ms, 300 ms, 500 ms, 1000 ms, and 2000 ms, TE was fixed at 46 ms. The b-values included 0, 1, 2, 10, and 600 s/mm². ADC was calculated with b=0 and b=600 s/mm² images. DDVD was the signal difference between on b=0 image and a very low b-value image (b=1, 2, 10 s/mm2). Thirty-five scans for each ADC data point and 23 scans for each DDVD data point were included.
RESULTS: Following the increase in TE from 46ms to 80ms, the ADC value increased by 23.9% (median) for the liver and 18.2% (median) for the spleen, while the ADCspleen/ADCliver ratio was smaller when TE was longer. Following the increase in TR from 200ms to 2000 ms, the ADC value decreased by 4.8% (median) for the liver and 14.6% (median) for the spleen, while the ADCspleen/ADCliver ratio was smaller when TR was longer. Following the increase in TE from 46ms to 80ms, there was a decrease in the DDVD value. DDVDspleen/DDVDliver ratios were greater when TE was long. Following the increase in TR from 200ms to 2000ms, there was a biphasic change in the DDVD value. The DDVD values were highest when TR was 500ms, and DDVDspleen/DDVDliver ratios followed a mono-phasic decrease.
CONCLUSION: TR and TE have very notable impact on the ADC and DDVD values of the liver and spleen.
KEY POINTS: · An increase of TE and an increase of TR are both associated with a decreasing ADCspleen/ADCliver ratio.. · Longer TE is associated with an increased DDVDspleen/DDVDliver ratio.. · The lesion detectability and lesion-to-tissue contrast by ADC and DDVD maps may be amplified by optimizing TE and TR values..
CITATION FORMAT: · Xu FY, Wáng YXJ. The Impact of TE and TR on Apparent Diffusion Coefficient and Diffusion-derived Vessel Density Quantification: Studies of Healthy Liver and Spleen. Rofo 2026; DOI 10.1055/a-2777-6695.