Usefulness of Biphasic Contrast Injection in Multidetector CT of the Head and Neck: A Comparison with Monophasic Contrast Injection

두경부 다중채널 전산화단층촬영에서 이상형(Biphasic) 조영제 투여의 유용성: 일상형(Monophasic)과의 비교

Purpose: The purpose of this study was to evaluate the value of biphasic injection of contrast media in a CT of the head and neck. Materials and Methods: In the first step, vessel and tissue attenuation was measured in four different protocol groups: M1 (monophasic, injection rate: 100 mL at 3 mL/sec, delay time: 70 sec); B1 (biphasic, 100 mL at 3 mL/sec, 70 sec); M2 (monophasic, 100 mL at 2 mL/sec, 70 sec); and B2 (biphasic, 100 mL at 2 mL/sec, 120 sec). The biphasic injection protocol was an initial volus injection of 50 mL contrast medium and an additional volus injection of 50 mL contrast medium at 35 sec after initial injection. In the second step, the tissue attenuation of two groups was measured with a different contrast media volume and phase: M3 (monophasic, 100 mL at 2 mL/sec, 90 sec) and B3 (biphasic, 80 mL at 2 mL/sec, 90 sec, initial volus injection of 40 mL and an additional volus injection of 40 mL at 55 sec after initial injection). The measured CT numbers from vessels and tissues were compared between the different protocol groups. Results: The vessel attenuation of B1 was higher than that of M1 and B2 (p < 0.05). Despite a longer delay time, the vessel attenuation of B2 was not significantly different from that of M1 and M2. There was no significant differentiation of tissue attenuation between each group. In the second study, the attenuation of vessel and tissue was not different between B3 and M3. Conclusion: Biphasic contrast injection leads to an increased attenuation of the vessel and also delays the optimal scan window.

목적: 이 연구는 두경부 multidetector CT (이하 MDCT)에서 이상형 조영제 투여의 효용성을 평가하기 위해 시행되었다. 대상과 방법: 첫 번째 연구에서는 네 군에서 다른 프로토콜을 이용하여 혈관과 조직조영증강을 측정하였다: M1(일상형, 투여속도: 100 mL at 3 mL/초, 스캔시간: 70초); B1(이상형, 100 mL at 3 mL/초, 70초); M2(일상형, 100 mL at 2 mL/초, 70초); and B2(이상형, 100 mL at 2 mL/초, 120초). 이상형 조영제 투여시에는 먼저 50 mL의 조영제를 투여한 후 35초 후에 추가적으로 50 mL의 조영제를 투여하였다. 두 번째 연구에서는 두 군에서 조영제 양과 상을 달리하여 조직조영증강을 측정하였다: M3(일상형, 100 mL at 2 mL/초, 90초) and B3(이상형, 80 mL at 2 mL/초, 90초, 먼저 40 mL의 조영제를 투여한 후 55초 후에 추가적으로 40 mL의 조영제를 투여). 총 여섯 군에서 측정된 혈관과 조직조영증강을 서로 비교하였다. 결과: 동일한 delay time에서는 B1이 M1과 B2보다 혈관조영증강이 높았다(p < 0.05). 긴 delay time에도 불구하고, B2는 M1과 M2에 비해 혈관조영증강의 유의한 차이가 없었다. 각 군 간에 조직조영증강은 차이가 없었다. B3와 M3 간에 혈관과 조직조영증강은 차이가 없었다. 결론: 두경부 MDCT에서 이상형 조영제 주입은 혈관의 조영증강을 증가시키고 적정 스캔시간을 지연시킨다.