Optimal dose and injection duration (injection rate) of contrast material for depiction of hypervascular hepatocellular carcinomas by multidetector CT

Purpose The aim of this study was to investigate the optimal dose and injection duration of contrast material (CM) for depicting hypervascular hepatocellular carcinomas (HCCs) during the hepatic arterial phase with multidetector row computed tomography (CT). Materials and methods The study population consisted of 71 patients with hypervascular HCCs. After unenhanced scans, the first (early arterial phase, or EAP), second (late arterial phase, or LAP), and third (equilibrium phase) scanning was started at 30, 43, and 180 s after injection of contrast material (CM). During a 33-s period, patients with a body weight ≤50 kg received 100 ml of non-ionic CM with an iodine concentration of 300 mg I/ml; patients whose body weight was >50 kg received 100 ml of CM with an iodine concentration of 370 mg I/ml. First, we measured enhancement in the abdominal aorta and tumor-to-liver contrast (TLC) during the EAP and LAP. Next, to investigate the relation between aortic enhancement and TLC during the LAP, two radiologists visually assessed the conspicuity of hypervascular HCCs during the LAP using a 3-point scale: grade 1, poor; grade 2, fair; grade 3, excellent. Finally, to examine the effect of the CM dose and injection duration on aortic enhancement during the EAP, we simulated aortic enhancement curves using test bolus data obtained for 10 HCC patients and the method of Fleischmann and Hittmair. Results A relatively strong correlation was observed between aortic enhancement during the EAP and TLC during the LAP (correlation coefficient r = 0.75, P < 0.001). The 95% confidence intervals for the population mean for aortic enhancement during EAP in patients with tumor conspicuity grades of 1, 2, and 3 were 188.5, 222.4; 228.8, 259.3; and 280.2, 322.5 HU (Hounsfield Unit), respectively. Thus, we considered the lower limit of the aortic enhancement value for excellent depiction of HCCs during EAP to be 280 HU. To achieve an aortic enhancement value of >280 HU for aortic enhancement simulations during EAP, the injection duration should be <25 s for patients receiving a CM dose of 1.7 ml/kg with 300 mg I/ml iodine and <30 s for those receiving 2.0 ml/kg. Conclusions For excellent depiction of hypervascular HCCs during the hepatic arterial phase, the injection duration should be <25 s in patients receiving a CM dose of 1.7 ml/kg with 300 mg I/ml iodine and <30 s for patients receiving 2.0 ml/kg.     

Efficacy of double arterial phase dynamic magnetic resonance imaging with the sensitivity encoding technique versus dynamic multidetector-row helical computed tomography for detecting hypervascular hepatocellular carcinoma

Purpose  The aim of this study was to evaluate the efficacy of double arterial phase dynamic magnetic resonance imaging (MRI) with the sensitivity encoding technique (SENSE dynamic MRI) for detection of hypervascular hepatocellular carcinoma (HCC) in comparison with double arterial phase dynamic multidetector-row helical computed tomography (dynamic MDCT). Materials and methods  A total of 28 patients with 66 hypervascular HCCs underwent both double arterial SENSE dynamic MRI and dynamic MDCT. The diagnosis of HCC was based on surgical resection (n = 7), biopsy (n = 10), or a combination of CT during arterial portography (CTAP), CT during hepatic arteriography (CTA), and/or the 6-month follow-up CT (n = 49). Based on alternative-free response receiving operating characteristic (ROC) analysis, the diagnostic performance for detecting HCC was compared between double arterial phase SENSE dynamic MRI and double arterial phase dynamic MDCT. Results  The mean sensitivity, positive predictive value, and mean Az values for hypervascular HCCs were 72%, 80%, and 0.79, respectively, for SENSE dynamic MRI and 66%, 92%, and 0.78, respectively, for dynamic MDCT. The mean sensitivity for double arterial phase SENSE dynamic MRI was higher than that for double arterial phase dynamic MDCT, but the difference was not statistically significant. Conclusion  Double arterial phase SENSE dynamic MRI is as valuable as double arterial phase dynamic MDCT for detecting hypervascular HCCs.     

Enhancement pattern analysis of hypervascular hepatocellular carcinoma on dynamic MR imaging with histopathological correlation: validity of portal phase imaging for predicting tumor grade

Purpose

To elucidate the correlation between hypervascular hepatocellular carcinoma (HCC) enhancement patterns on dynamic MR imaging and histological findings.

Materials and methods

Surgically proven 46 hypervascular HCCs of forty-one patients were enrolled. For each HCC, the signal intensity in the portal phase (SIPP) was evaluated. In this study, high, iso-, or low intensity in the portal phase was hypothesized as late, moderate, or early washout pattern, respectively. The SIPP of each HCC was correlated to histological grade and architectural subtypes that represent degrees of trabecular structure. For the trabecular HCCs, the thickness of tumor plate was also correlated for indirect estimation of tumor sinusoid.

Results

There was a significant correlation between the SIPP vs. histological grade and also vs. architectural subtypes, namely the degree of trabecular structure. Washout of hypervascular HCC occurred earlier as the histological grade advanced and the histological architecture got closer to pure trabecular HCC. For the trabecular HCCs, the thickness of tumor plate correlated significantly with SIPP or histological grade. Hypervascular HCCs with thicker tumor plates showed worse histological grade and earlier washout pattern.

Conclusions

Histological grade of hypervascular HCC may be predicted using SIPP. The thickness of tumor plate, resultantly the size of sinusoid between tumor plates, can account for the relationship between washout pattern and histological grade in the trabecular HCCs.     

下肢动脉CT成像中不同对比剂注射方案与对比剂剂量的相关性研究

目的 比较下肢动脉CT成像中2种不同对比剂注射方案对对比剂剂量的影响.方法 收集临床上怀疑下肢动脉疾病行CTA检查的患者50例,随机分为A、B组,对比剂碘普罗胺(350 mg I/mL).A组注射流率4mL/s,对比剂用量1.2 mL/kg.B组第1期5 mL/s注射20 mL,第2期3mL/s注射剩余量;B组对比剂总量=1.2 mL/kg×体质量-4 mL/s×(B方案对比剂注射时间-A方案对比剂注射时间).对2组腹主动脉-髂动脉段、股动脉-腘动脉段、小腿动脉段、足背或足底动脉段4个动脉段图像质量进行评分;测量4个动脉段CT值,记录2组对比剂剂量.均进行独立样本t检验.结果 B组4个动脉段图像质量评分、平均CT值均低于A组,差异均无统计学意义(P＞0.05).A组和B组对比剂剂量为(89.08士11.45)mL和(72.61士10.34)mL,差异有统计学意义(P＜0.05).结论 对比剂流率5 mL/s+3 mL/s分期注射可在不影响图像质量的前提下降低下肢动脉CTA的对比剂用量.     

能谱单能量结合低剂量对比剂与常规CT增强扫描在门静脉成像中的对比研究

目的:探讨能谱单能量(60 keV)结合低剂量对比剂方案在门静脉成像中的应用价值.方法:将50例行腹部CT增强的患者随机分为A、B两组(每组各25例),均采用非离子型对比剂优维显370(370 mg I/mL).A组行宝石能谱成像(GSI)扫描(60 keV),对比剂用量为0.9 mL/kg;B组行常规CT增强扫描(120 kVp),对比剂用量1.3 mL/kg.采用独立样本t检验对A、B两组的门静脉CT值、噪声、肝内、外门静脉对比噪声比(CNR)、主观质量评分、容积CT剂量指数(CTDIvol)及有效辐射量(ED)进行统计学分析.结果:A组的门静脉主干、左支及右支的CT值均高于B组(P均＜0.05);A组的门静脉主干、左支及右支的噪声均低于B组(P均＜0.05);A组的肝内门静脉CNR高于B组(P＝0.03＜0.05);A、B组肝外门静脉CNR无统计学差异(P＝0.90＞0.05).A组的主观评分(4.49±0.64)稍高于B组(4.35±0.65),但两组间差异无统计学意义(P＝0.41).A、B组的CTDIvol及ED均无统计学差异(P＝0.12,P=0.58),A组的对比剂碘摄入量[(23.06±3.18)g]较B组[(30.49±4.99) g]约较少25％ (P＜0.001).结论:在辐射量相当的条件下,单能量GSI结合低剂量对比剂在门静脉成像中优于常规CT增强扫描,且对比剂碘摄入量减少约25％.     

Evaluation of hypervascular hepatocellular carcinoma in cirrhotic liver: comparison of different concentrations of contrast material with multi-detector row helical CT--a prospective randomized study

Purpose

To evaluate two different iodine concentrations of contrast material for detecting hypervascular hepatocellular carcinomas (HCCs) in cirrhotic liver by multi-detector row helical CT (MDCT) when a fixed contrast material volume and injection rate is used.

Materials and methods

Institutional Review Board approval was obtained, and informed consent was obtained from all patients. In this prospective study, 105 patients were randomly assigned a group A (an iodine concentration of 300 mg I/mL), and a group B (an iodine concentration of 370 mg I/mL). In both groups the volume of contrast material was 100 mL and the injection rate was 4 mL/s. Fifty-two patients had 122 hypervascular HCCs. The diagnosis of HCCs was established histopathologically (n = 24) and by imaging findings (n = 98). Three readers independently analyzed four image sets: an arterial phase (AP), a portal phase (PP), an equilibrium phase (EP), and combined all three phase images set. Sensitivity, specificity, and diagnostic accuracy were calculated by receiver operating characteristic (ROC) analysis.

Results

The mean sensitivity for detecting hypervascular HCCs of the AP set, EP set, and combination set in group B (0.94, 0.81, and 0.93) was significantly higher than in group A (0.84, 0.69, and 0.80). Area under the ROC curve of the AP set and the combination set in group B (0.974 and 0.981) was significantly higher than in group A (0.939 and 0.958).

Conclusion

At the same contrast material volume and injection rate, higher iodine concentration of contrast material was effective for detecting hypervascular HCCs by MDCT.     

Histologic Characteristics of Hepatocellular Carcinomas Showing Atypical Enhancement Patterns on 4-Phase MDCT Examination

Objective

To retrospectively define which histologic characteristics of small-sized hepatocellular carcinomas (HCCs) are related to atypical dynamic enhancement on multi-detector computed tomography (MDCT) imaging.

Materials and Methods

Seventy-three patients with 83 HCCs (3 cm or less in diameter) were included in this study. All patients underwent 4-phase MDCT imaging and subsequent surgery within eight weeks. Two independent radiologists blinded to the histologic findings retrospectively classified the HCCs as either typical (showing increased enhancement on arterial phase images followed by washout in late phase images) or atypical lesions demonstrating any other enhancement pattern. From the original pathologic reports, various histologic characteristics including gross morphology, nuclear histologic grades, presence of capsule formation, and capsule infiltration when a capsule was present, were compared among the two groups.

Results

An atypical enhancement pattern was seen in 30 (36.2%) of the 83 HCCs. The mean size of atypical HCCs (1.71 ± 0.764) was significantly smaller than that of typical HCCs (2.31 ± 0.598, p < 0.001). Atypical HCCs were frequently found to be vaguely nodular in gross morphology (n = 13, 43.3%) and to have grade I nuclear grades (n = 17, 56.7%). Capsule formation was significantly more common in typical HCCs (p < 0.001). Capsular infiltration was also more common in typical HCCs (p = 0.001).

Conclusion

HCCs showing atypical dynamic enhancement on MDCT imaging are usually smaller than typical HCCs, vaguely nodular type in gross morphology in most cases, and well-differentiated in nuclear grades, and they lack of capsule formation or capsular infiltration.     

经导管肝动脉栓塞化疗联合华蟾素门静脉灌注治疗中期原发性肝癌疗效研究

目的探讨经导管肝动脉栓塞化疗(TACE)联合华蟾素门静脉灌注治疗中期原发性肝癌患者的临床疗效与预后。方法选取自2011年2月至2013年11月收治的中期原发性肝癌患者79例,其中,单独应用TACE的患者40例(单独组),联合应用TACE与华蟾素门静脉灌注的患者39例(联合组)。比较两组患者存活与门静脉侵犯情况,并分析其影响因素。结果单独组与联合组患者的1年存活率分别为62.5%(25/40)与82.1%(32/39),2年存活率分别为22.5%(9/40)与35.9%(14/39),3年存活率分别为7.5%(3/40)与17.9%(7/39);中位存活时间分别为15.0个月与18.0个月;门静脉癌栓发生率分别为82.5%(33/40)与61.5%(24/39)。两组比较,差异均有统计学意义(P<0.05)。华蟾素门静脉灌注、ChildPugh分级、甲胎蛋白水平及肿瘤大小是影响患者预后的独立危险因素。结论 TACE联合华蟾素门静脉灌注治疗可明显改善中期原发性肝癌患者的预后,值得临床推广。     

The effect of MR contrast medium dose on pituitary gland enhancement, microlesion enhancement and pituitary gland-to-lesion contrast conspicuity

Introduction The purpose of this study was to compare the differences in gland enhancement, microlesion enhancement and gland–lesion contrast ratio in patient groups in which half-dose (HD), standard-dose (SD) and double-dose (DD) contrast medium was used in pituitary MR imaging.Methods Pituitary gland enhancement and microlesion enhancement were measured and gland–lesion contrast ratios were calculated in 18 patients receiving HD (0.05 mmol/kg), 9 receiving SD (0.1 mmol/kg) and 13 receiving DD (0.2 mmol/kg) contrast medium. Gland enhancement and microlesion enhancement over baseline were determined employing DICOM region of interest measurements and compared after normalization to temporal lobe white matter. Contrast ratios and differences were also calculated and compared.Results Gland enhancement and lesion enhancement were greater with larger contrast medium doses (gland: HD 50%, SD 99%, DD 132%; microlesion: HD 19%, SD 54%, DD 86%). The gland–lesion contrast ratios were similar with the three doses (25.6%), reflecting expected similar fractional contrast medium distributions in spite of different doses. The signal difference between gland and microlesion, therefore, was a fixed percentage of gland enhancement (ΔS approximately 26%) with greater signal differences with larger contrast medium doses.Conclusion Greater gland-to-lesion signal differences with larger contrast medium doses would likely improve pituitary microlesion visualization and margin characterization aiding in microlesion detection as well as preoperative planning.     

Abdominal multi-detector row CT: Effectiveness of determining contrast medium dose on basis of body surface area

Purpose

To investigate the validity of determining the contrast medium dose based on body surface area (BSA) for the abdominal contrast-enhanced multi-detector row CT comparing with determining based on body weight (BW).

Materials and methods

Institutional review committee approval was obtained. In this retrospective study, 191 patients those underwent abdominal contrast-enhanced multi-detector row CT were enrolled. All patients received 96 mL of 320 mg I/mL contrast medium at the rate of 3.2 mL. The iodine dose required to enhance 1 HU of the aorta at the arterial phase and that of liver parenchyma at portal venous phase per BSA were calculated (EU_BSA) and evaluated the relationship with BSA. Those per BW were also calculated (EU_BW) and evaluated. Estimated enhancement values (EEVs) of the aorta and liver parenchyma with two protocols for dose decision based on BSA and BW were calculated and patient-to-patient variability was compared between two protocols using the Levene test.

Results

The mean of EU_BSA and EU_BW were 0.0621 g I/m²/HU and 0.00178 g I/kg/HU for the aorta, and 0.342 g I/m²/HU and 0.00978 g I/kg/HU for the liver parenchyma, respectively. In the aortic enhancement, EU_BSA was almost constant regardless of BSA, and the mean absolute deviation of the EEV with the BSA protocol was significantly lower than that with the BW protocol (P < .001), although there was no significant difference between two protocols in the hepatic parenchymal enhancement (P = .92).

Conclusion

For the aortic enhancement, determining the contrast medium dose based on BSA was considered to improve patient-to-patient enhancement variability.     

Re-evaluation of optimal dose of contrast medium for vascular enhancement in CT of the head and neck

Adequate contrast enhancement of major neck vessels is more important than that of a tumour itself in CT of most head and neck tumours because of differentiation from neck node metastases. Our purpose was to re-evaluate the dosage of contrast medium for adequate vascular enhancement in CT of the head and neck. In a blind prospective fashion, 60 patients with a variety of head and neck lesions were randomised into three equal groups receiving 0.75, 1.0, or 1.25 ml/kg of meglumine ioglycate, 300 mg/ml. Contrast medium was administered by injector at 2 ml/s. The scan time and interscan delay were each 1 s, and total scan time 50–180 s. The scan was started immediately after administration of two-thirds of the contrast medium. The degree of vascular enhancement was assessed visually and quantitatively. We visually scored the degree of vascular enhancement as excellent (4 points), good (3), fair (2) or poor (1). For quantitative study, after measuring the CT numbers of the common or internal carotid artery (CA), internal jugular vein (IJV) and adjacent muscle at three levels, were calculated mean vessel/muscle contrast ratios. The degree of enhancement of the CA and IJV tended to increase with dose of the contrast media, but no examination was rated as showing poor enhancement in any group. The mean visual assessment scores for 0.75, 1.0, and 1.25 ml/kg were 2.7, 2.9 and 3.1, respectively; the mean ICA/muscle contrast ratios were 1.58, 1.55 and 1.63, and those of IJV/muscle 1.65, 1.59 and 1.59. There was no significant difference between visual and quantitative assessment in any group. The results suggest that 0.75 ml/kg of contrast medium appears sufficient for vascular opacification for head and neck lesions when the CT scan can be completed in about 120 s. Received: 21 November 1995 Accepted: 28 December 1995     

不同肝功能分级的大肝癌TACE碘化油剂量与疗效的相关性研究

目的:探讨肝功能Child A级与Child B级TACE时,碘化油剂量对大肝癌的疗效影响。方法:回顾性分析106例大肝癌患者,按照碘化油用量分为A、B两组,术后4周CT扫描观察碘化油聚积形式、检测AFP水平和进行肝功能分级,并对1、2、3年生存率进行分析。结果:A组术后碘化油聚积为第一类型、第二类型的数量和血清AFP下降强度均明显高于B组,但术后肝功能分级较B组差,比较12、、3年生存率,ChildA级的两组有显著差异,A组高于B组。结论:肝功能分级为Child B级的大肝癌患者,为避免肝功能进一步损害,应适当减少栓塞剂的用量;而肝功能级别为Child A的肝癌患者,可以适当的加大碘化油栓塞的剂量,能获得较满意的近期和远期疗效。     

三维适形放疗联合肝动脉化疗栓塞治疗原发性肝癌伴门静脉癌栓的疗效分析

目的 观察三维适形放疗联合TACE对不能手术的原发性肝癌伴门静脉癌栓的临床疗效.方法 33例原发性肝癌合并门静脉癌栓患者,TACE 1～2次后,行三维适形放射治疗,大体肿瘤靶区只包括癌栓,不包括肝内原发灶,采用4～6个共面或非共面照射野,使90%的等剂量曲线覆盖PTV.照射总量45～60Gy,单次照射剂量2～4 Gy/次.结果 有效率（CR＋PR）为54.6%（18/33）,1、2年的生存率分别为45.5%和21.2%.无严重并发症出现.结论 三维适形放射治疗联合TACE对肝癌合并门静脉癌栓有较好的疗效.     

Visualization of right adrenal vein: Comparison with three phase dynamic contrast-enhanced CT

PurposeTo evaluate the visualization of the right adrenal vein (RAV) on dynamic contrast-enhanced computed tomography (CT) images in patients with primary aldosteronism.Materials and methodsWe evaluated 27 consecutive patients with primary aldosteronism who underwent contrast-enhanced dynamic CT and subsequent adrenal venous sampling. Scan delays were 10-, 20- and 60-s after a bolus-tracking program detected that the threshold of a 100 Hounsfield units (HU) increase in the abdominal aorta had been achieved. RAV visualization for each phase was evaluated by two readers using a four-point scale. The Friedman and McNemar tests were employed to compare the confidence ratings and the RAV visualization rates between the three phase images.ResultsThe RAV visualization rates were 20.4%, 83.3%, and 63.0%, for the first, second, and third phase, respectively. The RAV visualization rates were 92.6%, 83.3%, 63.0%, and 92.6% for all three phases combined, the first and second phase image combined, the first and third phase image combined, and second and third phase image combined. The combined second and third phase images had the highest RAV visualization rates compared with all other image combinations (P < 0.0001).ConclusionRAV visualization was significantly improved by combining the second and third phase images.     

Optimal iodine dose for 3-dimensional multidetector-row CT angiography of the liver

Purpose

To clarify the optimal iodine dose of contrast material for 3-dimensional multidetector-row CT angiography (3D-MDCTA) of the venous vasculature of the liver using volume rendering technique.

Materials and methods

This study included 103 patients who were randomly assigned to 5 contrast-enhanced MDCT protocol groups with different body-weight-tailored doses of contrast material: 500, 600, 630, 650, and 700 mgI/kg body weight. The arterial, portal, and hepatic parenchymal phases were obtained to evaluate enhancement values of the aorta, portal vein, and hepatic vein. Visualization of the portal and hepatic veins on the volume-rendering images of 3D-MDCTA was evaluated using a 5-point grade. Dunnett's test was used to compare the mean enhancement value and mean grades of image quality (700 mgI/kg dose group was control).

Results

The mean enhancement values of portal and hepatic vein in the group with 500 and 600 mgI/kg were significantly lower than those of the control group. During visual assessment, a significantly lower mean grades were observed in 500 mgI/kg groups for the portal vein, and 500 and 600 mgI/kg groups for hepatic vein. There were no significant intergroup differences in mean enhancement values and visual assessment among the groups using 630 mgI/kg or more.

Conclusion

Iodine doses of 630 mgI/kg was recommended for 3D-MDCTA.     

静脉留置针在CT及MRI对比剂注射中的应用

目的研究静脉留置针在CT,MRI对比剂注射中的应用并和常规头皮静脉针穿刺比较,以及观察拔针后两种按压方式对提高注射成功率和减少局部出血的效果。方法将502例运用高压注射器注射对比剂的增强患者分成留置针和头皮静脉针两组,观察比较对比剂外渗情况。然后,再在头皮针组内随机选120例分两组在拔针后将棉签分别垂直和平行于血管走行按压在血管上（A法和B法）,比较局部出血情况。结果留置针注射对比剂外渗的发生率（0．57％）低于头皮静脉针组对比剂外渗的发生率（3．6％）;A,B两种按压方式局部出血的发生率相差13．3％。结论在CT,MRI增强造影运用留置针进行注射和拔针后棉签平行于血管走行按压可有效减少局部出血及其他不良反应,值得推广。     

Tools of the trade for CTA: MDCT scanners and contrast medium injection protocols

The introduction of multi-detector row computed tomography (MDCT) scanners in 1998 ushered in new advances in CT angiography (CTA). The subsequent expansion of MDCT scanner capabilities, coupled with advances in understanding of contrast medium (CM) dynamics, has further improved the clinical availability and consistency of CTA. We will review recent advances in CT scanner technology and discuss early CM dynamics. Specifically, we describe an approach tailored to the available scanner technology and to patient size aimed at providing consistently robust CTA studies across all vascular territories. A rational method to design combined CTA scan/injection protocols to facilitate this goal will be described. Our current experience with a simplified protocol for CTA with 64-MDCT will also be explained.     

Phase‐based arterial input function measurements for dynamic susceptibility contrast MRI

In dynamic susceptibility contrast perfusion MRI, arterial input function (AIF) measurements using the phase of the MR signal are traditionally performed inside an artery. However, phase‐based AIF selection is also feasible in tissue surrounding an artery such as the middle cerebral artery, which runs approximately perpendicular to B₀ since contrast agents also induce local field changes in tissue surrounding the artery. The aim of this study was to investigate whether phase‐based AIF selection is better performed in tissue just outside the middle cerebral artery than inside the artery. Additionally, phase‐based AIF selection was compared to magnitude‐based AIF selection. Both issues were studied theoretically and using numerical simulations, producing results that were validated using phantom experiments. Finally, an in vivo experiment was performed to illustrate the feasibility of phase‐based AIF selection. Three main findings are presented: first, phase‐based AIF selections are better made in tissue outside the middle cerebral artery, rather than within the middle cerebral artery, since in the latter approach partial‐volume effects affect the shape of the estimated AIF. Second, optimal locations for phase‐based AIF selection are similar for different clinical dynamic susceptibility contrast MRI sequences. Third, phase‐based AIF selection allows more locations in tissue to be chosen that show the correct AIF than does magnitude‐based AIF selection. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.