Enhancement pattern of hilar cholangiocarcinoma: Contrast-enhanced ultrasound versus contrast-enhanced computed tomography

Objective

To compare the enhancement pattern of hilar cholangiocarcinoma on contrast-enhanced ultrasound (CEUS) with that on contrast-enhanced computed tomography (CECT).

Methods

Thirty-two consecutive patients with pathologically proven hilar cholangiocarcinomas were evaluated by both low mechanical index CEUS and CECT. The enhancement feature of the tumor, portal vein infiltration, and lesion conspicuity on them was investigated.

Results

In the arterial phase, the numbers of the lesions showing hyperenhancement, isoenhancement, and hypoenhancement, were 14 (43.8%), 14 (43.8%), and 4 (12.6%), on CEUS, and 12 (37.5%), 9 (28.1%), and 11 (34.4%), on CECT (P = 0.162). In portal phase, the numbers of the lesions showing hypoenhancement, isoenhancement, and hyperenhancement were 30 (93.8%), 1 (3.1%), and 1 (3.1%), on CEUS, and 23 (71.9%), 8 (25.0%), and 1 (3.1%), on CECT (P = 0.046). The detection rates for portal vein infiltration were 84.2% (16/19) for baseline ultrasound, 89.5% (17/19) for CEUS, and 78.9% (15/19) for CECT (all P > 0.05 between every two groups). CEUS significantly improved the lesion conspicuity in comparison with CECT. CEUS and CECT made correct diagnoses in 30 (93.8%) and 25 (78.1%) lesions prior to pathological examination (P = 0.125).

Conclusion

The enhancement pattern of hilar cholangiocarcinoma on CEUS was similar with that on CECT in arterial phase, whereas in portal phase hilar cholangiocarcinoma shows hypoenhancement more likely on CEUS. CEUS and CECT lead to similar results in evaluating portal vein infiltration and diagnosis of this entity.     

Diagnostic accuracy of phase-inversion tissue harmonic imaging versus fundamental B-mode sonography in the evaluation of focal lesions of the kidney

OBJECTIVE: We compared phase-inversion tissue harmonic imaging with fundamental B-mode sonography in the evaluation of focal lesions of the kidney. SUBJECTS AND METHODS: For our prospective study, 114 patients underwent sonography of the kidneys in both modes, fundamental B-mode sonography and phase-inversion tissue harmonic imaging, in a randomly chosen scanning order. Imaging parameters were standardized. Sonographic diagnoses were made under real-time conditions by the examining radiologist. All sonographic diagnoses were compared with a diagnostic reference modality: contrast-enhanced CT, contrast-enhanced MR imaging, or histopathology. Three radiologists different from the examiners evaluated overall image quality, lesion conspicuity, and fluid-solid differentiation for both modalities using hard-copy images. RESULTS: In 70 patients, fundamental B-mode sonography as the first technique depicted 73 of 111 lesions 10 mm or larger and enabled 71 lesions to be correctly characterized (sensitivity, 65.8%; accuracy, 64.0%). As the first mode, phase-inversion tissue harmonic imaging depicted 57 of 65 focal lesions and enabled 54 lesions to be accurately classified in 44 patients (sensitivity, 87.7%; accuracy, 83.1%). The differences in sensitivity and accuracy were statistically significant (95% confidence interval). For overall image quality, lesion conspicuity, and fluid-solid differentiation phase-inversion harmonic imaging was superior to fundamental B-mode sonography (p < 0.0001). CONCLUSION: Phase-inversion tissue harmonic imaging is superior to fundamental B-mode sonography in the sonography of focal kidney lesions because phase-inversion tissue harmonic imaging has better overall image quality, lesion conspicuity, and fluid-solid differentiation. In six cases, phase-inversion tissue harmonic imaging added crucial diagnostic information that changed patient management.     

Analysis of comparative performance of CEUS and CECT/MR LI-RADS classification: Can CEUS dichotomize LI-RADS indeterminate lesions on CT or MRI?

PurposeTo study the comparative performance of contrast-enhanced ultrasound (CEUS) and contrast-enhanced CT or MRI (CECT/MR) in evaluating liver lesions using the LI-RADS guidelines.MethodsRetrospective analysis of radiology database from July 2010 to April 2017 revealed 228 patients who had CECT/MR and CEUS. Patients at risk of hepatocellular carcinoma (HCC), had contemporaneous CEUS and CECT/CEMR studies within 3 months and adequate follow up were included; reviewed (2 reviewers) and graded according to the 2017 CEUS and 2018 CECT/MR LI-RADS guidelines. Reference standard was multidisciplinary clinical decisions, histology or follow-up imaging.ResultsThe study cohort consisted of 45 patients with 46 lesions. HCC were significantly larger than non-malignant (mean sizes of 2.5 and 1.4 cm, respectively, p<0.001). Intraclass correlation coefficient for CEUS review (0.941) was higher than of CECT/MR review (0.643). Mean area-under-ROC curve (AUC) for CEUS (0.994) was significantly higher than of CECT/MR (0.760) for all lesions (p=0.01). For lesions scored LR-3 by CECT/MR, the AUC was significantly higher for CEUS (0.978) than CECT/MR (0.500) (p<0.001). Twenty-one (of 27) lesions, classified LR-3 or LR-4 by CECT/MR were upgraded by CEUS and 20 were found to be HCC. Six lesions that were LR-3 on both CECT/MR and CEUS were found to be non-malignant. There was good concordance for LR-5 lesions between both techniques.ConclusionCEUS is useful for reassessment of lesions with intermediate probability (LR-3) or probable for HCC (LR-4) on CECT/MR. Lesions upgraded by CEUS tend to be HCC. Lesions that remain LR-3 on CEUS tend to be non-malignant.     

超声造影在诊断乳腺癌肝转移中的应用价值

目的:探讨超声造影(CEUS)在诊断乳腺癌肝转移中的应用价值。材料和方法:对89例常规超声疑似乳腺癌肝转移者行CEUS和增强CT(CECT)后,采用穿刺活检、手术病理、影像学随访超过半年临床最后确诊。结果:89例常规超声疑似乳腺癌肝转移经CEUS及相关检查临床最后确诊为良性41例。48例乳腺癌肝转移经CEUS明确诊断47例。CEUS对乳腺癌肝转移诊断的敏感度为97.92%(47/48),假阴性率为2.08%(1/48),特异度为100%(41/41),阳性预测值为100%(47/47),阴性预测值为97.62%(41/42)。经CEUS发现新增转移病灶10例。CEUS从常规超声53.93%(48/89)的诊断准确度提高到98.88%(88/89)。CEUS对乳腺癌肝转移的诊断率与CECT在统计学上无差异(P=0.833)。结论:CEUS能发现乳腺癌较小的肝转移灶,提高了超声诊断乳腺癌肝转移的鉴别能力和准确度。     

乏血供肝转移瘤超声造影与CT增强扫描的对比研究

目的:探讨乏血供肝转移瘤超声造影(CEUS)血流灌注特点及其与CT增强扫描的差异。方法:选择CT增强扫描提示为乏血供肝转移瘤的12例(20个病灶)行常规超声及造影检查。二维超声观察病灶的部位、大小、边界、内部回声;CEUS观察病灶各期的强化模式、强化水平,重点观察动脉期(0～25s),并与CT增强扫描进行比较。结果:12例共20个病灶,CT增强扫描动脉期:1个病灶轻度增强(5%),11个环形强化(55%),2个不均匀强化(10%),6个无强化(30%)。CEUS动脉期:11个病灶弥漫性均匀强化(55%),7个环形强化(35%),2个不均匀强化(10%)。结论:CEUS显示乏血供肝转移瘤动脉期血供情况优于CT增强扫描;对于CT增强扫描怀疑为乏血供肝转移瘤患者,尤其是单发转移瘤,CEUS检查对临床诊断和治疗有很大帮助。     

超声造影在肝癌病灶诊断及引导射频消融治疗中的应用价值

目的探讨超声造影（CEUS）在肝恶性肿瘤病灶诊断及引导射频消融（RFA）治疗中的应用价值。方法对经病理确诊并经RFA治疗的56例肝癌患者资料进行回顾性分析,术前比较增强cT、普通彩色多普勒超声（二维＋多普勒）和超声造影对肝癌（原发及转移）的检出率,观察二维及超声造影病灶图像差异及特点。对普通彩色多普勒超声引导组（62个病灶）和超声造影引导组（so个病灶）在术中引导RFA的消融效果进行对比并利用超声造影观察射频消融术后疗效。结果56例肝癌患者,112个病灶（原发灶36个,转移灶76个）。超声造影对肝癌病灶检出率为94．6％（106／112）,增强CT对肝癌病灶检出率为96．4％（108／112）,两者检出率比较差异无统计学意义0（x^2=0．42,P〉O．05）。普通彩色多普勒超声对肝癌病灶检出率为74．1％（83／112）,其与超声造影的检出率差异有统计学意义0（2=16,P〈0．05）。在普通彩色多普勒超声引导下进行RFA完全消融率为69％（43／62）,超声造影引导下完全消融率为84％（42／50）,两者的完全消融率差异无统计学意义舒=1．6,P〉0．05）。结论超声造影在RFA术前对肝脏肿瘤的诊断,术中对病灶的准确定位及实时引导穿刺,术后对手术疗效的随访观察都具有重要的应用价值。     

超声造影对肝脏局灶性病变的定量分析及临床价值研究

目的探讨超声造影对肝脏局灶性病变的定量分析结果及临床价值。方法选取2017年1月~2019年1月100例肝脏病变患者,根据病变性质分为恶性组(n=67)和良性组(n=33)。分别进行实时超声造影及彩色多普勒超声检查。应用时间-强度曲线(TIC曲线)分析超声造影图像。结合TIC曲线形态及由TIC曲线得到的病灶的始增时间、达峰时间、峰值强度、峰值减半时间,分析良恶性病灶造影灌注特点。分析肝癌病灶超声造影类型与彩色多普勒超声血流分级的肿瘤大小关系。结果恶性组TIC的始增时间、达峰时间、峰值减半时间均明显早于良性组,峰值强度明显强于良性组,差异均有统计学意义(P<0.01)。随着血流分级的升高,超声造影类型的环绕型、网络型比率有降低趋势,混合型、树枝型的比率有升高趋势。血流分级与超声造影类型间存在明显相关性(χ²=21.647,P=0.010)。肿瘤≤3 cm的病灶超声造影类型以环绕型和网络型为主。肿瘤> 3 cm的病灶超声造影类型以混合型和树枝型为主。肿瘤大小与超声造影类型有明显相关性(Z=-3.768,P=0.000)。肿瘤分化程度与超声造影类型间存在明显相关性(χ²=35.950,P=0.000)。结论实时超声造影能显示肝脏局灶性病变内部血流灌注情况、判断肿瘤大小及分化程度,根据造影增强方式和TIC曲线参数能够有效鉴别肝脏良恶性病灶。     

Detection and characterization of focal liver lesions with contrast-enhanced ultrasonography in patients with hepatitis C-induced liver cirrhosis

Background: Hepatitis C virus (HCV)-associated liver cirrhosis provides a major preneoplastic condition for hepatocellular carcinoma (HCC). Ultrasonography (US) is usually used for screening of HCC, but needs improvement.

Purpose: To assess whether use of a second-generation ultrasound contrast agent can improve characterization of focal liver lesions and detection of HCC in HCV-infected patients with liver cirrhosis.

Material and Methods: In total, 96 US studies in 49 HCV-infected patients with liver cirrhosis were performed. The patients were first examined with a baseline US. After this, a diagnostic decision was made and recorded. The patients were then re-examined with contrast-enhanced ultrasound (CEUS), and the diagnostic triage was repeated. The patients were followed up for at least 1 year.

Results: On baseline US, indeterminate focal lesions were found in 27 examinations. After CEUS, a confident diagnosis of HCC was made in eight of these examinations. In an additional eight US examinations, diagnosis of regenerative/dysplastic noduli was established. In one patient with no detectable focal lesion at baseline examination, an indeterminate malignant lesion was detected with CEUS. This lesion was further investigated with computed tomography and diagnosed as HCC.

Conclusion: Our study indicates that the use of CEUS significantly improves diagnostic confidence. CEUS improves the detection of HCC in patients with HCV-induced liver cirrhosis. Also, CEUS makes it possible to rule out malignancy in many cases where baseline US shows indeterminate focal lesions. In low-endemic countries, the use of CEUS in screening for HCC may be considered.     

Enhancement pattern of hepatocellular carcinoma: comparison of real-time contrast-enhanced ultrasound and contrast-enhanced computed tomography

We compared the enhancement pattern of 98 hepatocellular carcinoma nodules in 92 patients on contrast-enhanced ultrasound (CEUS) and contrast-enhanced computed tomography (CECT). Contrast-enhanced ultrasound was performed with SonoVue and a low mechanical index method. In arterial phase, 98 nodules were hyperenhancing on CEUS and 94 on CECT. In portal phase, 82 nodules were hypoenhancing on CEUS and 83 on CECT. Peripheral thin-rim-like enhancement was exhibited in 30 nodules on CEUS and 31 on CECT. Intratumoral vessels were visualized in 94 nodules on CEUS and 36 on CECT.     

Characterization of focal liver lesions with a new ultrasound contrast agent using continuous low acoustic power imaging: comparison with contrast enhanced spiral CT

PURPOSE: To evaluate the concordance of the enhancement patterns of a new ultrasound contrast agent (SonoVue) with those obtained with dual-phase contrast-enhanced spiral CT (CE-CT) in the characterization of focal liver lesions (FLLs). MATERIALS AND METHODS: Sixty-two patients with focal liver lesions discovered at ultrasound and also studied with CECT underwent contrast-enhanced ultrasound using continuous low acoustic power imaging after receiving a 2.4 ml bolus of the new US contrast agent SonoVue, consisting of a dispersion of sulphur hexafluoride microbubbles. The examinations were made using ATL HDI-5000, Acuson SEQUOIA and Aloka 5500 Prosound ultrasound systems with 5.2 MHz curved-array probes. The concordance between US and CE-CT images was evaluated on site by two radiologists blinded to CT RESULTS: The FLLs were assessed in the arterial (20 s after CM injection), portal (after 45-60 s) and late (after 120 s) phases for: 1) presence/absence of enhancement 2) distribution of enhancement (homogenous or target distribution, centripetal or centrifugal flow, and other), 3) qualitative enhancement pattern (hyperechoic, hypoechoic, or isoechoic) versus normal liver parenchyma. RESULTS: The concordance between SonoVue-enhanced US and CE-CT was 85%. Moreover during portal venous phase with CEUS it was possible to differentiate between malignancy or benignity of 91% of lesions. CONCLUSIONS: The preliminary data obtained in this study suggest that continuous low acoustic power imaging and contrast-enhanced US show similar results to CT in contrast distribution and contrast enhancement patterns.     

Focal liver lesions: can SonoVue-enhanced ultrasound be used to differentiate malignant from benign lesions?

OBJECTIVE: To evaluate whether contrast-enhanced ultrasound (CEUS) with SonoVue could differentiate malignant focal liver lesions (FLLs) from benign lesions and provide lesion type diagnoses. MATERIALS AND METHODS: Four hundred fifty-six patients with 554 FLLs were examined by CEUS with SonoVue using low mechanical index, nonlinear imaging techniques. Each lesion was characterized by 2 independent off-site readers as malignant or benign and given specific lesion type diagnosis, if possible, both at baseline ultrasound (US) and after SonoVue administration (CEUS). The final diagnosis was achieved by histopathology obtained from biopsy or surgical specimens, or by typical manifestation on contrast-enhanced CT or MRI. RESULTS: The diagnostic accuracies of the 2 readers were 41.9% and 35.2% for baseline US, which improved significantly to 87.2% and 87.9% for CEUS (P < 0.05). Interreader agreement also increased with CEUS compared with baseline US (ê value changed from 0.49 to 0.77). The accuracy for lesion type diagnosis was 38.4% and 32.5% for baseline US, which increased to 77.6% and 78.0% for CEUS (P < 0.05). CONCLUSIONS: CEUS with SonoVue improves differentiation between malignant and benign FLLs, and also provides improved lesion type (differential) diagnosis.     

Focal nodular hyperplasia: spoke-wheel arterial pattern and other signs on dynamic contrast-enhanced ultrasonography

OBJECTIVE: To evaluate the prevalence of spoke-wheel pattern and typical symptoms of focal nodular hyperplasia (FNH) by means of dynamic contrast-enhanced ultrasonography (CEUS) in relation to lesion size. METHODS: Twenty-eight patients were included in the trial, in whom, based on the CEUS, we raised suspicion of hypervascularized liver lesion; there were 30 lesions altogether. The final diagnosis of FNH was verified by means of CT, MRI or lesion biopsy. Majority of patients (26) were females, compared to 2 male, with average age of 33.3 years. Average lesion size was 45.6 mm. Besides the ultrasound examination, we used also "blood pool" ultrasound contrast agent of second generation, sulphur hexafluoride (BR1); we evaluated enhancement of the lesion until the late stage-within 5 min from application. RESULTS: In lesions larger than 3 cm (n=20), stellate vascular enhancement was found in 19 cases (95.0%) early in arterial phase. As for lesions smaller than 3 cm (n=10), spoke-wheel pattern was observed only in 3 cases (30%) and lesions smaller than 2 cm practically did not show this phenomenon at all (n=1; 17%). Generally, symptom of spoke-wheel pattern was observed in 22 cases, i.e. in 73.3%. In total, central scar was present in 63.3% (n=19) of cases. In lesions larger than 3 cm, it was present in 85.0% (n=17), in lesions smaller than 3 cm in 20% (n=2). CONCLUSION: Contrast-enhanced ultrasonography can be the final diagnostic method for FNH larger than 3 cm which has typical spoke-wheel vessel structure on CEUS. If this phenomenon is not present and the central scar is not visible, specific diagnosis of FNH cannot be based solely on CEUS findings.     

Real-time contrast-enhanced ultrasound of the spleen: examination technique and preliminary clinical experience

PURPOSE: To report our preliminary experience in the evaluation of the spleen using a real-time contrast-specific ultrasound module in combination with a second-generation contrast agent. MATERIALS AND METHODS: In a 7-month period, 55 patients (34 males and 21 females, aged 5-77 years) with spleen disorders were evaluated by means of contrast-enhanced ultrasound. Two patients were studied because of baseline evidence of an accessory spleen and both underwent ultrasound follow-up. Twenty-five patients were studied for abdominal trauma and results were correlated with those of helical CT. Three patients were examined for suspected splenic infarction and for all CT correlation was obtained. Finally, twenty-five subjects were examined for focal diseases, such as lymphomas (17 cases) and focal lesions (8 cases); contrast-enhanced US results were correlated with those of CT (8 cases), MRI (2 cases), ultrasound follow-up (8 cases), biopsy (2 cases) or splenectomy (1 case). After an initial baseline study, the contrast-enhanced examinations were carried out using a dedicated unit equipped with a continuous contrast-specific module at low acoustic pressure. The examination started immediately after rapid contrast injection and lasted approximately 4 minutes. In the comparison between baseline and contrast-enhanced ultrasound, the following aspects were considered: detection rate of parenchymal changes, lesion extent (equal to CT, under- or overestimated), and lesion conspicuity (lesion-to-parenchyma gradient, from 0 = absent to 3 = high). RESULTS: In the 2 patients with accessory spleen, an enhancement very similar to that of the adjacent parenchyma was present and a small vascular pedicle was noted. Among the trauma patients, 18 had a direct splenic injury and one showed splenic contraction and hypoperfusion due to shock. In 74% of cases, a peritoneal effusion was demonstrated both with baseline and contrast-enhanced ultrasound; perisplenic blood collections (58% of cases) were identified in 42% of patients by both baseline and contrast-enhanced ultrasound; post-traumatic infarction was always revealed by contrast-enhanced ultrasound (11% of cases) but never by baseline ultrasound; parenchymal injuries were detected with a sensitivity of 63% by baseline ultrasound and a sensitivity of 89% by contrast-enhanced ultrasound. Moreover, contrast-enhanced ultrasound revealed findings undetectable on conventional ultrasound: global splenic hypoperfusion in 2 cases (due to shock in one and pedicle avulsion in the other), intraparenchymal contrast collections in 21% of positive cases (as confirmed by CT), extrasplenic contrast leakage in 1 of 2 cases demonstrated by CT. Of the 3 cases of splenic infarction, baseline sonography only only identified two, whereas the contrast-enhanced examination clearly identified three. Contrast-enhanced ultrasound revealed 35 of 39 focal lesions in patients studied for Hodgkin's disease and splenic focal lesions. Baseline ultrasound had a lower sensitivity (23 lesions). Lesion extension shown by contrast-enhanced sonography was equivalent to that provided by standard methods in 88% of cases (underestimated in 9% and overestimated in 3%); baseline US correctly estimated lesion size in 52% of cases, under- and overestimating them in 35% and 13% of cases, respectively. Lesion conspicuity was graded as 1 (low) in 16%, 2 (moderate) in 67%, and 3 (high) in 17% of the cases identified by enhanced sonography. Baseline ultrasound was less effective: conspicuity was graded as 1 in 42%, 2 in 39%, and 3 in 19% of cases. CONCLUSIONS: The spleen is the ideal organ to be studied with second-generation contrast media due to its superficial location, high vascularity, small size and homogeneous texture. Contrast-enhanced ultrasound is a simple, poorly-invasive and accurate tool for the evaluation of splenic disorders. If our data are confirmed, it will be possible to reduce the use of more complex technologies such as CT and MRI.     

Phase-inversion sonography during the liver-specific late phase of contrast enhancement: improved detection of liver metastases

OBJECTIVE: The purpose of our study was to assess whether phase-inversion sonography during the late, liver-specific phase of contrast enhancement using Levovist improves the detection of hepatic metastases relative to unenhanced conventional B-mode sonography. SUBJECTS AND METHODS: Sixty-two patients were studied with unenhanced B-mode sonography and phase-inversion sonography 2.5 min after the injection of Levovist. All patients underwent one reference examination (CT, MR imaging, or intraoperative sonography). The conspicuity, number, size, and distribution of metastases before and after contrast administration as judged by a sonographer (who was unaware of other imaging findings) were compared with each other and with reference imaging. RESULTS: The conspicuity of metastases was improved by contrast-enhanced phase inversion in 94% of patients. Thirty-nine patients showed metastases on reference imaging; 36 of these were positive on baseline sonography and 38 on phase-inversion sonography. Phase-inversion sonography showed more reference imaging-confirmed metastases than baseline sonography in 28 patients (45%). The average number of confirmed metastases per patient was 3.06 for baseline sonography and 5.42 for contrast-enhanced phase-inversion sonography (p < 0.01). The average sensitivity for detecting individual metastases improved from 63% to 91%. Metastases of less than 1 cm were shown in 14 patients on baseline sonography, in 24 patients on phase-inversion sonography, and in 26 on reference imaging. Both sonographic techniques showed false-positive lesions in six patients. CONCLUSION: Contrast-enhanced phase-inversion sonography in the liver-specific phase of contrast enhancement using Levovist provides a marked improvement in the detection of hepatic metastases relative to unenhanced conventional sonography, without loss of specificity. Phase-inversion sonography was particularly advantageous in detecting small metastases and may be a competitive alternative to CT and MR imaging.     

Characterization of hypoechoic focal hepatic lesions in patients with fatty liver: diagnostic performance and confidence of contrast-enhanced ultrasound

The objective of this study was to assess the diagnostic performance of contrast-enhanced ultrasound (CEUS) to characterize hypoechoic focal hepatic lesions (HFHL) in fatty liver (FL). A study group of 105 patients with FL and 105 HFHLs (52 malignant and 53 benign) underwent CEUS after SonoVue administration. Two blinded readers independently reviewed baseline ultrasound (US) and CEUS scans and classified each lesion as malignant or benign on a five-point scale of confidence, and recorded whether further imaging work-up was needed. Sensitivity, specificity, areas under the receiver operating characteristic (ROC) curve (A (z)), and interobserver agreement were calculated. We observed that the diagnostic confidence improved after reviewing CEUS scans for both readers (A (z)=0.706 and 0.999 and A (z)=0.665 and 0.990 at baseline US and CEUS, respectively; p<0.0001). Inter-reader agreement increased (weighted k=0.748 at baseline US vs. 0.882 at CEUS). For both readers, after CEUS, the occurrence of correctly characterized lesions increased (from 27/105 [27.5%] to 94/105 [89.5%], and from 19/105 [18.1%] to 93/105 [88.6%], respectively; p<0.0001) and the need for further imaging decreased (from 93/105 [88.6%] to 26/105 [24.8%], and from 96/105 [91.4%] to 40/105 [38.1%], respectively; p<0.0001). We conclude that CEUS improves the diagnostic performance of radiologists in the characterization of HFHLs in FL and reduces the need for further imaging work-up.     

11C-5-hydroxytryptophan positron emission tomography after radiofrequency ablation of neuroendocrine tumor liver metastases

AimThe aim was to assess the feasibility of ¹¹C-5-hydroxy-tryptophan positron emission tomography (¹¹C-5-HTP-PET) in the follow-up after radiofrequency ablation (RFA) of liver metastases from neuroendocrine tumors (NETs).BackgroundContrast-enhanced computed tomography (CECT) and contrast-enhanced ultrasound (CEUS) are commonly used to evaluate the liver after RFA of NETs. In general, ¹¹C-5-HTP-PET is more sensitive in the visualization of NETs, but no studies have investigated its role after RFA.MethodsSix consecutive patients with liver metastases from NETs were subjected to RFA treatment. All patients underwent baseline imaging before RFA and on two occasions (1–2 and 6–11 months) after RFA. The imaging consisted of ¹¹C-5-HTP-PET, CEUS and CECT on all three occasions.ResultsThirty RFA areas were evaluated, and residual tumors (RTs) were depicted in eight areas (22%). ¹¹C-5-HTP-PET depicted RTs after RFA with maximum sensitivity (100%) and specificity (100%), using radiological follow-up as the gold standard. ¹¹C-5-HTP-PET detected five out of eight RTs earlier than CECT or CEUS. In general, the sensitivity of ¹¹C-5-HTP-PET exceeded that of CECT and CEUS for early visualization of NET liver metastases.Conclusion¹¹C-5-HTP-PET can be used in the follow-up after RFA for the purpose of detecting RT, and it provides additional information to CEUS and CECT by detecting new lesions.     

Dual contrast enhanced magnetic resonance imaging of the liver with superparamagnetic iron oxide followed by gadolinium for lesion detection and characterization

AIM: Iron oxide contrast agents are useful for lesion detection, and extracellular gadolinium chelates are advocated for lesion characterization. We undertook a study to determine if dual contrast enhanced liver imaging with sequential use of ferumoxides particles and gadolinium (Gd)-DTPA can be performed in the same imaging protocol. MATERIALS AND METHODS: Sixteen patients underwent dual contrast magnetic resonance imaging (MRI) of the liver for evaluation of known/suspected focal lesions which included, metastases (n = 5), hepatocellular carcinoma (HCC;n = 3), cholangiocharcinoma(n = 1) and focal nodular hyperplasia (FNH;n = 3). Pre- and post-iron oxide T1-weighted gradient recalled echo (GRE) and T2-weighted fast spin echo (FSE) sequences were obtained, followed by post-Gd-DTPA (0.1 mmol/kg) multi-phase dynamic T1-weighted out-of-phase GRE imaging. Images were analysed in a blinded fashion by three experts using a three-point scoring system for lesion conspicuity on pre- and post-iron oxide T1 images as well as for reader's confidence in characterizing liver lesions on post Gd-DTPA T1 images. RESULTS: No statistically significant difference in lesion conspicuity was observed on pre- and post-iron oxide T1-GRE images in this small study cohort. The presence of iron oxide did not appreciably diminish image quality of post-gadolinium sequences and did not prevent characterization of liver lesions. CONCLUSION: Our results suggest that characterization of focal liver lesion with Gd-enhanced liver MRI is still possible following iron oxide enhanced imaging.Kubaska, S.et al. (2001). Clinical Radiology, 56, 410-415 Copyright 2001 The Royal College of Radiology.     

Enhancement patterns of intrahepatic cholangiocarcinoma: comparison between contrast-enhanced ultrasound and contrast-enhanced CT

The aim of this study was to compare the enhancement pattern of intrahepatic cholangiocarcinoma (ICC) on contrast-enhanced ultrasound (CEUS) with that on contrast-enhanced computed tomography (CECT). 40 pathologically proven ICC lesions in 40 patients were evaluated retrospectively with both CEUS and CECT. The enhancement level and pattern in the dynamic phases on both CEUS and CECT were analysed. The diagnostic results of CEUS and CECT before pathological examination were also recorded. During arterial phases, the number of lesions that appeared as (i) peripheral irregular rim-like hyperenhancement, (ii) diffuse heterogeneous hyperenhancement, (iii) diffuse homogeneous hyperenhancement and (iv) diffuse heterogeneous hypoenhancement were 19 (47.5%), 9 (22.5%), 5 (12.5%) and 7 (17.5%), respectively, on CEUS, and 22 (55.0%), 3 (7.5%), 2 (5.0%) and 13 (32.5%), respectively, on CECT (p = 0.125). In the portal phase, the number of lesions showing hyperenhancement and hypoenhancement were 1 (2.5%) and 39 (97.5%), respectively, on CEUS, and 15 (37.5%) and 25 (62.5%) on CECT (p = 0.0001). CEUS made a correct diagnosis in 32 (80.0%) lesions before pathological examination; CECT made a correct diagnosis in 27 (67.5%) lesions (p = 0.18). In conclusion, the enhancement patterns of ICC on CEUS were consistent with those on CECT in the arterial phase, whereas in the portal phase ICC faded out more obviously on CEUS than on CECT. CEUS had the same accuracy as CECT in diagnosing ICCs, and so can be used as a new modality for the characterization of ICC.     

初探超声造影基于LI-RADS分类标准诊断肝细胞癌的可行性

目的：探讨基于肝脏影像报告和数据管理系统（LI-RADS）的超声造影检查诊断肝细胞癌（HCC）的可行性。方法：回顾性分析108例有肝癌高风险的单发肝脏病变患者的超声造影资料,并基于LI-RADS分类标准对肝脏病变进行分析评估,并与病理或临床诊断结果相对照。结果：108个病灶中LI-RADS 1～5类病灶共106个：1类和2类病灶19个,临床客观诊断结果均为良性（阴性预测值为100％）;3类病灶3个;22个4类病灶中17个为 HCC（阳性预测值为77．3％）;62个5类病灶中有54个为 HCC（阳性预测值为87．1％）。受试者工作特征（ROC）曲线下面积为0．83（P＜0．001）。若将LI-RADS 3～5类病灶归为阳性,基于LI-RADS的超声造影检查对HCC的诊断符合率为83．9％（92／106）,敏感度为100％（73／73）,特异度为57．6％（19／33）,阳性预测值为83．9％（73／87）,阴性预测值为100％（19／19）;若将 LI-RADS 3类病灶排除、1～2类病灶归为阴性、4～5类病灶归为阳性,则诊断符合率为87．4％（90／103）,敏感度为100％（71／71）,特异度为59．4％（19／32）,阳性预测值为84．5％（71／84）,阴性预测值为100％（19／19）。结论：超声造影检查中应用LI-RADS分类标准诊断 HCC具有一定的可行性。     

超声造影与增强CT对肾癌的诊断分析

目的:本研究旨在比较超声造影(CEUS)和增强CT(CECT)在肾癌病灶中的诊断价值,探讨超声造影在肾癌的诊断价值。方法:对54例患者临床诊断为肾脏内占位性病灶进行CEUS和CECT检查,通过分析病灶CEUS和CECT的特点,比较两种方法的诊断效能。结果:54个病灶中34个为肾脏恶性肿瘤,20个为肾脏良性病灶,CEUS和CECT诊断敏感性、特异性、准确性、阳性预测值、阴性预测值分别为97.05%、85.0%、92.59%、91.67%、94.44%与91.18%、80.00%、87.04%、88.57%、84.21%。两种方法诊断差异无统计学意义(P>0.05)。结论:分析比较CEUS和CECT在诊断肾癌过程中,两种方法诊断效能无明显差异,均能为临床诊断提供重要依据,但CEUS对微循环灌注方面及假包膜的观察优于CECT;CEUS定量评价肾肿瘤血管现处于动物实验阶段,临床上特异指标的找寻仍有待于进一步研究。