Can contrast-enhanced ultrasonography replace multidetector-computed tomography in the detection of liver metastases from colorectal cancer?

Purpose

To compare the sensitivity and specificity of contrast-enhanced ultrasonography (CEUS) and 4-slice multidetector-computed tomography (MDCT) in the detection of liver metastases in patients with colorectal cancer (CRC).

Materials and methods

Candidates for this prospective study were 461 consecutive patients referred to the Department of Colorectal Surgery, Aarhus University Hospital with primary or local recurrence of CRC. The patients underwent liver ultrasonography (US), CEUS, MDCT and intraoperative ultrasonography (IOUS). Fine-needle biopsy was performed on all suspicious lesions. The examinations were interpreted blindly and the combination of US, CEUS, biphasic MDCT, IOUS, follow up and biopsy was the gold standard.

Results

Three hundred and sixty-five patients were included. All patients had undergone preoperative US, CEUS and MDCT and 65.5% had received IOUS. The gold standard found liver metastases in 54 patients (14.8%). Multidetector CT found significantly more metastases than CEUS in 15 (28%) of the patients (p = 0.02). In a patient-by-patient analysis MDCT had a non-significantly higher sensitivity in the detection of liver metastases compared to CEUS (0.89 versus 0.80, p = 0.06). The specificity of CEUS (0.98) was slightly better than that of MDCT (0.94) (p = 0.02).

Conclusion

Multidetector CT found significant more metastases than CEUS, and MDCT had in patient-by-patient analysis a non-significant better sensitivity (p = 0.06) in detecting liver metastases in patients with CRC.     

Contrast enhanced ultrasound in the detection of liver metastases: a prospective multi-centre dose testing study using a perfluorobutane microbubble contrast agent (NC100100)

Objective

To conduct a dose testing analysis of perfluorobutane microbubble (NC100100) contrast-enhanced ultrasound (CEUS) to determine the optimal dose for detection of liver metastases in patients with extra-hepatic primary malignancy.

Methods

157 patients were investigated with conventional US and CEUS. CEUS was performed following intravenous administration of perfluorobutane microbubbles (using one dose of either 0.008, 0.08, 0.12 or 0.36 μL/kg body weight). Three blinded off-site readers recorded the number and locations of metastatic lesions detected by US and CEUS. Contrast enhanced CT and MRI were used as the “Standard Of Reference” (SOR). Sensitivity, specificity and accuracy of liver metastasis detection with US versus CEUS, for each dose group were obtained. Dose group analysis was performed using the Chi-square test.

Results

165 metastases were present in 92 patients who each had 1–7 lesions present on the SOR. Sensitivity of US versus CEUS (for all doses combined) was 38% and 67% (p?=?0.0001). The 0.12 dose group with CEUS (78%) had significantly higher sensitivity and accuracy (70%) compared to other dose groups (p?Conclusion The diagnostic performance of CEUS is dose dependent with the 0.12 μL/kg NC100100 dose group showing the greatest sensitivity and accuracy in detection of liver metastases.     

Contrast-enhanced ultrasonography in the follow-up of patients with hepatic metastases from breast carcinoma

PURPOSE: Oncological treatment planning relies on the evaluation of treatment response, which is defined by the change in size of measurable lesions. The purpose of this study was to evaluate the use of contrast-enhanced ultrasound (CEUS) to obtain a precise measurement of hepatic metastases in breast cancer patients with fatty-liver disease. MATERIALS AND METHODS: Twelve consecutive patients with 25 liver metastases from breast cancer and fatty liver disease, as defined by US criteria, were enrolled in this prospective study. All patients underwent conventional US, CEUS and multidetector computed tomography (MDCT), used as the gold standard for measuring the maximum diameter of lesions. Agreement between US, CEUS and MDCT measurements was analysed using Altman-Bland plots; 95% confidence limits were calculated for the difference among means. RESULTS: Mean diameter as measured by MDCT was 26.2 mm (range 11-83). US allowed measurement of 20/25 lesions. In 15 lesions, CEUS measurements were more accurate than those obtained by US. The difference among means was 1.1 mm with a 95% confidence interval (-9.2, 11.4) for US measurements and 0.6 mm with a 95% confidence interval (-2.0, 3.1) for CEUS. CONCLUSIONS: Our preliminary data show that CEUS can be used to obtain more accurate measurements than conventional US for the follow-up of patients with metastases in fatty liver.     

Performance of imaging modalities in diagnosis of liver metastases from colorectal cancer: A systematic review and meta‐analysis

Surgery of liver metastases can be effective, and the appropriate selection of surgical candidates relies first on imaging. Different techniques are available, but information on their relative performance is unclear. The aim of this overview is to assess the imaging modality performance in the diagnosis of colorectal cancer (CRC) liver metastases. MEDLINE and EMBASE were searched for articles published from January 2000 to August 2008. Eligible trials had to be conducted on patients with diagnosis/suspicion of CRC liver metastases, comparing more than two modalities among MRI, computed tomography (CT), positron emission tomography using fluoro‐18‐deoxyglucose (FDG‐PET), ultrasonography (US). Pooled estimates of sensitivity, specificity were calculated and pair‐wise comparisons were performed. Of 6030 screened articles, 25 were eligible. Sensitivity and specificity on a per‐patient basis for US, CT, MRI, and FDG‐PET were 63.0% and 97.6%, 74.8% and 95.6%, 81.1% and 97.2, and 93.8% and 98.7%, respectively. On a per‐lesion basis, sensitivity was 86.3%, 82.6%, 86.3%, and 86.0%, respectively. Specificity was reported in few studies. MRI showed a better sensitivity than CT in per‐patient (odds ratio [OR]: 0.69; 95% confidence interval [CI]: 0.47–0.99; P = 0.05) and in per‐lesion analysis (OR: 0.66; 95% CI: 0.55–0.80; P < 0.0001). In per‐lesion analysis, the difference was higher when liver‐specific contrast agents were administered. Available evidence supports the MRI use for the detection of CRC liver metastases. J. Magn. Reson. Imaging 2010;31:19–31. © 2009 Wiley‐Liss, Inc.     

Comparison of contrast-enhanced ultrasonography versus baseline ultrasound and contrast-enhanced computed tomography in metastatic disease of the liver: diagnostic performance and confidence

Aim: The aim of this study was to compare contrast-enhanced ultrasonography (CEUS) to baseline US and contrast-enhanced computed tomography (CT) in metastatic disease of the liver diagnosed or suspected by US during presurgical staging or postsurgical follow-up for primary malignancies. Materials and methods: Two hundred-fifty-three patients considered suitable for US due to the complete explorability of the liver and with one to five proven or suspected liver metastases at baseline US were included. All patients underwent US before and after microbubble injection, and multiphase contrast-enhanced CT. Independent panels of readers reviewed US and CT scans and recorded liver metastases according to a 5-grade scale of diagnostic confidence. Sensitivity, specificity (diagnostic performance) and area under the receiver operating characteristics (ROC) curve (diagnostic confidence) were calculated. Results: Reference standards revealed no metastases in 57/253, more than five in 59/253, and one to five in 137/253 patients. In patients with one to five metastases, CEUS versus baseline US revealed more metastases in 64/137 and the same number in 73/137 patients while CEUS versus CT revealed more metastases in 10/137, the same number in 99/137, and lower number in 28/137. Sensitivity, specificity, and area under ROC curve of CEUS (83%, 84%, 0.929, respectively) differed from baseline US (40%, 63%, 0.579, respectively; P<0.01) while did not differ from CT (89%, 89%, 0.945, respectively; P>0.05). Conclusion: CEUS improved liver metastases diagnosis in comparison with baseline US while it revealed similar diagnostic performance and confidence to contrast-enhanced CT in patients considered suitable for US and with proven or suspected liver metastases at baseline US.     

Improved detection of hepatic metastases with pulse-inversion US during the liver-specific phase of SHU 508A: multicenter study

PURPOSE: To compare conventional B-mode ultrasonography (US) alone with the combination of conventional B-mode US and contrast material-enhanced (SHU 508A) late-phase pulse-inversion US for the detection of hepatic metastases by using dual-phase spiral computed tomography (CT) as the standard of reference. MATERIALS AND METHODS: One hundred twenty-three patients underwent conventional US, US in the liver-specific phase of SHU 508A, and single-section spiral CT. US and CT images were assessed by blinded readers. Differences in sensitivity, specificity, and the number and smallest size of metastases at conventional and contrast-enhanced US were compared by using CT as the standard of reference. Lesion conspicuity was assessed objectively (quantitatively) and subjectively by one reader before and after contrast material administration. RESULTS: In 45 of 80 (56%) patients with metastases, more metastases were seen at contrast-enhanced US than at conventional US. In three of these patients, conventional US images appeared normal. The addition of contrast-enhanced US improved sensitivity for the detection of individual metastases from 71% to 87% (P <.001). On a patient basis, sensitivity improved from 94% to 98% (P =.44), and specificity improved from 60% to 88% (P <.01). Contrast enhancement improved the subjective conspicuity of metastases in 66 of 75 (88%) patients and the objective contrast by a mean of 10.8 dB (P <.001). Contrast-enhanced US showed more metastases than did CT in seven patients, and CT showed more than did contrast-enhanced US in one of 22 patients in whom an independent reference (magnetic resonance imaging, intraoperative US, or pathologic findings) was available. CONCLUSION: Contrast-enhanced US improved sensitivity and specificity in the detection of hepatic metastases.     

Contrast ultrasound in hepatocellular carcinoma at a tertiary liver center: First Indian experience

AIM: To assess the role of contrast enhanced ultrasonography in evaluation of hepatocellular carcinoma (HCC) at the first Indian tertiary liver center. METHODS: Retrospective analysis of contrast enhanced ultrasound (CEUS) examinations over 24 mo for diagnosis, surveillance, characterization and follow up of 50 patients in the context of HCC was performed. The source and indication of referrals, change in referral rate, accuracy and usefulness of CEUS in a tertiary liver center equipped with a 64 slice dual energy computer tomography (CT) and 3 tesla magnetic resonance imaging (MRI) were studied. Sonovue (BR1, Bracco, Italy, a second generation contrast agent) was used for contrast US studies. Contrast enhanced CT/MRI or both were performed in all patients. The findings were taken as a baseline reference and correlation was done with respect to contrast US. Contrast enhanced MRI was performed using hepatocyte specific gadobenate dimeglumine (Gd-BOPTA). Iomeron (400 mg; w/v) was used for dynamic CT examinations. RESULTS: About 20 (40%) of the examinations were referred from clinicians for characterization of a mass from previous imaging. About 15 (30%) were performed for surveillance in chronic liver disease; 5 (10%) examinations were performed for monitoring lesions after radiofrequency ablation (RFA); 3 (6%) were post trans-arterial chemoembolization (TACE) assessments and 3 (6%) were patients with h/o iodinated contrast allergy. About 2(4%) were performed on hemodynamically unstable patients in the intensive care with raised alpha fetoprotein and 2(4%) patients were claustrophobic. The number of patients referred from clinicians steadily increased from 12 in the first 12 mo of the study to 38 in the last 12 mo. CEUS was able to diagnose 88% of positive cases of HCC as per reference standards. In the surveillance group, specificity was 53.3% vs 100% by CT/MRI. Post RFA and TACE specificity of lesion characterization by CEUS was 100% in single/large mass assessment, similar to CT/MRI. For non HCC lesions such as regenerative and dysplastic nodules, the specificity was 50% vs 90% by CT/MRI. The positive role of CEUS in imaging spectrum of HCC included a provisional urgent diagnosis of an incidentally detected mass. It further led to a decrease in time for further management. A confident diagnosis on CEUS was possible in cases of characterization of an indeterminate mass, in situations where the patient was unfit for CT/MRI, was allergic to iodinated contrast or had claustrophobia, etc.CEUS was also cost effective, radiation free and an easy modality for monitoring post RFA or TACE lesions. CONCLUSION: CEUS is a valuable augmentation to the practice of ultrasonography, and an irreplaceable modality for confounding cases and interpretation of indeterminate lesions in imaging of HCC.     

Preoperative assessment of focal liver lesions: multidetector computed tomography challenges magnetic resonance imaging

PURPOSE: To investigate prospectively multidetector computed tomography (CT) (MDCT) and magnetic resonance (MR) imaging (MRI) in the preoperative assessment of focal liver lesions. MATERIAL AND METHODS: Multiphasic MDCT and conventional gadolinium-enhanced MRI were performed on 31 consecutive patients prior to hepatic surgery. All images were blindly analyzed as consensus reading. Lesion counts and their relation to vascular structures and possible extrahepatic disease were determined. The data from the MDCT and MRI were compared with the results obtained by intraoperative ultrasound (IOUS) and palpation. Histopathologic verification was available. RESULTS: At surgery, IOUS and palpation revealed 45 solid liver lesions. From these, preoperative MDCT detected 43 (96%) and MRI 35 (78%) deposits. MDCT performed statistically better than MRI in lesion detection (P=0.008). Assessment of lesion vascular proximity was correctly determined by MDCT in 98% of patients and by MRI in 87%. Statistical difference was found (P=0.002). IOUS and palpation changed the preoperative surgical plan as a result of extrahepatic disease in 8/31 (26%) cases. In MDCT as well in MRI extrahepatic involvement was suspected in two cases. CONCLUSION: MDCT was superior to MRI and nearly equal to IOUS in liver lesion detection and in the determination of lesion vascular proximity. However, both techniques fail to reliably detect extrahepatic disease.     

Focal liver lesions in cirrhosis: value of contrast-enhanced ultrasonography compared with Doppler ultrasound and α-fetoprotein levels

Purpose

This study aimed to evaluate the diagnostic value of contrast-enhanced ultrasound (CEUS) in characterising focal liver lesions in cirrhosis and to validate its use in lesions discovered during surveillance for hepatocellular carcinoma (HCC).

Materials and methods

Between 2003 and 2006, 128 cirrhotic patients with focal liver lesions at baseline ultrasonography (US) were studied by power colour Doppler US (Doppler US) and CEUS. Serum alpha-fetoprotein (AFP) levels were assessed in all patients. Fine-needle biopsy or other reference modalities such as computed tomography (CT), magnetic resonance imaging (MRI) or digital subtraction angiography (DSA) were used as the gold standard. The accuracy of baseline US, Doppler US, AFP levels, combined US and AFP levels and combined US, Doppler US and CEUS in characterising focal liver lesions was assessed. Diagnostic performance was compared using the McNemar test.

Results

A total of 207 focal liver lesions (101 benign and 106 malignant) were identified in 128 patients. CEUS sensitivity and specificity for lesion characterisation were 96.2% and 97.0%, respectively, whereas its positive and negative predictive values were 97.1% and 96.1%. CEUS accuracy was 96.6%, higher than that of US (72.0%), Doppler US (70.0%), AFP levels (65.7%), combined US and Doppler US (70.0%) and combined US and AFP levels (90.3%). The differences between US and CEUS were statistically significant (p<0.05).

Conclusions

CEUS can characterise focal liver lesions with 96.6% accuracy, a value higher than US, Doppler US, AFP levels, combined US and AFP levels and combined US and Doppler US. CEUS should therefore be used to characterise focal liver lesions detected during HCC surveillance of cirrhotic patients.     

超声综合检查和99Tc^m-硫胶体检测对乳腺癌前哨淋巴结的价值比较

目的探讨超声综合检查,包括经皮超声造影(CEUS)和常规超声检查,或99Tc^m-硫胶体前哨淋巴结检测对乳腺癌前哨淋巴结(SLN)的诊断价值比较。方法选取本院进行乳腺癌检查的患者120例为研究对象。患者均行常规超声、CEUS、99Tc^m-硫胶体前哨淋巴结检测,并以手术病理结果为标准,以ROC曲线分析常规超声、CEUS、99Tc^m-硫胶体前哨淋巴结检测对乳腺癌前哨淋巴结的诊断价值。结果120例乳腺癌患者中,经病理学诊断共检出168个淋巴结,其中转移性62个,非转移性106个。且以病理检查为标准,常规超声检查对乳腺癌前哨淋巴结转移的敏感度为69.4%,特异度为95.3%;CEUS检查的敏感度为83.9%,特异度为97.2%;99Tc^m-硫胶体检查的敏感度为88.7%,特异度为98.1%;三者联合检查的敏感度为93.5%,特异度为99.1%。另ROC曲线分析显示,常规超声、CEUS及99Tc^m-硫胶体检查及三者联合诊断的乳腺癌前哨淋巴结转移的AUC为0.823、0.905、0.934、0.963,联合诊断价值更高。结论CEUS、99Tc^m-硫胶体前哨淋巴结检测对乳腺癌前哨淋巴结的诊断价值均高于常规超声,且三者联合诊断敏感度、特异性更高。     

Radio-frequency ablation of hepatic metastases: postprocedural assessment with a US microbubble contrast agent--early experience.

PURPOSE: To evaluate contrast agent-enhanced ultrasonography (US) in the detection of untreated tumor after radio-frequency (RF) ablation of hepatic metastases. MATERIALS AND METHODS: Twenty patients with solitary colorectal liver metastases underwent percutaneous RF tumor ablation. Pre- and postablation imaging was performed with nonenhanced and enhanced color and power Doppler US and contrast-enhanced helical computed tomography (CT). Initial follow-up CT and US were performed 24 hours after ablation. The findings at US and CT were compared. RESULTS: Nonenhanced US demonstrated intratumoral signal in 15 of 20 metastases before ablation. This signal increased after contrast agent administration. Contrast-enhanced US performed 24 hours after ablation demonstrated residual foci of enhancement in three tumors, whereas no US signals were seen in any tumor on nonenhanced scans. CT demonstrated small (< 3-mm) persistent foci of residual enhancement in these three tumors and in three additional lesions that were not seen at US (US sensitivity, 50%; specificity, 100%; diagnostic agreement with CT, 85%). All six patients with evidence of residual tumor underwent repeat RF ablation. CONCLUSION: Contrast-enhanced US may depict residual tumor after RF application and thereby enable additional directed therapy. The potential reduction in treatment sessions and/or ancillary imaging procedures might increase the ease and practicality of percutaneous ablation of focal hepatic metastases.     

Role of multidetector CT and FDG-PET/CT in the diagnosis of local and distant recurrence of resected rectal cancer

PURPOSE: The aim of this study was to compare the diagnostic value of multidetector computed tomography (MDCT) and F18-fluorodeoxyglucose positron emission tomography-computed tomography (FDG-PET/CT) for the detection of local and distant recurrence in patients operated on for rectal cancer. MATERIALS AND METHODS: Sixty-seven patients who underwent radical surgery for rectal cancer and were followed up with FDG-PET/CT and MDCT were included in this retrospective study. The FDG-PET/CT and MDCT findings were independently compared with histological sampling or 2 years' follow-up. RESULTS: Local recurrence occurred in 15/67 patients. MDCT diagnosed local recurrence in 15/15 cases and FDG-PET/CT in 14/15. Sensitivity and specificity were 100% and 98% for MDCT and 93% and 98% for FDG-PET/CT, respectively. Hepatic lesions were found in 17/67 patients. All hepatic metastases were detected by both techniques. Pulmonary metastases occurred in 8/67 patients: they were correctly identified in all cases by MDCT and in 6/8 by FDG-PET/CT. CONCLUSIONS: MDCT and FDG-PET/CT showed high sensitivity and specificity for the detection of local recurrence of rectal cancer. Both techniques were equally accurate for the detection of hepatic metastases. MDCT showed slightly higher sensitivity and positive predictive value in detecting pulmonary metastases compared with FDG-PET/CT.     

Characterisation of focal liver lesions undetermined at grey-scale US: contrast-enhanced US versus 64-row MDCT and MRI with liver-specific contrast agent

Purpose

The aim of this study was to assess the role of contrast-enhanced ultrasonography (CEUS) in the characterisation of focal liver lesions in comparison with multidetector computed tomography (MDCT) and magnetic resonance imaging (MRI) with liver-specific contrast agent.

Materials and methods

One hundred and eighty-seven focal liver lesions, 91 malignant and 96 benign (mean size 3.2 cm) — proved by biopsy (n=12), histology (n=4), MDCT (n=108), MRI (n=44) MDCT/MRI (n=19) — in 159 patients were studied by CEUS. Two expert radiologists consensually evaluated the contrast-enhancement patterns at CEUS. For each lesion, they assessed: (a) nature (benign, malignant, not assessable), (b) specific diagnosis and (c) need for further radiological evaluation. Sensitivity, specificity, positive and negative predictive values and diagnostic accuracy of CEUS were calculated.

Results

A total of 167/187 (89.3%) lesions were correctly assessed as benign or malignant at CEUS, whereas 14/187 (7.5%) lesions remained undetermined and 6/187 (3.2%) were incorrectly assessed. Sensitivity, specificity, positive and negative predictive values and diagnostic accuracy of CEUS were, respectively, 89%, 89.6%, 89%, 89.6% and 89.3%. The need for further radiological evaluation decreased to 46/187 (24.6%) lesions after CEUS (p<0.001).

Conclusions

In selected cases, CEUS can be considered an effective alternative to MDCT and MRI and reduce the need for further radiological workup.     

^18F-FDGPET／CT与超声造影在肝细胞癌复发判断中的对比研究

目的比较18F—FDGPET／CT与超声造影（CEUS）在HCC治疗后复发监测中的效能。方法回顾性分析27例HCC治疗后（15例部分切除术、12例射频消融）患者资料（男22例,女5例;平均年龄47岁）,患者治疗后均行18F．FDGPET／CT及CEUS监测肿瘤复发,2种检查间隔时间在2周内,间隔期间未接受任何治疗。依据病理或随访（〉6个月）结果,计算PET／CT与CEUS诊断HCC复发的灵敏度、特异性及准确性。比较CEUS与PET／CT对CEUS阳性患者和CEUS阴性患者的诊断效能。采用McNemar检验分析数据。结果27例治疗后HCC患者中,25例存在肝内复发,其中11例合并肝外转移;2例肝内未见复发,但有肝外转移。18F-FDGPET／CT及CEUS对肝内病灶检出的灵敏度分别为92．0％（23／25）和60．0％（15／25）,特异性均为2／2,准确性分别为92．6％（25／27）和63．0％（17／27）。15例CEUS阳性患者中,18F．FDGPET／CT及CEUS对肝内病灶检出的灵敏度及准确性均为100％（15／15）;12例CEUS阴性患者中,18F—FDGPET／CT及CEUS对肝内病灶检出的灵敏度分别为8／10和0,特异性均为2／2,准确性分别为83．3％（10／12）和16．7％（2／12）。18F-FDGPET／CT灵敏度及准确性明显高于CEUS,尤其是CEUS阴性组（x2=5．373和5．250,均P〈O．05）。18F-FDGPET／CT对肝外转移病灶的诊断灵敏度为100％（13／13）。结论18F—FDGPET／CT在评估HCC治疗后患者肝内肿瘤复发方面的灵敏度及准确性明显优于CEUS,并能有效发现肝外转移,可作为CEUS阴性而临床高度怀疑复发和转移的HCC患者的有效补充检查手段。     

Nachweis und Charakterisierung von Lebermetastasen

Since the advent of second generation ultrasound (US) contrast agents, ultrasound has caught up with other imaging modalities for the detection and characterization of liver metastases and as a result of its high temporal and spatial resolution it can in some cases even be superior to computed tomography (CT) and magnetic resonance imaging (MRI). Many studies have demonstrated a sensitivity and specificity of over 90%. Due to its high temporal resolution contrast-enhanced US (CEUS) is capable of detecting even a very short duration of hyper-enhancement during the arterial phase. Radiation protection and lack of adverse effects on renal or thyroid function are additional arguments why CEUS should be recommended as the first imaging modality in the evaluation of hepatic metastases in cases of favorable scanning conditions.     

Additional value of contrast enhanced intraoperative ultrasound for colorectal liver metastases

BACKGROUND: Substantial recurrence rates following partial liver resection for colorectal liver metastases (CRM) imply that small metastases remain undetected using intraoperative ultrasound (IOUS). The aim of this study was to evaluate the additional value of contrast enhanced IOUS (CE-IOUS) when compared to preoperative contrast enhanced computed tomography (CE-CT) and IOUS in liver surgery for CRM. METHODS: After obtaining informed consent, 39 consecutive patients with CRM were included prospectively for evaluation. The study population consisted of 26 male and 13 female patients with a median (range) age of 62 (49-83) years. A lesion-per-lesion analysis was performed with histopathological examination as the reference standard after resection and follow-up for unresected lesions. The added value of CE-IOUS in correctly diagnosing malignant lesions was statistically evaluated, using receiver operating characteristic curves. RESULTS: A total of 234 lesions were identified, 137 of which were malignant, according to the reference standard. The addition of CE-IOUS did not improve the diagnostic accuracy when compared to the combination of CE-CT and IOUS (P=0.617). In one of two patients with newly detected lesions on CE-IOUS the extent of resection changed. CONCLUSIONS: The addition of CE-IOUS to preoperative CE-CT and IOUS does not improve the ability to characterize already detected lesions. In a small number of patients it appears to facilitate the detection of new metastatic lesions with implications on surgical strategy.     

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.     

Quantification of hepatic arterial and portal venous flow using ultrasound contrast agents for early detection of liver metastases of colorectal cancers

PURPOSE: To quantify liver blood flow using US contrast agents and to evaluate arterial and portal changes in control patients and patients with liver metastases. MATERIALS AND METHODS: Twenty eight patients were included in this study, 8 controls (M0) and 20 patients with liver metastases from colon carcinoma (M+). Hepatic blood flow from hepatic artery and portal vein were determined using quantification of enhancement after contrast injection using Power Doppler US. The ratio of enhancement rise from artery and vein allows calculation of Contrast Enhanced Doppler Perfusion Index (CEDPI) as previously described for Doppler Perfusion Index (DPI). RESULTS: A significant difference was noted for CEDPI between controls (0.49 +/- 0.07) and liver with metastases (0.70 +/- 0.12). CONCLUSION: This functional method of evaluation of liver blood flow was easy to perform, and would be valuable for early detection of overt micro-metastases before anatomical changes observed by conventional imaging. This is helpful for accurate staging of colon carcinoma.     

Detection of metastatic bone lesions in breast cancer patients: fused (18)F-Fluoride-PET/MDCT has higher accuracy than MDCT. Preliminary experience

Purpose

So far, no studies comparing ¹⁸F-Fluoride-PET/CT and MDCT for the detection of bone metastases are available. We compared the accuracy of ¹⁸F-Fluoride-PET/CT (MDCT: 3.75 mm thickness-image-reconstruction), whole-body Multi-Detector-CT (MDCT: 1.25 mm thickness-image-reconstruction) and ¹⁸F-Fluoride-PET/MDCT (MDCT: 1.25 mm thickness-image-reconstruction) in identifying bone metastases in breast cancer patients.

Methods

We studied 39 breast cancer patients for bone metastases. Imaging was performed on an integrated PET/MDCT-system; CT images were reconstructed at 3.75 mm and 1.25 mm thickness. Two nuclear medicine physicians and one radiologist interpreted blindly ¹⁸F-Fluoride-PET/CT, ¹⁸F-Fluoride-PET/MDCT and MDCT. MDCT at 12 months served as the standard of reference.

Results

Overall, 662 bone lesions were detected in our analysis. Of these, 542 were malignant and 120 were benign according to the standard of reference. ¹⁸F-Fluoride-PET/CT detected 491 bone metastases, 114 (23%) of which displayed no clear morphological changes on MDCT, whereas MDCT detected 416 bone metastases, 39 (9.3%) of which showed no ¹⁸F-Fluoride-PET uptake. Overall sensitivity and specificity were: 91% and 91%, respectively, for ¹⁸F-Fluoride-PET/CT, and 77% and 93% for MDCT. The integrated assessment of ¹⁸F-Fluoride-PET/MDCT yielded sensitivity and specificity values of 98% and 93%, respectively.

Conclusions

¹⁸F-Fluoride-PET/MDCT has higher diagnostic accuracy than ¹⁸F-Fluoride-PET/CT and MDCT for the evaluation of bone metastases in breast cancer.     

Comparison of diagnostic performance of unenhanced vs SonoVue - enhanced ultrasonography in focal liver lesions characterization. The experience of three Italian centers

PURPOSE: To evaluate the diagnostic performance of contrast-enhanced US with SonoVue (Bracco, Milan, Italy) compared to baseline US in focal hepatic lesions characterization. MATERIALS AND METHODS: A comprehensive number of four operators from 3 hospitals evaluated 57 consecutive patients with 60 focal hepatic lesions (28 hepatocellular carcinomas, 11 metastases, 13 hemangiomas, 1 hepatocellular adenoma and 7 focal nodular hyperplasias) by baseline gray-scale ultrasound (US) and color Doppler US. The same lesions were subsequently scanned by contrast-enhanced US after intravenous bolus administration of 2,4-4,8 ml of SonoVue by employing intermittent high or continuous low transmit power imaging. The diagnosis of lesions nature (benign or malignant) and histotype proposed by the on-site operator was finally compared to the definite diagnosis reached by reference procedures (multiphasic contrast-material enhanced helical-computed tomography or magnetic resonance in 24 lesions and fine needle US guided biopsy in 36 lesions). Diagnostic performance (sensitivity, specificity and overall accuracy expressed by the agreement with the reference procedures) of baseline and contrast enhanced US were compared. RESULTS: Differences in sensitivity (baseline vs contrast-enhanced US: 13/39 [33%] vs 32/39 [82%]), specificity (baseline vs contrast-enhanced US: 12/21 [57%] vs 16/21 [76%]) and overall accuracy (baseline vs contrast-enhanced US: 25/60 [41%] vs 47/60 [78%]) were significant (p<0.05; McNemar test). CONCLUSIONS: SonoVue-enhanced US determined a significant improvement in diagnostic performance in the characterization of focal liver lesions if compared to baseline US.