Influence of limited examination conditions on contrast-enhanced sonography for characterising liver lesions.

AIM: To assess the influence of difficult examination conditions onto the diagnostic performance of CEUS (contrast-enhanced ultrasound) in focal liver lesions (FLL). METHODS: 77 liver CEUS examinations of 75 patients were analysed retrospectively. CEUS was performed as the first diagnostic procedure by one experienced sonographer after bolus injection of 1.0 up to 2.4 ml sulphur hexafluoride microbubbles using a high-end ultrasound device with a high resolution multifrequency probe (1-6 MHz). The combination of complementary imaging (CT or MRI), histology and CEUS follow up of at least 6 months was considered. Cross tables were used to define the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and diagnostic accuracy. Chi-Square Test analysed categorical data. RESULTS: The patients were between 18 and 84 years old (mean 62±11 years). 26 patients suffered from liver cirrhosis (33.8%). 52 patients (67.5%) received therapy for an oncological disease. The final diagnosis showed 52 malignant FLLs including 24 hepatocellular carcinomas (HCCs), 9 cholangiocellular carcinomas (CCCs) and 19 metastases from different primary tumors. In the other 25 patients no malignant lesions could be detected, three of them presenting however liver haemangioma and two of them liver cysts. The overall lesions' size according to the CEUS findings ranged from 7 to 100 mm (mean 31.1±22.6 mm). Under good examination conditions the malignant potential of a tumor was diagnosed correctly by CEUS in 98.0% of cases (Sensitivity 97.1%, Specificity 100%, PPV 100%, NPV 94.1%, diagnostic accuracy 98.0%). Limited examination conditions (e.g. obesity, meteorism) were present in 35.1% of cases with a decrease of the diagnostic accuracy to 92.6% (Sensitivity 100%, Specificity 77.8%, PPV 90.0%, NPV 100%). CONCLUSION: Despite the influence of difficult examination conditions, CEUS is - in the hands of an experienced sonographer - an excellent diagnostic procedure for the assessment of liver lesions.

Effect of iodinated contrast media on renal perfusion: A randomized comparison study in pigs using quantitative contrast-enhanced ultrasound (CEUS).

The administration of iodinated contrast media (CM) can cause microcirculatory disorder leading to acute renal dysfunction. In a prospective, randomized investigation two CM (Iodixanol vs Iopromide) were compared in 16 pigs. Each animal received 10 intra-aortal injections (5 ml Iodixanol or 4.32 ml Iopromide). Microcirculation was assessed using contrast-enhanced ultrasound (CEUS) directly on the kidney surface using time-to-peak (TTP) and blood-volume-analysis. Macroscopic observations were documented. Post mortem residual CM distribution in the kidneys was detected using X-ray. TTP was significantly prolonged over the descending vasa recta of the Iopromide group. This coincided with a visible marble-like pattern on the kidney surface occurring in 30 out of 80 Iopromide-injections but in 4 out of 80 Iodixanol-injections (p = 0.007). The blood volume over the entire kidney did not change after Iodixanol-application, but decreased by about 6.1% after Iopromide-application. The regional blood volume in the renal cortex showed a tendency to decrease by about 13.5% (p = 0.094) after Iodixanol-application, and clearly decreased by about 31.7% (p = 0.022) after Iopromide-application. The study revealed a consistent influence of repeated injections of two different CM on the kidney perfusion using three different imaging methods (CEUS analysis, macroscopic observation and X-ray analysis).

Contrast-enhanced ultrasound to evaluate organ microvascularization after operative versus endovascular treatment of visceral artery aneurysms.

PURPOSE: To evaluate the organ microvascularization after operative versus endovascular treatment of visceral artery aneurysms (VAAs) by contrast-enhanced ultrasound (CEUS) and colour-coded duplex sonography (CCDS). METHOD AND MATERIALS: Between April 1995 to January 2016, 168 patients (78 males, 90 females; median age: 62 years) were diagnosed with VAAs at our hospital site. 60/168 patients (36%) fulfilled treatment criteria and had either open (29/60, 48%) or endovascular (31/60, 52%) aneurysm repair. Patients' characteristics and presentations were consecutively reviewed. Technical success and organ microvascularization were determined by CCDS/CEUS and correlated to computed tomography angiography (CTA) or magnetic resonance imaging (MRI). RESULTS: 18/60 patients (30%) presented with acute bleeding. 16/18 emergency patients (89%) were treated by endovascular means. After emergency treatment, two patients showed segmental liver malperfusion by CEUS and CTA. One small bowel resection had to be performed.42/60 patients (70%) were electively treated. 27/42 patients (64%) had open and 15/42 (36%) endovascular aneurysm repair. There were no liver or bowel infarctions after elective treatment of hepatic or mesenteric artery aneurysms (n = 13) in CCDS/CEUS and in CTA. Treatment of patients with splenic or renal artery aneurysms led to partial or complete organ loss in 42% (8/19) after operative and in 50% (5/10) after endovascular treatment (p < 0.05). CONCLUSION: The endovascular approach is the preferred therapeutic option in emergency to control bleeding. In contrast to hepatic or mesenteric procedures, patients for elective splenic or renal artery aneurysm repair have to be evaluated very carefully because of a high rate of partial or complete organ loss demonstrated by CEUS - either after open or endovascular aneurysm repair.

Percutaneous Ablation of Hepatic Tumors Using Irreversible Electroporation: A Prospective Safety and Midterm Efficacy Study in 34 Patients.

PURPOSE: To evaluate the safety and efficacy of percutaneous irreversible electroporation (IRE) of primary and secondary liver cancer unsuitable for resection or thermal ablation. MATERIALS AND METHODS: In this prospective, single-center study, 65 malignant liver tumors (hepatocellular carcinoma, n = 33; cholangiocellular carcinoma, n = 5; colorectal cancer metastasis, n = 22; neuroendocrine cancer metastasis, n = 3; testicular cancer metastasis, n = 2) in 34 patients (27 men, 7 women; mean age, 59.4 y ± 11.2) were treated. Local recurrence-free survival (LRFS) according to the Kaplan-Meier method was evaluated after a median follow-up of 13.9 months. RESULTS: Median tumor diameter was 2.4 cm ± 1.4 (range, 0.2-7.1 cm). Of 65 tumors, 12 (18.5%) required retreatment because of incomplete ablation (n = 3) or early local recurrence (n = 9). LRFS at 3, 6, and 12 months was 87.4%, 79.8%, and 74.8%. The median time to progressive disease according to modified Response Evaluation Criteria In Solid Tumors was 15.6 months. Overall complication rate was 27.5% with six major complications and eight minor complications. Major complications included diffuse intraperitonal bleeding (n = 1), partial thrombosis of the portal vein (n = 1), and liver abscesses (n = 4). Minor complications were liver hematomas (n = 6) and clinically inapparent pneumothoraces (n = 2). CONCLUSIONS: IRE showed promising results regarding therapeutic efficacy for the percutaneous treatment of liver tumors; however, significant concerns remain regarding its safety.

Diffusion-weighted imaging in oral squamous cell carcinoma using 3 Tesla MRI: is there a chance for preoperative discrimination between benign and malignant lymph nodes in daily clinical routine?

BACKGROUND: Preoperative staging of cervical lymph nodes is important to determine the extent of neck dissection in patients with oral squamous cell carcinoma (OSCC). PURPOSE: To evaluate whether a preoperative discrimination of benign and malignant cervical lymph nodes with diffusion-weighted imaging (DWI) (3T) is feasible for clinical application. MATERIAL AND METHODS: Forty-five patients with histological proven OSCC underwent preoperative 3T-MRI. DWI (b = 0, 500, and 1000 s/mm(2)) was added to the standard magnetic resonance imaging (MRI) protocol. Mean apparent diffusion coefficients (ADCmean) were measured for lymph nodes with 3 mm or more in short axis by two independent readers. Finally, these results were matched with histology. RESULTS: Mean ADC was significantly higher for malignant than for benign nodes (1.143 ± 0.188 * 10(-3) mm(2)/s vs. 0.987 ± 0.215 * 10(-3) mm(2)/s). Using an ADC value of 0.994 * 10(-3) mm(2)/s as threshold results in a sensitivity of 80%, specificity of 65%, positive predictive value of 31%, and negative predictive value of 93%. CONCLUSION: Due to a limited sensitivity and specificity DWI alone is not suitable to reliably discriminate benign from malignant cervical lymph nodes in daily clinical routine. Hence, the preoperative determination of the extent of neck dissection on the basis of ADC measurements is not meaningful.

Factors associated with short-term local recurrence of liver cancer after percutaneous ablation using irreversible electroporation: a prospective single-center study.

PURPOSE: To evaluate the risk factors associated with short-term local recurrence of malignant liver lesions after irreversible electroporation (IRE). MATERIALS AND METHODS: Thirty-nine consecutive patients (79 malignant liver lesions) were treated with IRE, of whom 14 were excluded from the analysis (including 12 without 6 mo of follow-up and two with incomplete ablation). The remaining 25 patients (aged 59.4 y ± 11.2) had 48 malignant liver lesions, including 22 hepatocellular carcinomas (HCCs), six cholangiocellular carcinomas, and 20 metastatic liver cancers. Multivariate analyses were used to evaluate the associations of risk factors with early recurrence. The characteristics of patients, lesions, and IRE procedures were assessed by logistic regression. RESULTS: Fourteen of the 48 treated lesions (29.2%) showed early local recurrence after 6 months. Tumor volume (< 5 cm(3) vs ≥ 5 cm(3); P = .022) and underlying disease type (HCC, cholangiocellular carcinoma, or metastatic disease; P = .023) were independently associated with early local recurrence. However, distances to the surrounding portal veins (< 0.5 cm vs ≥ 0.5 cm; P = .810), hepatic veins (P = .170), hepatic arteries (P = .761), and bile ducts (P = .226) were not significantly associated with local recurrence. CONCLUSIONS: Because short distances to the surrounding vessels were not associated with early local recurrence, percutaneous IRE might provide an alternative treatment option for perivascular tumors. However, patients with larger tumor volumes appeared to be poor candidates for percutaneous IRE. Regarding the different types of treated lesions, patients with HCC had significantly better outcomes.

Contrast-enhanced ultrasound (CEUS) detects effects of vascular disrupting therapy in an experimental model of gastric cancer.

OBJECTIVE: To assess the effects of vascular-disrupting agent (VDA)-based therapy including monitoring of therapeutic efficacy with contrast-enhanced ultrasound (CEUS) in a gastric cancer model. MATERIALS & METHODS: Gastric cancer cell lines and endothelial cells were used. Effects of the VDA ASA404 on cells were determined by MTT assays and Western blotting in vitro. Therapeutic efficacy of ASA404 was assessed in vivo in a subcutaneous mouse model in combination with paclitaxel. CEUS with TIC (time intensity curve) analyses was employed to measure tumor perfusion. Finally, tumor tissue was harvested and processed for histological work-up. RESULTS: In vitro, ASA404 impaired growth of ECs upon stimulation with conditioned media from gastric cancer cells. No direct effects on tumor cells were observed. In vivo treatment with ASA404 in combination with paclitaxel led to significant decrease of tumor microvascularization as determined by CEUS. Furthermore, combination of ASA404 with paclitaxel showed a significant inhibition of tumor growth which was paralleled by strong reduction of tumor cell proliferation and vessel area. CONCLUSION: VDA-based therapy in combination with paclitaxel, and therapy monitoring by CEUS, appears to be a promising strategy for gastric cancer.

Intraoperative high resolution linear contrast enhanced ultrasound (IOUS) for detection of microvascularization of malignant liver lesions before surgery or radiofrequeny ablation.

OBJECTIVE: The aim of this study was to evaluate the value of linear contrast enhanced intraoperative ultrasound (CE-IOUS) to improve detection of malign liver tumors lesions before surgery or radiofrequency ablation (RFA). MATERIALS AND METHODS: 50 patients were included for surgery of malignant liver tumors (mean age 61 years (19-80); male n = 35, female n = 15), suffering from HCC (n = 15), colorectal liver-metastasis (n = 28), CCC (n = 2) or other malign liver lesions (n = 5). Preoperative CE-CT (n = 38), CE-MRI (n = 23) or PET-CT (n = 8) confirmed hepatic tumor manifestation. Before undergoing surgery, intraoperative conventional (IOUS) as well as CE-IOUS were performed by one experienced examiner in all cases using multifrequency linear probes (6-9 MHz, 6-15 MHz; LOGIQ E9; GE Healthcare, Milwaukee, WI, USA). CE-IOUS was performed after bolus injection of 5 ml up to 15 ml SonoVue(®) (Bracco Imaging SpA, Milan, Italy). Digitally stored images of CE-IOUS were compared with fundamental B-Scan and preoperative imaging (CE-CT, CE-MRI and PET-CET). RESULTS: In 28 of 50 patients (56%), additional lesions were found using CE-IOUS (mean tumor size 8 mm, range 4-12 mm). This resulted in a change of surgical strategy or the intraoperative application of RFA in 27 patients (54%). Modification of therapy due to additionally found liver lesions was statistically significant (p < 0.05). Comparing conventional IOUS and CE-IOUS, 14 additional lesions in 10 patients were seen by CE-IOUS. All lesions seen in B-scan could also be detected with CE-IOUS. SUMMARY: This is the first study using contrast-enhanced ultrasound with high resolution linear probes for intraoperative detection of malignant liver lesions. Compared to preoperative imaging and also conventional IOUS more than 50% additional lesions were found leading to therapeutic consequences of patients. A recently started prospective study has to show whether these changes in the surgical or interventional therapy will influence morbidity, mortality and especially the recurrence rate.

Magnetic resonance enterography with and without biphasic contrast agent enema compared to conventional ileocolonoscopy in patients with Crohn's disease.

BACKGROUND: Magnetic resonance imaging (MRI) of the bowel is a valuable diagnostic tool for assessing disease activity in patients with inflammatory bowel disease (IBD). We compared magnetic resonance enterography (MRE) with and without water enema to conventional ileocolonoscopy to evaluate the advantage of a water enema for MRI diagnostics of Crohn's disease (CD). METHODS: We prospectively evaluated 50 patients with known CD. MRE with enema was performed in 23 cases, whereas 27 patients received an MRE without enema. All patients underwent conventional ileocolonoscopy. We assessed the degree of inflammation in both modalities, evaluating up to seven bowel segments in each patient. We compared MRE with and without rectal enema to each other and to conventional ileocolonoscopy. RESULTS: MRE achieved a sensitivity and specificity of 100% and 74%, respectively, for detection of inflammation in the terminal ileum with enema and a sensitivity and specificity of 72% and 87%, respectively, without enema. Considering the colon, MRE with enema had a sensitivity of 79% (specificity 96%), while the examination without enema showed a sensitivity of 38% (specificity 99%). MRE with enema proved statistically superior to MRE without enema in detecting inflammation in the terminal ileum, ascending colon, and rectum (P < 0.05). CONCLUSIONS: MRE with enema is a valuable diagnostic tool for assessing inflammation in CD patients. Water enema is well tolerated and significantly improves detection of inflammation in the terminal ileum. Water enema should therefore be included in MRE protocols for CD patients.

Dynamic contrast-enhanced MRI as a valuable non-invasive tool to evaluate tissue perfusion of free flaps: Preliminary results.

Early detection of a compromised circulation of free flaps and an immediate revision may lead to higher rates of flap salvage. The aim of this study was to evaluate the perfusion of the entire flap using dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI). DCE was performed in 11 patients after flap transplantation using an optimized 3D gradient echo sequence to cover the whole flap. The percentage increase of signal intensity over time was evaluated for the free flap as well as for a reference tissue. Furthermore, normalized signal increase was calculated as the ratio of signal increase within the flaps to the signal increase in the reference tissue. Signal increase in free flaps and reference tissue was compared using the Wilcoxon-test (p < 0.05), normalized signal increase in normally perfused (n = 9) and in flaps with compromised perfusion (n = 2) using Mann-Whitney-test (p < 0.05). Signal increase within normally perfused flaps was similar to the reference tissue. In flaps with compromised perfusion the increase was significantly lower than in reference tissue. Normalized signal increase in adequately perfused flaps and flaps with compromised perfusion also showed a significant difference. DCE MRI may be a valuable non-invasive tool to evaluate tissue perfusion of the complete free flap.