Improved Detection of preclinical Colorectal Liver Metastases by High Resolution Ultrasound including Molecular Ultrasound Imaging using the targeted Contrast Agent BR55.

PURPOSE: Aim of the present study was to investigate the sensitivity of high resolution ultrasound (HRU), standard contrast-enhanced ultrasound (CEUS) and CEUS using a novel vascular endothelial growth factor receptor 2 (VEGFR2)-targeted contrast agent for the detection of hepatic metastases in a mouse model of colorectal cancer using clinical standard technology. MATERIALS AND METHODS: The human colon cancer cell line HT29, transfected with luciferase cDNA for in vivo bioluminescence monitoring, was injected intrasplenically into CB17.SCID mice. Mice were monitored weekly by bioluminescence and after 2 and 4.5 weeks by HRU and CEUS. Contrast media (untargeted BR1, targeted BR55) was applied and digital cine loops from the arterial phase (15 - 45 sec), portal venous phase (50 - 120 s) and late phases (3 - 5 min, 1hour) of the whole liver were analyzed. Data were correlated with postmortem histopathology. RESULTS: Without contrast enhancement, lesions > 4 mm were reliably detected. After use of untargeted CEUS, lesions > 2 mm were reliably detected and enhanced rim vascularization and late-phase wash-out was shown. With BR55, lesions > 0.8 mm were reliably detected with excellent documentation of vascularization. A persistent contrast enhancement was seen > 30 min after injection. Contrast-enhancement patterns with BR55 significantly correlated with CD31 (R2 = 0.74) and VEGFR2-immunohistochemistry (R2 = 0.66). CONCLUSION: Detection of metastases by HRU and CEUS was earlier and more accurate than monitoring via bioluminescence. In vivo monitoring of hepatic micrometastases can thus be performed without prior modification of cancer cells using standard technology.

Incidence of bleeding in 8172 percutaneous ultrasound-guided intraabdominal diagnostic and therapeutic interventions - results of the prospective multicenter DEGUM interventional ultrasound study (PIUS study).

PURPOSE: To analyse the incidence of bleeding after percutaneous ultrasound guided diagnostic and therapeutic intraabdominal interventions in a prospective multicentre study (DEGUM percutaneous interventional ultrasound study). MATERIALS AND METHODS: Within a time period of 2 years diagnostic and therapeutic intraabdominal interventions (with the exclusion of ascites paracentesis) performed percutaneously under continuous ultrasound (US) guidance were prospectively assessed using a pseudonymized standardized web site entry form. Number and type of intervention, operator experience, patient characteristics, medication, lab data as well as technical aspects of the procedure and bleeding complications were analysed according to the interventional radiology standards. RESULTS: 8172 US-guided intraabdominal interventions (liver n = 5903; pancreas n = 501, kidney n = 434, lymph node = 272, biliary system n = 153, spleen n = 63, other abdominal organs and extra-organic targets n = 999) were analysed in 30 hospitals. The majority were diagnostic biopsies including 1780 liver parenchyma, 3400 focal liver lesions and 404 pancreatic lesions. 7525 interventions (92.1 %) were performed in hospitalized patients (mean age 62.6 years). Most operators were highly experienced in US-guided interventions (> 500 interventions prior to the study n = 5729; 70.1 %). Sedation was administered in 1131 patients (13.8 %). Needle diameter was ≥ 1 mm in 7162 punctures (87.9 %) with main focus on core needle biopsies (18 G, n = 4185). Clinically relevant bleeding complications with need of transfusion (0.4 %), surgical bleeding control (0.1 %) and radiological coiling (0.05 %) were very rare. Bleeding complications with fatal outcome occurred in four patients (0.05 %). The frequency of major bleeding complications was significantly higher in patients with an INR > 1.5 (p < 0.001) and patients taking a medication potentially interfering with platelet function or plasmatic coagulation (p < 0.0333). CONCLUSION: This prospective multicentre study confirms the broad spectrum of percutaneous US-guided intraabdominal interventions. However diagnostic liver biopsies dominate with the use of core needle biopsies (18 G). Percutaneous US-guided interventions performed by experienced sonographers are associated with a low bleeding risk. Major bleeding complications are very rare. A pre-interventional INR < 1.5 and individual medication risk assessment are recommended.

Preoperative differentiation of thyroid adenomas and thyroid carcinomas using high resolution contrast-enhanced ultrasound (CEUS).

BACKGROUND: To evaluate the impact of high-resolution contrast-enhanced ultrasound (CEUS) in combination with Color Coded and Power Doppler Sonography (CCDS/PD) in the preoperative differentiation of thyroid adenomas and thyroid carcinomas. METHODS: A total of 101 patients (55 female, median age 54 years) underwent surgery for thyroid adenoma and thyroid carcinoma. CCDS/PD and CEUS were performed in all patients by an experienced examiner using a multifrequency linear transducer (6-9 or 6-15 MHz) and were digitally stored. Reading of the ultrasound images was performed by two experienced radiologists in consensus. A histopathological evaluation was obtained as standard of reference in all patients. RESULTS: Altogether, 75 thyroid adenomas and 26 thyroid carcinomas were detected. Mean diameter of thyroid adenomas and thyroid carcinomas was 27 mm and 32 mm, respectively. The differences in microcirculation of thyroid adenomas and thyroid carcinomas were statistically highly significant (p <  0.01). Representative features for thyroid adenomas were either no wash-out or wash-out with persisting edge in late phase, for thyroid carcinomas a complete wash-out in late phase. Thus, a calculation of sensitivity, specificity, positive and negative predictive value of 81% , 92% , 97% and 63%, respectively, for the differentiation of benignity and malignancy was possible. CONCLUSIONS: Dynamic evaluation of microcirculation using CEUS and CCDS/PD enables a more reliable preoperative discrimination between thyroid adenomas and thyroid carcinomas.

New economic training model for installing ultrasound-guided drainages.

Abscesses and circumscribed collections of fluid are frequently found as complications of infectious diseases or surgery. Drainage is often indicated. We have established a new, economic, easy-to-make model to learn and improve competence in installing ultrasound-guided drainage. Up to fifteen water balloons (size 30 - 50 mm) were placed in a plastic box which then was filled with instant custard powder mixed with water. Spiral computed tomography (CT) of this box was performed. Experienced (n = 8) and inexperienced examiners (n = 8) drained the balloons via a direct puncture technique using either ultrasound-guidance alone or volume navigation with image fusion (ultrasound and CT) with needle tracking. Trainees filled out a questionnaire (before and after training) asking for information on their experience in ultrasound, in installing drainages and evaluating the new model. The time needed for installing the drainage was measured. None of the participants had ever attended a course on drainage installation. Only a few of the experienced examiners (n = 3) would autonomously install a drainage into a fluid collection with a size exceeding 4 cm before training. After training all participants felt more confident in ultrasound and in installing drainages into abscesses or other fluid collections. Most of the participants rated additional volume navigation with image fusion as a helpful tool. Ultrasound-guided drainage of abscesses can be trained easily with this new and economic model. Students and physicians can improve their skills and gain confidence in performing ultrasound-guided interventions.

[A 43-year-old patient with character changes, recurrent impaired consciousness and retrograde amnesia]. / 43-jähriger Patient mit Wesensveränderung, rezidivierenden Bewusstseinsstörungen und retrograder Amnesie.

A 43-year-old male patient with recurring impaired consciousness and retrograde amnesia was admitted to the department of neurology. During the neurological evaluation no pathological findings could initially be revealed but one day the patient was confused again and presented with inadequate behavior: at this time a blood glucose value of 40 mg/dl was measured. For further evaluation the patient was transferred to our department. As the reason for the impaired consciousness was suspected to be of neuroglucopenic origin a rapid adrenocorticotropic hormone (ACTH) stimulation test was first performed to rule out adrenal insufficiency. For further evaluation a fasting test was conducted: after 48 h an episode with neuroglucopenic symptoms occurred again which disappeared after intravenous administration of glucose. The laboratory results of glucose, insulin and c-peptide determined at this point in time led to the diagnosis of an insulinoma. By ultrasound examination a hypoechogenic lesion 1.5 cm in size could be shown in the head of the pancreas and was confirmed by magnetic resonance imaging (MRI). After duodenum-preserving partial pancreatic head resection with enucleation of the insulinoma no further neuroglucopenic symptoms occurred.

Comparison between a clinical activity index (Harvey-Bradshaw-Index), laboratory inflammation markers and quantitative assessment of bowel wall vascularization by contrast-enhanced ultrasound in Crohn's disease.

PURPOSE: Due to its character as a remitting inflammatory disease, patients suffering from Crohn's disease (CD) often undergo several imaging studies subjecting the mostly young patients to ionizing. Contrast enhanced ultrasound for capillary microvascular assessment might be a new diagnostic tool for identifying the activity of inflammation by ultrasound techniques. MATERIALS AND METHODS: We prospectively evaluated 45 patients with proven Crohn's disease performing contrast enhanced ultrasound (CEUS) and laboratory assessment including C-reactive protein (CRP), leucocytes and hematocrit as well as calculating the Harvey-Bradshaw Index (HBI). Thereafter, we applied the quantification software Qontrast(®) to obtain contrast-enhanced sonographic perfusion maps. RESULTS: Analysis of the 41 finally included patients revealed a correlation of CRP to HBI and TTP[s], respectively. Moreover, an association was found for HBI and TTP[s] and for HBI and TTP[s]/Peak [%]. Analysis of 34 patients with a Peak [%] ≥ 25 showed a close association of HBI and CRP. Besides, in these patients CRP correlated to TTP[s] and to TTP[s]/Peak [%]. We found a strong negative correlation between HBI and TTP[s] (r = -0.645, p<0.01), thus, the higher the clinical activity the shorter the time-to-peak. CONCLUSION: Quantitative evaluation with CEUS, particularly the calculation of TTP[s] in patients with a Peak [%] ≥ 25, provides a simple method to assess the inflammatory activity in CD.

[Contrast-enhanced sonographic drainage control: a feasibility study]. / Kontrastmittelsonografische Drainagenkontrolle: eine Feasibility-Studie.

Liver abscesses still represent a life-threatening disease. Interventional abscess puncture and/or drainage are often the most adequate treatment. The aim of our study was the evaluation of drainage control with contrast-enhanced sonography. We included 15 patients in our feasibility study, three of whom had infected liver cysts, three had abscesses after liver resection or transplantation, six had intrahepatic abscesses and three had abscesses of other localisations. For drainage control with contrast-enhanced sonography we administered 1 mL of the contrast agent SonoVue® (Bracco, Germany) diluted in 10 mL of 0.9 % of NaCl through the indwelling drainage or an 18-G Chiba needle. A total of 28 sonographic controlled examinations was performed. The position of the drainage, as well as the size of the abscess itself could be demonstrated in all cases. Furthermore, possible septs or the communication of different abscess regions could be seen. Drainage remained in position for an average of 13.3 days. Assessment of drainage position and size of the abscess region is of clinical relevance. The main advantages of the described examination with contrast-enhanced sonography are the lack of radiation and the low costs due to the small amount of contrast medium used.

Clinical signs in the diagnosis of deep vein thrombosis.

AIM: Deep vein thrombosis (DVT) is an insidious disease wherein more than 15 different clinical signs are described. The aim of this work was to focus on these clinical signs and to test them for their importance in making a diagnosis of DVT. METHODS: All patients treated with a tentative diagnosis of DVT in the emergency department were asked to take part in the study. Out of the 254 patients who were examined in order to exclude DVT, 204 patients agreed to participate in the study. The patients who agreed to take part were tested for fifteen clinical examination signs. The Wells score was then determined. RESULTS: Sixty-two were diagnosed with DVT. For 142 patients, DVT could be ruled out. The probability of DVT for 9 signs together is 88%, and for 3 signs is 78%. The negative predictive values are 91-95%. The combination of the clinical signs showed a specificity of 100%, independent if the patients were old, comorbid, and were diagnosed with the thrombosis in the lower limbs. The determination of the Wells score resulted in no convincing evidence for or against the diagnosis of DVT. CONCLUSION: We suggest a modified Wells score integrating missing clinical signs with more reliable predictive values. Even with the availability of ultrasound, clinical signs have not become superfluous. They are quick to carry out, safe, cheap and an important addition to the Wells score, particularly for multimorbid and elderly patients.

Comparison between preoperative quantitative assessment of bowel wall vascularization by contrast-enhanced ultrasound and operative macroscopic findings and results of histopathological scoring in Crohn's disease.

PURPOSE: Patients with Crohn's disease (CD) often undergo several radiological imaging studies, which - with the exception of MRI and US - subject patients to ionizing radiation. Thus, efforts have been made to identify the inflammation activity using ultrasound techniques. The aim of our study was to describe the perfusion pattern of the inflamed bowel wall in CD using contrast-enhanced ultrasound (CEUS) and specific quantification software for perfusion assessment. Moreover, we compared these findings with the operative macroscopic findings as well as with the transparietal histopathological findings of surgical specimens applying an advanced histopathological scoring system. MATERIALS AND METHODS: We prospectively performed CEUS in 20 consecutive patients with proven CD and planned bowel surgery due to CD within the next 15 days. We then applied the quantification software Qontrast to obtain contrast-enhanced sonographic perfusion maps. The surgeon defined the clinical behavior of CD according to the Vienna classification. The resected segments were then assessed by a pathologist using an advanced scoring system. We compared the results of CEUS, macroscopic findings and histopathological scoring. RESULTS: We found a strong negative correlation (r = - 0.677, p < 0.01) between the histopathological score and the time-to-peak (TTP). Moreover, we detected a strong correlation between TTP and single parameters of the histopathological scoring system. CONCLUSION: Ultrasound as a widely available radiation-free imaging method would be preferable for assessing inflammatory activity of CD, particularly since the ultrasound findings correlate significantly with a histopathological scoring system.

Image fusion with volume navigation of contrast enhanced ultrasound (CEUS) with computed tomography (CT) or magnetic resonance imaging (MRI) for post-interventional follow-up after transcatheter arterial chemoembolization (TACE) of hepatocellular carcinomas (HCC): Preliminary results.

AIM: The assessment of the immediate post-interventional microcirculation and perfusion following transcatheter arterial chemoembolization (TACE) with new real time imaging fusion technique (VNav) of computed tomography (CT) or magnetic resonance imaging (MRI) with contrast enhanced ultrasound (CEUS) compared to follow-up. MATERIAL: Following TACE an image fusion of CEUS with CT or MRI of the liver was performed in 20 patients (18 men, 2 women; age 29-75 years) with confirmed hepatocelluar carcinoma (HCC) to evaluate the post-interventional tumor vascularization and perfusion of HCC tumor lesions. Image fusion with CEUS performed immediately was compared with the result at the end of TACE (DSA), with post TACE CT (non-enhanced CT within 24 hours) and with follow up CT (enhanced CT after 6 weeks) after embolization. Ultrasound was performed using a 1-5 MHz multifrequency SonoVue transducer (LOGIQ 9/GE) after a bolus injection of 2-4ml SonoVue® with contrast harmonic imaging (CHI). Thirteen examinations were fused with a contrast enhanced CT, 7 with a MRI performed before TACE. RESULTS: The post-interventional volume navigation image fusion of CT or MRI with CEUS showed differences regarding the residual tumor perfusion compared to other modalities. The correlation (Spearman-test) between the perfusion result at the end of TACE, non-enhanced CT after TACE and image fusion with CEUS was 0.42 and 0.50. The difference between the result at the end of TACE and the fusion with CEUS was significant (p < 0.05, Wilcoxon-test). The correlation between fusion of CEUS with CT/MRI and follow-up CT (after 6 weeks) was 0.64, the difference was not significant (p > 0.05). The differences between native CT within 24 hours after TACE and follow up CT after 6 weeks or fusion of CEUS and CT/MRI were significant (p < 0.05). The inter-observer variability was 0.61 at the end of TACE, 0.58 at non-enhanced CT (within 24 hours), 0.87 at fusion CEUS with CT/MRI and 0.74 at follow up CT after 6 weeks (Cohens Kappa test). CONCLUSION: Image fusion with volume navigation (VNav) of CEUS with CT or MRI allows an accurate localisation of foci in patients with HCC. This exact mapping permits an easier control and evaluation of the results after TACE. The fusion of CEUS and CT or MRI allows a better evaluation of the microcirculation and the residual tumor perfusion at an earlier point of time than usual modalities of therapy control like non-enhanced CT. This might lead to a more differentiated monitoring of therapy.

Innovations in contrast enhanced high resolution ultrasound improve sonographic imaging of the intestine.

The aim was to describe the perfusion pattern of the inflamed bowel wall and the surrounding tissue in inflammatory bowel disease and diverticulitis of the sigmoid colon applying a high resolution matrix transducer and the new hybrid technique. We performed contrast enhanced ultrasound (CEUS) using an updated version of the 1-5 MHz (C1-5-D convex probe) and the 6-9 MHz probe (9L-D linear probe) as well as a matrix 6-15 MHz transducer (ML 6-15-D Matrix Array Linear Probe) and updated post-processing procedures to examine microvascularization of inflamed bowel wall in Crohn's disease (11 patients), ulcerative colitis (1 patient) and diverticulitis of the sigmoid colon (2 patients). Assessment of mural microvascularization was successful as well as identification of fistulas (2 patients) and covered perforation (1 patient). Moreover analysis of time intensity curves revealed increase of signal intensity up to 20 dB. Summarizing, application of high resolution linear probes and use of updated post-processing methods substantially improve detection of inflammation-caused increased microcirculation of the bowel wall and the surrounding tissue as well as identification of complications as fistulas or covered perforations.

Sono-hepatic-arteriography (Sono-HA) in the assessment of hepatocellular carcinoma in patients undergoing transcatheter arterial chemoembolization (TACE).

PURPOSE: The aim of our study was to evaluate sono-hepatic-arteriography in patients with hepatocellular carcinoma undergoing transcatheter arterial chemoembolization. MATERIALS AND METHODS: We evaluated 15 patients with hepatocellular carcinoma undergoing TACE who presented in our institution from February 2006 to May 2008. All patients underwent a conventional B-mode ultrasound examination using a high-end machine and a multi-frequency transducer (2.5 - 4 MHz) before dynamic contrast-enhanced ultrasound examination was carried out. For the sono-hepatic-arteriography 1 ml SonoVue was injected as a bolus using the formerly placed intraarterial catheter. Biphasic enhanced computed tomography was performed using a 16-slice CT scanner up to 48 hours before transcatheter arterial chemoembolization and during follow-up. RESULTS: The lesion size (of the largest lesion) ranged from 1 to 13 centimeters in their largest diameter (mean: 4.8 cm). Contrast-enhanced ultrasound diagnosed more lesions than B-mode sonography in eight cases and more lesions than computed tomography in 5 patients. The findings of sono-hepatic-arteriography were correct in fourteen cases (93.3 %). Direct impact on patient management was seen in eleven patients (73.3 %). CONCLUSION: We were able to show that the application of an intraarterial sonographic contrast agent during embolization is able to diagnose new lesions on the one hand and to assess the embolization success on the other. This might improve transcatheter arterial chemoembolization results and patient outcome.

Semiquantitative characterization of hepatocellular carcinoma (HCC)--perfusion with contrast-enhanced ultrasound and perfusion analysis.

BACKGROUND: At the moment, there is only poor specificity of HCC-detection in tumors smaller than 2 cm in a cirrhotic liver. Thus, efforts have to be made to optimize the distinction between regenerative nodules and HCC. AIMS: The aim of our study was to describe the particular perfusion pattern of hepatocellular carcinoma using a specific quantification software. METHODS: We evaluated 25 patients with proven hepatocellular carcinoma, who underwent dynamic contrast-enhanced ultrasound (CEUS) using a second generation contrast agent (SonoVue, Bracco, Germany). Retrospectively, we applied the quantification software Qontrast (Bracco, Milan, Italy) to obtain contrast-enhanced sonographic perfusion maps for each lesion. RESULTS: We found a close positive correlation of the perfusion parameters peak, time-to-peak and regional blood volume between the entire tumors, the center (center/total) and the periphery of the tumors (periphery/total), respectively. Moreover, we found significant higher peak values, a significant higher regional blood volume and a trend to lower time-to-peak in the center of the tumors compared to the tumor periphery. CONCLUSION: These results suggest a better established vascular bed in the center of the tumors. This could be a sonographic marker of HCC in contrast to regenerative nodules.

[Localisation of hepatic lesions to liver segments according to sonography (US), computed tomography (CT) and surgery (OP): a comparative study]. / Untersuchung der Segmentzugehörigkeit von Leberraumforderungen in Sonografie (US), Computertomografie (CT) und intraoperativ (OP): eine Vergleichsstudie.

INTRODUCTION: The localisation of focal liver lesions is usually performed according to the Couinaud classification system. The exact description of localisation and size of liver lesions is especially important for surgical procedures. The aim of this prospective study was the evaluation of differences and agreements in the localisation and size of hepatic lesions as found by ultrasound (US), computed tomography (CT) and according to the intraoperative status (OP). MATERIAL AND METHODS: 32 patients (21 male, 11 female) were enrolled in the study. The results obtained from sonography, computed tomography and surgery were classified into 5 categories for localisation and for size, respectively. RESULTS: According to the agreement between sonography and computed tomography, 25 % of all hepatic lesions were classified into category 1 (exact agreement), whereas 40.6 % were ranked into category 2 (almost exact agreement). Correlating sonography and intraoperative results, 31.3 % of the lesions were classified into category 1 and 46.9 % into category 2. In the comparison of CT with OP, 34.4 % of the lesions were found to be in category 1 and 43.8 % in category 2. Concerning the size of the lesions, almost half of the tumours (46.9 %) were classified into category 1 on the basis of the correlation between US and CT and 21.9 % on the basis of the correlation between US and OP. DISCUSSION: The localisation and description of the size of hepatic lesions is mainly similar or even identical on the basis of the different methods. Further improvements might be achieved by the introduction of a consistent nomenclature.

New real-time image fusion technique for characterization of tumor vascularisation and tumor perfusion of liver tumors with contrast-enhanced ultrasound, spiral CT or MRI: first results.

AIM: Evaluation and characterization of the vascularisation and perfusion of liver tumors by means of image fusion of dynamic contrast-enhanced ultrasound (CEUS), multidetector-CT (MD-CT) or magnetic resonance imaging (MRI) with the ultrasound navigation technique. MATERIAL: For interventional planning a real-time image fusion involving CEUS (LOGIQ E9, GE) was performed in 20 patients (12 men, 8 women, age 43-69 years, median 54) with histologically confirmed malignant liver tumors (9 x hepatocellular carcinoma (HCC), 5 x metastases, 2 x hemangiomas, 1 x cholangiocellular carcinoma (CCC), 1 x lymphoma, 1 x neuroendocrine tumor, 1 x focal nodular hypoplasia (FNH)). In 17 patients the real-time CEUS was fused with contrast-enhanced MD-CT and in three patients with contrast-enhanced MRI (Gd-DTPA and liver-specific contrast medium Resovist. All of the ultrasound examinations were performed by an experienced examiner with a multi-frequency probe (2-5 MHz, LOGIQ E9, GE); dynamic image sequences up to 3 minutes in true agent detection mode of contrast harmonic imaging (CHI) were documented. An evaluation of the tumor was performed by the characterization of the dynamics of the contrast medium and microperfusion with CEUS, fused with MD-CT or MRI. RESULTS: In 18/20 cases there was an accurate agreement with respect to the segmental localization of the tumor lesion. In 2/20 cases the localization was comparable with the image fusion of CEUS and reference imaging (a total of at least 65 lesions: 3 x 1 lesion, 5 x 2 lesions, 8 x 3 lesions, 2 x 5 lesions, 1 x 8 lesions, 1 x at least 10 lesions (multifocal)). With image fusion a certain characterization was attained in 17/20 cases. In 3/20 cases (lymphoma after liver transplantation, multifocal CCC, metastases of a neuroendocrine tumor) the diagnosis was at first doubtful and had to be confirmed histologically. In patients with HCC an evaluation of the tumor perfusion was feasible in all 9 cases (8/9 after local trans-arterial chemoembolization (TACE), 1/9 after radio frequency ablation (RFA)). A tendency toward the identification of more lesions with image fusion of CEUS and CT than with contrast-enhanced CT alone could be recognized (p=0.059). CONCLUSION: Applying a new real-time fusion technique of MD-CT or MRI with CEUS new possibilities for the evaluation, intervention and monitoring of the therapy of liver lesions were made possible, since the method also comprised the dynamic microperfusion.

Contrast-enhanced ultrasound in diagnosing liver malignancy.

PURPOSE: The use of contrast enhancers has widened the possibilities of sonographic imaging, and allows the differentiation of characteristic enhancement patterns leading to diagnosis in focal liver lesions. The aim of our study was to evaluate contrast ultrasound signs in diagnosing malignant liver lesions. METHODS: 86 patients with 100 solid liver lesions were enrolled. A baseline gray-scale sonogram was obtained with a multifrequency 4 C convex array probe, followed by contrast-enhanced sonography with a low mechanical index (<0.2) over 300 seconds. Final diagnosis was confirmed by histology or in case of haemangioma by CT/NMR and quantitative contrast harmonic imaging (CHI) with perfusion analysis (contrast). RESULTS: 55 malignant (6 HCC, 46 secondary malignant lesions - 3 of them lymphoma, 3 cholangiocarcinoma), and 45 benign lesions (8 FNH, 1 von Meyenburg complex, 1 granuloma, 3 adenoma, 21 hemangioma, 2 focal fat storage imbalances, 7 abscesses, one scar, and in one case normal liver) were found. 51/55 malignant (all but one filia and three HCC), but also 17/45 benign lesions showed hypoperfusion in the late phase. The ultrasound pattern in the arterial phase differed in malignant lesions: 22 lesions were initially hypervascular, 20 had rim enhancement and in 13 lesions there was a non-specific vascularisation. In all but one malignant lesion a diminishing of contrast agent in the late phase compared to the arterial phase with respect to the surrounding liver tissue was observed. Only three benign lesions with this later sign were falsely diagnosed as malignant: one adenoma, one epitheloid granuloma, and a scar. Quantitative perfusion pattern was analyzed exemplary. Diminishing of contrast agent in the late phase compared to the arterial phase with respect to the surrounding liver tissue as a sign for malignancy had a positive predictive value of 95%, a sensitivity of 98%, a negative predictive value of 98%, and a specificity of 93%. CONCLUSIONS: Diminishing of contrast agent in the late phase compared to the arterial phase with respect to the surrounding liver tissue is a helpful sign in contrast enhanced ultrasound to diagnose malignancies.

Quantitative assessment of bowel wall vascularisation in Crohn's disease with contrast-enhanced ultrasound and perfusion analysis.

Patients with inflammatory bowel disease (IBD) often undergo several radiologic imaging studies, which - with the exception of magnetic resonance imaging (MRI) and B-scan ultrasound (US) - subject patients to ionizing radiation. With contrast enhanced ultrasound microvascular imaging of the bowel is possible. Hence, the aim of our study was to assess the perfusion pattern of inflamed bowel walls in Crohn's disease compared with healthy volunteers quantitatively using a specific quantification software. We evaluated 4 volunteers and 20 patients with proven Crohn's disease, who went through an active episode based on clinical symptoms and complementary imaging by MRI (19 patients) and computed tomography (1 patient), respectively, with dynamic contrast-enhanced ultrasound (CEUS) using a second generation contrast agent (SonoVue, Bracco, Germany). Retrospectively, we applied the quantification software Qontrast (Bracco, Italy) to obtain contrast-enhanced sonographic perfusion maps for each lesion. Patients had significant higher peak values (median 46.86, lower quartile 37.91, upper quartile 53.20) and significant higher regional blood volume (median 2133.65, lower quartile 1202.90, upper quartile 2820.44) than volunteers. Considering the very low peak value of the healthy, it is easy to understand that the time-to-peak was significantly shorter in the volunteers (median 4.45, lower quartile 1.82, upper quartile 6.88) than in the patients (median 12.15, lower quartile 9.18, upper quartile 15.74). Our study showed clear differences between inflamed and normal bowel wall vascularity regarding all perfusion parameters. These results show that a quantitative assessment of the bowel wall vascularisation and inflammation, respectively, is possible. The software used here enables us to collect data, not only in a semi-quantitative but also in a reproducible, quantitative manner which is comparable with the evaluation of CT or MRI generated data.

[Diagnostic and therapeutic consequences of abnormal ultrasound findings]. / Diagnostische und therapeutische Konsequenz von Ultraschallbefunden.

BACKGROUND AND OBJECTIVE: The aim of this study was to evaluate the diagnostic and therapeutic consequences arising from abnormal ultrasound findings in a multidisciplinary setting in the University of Regensburg Clinical Centre. PATIENTS AND METHODS: The results of 1162 randomly selected ultrasound examinations (on 671 males and 491 females) from a total of 14,301 at an interdisciplinary ultrasound unit were analysed. The investigators recorded the findings in a routinely used standardized manner. The records and discharge reports of each patient were then evaluated with regard to the diagnostic and therapeutic consequences of the findings. RESULTS: There were 1843 abnormal findings in 901 patients. In 114 patients (6.2 %) no adequate diagnostic measures had been undertaken or recommended at discharge, but the reasons for the decisions taken could not be judged (value 4). 72.1 % of all patients were recruited from departments of internal medicine. However, the highest percentage of findings without adequate consequences were found to be in patients of the departments of oral and maxillofacial surgery, dermatology and nuclear medicine. CONCLUSION: The number of ultrasound examinations that had been done without adequate consequences was comparatively low at 6.2 %. But perhaps this number can be further reduced by improved wording of the examination reports.

Microcirculation and perfusion with contrast enhanced ultrasound (CEUS) in Crohn's disease: first results with linear contrast harmonic imaging (CHI).

AIM: To evaluate a newly introduced high resolution linear transducer for vascularization and mural perfusion assessment using contrast harmonic imaging (CHI) with quantitative time intensity curve analysis (TIC) in patients with active Crohn's disease (CD). MATERIAL AND METHODS: We prospectively evaluated 14 consecutive patients (7 women, 7 males, age range 19-42 years, median 28 years) with histologically proven CD having an acute episode of the disease applying contrast enhanced MRI and high resolution ultrasound. For the ultrasound we used a newly introduced high resolution linear multi-frequency transducer (6-9 MHz, Logiq 9, GE). Ultrasound was performed by an experienced radiologist applying color coded Doppler sonography (CCDS), power Doppler (PD) and contrast enhanced CHI using the 'true agent detection mode'. Additionally, 5 healthy volunteers were examined by ultrasound applying CCDS, PD and CHI. After the injection of 2.4 ml ultrasound contrast agent (SonoVue) the dynamic CHI cine sequences were recorded as digital raw data for 60 seconds. Therefore we were able to perform a quantitative perfusion analysis using TIC retrospectively. CCDS, PD and CHI with TIC were compared and analyzed. RESULTS: In all 14 patients MRI showed inflammatory changes in the terminal or pre-terminal ileum. Using PD and CCDS enlarged vessels surrounding the bowel wall were visualized in all patients. PD as well as CCDS diagnosed just in 9 of 14 patients augmented mural vessels. Having CHI with TIC increased mural contrast enhancement was diagnosed in all 14 patients. Patients with CD showed a maximum enhancement 36 s after injection with 9 dB (range 5.9-13.2 dB), while healthy volunteers reached the maximum level of 2.8 dB (range 2-3.8 dB) after 23 s (p<0.05). CONCLUSION: Using high resolution linear transducer mural perfusion changes in active Crohn's disease can be appreciated applying CHI with TIC. This technique could be an effective dynamic imaging modality for diagnosis and especially follow-up examination to monitor treatment in CD.