Modern Ultrasound Diagnostic Procedures in an Interdisciplinary Ultrasound Department: Challenge and Opportunities for Radiologists

Interdisciplinary ultrasound departments are sources for modern and effective ultrasound diagnostic procedures. Radiologists have a very important role as part of these centers for the establishment of new diagnostic ultrasound modalities like contrast-enhanced ultrasound (CEUS), image fusion between US and computed tomography (CT) and magnetic resonance tomography (MRI), resulting in new interventional procedures. Data acquisition and the development of solutions for PACS are also important points.

Evaluating post-interventional occlusion grades of cerebral aneurysms with transcranial contrast-enhanced ultrasound (CEUS) using a matrix probe

PURPOSE

The main goal of cerebral endovascular aneurysm therapy is the complete occlusion of the aneurysm. Along with the development of new aneurysm treatment devices, repeated controls are necessary. We examined whether contrast-enhanced ultrasound can help to monitor aneurysms after endovascular treatment.

MATERIALS AND METHODS

We prospectively examined 12 patients after coiling (7 patients) or flow diverter (FD) implantation (5 patients). These patients were examined with transcranial contrast-enhanced ultrasound using a matrix probe (1 - 5 MHz). Doppler sonography, Power Doppler, contrast harmonic imaging (CHI) and Power Doppler sonography (CPD) were included in the examination. Digital subtraction angiography with 3 D reconstructions served as the gold standard. Two radiologists decided in consensus about the degree of aneurysm occlusion separately in CEUS and digital subtraction angiography using a 4-point grading scheme.

RESULTS

The degree of occlusion of the 12 aneurysms comparing the two imaging modalities was identical in 10 cases. In two cases CHI and CPD showed a small aneurysm remnant after coiling in the center of the coil pack while in digital subtraction angiography the aneurysms seemed completely occluded.

CONCLUSION

The investigation indicates that contrast-enhanced ultrasound is a supportive, noninvasive method for post-interventional controls of intracranial aneurysms due to its ability to display not only macro- but also microvascularization.

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.

[Interventional sonography of the liver and kidneys]

CLINICAL/METHODICAL ISSUE

Optimization of ultrasound guided interventional procedures of the liver and kidneys using new imaging methods.

STANDARD RADIOLOGICAL METHODS

Punctures, biopsies, drainage, intraoperative ultrasound, fusion, embolization in correlation with ultrasound and other imaging methods.

METHODICAL INNOVATIONS

Real-time-sonography, contrast-enhanced ultrasound (CEUS) and fusion for planning, monitoring and postinterventional control.

PERFORMANCE

The use of CEUS enables better detection, characterization and execution of interventional procedures. Fusion facilitates detection.

ACHIEVEMENTS

The CEUS procedure is superior for detection and characterization of smaller lesions in comparison to the B scan. Fusion enables the performance of difficult interventional procedures.

PRACTICAL RECOMMENDATIONS

The B scan is the standard imaging method but CEUS and fusion could be helpful for smaller lesions.

Postoperative monitoring of local and free flaps with contrast-enhanced ultrasound (CEUS)--analysis of 112 patients

PURPOSE

Tissue defects are a common problem in trauma surgery and oncology. Flap transplantation is often the only therapy to cover such defects. Several monitoring systems are currently available but none has made it to the clinical routine. The aim of this study was to assess perfusion disturbances of local and free flaps using contrast-enhanced ultrasound (CEUS).

MATERIALS AND METHODS

112 patients were examined during the first 72 hours after operation. CEUS was performed by one experienced examiner with a linear transducer (6 - 9 MHz, LOGIQE9/GE) after a bolus injection of 2.4 ml sulfohexa-fluoride microbubbles (SonoVue®, Bracco, Italy). Retrospective vascular perfusion was quantified by evaluating the stored DICOM cine loops using the perfusion software QONTRAST® (Bracco, Italy). Over a total penetration depth of 3 cm, every centimeter was analyzed separately. 27 complications were observed. Complete flap loss was only seen in 4 cases, while 23 flaps had to undergo minor revision and survived.

RESULTS

Regarding the complete flap size, quantitative analysis showed significantly higher perfusion values in patients without complications compared to patients with complications: PEAK 16.5 vs. 10.0 (p = 0.001), TTP 32.6 vs. 22.2 (p = 0.001), RBV: 738.8 vs. 246.2 (p < 0.001), RBF 17.5 vs. 10.1 (p < 0.001) and MTT 43.1 vs. 29.5 (p = 0.001). Analysis of the correlation of the different flap types, age, sex and etiology of the tissue defect to the complication rate showed no statistical correlation.

CONCLUSION

CEUS was capable of detecting vascular disturbances after flap transplantation. TTP, RBV and MTT seem to be the most accurately parameters and are not susceptible to malfunction during measurement.

Monitoring during hepatic radiofrequency ablation (RFA): comparison of real-time ultrasound elastography (RTE) and contrast-enhanced ultrasound (CEUS): first clinical results of 25 patients

PURPOSE

To evaluate the reliability of ultrasound elastography for delineating thermal ablation defects post-radiofrequency ablation (RFA) by comparing lesion dimensions determined by real-time elastography (RTE) with the findings of contrast-enhanced ultrasound (CEUS).

MATERIALS AND METHODS

A total of 21 malignant liver tumors were percutaneously ablated using RFA. Color-coded elastography and CEUS were performed by one experienced examiner, using a 1 - 5 MHz multi-frequency convex transducer (LOGIQ E9, GE). Lesions were examined using CEUS and real-time elastography (RTE) to assess ablation defects. Measurements of lesions (long axis, short axis, and area) representing the same image plane used for elastography were taken during CEUS examination and compared to the measurements obtained from the elastograms. All measurements were performed by two independent observers.

RESULTS

A statistically significant correlation in vivo between RTE and CEUS measurements with respect to the lesion's principal axis and area (r = 0.876 long axis, r = 0.842 short axis and r = 0.889 area) was found. Inter-rater reliability assessed with the concordance correlation coefficient was substantial for all measurements (ρc ≥ 0.96) Overall, elastography slightly underestimated the lesion size, as judged by the CEUS images.

CONCLUSION

These results support that RTE could potentially be used for the routine assessment of thermal ablation therapies.

Dynamic evaluation and quantification of microvascularization during degradable starch microspheres transarterial Chemoembolisation (DSM-TACE) of HCC lesions using contrast enhanced ultrasound (CEUS): a feasibility study

PURPOSE

To evaluate the time dependent changes of microcirculation in hepatocellular carcinoma (HCC) lesions during degradable starch microsphere (DSM)-TACE using contrast enhanced ultrasound (CEUS).

MATERIALS AND METHODS

A total of 48 CEUS examinations were performed (1-5 MHz, convex probe) in 6 selected patients who underwent DSM-TACE with EmboCept®S for the treatment of HCC lesions. I.v. application of ultrasound contrast media was performed before and 24 hours post embolization. In addition i.a. contrast application was performed via the angiographic catheter right before and after the embolization and during a follow up time of 2 hours every 30 minutes. The capillary circulation of the treated HCC lesions was analyzed and quantitative perfusion analysis was performed using a perfusion software by two experienced radiologists in consensus.

RESULTS

A significantly reduced microvascularization was seen right after DSM-TACE in all cases using CEUS. The reduction of PEAK, RBV (regional blood volume) and RBF (regional blood flow) compared to preembolization values was highly significant. Mean PEAK was 34.3 ± 13.1 prior to embolization and 9.4 ± 9.1 post embolization (p < 0.001). Mean RBV was 446.5 ± 122.4 prior to embolization and 70.9 ± 23.8 post embolization (p < 0.001). The corresponding figures for RBF were 34.7 ± 13.4 prior- and 4.8 ± 3.4 post embolization (p < 0.001). During follow up a stepwise revascularization of the lesions was documented: 90 minutes post embolization perfusion parameters were not significantly different from prae-embolization values.

CONCLUSION

In this feasibility study, capillary perfusion quantification of HCC lesions after DSM-TACE could be demonstrated using CEUS. Using quantitative perfusion analysis it was possible to quantify the transient embolizing effect of DSM-TACE.

Degradable starch microspheres transarterial chemoembolisation (DSM-TACE) of HCC: Dynamic Contrast-Enhanced Ultrasonography (DCE-US) based evaluation of therapeutic efficacy using a novel perfusion software

PURPOSE

To evaluate therapeutic efficacy of degradable starch microsphere (DSM)-TACE in hepatocellular carcinoma (HCC) using Dynamic Contrast-Enhanced Ultrasonography (DCE-US) based perfusion analysis.

MATERIALS AND METHODS

A total of 60 DCE-US examinations were performed in 15 selected patients who underwent DSM-TACE with EmboCept®S for the treatment of advanced HCC. DCE-US was performed via i.v. application of ultrasound contrast media before and 24 hours post embolization. In addition DCE-US was performed with i.a. contrast application via the angiographic catheter right before and after the embolization. Microcirculation of embolized HCC lesions was quantified using a dedicated perfusion software by two experienced radiologists in consensus.

RESULTS

Significant reduction of microvascularization (PE, WiAUC and WiR) was seen right after DSM-TACE and during 24 hour follow-up. Mean PE was 342.22 ± 97.80 prior to embolization, 59.28 ± 29.74 post embolization (p = 0.019) and 18.83 ± 7.03 during follow-up (p ≤ 0.01). Mean WiAUC was 1103.21 ± 432.05 prior to embolization 267.69 ± 151.80 post embolization (p = 0.023) and 105.10 ± 44.43 during 24 hour follow-up (p ≤ 0.01). The corresponding values for WiR were 224.91 ± 57.97 prior-, 38.14 ± 18.80 post embolization (p = 0.034) and 6.97 ± 2.68 during follow up (p ≤ 0.01).

CONCLUSION

In this study, therapeutic efficacy of DSM-TACE in HCC using DCE-US based perfusion analysis could be demonstrated.

High resolution ultrasound including elastography and contrast-enhanced ultrasound (CEUS) for early detection and characterization of liver lesions in the humanized tumor mouse model

PURPOSE

In this study we investigated the sensitivity of high resolution ultrasound (HRU) in the detection of small liver tumors and its microcirculation in a humanized tumor mouse model (HTM). These mice develop a complete human immune system and human breast cancer growth in the liver which allows the investigation of antibody based immunotherapies under human like conditions.

METHOD

HTM were generated by the co-transplantation of human breast cancer cells and human hematopoietic stem cells. HRU, Doppler sonography (CCDS), contrast enhanced ultrasound (CEUS) and color-coded elastography were performed on all HTM and confirmed by histopathological assessment.

RESULTS

Using HRU and CEUS, noncystic solid liver lesions between 2 and 11 mm (mean 3.5 mm) size were detectable in HTM. Granulomatous areas were identified by B-scan imaging, showing areas of higher stiffness in elastography and areas without contrast media uptake in the late phase (CEUS). In addition, CEUS detected capillary microcirculation of benign and malignant liver lesions smaller than 10 mm.

CONCLUSION

Beyond human breast cancer HTM additionally developed small parenchymal liver lesions, which could be characterized by HRU in combination with CEUS and elastography in-vivo. Nevertheless, the defined diagnoses of solid liver lesions less than 5 mm require confirmation by histopathology.

First results of endocavity evaluation of the microvascularization of malignant prostate tumors using contrast enhanced ultrasound (CEUS) including perfusion analysis: first results

AIM

Detection of prostate cancer lesions using transrectal contrast enhanced ultrasound (CEUS) of the prostate utilizing quantitative perfusion analysis.

METHOD

20 patients (mean age 63 years, 47-71) with biopsy proven prostate cancer underwent transrectal ultrasound (TRUS) prior to radical prostatectomy by 2 experienced examiners using a multifrequency endocavitary probe (5-9 MHZ, LOGIQ E9, GE Healthcare, Chalfont St Giles, UK) to detect cancer-suspect lesions. CEUS was performed dynamically up to 3 Min after bolus injections of 2.4 ml SonoVue® (BRACCO, Italy). Digital cine loops were analyzed by an independent blinded examiner using perfusion quantification software with colour-coded parametric images in order to define suspect regions based on the perfusion-related parameters early wash in rate (WIR), mean transit time (MTT) and rise time (RT). The results of CEUS perfusion analysis were compared with the histopathology after surgery, obtained from whole mount sections.

RESULTS

After prostatectomy and histopathology, 34 prostate cancer foci were found in 20 patients. In 30/34 cases an early enhancement within the tumor was detected by CEUS perfusion analysis without early wash out. By evaluating the MTT and RT tumor detection was possible in 29/34 and 25/34 cases. The highest detection rate of prostate cancers was obtained by analysis of early contrast enhancement (priot to the normal prostate parenchyma), with a sensitivity of 88%, specificity 100%, NPP 60%, PPV 90%, in clinically suspicious cases with good correlation to the postoperative histopathological findings (r = 0.728).

CONCLUSION

This pilot study demonstrates, that quantitaive analysis of perfusion parameters obtained with transrectal CEUS could be helpful for characterization of neoplastic microcirculation of prostate cancer, for preoperative localization of cancer-suspect areas and for therapy guidance and management.

Percutaneous irreversible electroporation (IRE) of hepatic malignant tumours: contrast-enhanced ultrasound (CEUS) findings

PURPOSE

The aim of this study is to describe the image findings of contrast-enhanced ultrasound (CEUS) after irreversible electroporation (IRE), and to assess its usefulness in relation to the evaluation of the ablation status using a dynamic recording of the microvascularisation.

MATERIAL AND METHOD

In this prospectively designed study, a percutaneous IRE was performed for the treatment of malignant hepatic lesions in a total of 15 patients following the interdisciplinary diagnosis. The lesions were documented using CEUS before, immediately after and 20 minutes after the ablation. The acquired CEUS image data was subsequently independently retrospectively evaluated by 2 experienced radiologists and assessed in relation to microvascularisation using a 5 point scale.

RESULTS

Using CEUS, a significant reduction in the microcirculation of the lesions, both centrally and marginally, could be detected following IRE (p < 0.001 and p < 0.001). The mean evaluation of the central microcirculation was reduced from 3.13 ± 1.38 to 0.47 ± 0.64 (p < 0.01). For the peripheral area of the lesion and the ablation margin, there was a reduction of 3.37 ± 1.13 to 1.57 ± 0.46 (p = 0.001). There was no significant reduction in the macrocirculation.

CONCLUSION

Within the framework of this study, it could be demonstrated that, in the course of IRE, a rapid significant reduction of the microcirculation in the ablation area occurred.

Quantitative assessment of bone microvascularization after osteocutaneous flap transplantation using contrast-enhanced ultrasound (CEUS)

BACKGROUND

Extensive wound defects frequently have to be covered by free flap transplantation. A monitoring device for measuring capillary level perfusion of bone is currently not available.

OBJECTIVE

The aim of the study was to detect complications after osteocutaneous flap transplantation using contrast-enhanced ultrasound (CEUS). Additionally quantitative analysis was performed by special perfusion software (QONTRAST®; Bracco, Italy).

METHODS

22 patients were examined after osteocutaneous flap transplantation during the first 72 h after operation. CEUS was performed with a linear transducer (6-9 MHz, LOGIQ E9/GE) after bolus injections of 2.4 ml ultrasound contrast agent (SonoVue®; Bracco, Italy). The osseous perfusion and soft tissue perfusion were analyzed separately and quantitative perfusion analysis was performed. Five patients had to undergo reoperation due to compromised flap microvascularization.

RESULTS

In all 5 complications reduced osseous and soft tissue perfusion was seen using CEUS. Additionally using the perfusion parameters TTP (time to PEAK), RBV (regional blood volume), RBF (regional blood flow) und MTT (mean transit time), significantly lower soft tissue and osseous perfusion was detected.

CONCLUSION

CEUS seems to be capable of detecting vascular disturbances and of assessing microvascularization of the osseous component after osteocutaneous flap transplantation.

Tissue-specific expression of occludin, zona occludens-1, and junction adhesion molecule A in the duodenum, ileum, colon, kidney, liver, lung, brain, and skeletal muscle of C57BL mice

Tight junctions are the most apically positioned intercellular junction and play many roles such as securing adjacent cells, forming barriers from extracellular materials, and facilitating paracellular transport. Occludin and junction adhesion molecule A (JAM-A) are classified as transmembrane proteins that are directly involved in paracellular transport. Zona occludens-1 (ZO-1) is a protein that contains a PDZ domain which forms a binding site for other tight junction proteins. In this study, we assessed the differential expression of these tight junction components in various mouse organs including the intestine (duodenum, ileum, and colon), kidney, liver, lung, brain, and skeletal muscle. Realtime PCR and Western blot assays were performed to measure the gene and protein expression of occludin, JAM-A, and ZO-1. Similar levels of occludin gene expression were detected in all tissues except for skeletal muscle in which occludin expression was not found. The JAM-A and ZO-1 genes were highly expressed in all the tested tissues. Localization of occludin, JAM-A, and ZO-1 was determined by immunohistochemistry. These proteins were detected in the intercellular apical junctions in each tissue except for occludin (which was not observed in skeletal muscle). These immunostaining data were consistent with the gene expression profiles we obtained. Our results suggest that occludin, JAM-A, and ZO-1 genes are normally expressed in the intestine, kidney, liver, lung, and brain indicating that these factors may be essential for maintaining appropriate physiological concentration of ions, solutes and water.

Sonoelastography can be used to monitor the restoration of Achilles tendon elasticity after injury

PURPOSE

The aim of the current study was to evaluate an ultrasound approach for depicting elastic recovery after stem cell application on injured Achilles tendons.

MATERIALS AND METHODS

A rabbit Achilles tendon injury model was used and randomized hind limbs received an extracellular matrix either with autologous mesenchymal stem cells (group 2, n = 6) or without (group 3, n = 6). The cells were harvested from the rabbits' nuchal fat body. Untreated Achilles tendons (group 1, n = 6) served as controls. Specimens were harvested after 8 weeks and analyzed longitudinally for elasticity using a high resolution 6-15 MHz matrix linear probe. For each tendon, real-time color-coded sonoelastography sequences were recorded for 20 seconds and 10 color histogram frames were obtained. Defined regions of interest (ROIs) were placed on the injury (n = 3) and on the adjacent uninjured tendon tissue (n = 3). In total, 180 measurements were obtained for semi-quantitative analysis.

RESULTS

Repeated measures ANOVA demonstrated a higher elasticity for the stem cell-seeded matrix (group 2) in comparison to the unseeded matrix (group 3) (p < 0.001). No significant difference was found between the injured tendon tissue treated with stem cell-seeded matrix (group 2) and the uninjured Achilles tendons (group 1) (p > 0.05). Moreover, no differences were found between the measurements at different points in time (p > 0.05).

CONCLUSION

Our results indicate that autologous mesenchymal stem cell application successfully restores the mechanical properties of injured tendon tissue. Furthermore, sonoelastography makes it possible to monitor the elasticity of injured Achilles tendons.

Additional effects of bisphenol A and paraben on the induction of calbindin-D(9K) and progesterone receptor via an estrogen receptor pathway in rat pituitary GH3 cells

There are concerns about the combined estrogenic effects of chemicals since mixtures of these chemicals exist in our environment. This study investigated potential additional interactions between bisphenol A (BPA) and isobutylparaben (IBP), which are major xenoestrogens used in the manufacture of plastics, cosmetics, drugs, and other products. The combined effects of these two chemicals were analyzed by measuring the expression of calbindin-D(9k) (CaBP-9k) in rat pituitary cancer GH3 cells. GH3 cells were treated with single and combination doses of both chemicals (BPA single doses: 10(-7), 10(-6) and 10(-5) M; IBP single doses: 10(-7), 10(-6) and 10(-5) M, and each of the BPA and IBP doses combined). Prior to treatment, cells were temporarily transfected with a plasmid containing an ERE-luciferase reporter gene. Luciferase activity was measured as an indicator of ER activation by 17β-estradiol (E2), BPA, and IBP. BPA (10(-5) M) combined with IBP (10(-7) M and 10(-6) M) induced a significant increase in the luciferase activity. Twenty-four hours after treatment, dose-dependent effects were observed in both single and combined dose groups, and several combination doses induced significant increases in the expression of CaBP-9k and progesterone receptor (PR) at both transcriptional and translational levels. Pre-treatment with ICI 182,780, a pure estrogen antagonist, significantly reversed BPA- and IBP-induced CaBP-9k and PR upregulation in GH3 cells. Taken together, these results indicate that BPA and IBP may have additionally increased estrogenic potency via an estrogen receptor-mediated pathway.

Contrast enhanced ultrasound (CEUS) and time intensity curve (TIC) analysis in compartment syndrome: first results

OBJECTIVE

Purpose of this study was to monitor changes of microcirculation in acute compartment syndrome using contrast enhanced ultrasound (CEUS) and to assess the modified perfusion with a special quantification software.

METHODS

8 patients with trauma of the lower limb or the upper extremity were enrolled after acute compartment syndrome was diagnosed clinically and by intracompartmental pressure measurement. The qualitative analysis of the corresponding compartment was assessed using B-scan mode and CEUS simultaneously. CEUS was performed using a multifrequence probe (6-9 MHz, LOGIQ E9 GE) after a i.v. bolus injection of 2 × 2.4 ml contrast agent (SonoVue(®), Bracco, Italy). Digital raw data were stored as cine loops up to 2 minutes. Retrospectively semiquantitative perfusion analysis was performed using time intensity curve analysis and the quantification software QONTRAST(®).

RESULTS

6 out of 8 patients had to be operated due to clinical symptoms and to a pressure perfusion gradient lower than 30 mm Hg. 2 out of 8 were treated conservatively. In all patients haematomas were seen in B-scan mode. No necrosis could be detected. In the TIC analysis low levels of time to peak (20.0 ± 12.1) and area under the curve (118.4 ± 87.8) were observed in acute compartment syndrome. Similarly results have been obtained using the perfusions parameter PEAK (11.1 ± 5.7), time to PEAK (14.7 ± 9.7), regional blood volume (257.1 ± 192.6), and regional blood flow (12.1 ± 6.5) in QONTRAST(®) perfusion software.

CONCLUSION

CEUS may be capable of differing between acute compartment syndrome and imminent compartment syndrome.

Bedside diagnosis of pleural effusion with a latest generation hand-carried ultrasound device in intensive care patients

BACKGROUND

Further development established hand-carried ultrasound (HCU) imagers in daily clinical workflow providing several advantages such as fast bedside availability and prompt diagnosis.

PURPOSE

To evaluate the diagnostic yield of a latest generation HCU imager compared to chest radiography (CR) for the detection of pleural effusion (PE) in intensive care patients.

MATERIAL AND METHODS

Forty-eight hemithoraces of 24 patients on surgical intensive care units were enrolled in this study. All hemithoraces were evaluated using both HCU and CR. Definite diagnosis of PE was achieved using a high-end ultrasound system as standard of reference. Statistical analysis was performed using 2 × 2 tables and a McNemar test. A P value of <0.05 was considered statistically significant.

RESULTS

PE was present in 35 of 48 hemithoraces (73%). The HCU examination was carried out technically successfully in all hemithoraces. Sensitivity and specificity of HCU for the diagnosis of PE was 91% and 100%, respectively, whereas sensitivity and specificity of CR was 74% and 31%, respectively. The difference between HCU and CR was statistically significant with respect to specificity but not sensitivity (P = 0.008 and P = 0.11, respectively).

CONCLUSION

Due to its ease of use and its high diagnostic yield HCU systems of the latest generation constitute a helpful technique for the primary assessment of PE.

Contrast-enhanced ultrasound for differential diagnosis of suspected GvHD in patients after allogeneic transplantation

GvHD is a serious complication in patients after allo-SCT, presenting with unspecific symptoms such as abdominal pain or cramps and diarrhea. Early diagnosis of GvHD, after differentiation from other causes leading to the same symptoms, such as viral or bacterial enteritis, is highly important because the time needed for diagnosing GvHD is directly correlated to a worsening of the outcome. We examined 23 patients presenting with the abdominal symptoms mentioned above, of whom 20 had received an allo-SCT in their history and were thus potential candidates for enteric GvHD. The other three patients were included because they also presented with abdominal symptoms similar to those of GvHD, which could be ruled out due to their history. We wanted to evaluate CEUS in these patients as an additional subgroup to gain more data on the value of CEUS in early detection of enteral GvHD and in the differentiation of GvHD against other causes of abdominal discomfort. All patients underwent CEUS with particular attention to penetration of the intravenously applied microbubbles in the bowel lumen. In the patients having allo-SCT in their history we strove to achieve histological confirmation of GvHD of the GI-tract. The resulting examinations were documented digitally. Out of 17 patients with confirmed GvHD of the GI tract, 14 showed penetration of the intravenously applied microbubbles into the bowel lumen, leading to a sensitivity and specificity of 82% and 100% for transmural bubble penetration for GvHD of the GI-Tract, since the patients without GvHD of the GI tract showed no transmural bubble penetration. In patients with viral or bacterial infections of the GI tract, no transmural penetration of the microbubbles into the bowel lumen was observed. For microbubble penetration as a criterion for GvHD of the GI-Tract, this leads to a negative predictive value (NPV) of 67%, and a positive predicative value (PPV) of 100%.