Comprehensive characterization of RB1 mutant and MYCN amplified retinoblastoma cell lines.

In retinoblastoma research tumor-derived cell lines remain an important model to investigate tumorigenesis and new therapy options, due to limited tumor material and lack of adequate animal models. A panel of 10 retinoblastoma cell lines was characterized with respect to mutation, methylation and expression of RB1 and MYCN. These established retinoblastoma cell lines represent the most frequent types of RB1 inactivation and together with the MYCN amplification status, three classes can be distinguished: RB1mut/MYCNnonA, RB1mut/MYCNA and RB1wt/MYCNA. MYCN amplification was identified in five cell lines, whereby two of them, RB522 and RB3823, harbor no aberration in RB1. Targeted sequencing of 160 genes often mutated in cancer identified only few variants in tumor-associated genes other than in RB1. None of these variants was recurrent. mRNA expression analyses of retinal markers, cell cycle regulators and members of the TP53 signaling pathway revealed a high variability between cell lines but no class-specific differences. The here presented thorough validation of retinoblastoma cell lines, including microsatellite analysis for cell line authentication, provides the basis for further in vitro studies on retinoblastoma.

Neutron Diffraction Study of Macrostress and Microstress in Al-Al2O3-Based Corrosion Protection Coating Obtained by Cold Spray (Dynamic Metallization).

Protective coatings based on an Al-Al2O3 metal matrix composite (MMC) were sprayed using dynamic metallization (DM), a low-pressure cold spray variant. A series of samples approximately 1 mm in thickness were sprayed using different spray process parameters (temperature, velocity) and different feedstock powder compositions (Al, Zn, Al2O3). This resulted in MMCs of different phase compositions and slightly different physical conditions of coating formation. The through-thickness residual stresses that accumulate in coatings during the spray process were studied using neutron diffraction in all phases comprising the MMCs. The overall residual stress in the coating (macrostress) was compressive, which is in good agreement with the data on residual stress observed in other cold spray coatings, accumulating as a result of the peening process. However, due to the slightly elevated spray temperature characteristic of DM in comparison with other cold spray variants, thermal stresses are also present and play an equally important role in the accumulation of residual stress in each phase. Because of the multi-phase composition and thermal mismatch between the metal and ceramic components of the MMC, inter-phase microstresses also accumulate. A micro-mechanical explanation of the observed tensile microstress in Al/Zn versus compressive stress in Al2O3 is proposed.

Multiaxial constitutive behavior of an interstitial-free steel: Measurements through X-ray and digital image correlation.

Constitutive behaviors of an interstitial-free steel sample were measured using an augmented Marciniak experiment. In these tests, multiaxial strain field data of the flat specimens were measured by the digital image correlation technique. In addition, the flow stress was measured using an X-ray diffractometer. The flat specimens in three different geometries were tested in order to achieve 1) balanced biaxial strain, and plane strain tests with zero strain in either 2) rolling direction or 3) transverse direction. The multiaxial stress and strain data were processed to obtain plastic work contours with reference to a uniaxial tension test along the rolling direction. The experimental results show that the mechanical behavior of the subjected specimen deviates significantly from isotropic behavior predicted by the von Mises yield criterion. The initial yield loci measured by a Marciniak tester is in good agreement with what is predicted by Hill's yield criterion. However, as deformation increases beyond the vonMises strain of 0.05, the shape of the work contour significantly deviates from that of Hill's yield locus. A prediction made by a viscoplastic self-consistent model is in better agreement with the experimental observation than the Hill yield locus with the isotropic work-hardening rule. However, none of the studied models matched the initial or evolving anisotropic behaviors of the interstitial-free steel measured by the augmented Marciniak experiment.

[Detection of intrinsic ligament and TFCC lesions of the wrist. Direct versus indirect MRI arthrography]. / Detektion intrinsischer Band- und TFCC-Läsionen des Handgelenks. Indirekte vs. direkte MR-Arthrographie.

BACKGROUND: The purpose of this study was to validate the diagnostic value of direct magnetic resonance imaging (dMRI) arthrography and indirect MRI (iMRI) arthrography concerning intrinsic ligament injuries and tears of the triangular fibrocartilage complex (TFCC). PATIENTS AND METHODS: A randomized prospective trial was conducted with patients who presented with wrist pain potentially due to carpal lesions and 10 patients aged 19-60 years (3 female and 7 male) were included. Between the clinical examination and the diagnostic and therapeutic arthroscopy, dMRI and iMRI arthrography were performed for the diagnostics of injuries of the intrinsic ligaments or the TFCC. The results of dMRI and iMRI arthrography were evaluated by two radiologists blinded to the injuries of the patients and a consensus was reached. The results were compared with the findings obtained by arthroscopy. RESULTS: In the arthroscopy five lesions of the scapholunate ligament (SL), one of the lunotriquetral ligament (LT) and seven of the TFCC were identified. The sensitivity of iMRI and dMRI for carpal ligament lesions (SL and LT) was low (50 %) whereas the specificity was high (93 %). For injuries of the TFCC the sensitivity (up to 100 %) and the specificity (100 %) were both excellent. The area under the curve (AUC) in the receiver operating characteristics (ROC) analysis was high for TFCC lesions in both dMRI and iMRI arthrography. CONCLUSION: Indirect MRI arthrography is a suitable method for detection of injuries of the TFCC and intrinsic ligaments of the wrist with good sensitivity and specificity. Despite the low number of patients the results of this study showed that there were no essential differences between dMRI and iMRI arthrography with respect to the diagnostic value for carpal injuries of the wrist.

[Comparison of Intravitreal Dexamethasone Implant versus Intravitreal Ranibizumab as a First-Line Treatment of Macular Oedema due to Retinal Vein Occlusion]. / Vergleich von intravitrealem Dexamethason-Implantat mit intravitrealem Ranibizumab als Erstbehandlung des Makulaödems bei retinalen venösen Gefäßverschlüssen.

PURPOSE: The present study investigated the treatment effect of dexamethasone implant (Ozurdex®, group 1) and anti-VEGF injection (Lucentis®, group 2) in course of macular oedema due to retinal vein occlusion in a retrospective, non-randomised case series. MATERIAL AND METHODS: Group 1 comprised 60 patients (31 with CRVO and 29 with BRVO) and group 2 included 52 patients, 27 with CRVO and 25 with BRVO) and both groups were further treated in case of recurrence. Preoperative and in monthly intervals best corrected visual acuity (BCVA), central retinal thickness using SD-OCT (Spectralis, Heidelberg Engineering), intraocular pressure, biomicroscopy status and a fundus photo documentation (Optomap) were evaluated. The primary clinical endpoint was visual acuity 12 months after the first intravitreal therapy, while secondary endpoints included the central retinal thickness change and safety of therapy. RESULTS: In group 1, an increase of BCVA (± standard deviation) of 8.4 (± 1.9) letters was observed in CRVO patients and a gain of 10.7 (± 3.8) letters in BRVO patients after 12 months, while in group 2, an increase of BCVA of 6.9 (± 1.9) letters (CRVO) compared to 12.5 (± 3.7) letters (BRVO) was observed after the same time span. In both groups a significant reduction in retinal thickness was achieved. An increase of intraocular pressure above 5 mmHg was observed in nearly half of the cases In group 1, but was well controlled by conservative antiglaucomatous therapy. We observed a progression of lens opacity in approximately 50 % of the cases in group 1. CONCLUSION: The treatment with Ozurdex compared to Lucentis appears to provide a trend towards a better although not significant visual acuity increase after 12 months in CRVO patients. A similar trend favouring anti-VEGF treatment with Lucentis was seen in patients with BRVO. However, the lens status and age of the patient should be taken into account when considering a treatment with Ozurdex.

Spironolactone in the treatment of central serous chorioretinopathy - a case series.

BACKGROUND: The pathogenesis of central serous chorioretinopathy (CSC) is still poorly understood. An animal model of CSC proved that the mineralocorticoid receptor [1] of the choroid also plays a role in CSC. Since there is still no evidence-based therapy for non-self-limiting CSC, this case series evaluates the effect of oral spironolactone in CSC patients. METHODS: In this interventional, uncontrolled, prospective case series, we present 18 consecutive CSC patients. Patients were treated with spironolactone 25 mg twice daily (Spironolacton AL® 50 mg, ALIUD PHARMA) for up to 12 weeks. Follow-up examinations with BCVA, OCT, and EDI-OCT were performed at 1, 2, and 3 months after starting the treatment. Main outcome measure was a change of subretinal fluid (SRF) (in micrometers) measured by optical coherence tomography. Secondary outcome was a change in central retinal thickness (CRT) (in micrometers) measured by OCT and a change in BCVA. RESULTS: The subretinal fluid (SRF; mean) decreased from 219 µm (baseline) to 100 µm (visit 3) (difference 119 µm). Total central retinal thickness (CRT; mean) decreased from 405 µm before treatment (baseline) to 287 µm after treatment (difference 118 µm). The BCVA (in logMAR; mean) increased from 0.32 at baseline to 0.20 at visit 3. CONCLUSION: Our case series could confirm a positive influence of spironolactone on the course CSC. Longer follow-up with a larger number of cases could provide more data about the long-term efficiency, recurrences, and safety of this well-tolerated and non-invasive treatment option of CSC.

Impact of encorafenib on survival of patients with BRAFV600E-mutant metastatic colorectal cancer in a real-world setting.

PURPOSE: Patients with BRAFV600E-mutant metastatic colorectal cancer (mCRC) have a dismal prognosis. The best strategies in these patients remain elusive. Against this background, we report the clinical course of patients with BRAFV600E-mutant mCRC to retrieve the best treatment strategy. PATIENTS AND METHODS: Clinico-pathological data were extracted from the electronic health records. Kaplan-Meier method was used to estimate overall (OS) and progression-free survival (PFS). Objective response rate (ORR) was assessed according to RECIST 1.1. RESULTS: In total, 51 patients were enrolled. FOLFOXIRI was administered to 12 patients; 29 patients received FOLFOX or FOLFIRI as first-line treatment. Median OS was 17.6 months. Median PFS with FOLFOXIRI (13.0 months) was significantly prolonged (HR 0.325) as compared to FOLFOX/FOLFIRI (4.3 months). However, this failed to translate into an OS benefit (p = 0.433). Interestingly, addition of a monoclonal antibody to chemotherapy associated with superior OS (HR 0.523). A total of 64.7% patients received further-line therapy, which included a BRAF inhibitor in 17 patients. Targeted therapy associated with very favourable OS (25.1 months). CONCLUSION: Patients with BRAFV600E-mutated mCRC benefit from the addition of an antibody to first-line chemotherapy. Further-line treatment including a BRAF inhibitor has a dramatic impact on survival.

Smaller panel, similar results: genomic profiling and molecularly informed therapy in pancreatic cancer.

BACKGROUND: Pancreatic cancer has a dismal prognosis. One reason is resistance to cytotoxic drugs. Molecularly matched therapies might overcome this resistance but the best approach to identify those patients who may benefit is unknown. Therefore, we sought to evaluate a molecularly guided treatment approach. MATERIALS AND METHODS: We retrospectively analyzed the clinical outcome and mutational status of patients with pancreatic cancer who received molecular profiling at the West German Cancer Center Essen from 2016 to 2021. We carried out a 47-gene DNA next-generation sequencing (NGS) panel. Furthermore, we assessed microsatellite instability-high/deficient mismatch repair (MSI-H/dMMR) status and, sequentially and only in case of KRAS wild-type, gene fusions via RNA-based NGS. Patient data and treatment were retrieved from the electronic medical records. RESULTS: Of 190 included patients, 171 had pancreatic ductal adenocarcinoma (90%). One hundred and three patients had stage IV pancreatic cancer at diagnosis (54%). MMR analysis in 94 patients (94/190, 49.5%) identified 3 patients with dMMR (3/94, 3.2%). Notably, we identified 32 patients with KRAS wild-type status (16.8%). To identify driver alterations in these patients, we conducted an RNA-based fusion assay on 13 assessable samples and identified 5 potentially actionable fusions (5/13, 38.5%). Overall, we identified 34 patients with potentially actionable alterations (34/190, 17.9%). Of these 34 patients, 10 patients (10/34, 29.4%) finally received at least one molecularly targeted treatment and 4 patients had an exceptional response (>9 months on treatment). CONCLUSIONS: Here, we show that a small-sized gene panel can suffice to identify relevant therapeutic options for pancreatic cancer patients. Informally comparing with previous large-scale studies, this approach yields a similar detection rate of actionable targets. We propose molecular sequencing of pancreatic cancer as standard of care to identify KRAS wild-type and rare molecular subsets for targeted treatment strategies.

[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.

[PACS: acceptance by orthopedic surgeons]. / PACS: Akzeptanz bei Orthopäden und Unfallchirurgen.

PURPOSE: The goal of the study was to evaluate the acceptance of a web-based picture archiving and communication system (PACS) by orthopedic surgeons 1 year after implementation. MATERIALS AND METHODS: One year after the implementation of a web-based PACS all physicians were surveyed with a standardized questionnaire. Questions included: speed of PACS, quality of clinicoradiological meetings, quality of monitors, PACS training, and performance. Data were evaluated separately for the Department of Orthopedic Surgery and the reference group of all other physicians. RESULTS: Among the respondents, 92% of the orthopedic surgeons stated there was a reduction of time required to receive images, and 64% concluded that patient care was faster. Archived images were received in less than 5 min in 82% after PACS and in 8% before PACS. The clinicoradiological meetings improved with PACS in 100% due to beamer presentation. All would recommend a PACS. The equipment to view images in the operating theater was assessed as being good or very good by 83%; monitor quality was judged better for the outpatient clinics (100% good or very good). Conventional radiograms were missed at the ward rounds by 56%. Training for PACS was considered sufficient by 67%, and 15% asked for refresher courses. In the reference group 60% asked for refresher courses. In the comparison of orthopedic surgeons with the reference group PACS was judged better especially concerning the viewing software and quality of monitors. CONCLUSION: There is an over all acceptance of PACS by physicians outside the radiology department. The availability of images was not only facilitated it was faster as well. However, the quality of monitors in the operating theater should be improved. To achieve sustained success of PACS consistent training on PACS and its features is necessary. Conventional radiograms were often missed at the ward rounds.

Immunohistochemical Profile and 47-Gene Next-Generation Sequencing (NGS) Solid Tumor Panel Analysis of a Series of 13 Strumal Carcinoids.

Strumal carcinoid is an extraordinary rare tumor of the ovary consisting of thyroid tissue intermixed with neuroendocrine tumor component. The cellular origin of strumal carcinoids has been an area of debate. There is also little data on detailed immunohistochemical and molecular characteristics of these neoplasms. For this reason, this series investigated the characteristics of a series of 13 strumal carcinoids using immunohistochemical markers and a 47-gene next-generation sequencing (NGS) solid tumor panel analysis. Both cellular components showed thyroglobulin expression in all tumors. TTF-1 expression was noted in both cellular components of 11 cases. Chromogranin A was positive in both components of most tumors (n = 12, 92.3% in the neuroendocrine component and n = 10, 76.9% in the thyroid follicular component). Synaptophysin stained the neuroendocrine component of all cases, and it was also identified in the follicular thyroid component of a single case. All tumors were negative for CDX2 and calcitonin. ISLET1 was positive in the neuroendocrine component of 8 cases (6.5%). With the exception of one case, all tumors were positive for SSTR2a. The tumors were associated with a low Ki67 labeling index. All cases were microsatellite stable and no pathogenic mutations were identified using a 47-gene NGS solid tumor analysis. This series underscored that strumal carcinoids are distinct neuroendocrine tumors. The synchronous expression for thyroid follicular epithelial and neuroendocrine differentiation biomarkers may suggest a precursor cell origin displaying mixed-amphicrine differentiation. While strumal carcinoids can be diagnosed by their typical morphology and immunohistochemical profile, frequent SSTR expression may serve as a potential theranostic biomarker in the management of affected patients. In addition, the absence of common driver mutations in the NGS solid tumor panel may suggest that these neoplasms seem to be genetically unrelated to follicular epithelial-derived thyroid tumors and potentially different than other commonly identified well-differentiated neuroendocrine neoplasms. Therefore, further studies focusing on molecular characteristics of this entity are still needed.

Fracture Mechanics Approach to Splitting in Low Spring Index Cold Coiling Process.

This paper is an attempt to understand the coil splitting phenomena by means of fracture mechanics. The methods used combine the residual stress measurement with neutron and finite element analysis. The support of the metallurgical evaluation is used as evidence to justify the use of the fracture mechanics concept. Comparing coil springs manufactured at two different manufacturing lines, namely N1 and N6, residual stress distributions in three main directions were measured using neutron diffraction. The results of the residual stress measurement were then converted into the stress intensity factor to enable the analysis in fracture mechanics. The mixed-mode analysis of opening, Mode I, and in-plane shearing, Mode II, is used to solve the splitting problem. The discrepancy between the coil made at N1 and N6 was identified and taken into account in terms of the profile difference. Based on this difference, an FEA simulation was conducted. The results support the experimental finding, which is that the shape of the coil manufactured influences the pattern of the residual stress, which leads to different splitting behaviors. This simple analysis helps practitioners understand why, and how, some cold coiled products split after manufacturing. It is concluded that this very basic concept of fracture mechanics can be used to establish the limit of the cold coiling process by evaluation of the mixed-mode stress intensity factor to the fracture toughness of the material.

Coexpression profile of leukemic stem cell markers for combinatorial targeted therapy in AML.

Targeted immunotherapy in acute myeloid leukemia (AML) is challenged by the lack of AML-specific target antigens and clonal heterogeneity, leading to unwanted on-target off-leukemia toxicity and risk of relapse from minor clones. We hypothesize that combinatorial targeting of AML cells can enhance therapeutic efficacy without increasing toxicity. To identify target antigen combinations specific for AML and leukemic stem cells, we generated a detailed protein expression profile based on flow cytometry of primary AML (n = 356) and normal bone marrow samples (n = 34), and a recently reported integrated normal tissue proteomic data set. We analyzed antigen expression levels of CD33, CD123, CLL1, TIM3, CD244 and CD7 on AML bulk and leukemic stem cells at initial diagnosis (n = 302) and relapse (n = 54). CD33, CD123, CLL1, TIM3 and CD244 were ubiquitously expressed on AML bulk cells at initial diagnosis and relapse, irrespective of genetic characteristics. For each analyzed target, we found additional expression in different populations of normal hematopoiesis. Analyzing the coexpression of our six targets in all dual combinations (n = 15), we found CD33/TIM3 and CLL1/TIM3 to be highly positive in AML compared with normal hematopoiesis and non-hematopoietic tissues. Our findings indicate that combinatorial targeting of CD33/TIM3 or CLL1/TIM3 may enhance therapeutic efficacy without aggravating toxicity in immunotherapy of AML.

[Non-trauma-associated additional findings in whole-body CT examinations in patients with multiple trauma]. / Nicht traumaassozierte Nebenbefunde bei Ganzkörpercomputertomografien im Rahmen der Polytraumadiagnostik.

PURPOSE: Whole-body CT scans for patients with multiple trauma represent an increasingly accepted first diagnostic tool. The multidetector approach in particular provides appropriate diagnostic algorithms for detecting nearly all relevant traumatic findings in a short time with a high grade of sensitivity and specificity. Non-trauma-associated additional findings are commonly depicted based on these CT examinations. The aim of this study is to evaluate the number and quality of these additional findings in consecutive patients with multiple trauma. MATERIALS AND METHODS: Between 3 / 04 and 8 / 06 we scanned 304 patients according to our dedicated multiple trauma protocol. The examination protocol includes a head scan without intravenous contrast followed by a whole-body scan including the neck, thorax and abdomen acquired by a 16-row CT Scanner (Siemens, Sensation 16). The CT scans were retrospectively analyzed by two radiologists with respect to non-trauma-associated findings. Lesions were assessed according to their clinical relevance (highly relevant, moderately relevant, not relevant). For patients with highly relevant findings, additional follow-up research was performed. RESULTS: The average age was 43 years (range 3 - 92). 236 of the patients were male (77.6 %), 68 female (22.4 %). 153 patients (50.3 %) had additional non-trauma-associated findings. In 20 cases (6.6 %) lesions with high clinical relevance were detected (e. g. carcinoma of the kidney or the ovary). In 71 patients (23.4 %) findings with moderate relevance were described. In 63 patients (20.7 %) additional findings without major relevance were diagnosed. CONCLUSION: Whole-body CT scans of patients randomized by a trauma show a considerable number of non-trauma-associated additional findings. In about 30 % of cases, these findings are clinically relevant because further diagnostic workup or treatment in the short or medium-term is needed. The results of these analyses emphasize the diagnostic value of CT examinations with high demands on the examining radiologist.

[Stenting in the treatment of chronic mesenteric ischemia: technical and clinical success rates]. / Chronische mesenteriale Ischämie: Technische und klinische Erfolgsrate der perkutanen Stentangioplastie.

PURPOSE: To evaluate the technical and clinical success rates of percutaneous stent revascularization in the treatment of chronic mesenteric ischemia (CMI). PATIENTS AND METHODS: 17 patients (12 female) with typical symptoms of CMI were treated by percutaneous stent placement for stenoses of the splanchnic arteries (celiac trunk; superior mesenteric artery, SMA; inferior mesenteric artery, IMA). The primary and secondary technical success, primary and secondary clinical success, and the long-term clinical outcome were determined. RESULTS: A total of 24 stents were implanted in 21 splanchnic arteries (12 stents in the celiac trunk, 11 in the SMA and 1 in the IMA). The primary technical success rate was 91% (19/21 arteries), the secondary technical success rate was 95% (21/22 arteries). Clinical follow-up was available for 16 patients. The primary clinical success rate was 81% (13/16 patients). Following two secondary interventions, the secondary clinical success rate was 94% (15/16 patients). Long-term clinical success was achieved in 15 of 16 patients (94%) with a mean follow-up of 26 months. One patient died within 30 days of the intervention and two patients demonstrated major complications (1 dissection, 1 stent dislocation). None of the patients required surgical revascularization and none of the patients died due to recurrent mesenteric ischemia. CONCLUSION: Percutaneous stent placement for the treatment of CMI can be performed with a high technical and clinical success rate as well as an excellent long-term clinical outcome.

Intraarterial gadolinium-enhanced magnetic resonance angiography of the renal arteries in humans: feasibility, contrast agent reduction, and accuracy for detection of stenoses.

OBJECTIVE: Feasibility of intraarterial MR angiography of the renal arteries and comparison of the accuracy of intraarterial MR angiography with selective intraarterial digital subtraction angiography (DSA) for detection of stenoses. MATERIALS AND METHODS: Ten consecutive patients (mean, 68 years) with suspected renal artery stenosis underwent a digital subtraction angiography and an intraarterial gadolinium-enhanced MR angiography, performed on a 1.5-T system. For intraarterial MR angiography 60 ml diluted contrast agent (10 ml gadodiamide in 50 ml 0.9% saline solution) was injected through a conventional angiography catheter placed in the suprarenal abdominal aorta using a flow rate of 3.5 ml/s. A three-dimensional (3D) gradient-echo sequence was performed. Differences in the quantitative measurement of stenoses of lesions between DSA and intraarterial MR angiography were evaluated by three observers. Overall impression of the intraarterial MR angiography was documented on a four-point scale (1 = excellent to 4 = poor). Interobserver variability was calculated. RESULTS: Intraarterial MR angiography of the renal arteries was feasible in all patients (100%) with a mean overall impression of all images of 1.8 (SD: 0.71). One of 9 accessory renal arteries was not visualized with intraarterial MR angiography. The overall sensitivity/specificity for detection of significant stenoses (>or=50% stenosis) were 83%/87%. Interobserver variability of intraarterial MR angiography ranged between fair and substantial (0.359-0.622). CONCLUSION: Intraarterial MR angiography of the renal arteries in humans is feasible and has an acceptable sensitivity in detecting stenoses using injections of diluted contrast agent at concentrations as low as 17%.

Contrast harmonic ultrasound and indocyanine-green fluorescence video angiography for evaluation of dermal and subdermal microcirculation in free parascapular flaps.

PURPOSE: Contrast harmonic ultrasound (CHI) with a linear transducer is a new diagnostic approach that allows dynamic and quantitative flow detection of tissue perfusion in microsurgery. The aim of the study was the evaluation of perfusion of the dermal and subdermal layers of microvascular tissue transplants with CHI in comparison to ICG-fluorescence angiography. MATERIAL AND METHOD: In a prospective clinical study Indocyanine-Green Fluorescence Video Angiography and Contrast Enhanced High Resolution Ultrasound (5-10 MHz; linear transducer; Logiq 9; GE) were used for evaluation of the microcirculation in 10 transplanted free parascapular flaps. Two regions were analysed, the centre of the flap and the region of the anastomosis. The perfusion patterns of both methods were compared. RESULTS: The perfusion indexes measured by ICG-fluorescence angiography correlated very precisely in all patients with the quantitative perfusion curves of contrast-enhanced US with CHI. Two flaps with slow filling and low dye intensity showed low contrast enhancement in CHI with modified perfusion curves with slow increase. In two cases a reduced perfusion and filling were found. There were no statistical differences between the two diagnostic methods (p>0.01). CONCLUSION: CHI improves US detections of dermal and subdermal microcirculation in comparison to ICG fluorescence angiography. CHI is a new diagnostic method for postoperative monitoring of free flaps.