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The purpose of this study was to outline lower leg vessel anatomy and to investigate reliability and limitations of magnetic resonance angiography (MRA) in patients proposed for microvascular fibula transplantation (free fibula flap (FFF)). We retrospectively investigated MRAs of 99 patients considered for FFF. Frontal MRA planes and maximal intensity projections (MIPs) were evaluated for fibula lengths, anatomical branching pattern, arterial stenoses and fibular perforator positions in both legs (n=198). Normal branching patterns were observed in 168 (85.3%) legs. Twenty-nine (14.7%) legs presented abnormal branching patterns. Once (0.5%) the anterior, 19 times (9.6%) the posterior tibial artery were absent or hypoplastic. Nine (4.6%) lower legs presented an arteria peronea magna. Average length of the tibiofibular trunk (TFT) was 3.3±0.15cm. A total of 492 perforators were found with an average of 2.5 (±0.82±0.99) perforators per leg. A mapping of perforator run-offs was illustrated true to scale. Lower limb stenoses were distributed in the anterior tibial artery (14.1%), in the posterior tibial artery (11.1%) and in the fibular artery (8.1%). Smoking (P=0.828), diabetes (P=0.727) and peripheral arterial occlusive disease (P=0.172) did not correlate with presence of stenoses. Preoperative lower limb angiography avoids postoperative complications. MRA reliably and non-invasively identifies anatomical variants and arterial stenoses without radiation. Illustration of perforator run-offs enhances incision planning for fibula harvest., (Copyright © 2019 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.)

Objective: The aim of our study was to systematically compare two-point Dixon fat suppression (FS) and spectral FS techniques in contrast enhanced imaging of the head and neck region., Methods: Three independent readers analysed coronal T 1 weighted images recorded after contrast medium injection with Dixon and spectral FS techniques with regard to FS homogeneity, motion artefacts, lesion contrast, image sharpness and overall image quality., Results: 85 patients were prospectively enrolled in the study. Images generated with Dixon-FS technique were of higher overall image quality and had a more homogenous FS over the whole field of view compared with the standard spectral fat-suppressed images (p < 0.001). Concerning motion artefacts, flow artefacts, lesion contrast and image sharpness no statistically significant difference was observed., Conclusion: The Dixon-FS technique is superior to the spectral technique due to improved homogeneity of FS and overall image quality while maintaining lesion contrast. Advances in knowledge: T 1 with Dixon FS technique offers, compared to spectral FS, significantly improved FS homogeneity and over all image quality in imaging of the head and neck region.

Purpose: Retrospective evaluation of our experience with the use of flow diverters (FD) for the endovascular treatment of direct carotid-cavernous sinus fistulae (diCCF)., Methods: Between 2011 and 2015, 14 consecutive patients with 14 diCCF were treated with FD alone or in combination with other implants in a single institution., Results: A total of 21 sessions were performed in 14 patients. FD placement was technically successful in all cases without an adverse event. Patients were treated with FD alone (n = 5), FD and covered stents (n = 2), FD and coils (n = 7). A total of 59 FD (24 Pipeline Embolization Device, Medtronic; 35 p64 Flow Modulation Device, phenox), 291 coils, and 3 stent grafts were used. Three of 14 diCCF were completely occluded after the 1 st  session, a minor residual shunt was found in 7/14, and in the remaining 4/14 patients, the shunt volume was reduced significantly. The mean follow-up period encompassed 20 months. Additional treatment included transvenous coil occlusion (n = 3) and/or further FD deployment (n = 5). An asymptomatic internal carotid artery (ICA) occlusion was encountered in 2 patients, related to an interruption of antiaggregation. At the last follow-up, 10/14 patients were free from ocular symptoms (71 %), 2 had residual exophthalmos, and no patient had clinical deterioration., Conclusion: The usage of FD for the treatment of diCCF is straightforward. Injury of the cranial nerves can be avoided. In most cases, ocular symptoms improve. Several FD layers and/or an adjunctive venous coil occlusion are required. Complete occlusion of a diCCF may take weeks or months and long-term antiaggregation is required. In the future, a flexible stent graft might be a better solution.

Objective: Evaluating vascular autonomization of pedicled and microvascular free flaps for soft tissue reconstruction in the head and neck area by means of postoperative quantitative measurement of dynamic contrast values obtained with contrast-enhanced ultrasound., Methods: 8/18 patients underwent lip reconstruction with a pedicle flap, 10 patients reconstruction of other parts of the head with a microvascular free transplant. Ultrasound examinations were conducted within the 1st postoperative week and 4 weeks after surgery. After the intravenous bolus of the ultrasound contrast agent, examinations were carried out for 30 sec without compression followed by 30 sec with compression of the vascular pedicle in bolus and flash kinetics. Digital cine loops were analyzed off-line with a quantification software (VueBox™) to determine the Rise Time (RT) between flap tissue with and without compression., Results: Measurements showed increasing autonomous perfusion, independent of the vascular pedicle. No transplant was lost, but 4/10 patients with a microvascular flap and 1/8 patients with a pedicle flap developed postoperative complications. RT values for the pedicled and microvascular flaps obtained under compression differed significantly between the 1st and the 4th week (p = 0.025)., Conclusions: Reliable neovascularization was achieved 4 weeks postoperatively. CEUS showed to be a useful method for assessing the degree of autonomization of pedicle and microvascular free flaps.

Background: Preoperative staging of cervical lymph nodes is important to determine the extent of neck dissection in patients with oral squamous cell carcinoma (OSCC)., Purpose: To evaluate whether a preoperative discrimination of benign and malignant cervical lymph nodes with diffusion-weighted imaging (DWI) (3T) is feasible for clinical application., Material and Methods: Forty-five patients with histological proven OSCC underwent preoperative 3T-MRI. DWI (b = 0, 500, and 1000 s/mm(2)) was added to the standard magnetic resonance imaging (MRI) protocol. Mean apparent diffusion coefficients (ADCmean) were measured for lymph nodes with 3 mm or more in short axis by two independent readers. Finally, these results were matched with histology., Results: Mean ADC was significantly higher for malignant than for benign nodes (1.143 ± 0.188 * 10(-3) mm(2)/s vs. 0.987 ± 0.215 * 10(-3) mm(2)/s). Using an ADC value of 0.994 * 10(-3) mm(2)/s as threshold results in a sensitivity of 80%, specificity of 65%, positive predictive value of 31%, and negative predictive value of 93%., Conclusion: Due to a limited sensitivity and specificity DWI alone is not suitable to reliably discriminate benign from malignant cervical lymph nodes in daily clinical routine. Hence, the preoperative determination of the extent of neck dissection on the basis of ADC measurements is not meaningful., (© The Foundation Acta Radiologica 2015.)

The aim of our study was to evaluate, whether the analysis of time intensity curves (TIC) of contrast enhanced ultrasound (CEUS) could help to differentiate between thyroid adenomas and carcinomas in daily clinical routine.B-mode, Colour Coded Doppler Sonography (CCDS), Power Doppler (PD) and CEUS were applied for 50 patients (27 men, 23 women; mean age 51 years, range 16-81 years).CEUS cine-sequences were analysed using time intensity curves (TIC) and calculating time to peak (TTP) as well as the area under the curve (AUC).All 20 patients with carcinomas presented with a complete wash-out in the late phase of CEUS while this occurred only in three out of the 30 patients with adenomas.Marked differences were observed between adenomas and carcinomas concerning the mean AUC in the surrounding thyroid tissue (p = 0.041). In addition, TTP differed clearly between the centre and the surrounding of the carcinomas (p < 0.05) as well as between TTP in the border area and the surrounding tissue (p = 0.01). CEUS in combination with TIC analysis allows a dynamic evaluation of the microvascularisation of thyroid nodules and is helpful for the differentiation of benign and malignant nodules.

Purpose: The BLADE (PROPELLER) technique reduces artefacts in imaging of the cervical spine in sagittal orientation, but till now failed to do so in axial orientation, because here it increased through plane CSF-flow artefacts, which spoiled the benefit of BLADE artefact reduction "in plane". The aim of this study was to compare a BLADE sequence with optimised measurement parameters in axial orientation to T2-TSE., Materials and Methods: Both sequences were compared in 58 patients with 31 discal, 16 bony and 11 spinal cord lesions. Image sharpness, reliability of spinal cord depiction, CSF flow artefacts and lesion detection were evaluated by 3 independent observers. Additionally the observers were asked which sequence they would prefer for diagnostic workup. Statistical evaluations were performed using sign and χ2 test., Results: BLADE was significantly superior concerning image sharpness, spinal cord depiction and overall lesion detection. BLADE was rated better for most pathologies, for bony lesions the differences compared with TSE were statistically significant. Regarding CSF-flow artefacts both sequences showed no difference. All readers preferred BLADE in side by side reading., Conclusion: An optimised axial T2 BLADE sequence decreases the problems of increased through plane CSF-flow artefacts in this orientation. By reducing various other artefacts it yields better image quality and has the potential to reduce the number of non-diagnostic examinations especially in uncooperative patients., Key Points: T2 BLADE/PROPELLER sequences proofed to reduce artefacts in sagittal spine imaging. BLADE/PROPELLER improve image quality, but can aggravate CSF flow artefacts in axial orientation. Optimised parameter setting for axial T2 BLADE reduces "through-plane" CSF artefacts aggravation. Optimised axial T2 BLADE reduces non-diagnostic examinations especially in uncooperative patients., (© Georg Thieme Verlag KG Stuttgart · New York.)

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., (© Georg Thieme Verlag KG Stuttgart · New York.)

Purpose: PET has been proven to be helpful in the delineation of gross tumour volume (GTV) for external radiation therapy in several tumour entities. The aim of this study was to determine if [(11)C]choline PET could be used to localize the carcinomatous tissue within the prostate in order to specifically target this area for example with high-precision radiation therapy., Methods: Included in this prospective study were 20 patients with histological proven prostate carcinoma who underwent [(11)C]choline PET/CT before radical prostatectomy. After surgical resection, specimens were fixed and cut into 5-mm step sections. In each section the area of the carcinoma was delineated manually by an experienced pathologist and digitalized, and the histopathological tumour volume was calculated. Shrinkage due to resection and fixation was corrected using in-vivo and ex-vivo CT data of the prostate. Histopathological tumour location and size were compared with the choline PET data. Different segmentation algorithms were applied to the PET data to segment the intraprostatic lesion volume., Results: A total of 28 carcinomatous lesions were identified on histopathology. Only 13 (46 %) of these lesions had corresponding focal choline uptake. In the remaining lesions, no PET uptake (2 lesions) or diffuse uptake not corresponding to the area of the carcinoma (13 lesions) was found. In the patients with corresponding PET lesions, no suitable SUV threshold (neither absolute nor relative) was found for GTV segmentation to fit the volume to the histological tumour volume., Conclusion: The choline uptake pattern corresponded to the histological localization of prostate cancer in fewer than 50 % of lesions. Even when corresponding visual choline uptake was found, this uptake was highly variable between patients. Therefore SUV thresholding with standard algorithms did not lead to satisfying results with respect to defining tumour tissue in the prostate.

Intracranial hypotension is a rare cause of persistent headache mostly originating from a dural CSF leak. If a conservative treatment fails, a minimally invasive EBP can lead to a successful sealing of such a leak. Independent of the leakage site, an EBP is usually applied at the lumbar level with varying success. We used CT myelography to detect the site of the dural leakage, then immediately applied a targeted EBP at the corresponding level to patch the leak. Seven patients from our clinic were treated with a single targeted EBP in the lumbar or cervical spine. Within 24 hours, 6 patients experienced a considerable relief of symptoms; 1 patient went into remission after a repeat procedure. Our preliminary data suggest that a CT-guided, CT myelography-assisted targeted EBP is a safe and effective treatment for persistent spinal CSF leaks.

Purpose: Quantitative measurement of dynamic contrast values obtained by contrast-enhanced ultrasound (CEUS) for evaluating microvascularization in osseous and osseocutaneous free flaps used for maxillofacial reconstructions., Patients and Methods: 22 patients (6 women, 16 men, mean age: 57 years, range: 47 to 82 years) who had received mandibular reconstructions with 3 avascular and 19 microvascular free osseous or osseocutaneous transplants were included in this trial. 16 patients had received a microvascular osseocutaneous fibular flap, 2 patients a microvascular osseous fibular flap and 1 patient a microvascular osseous iliac crest flap. Patients were followed up for 12 months on average (range: 3 to 20 months). Ultrasound examination was carried out by one experienced examiner with a linear probe (6-9 MHz, LOGIQ E9, GE) after the intravenous bolus injection of 2.4 ml contrast agent (SonoVue®, BRACCO, Germany). Digital cine loops were analysed with a quantification software (VueBox™) for determining wash-in parameters: Rise Time (RT), Peak Enhancement (PE), Wash-in Area Under the Curve (WiAUC) and Wash-in Rate (WiR). Results were compared with the patients' postoperative clinical outcome., Results: For the bone area the median of the RT was 10.0 s (range 3.1 to 65.0 s), for the ratio between bone tissue and soft tissue for the PE the median was 10.4% (range 2.6 to 29.8%), the median for the WiAUC was 11.1% (range 1.5 to 77.7%) and the median for the WiR was 5.7 %(range 0.7 to 61.1%). None of the patients with microvascular osseocutaneous and osseous flaps showed any signs of transplant bone loss, which corresponded with the qualitative CEUS assessment. The patients with microvascular re-anastomosed transplants showed widely varying values for the investigated parameters (RT, PE, WiAUC, WiR). For patients with avascular bone transplants, these parameters were reduced to zero values for the bone area resulting in a significant difference (p < 0.05) for the PE compared to the patients with microvascular bone transplants., Conclusion: CEUS allowed the qualitative assessment of bone microvascularization by observing the transition of the contrast agent from the periostal area into the bone. However, defining a critical lower border by quantification of bone perfusion was difficult because of the inconstant perfusion of the bone transplants used in the trial.

Purpose: Evaluation of two complementary methods, i.e. luminescence ratiometric oxygen imaging (LROI) and contrast-enhanced ultrasound (CEUS) for postoperative evaluation of the perfusion of osseocutaneous fibular free flaps used for mandibular reconstructions., Patients and Methods: 15 patients with microvascular re-anastomosed osseocutaneous fibular flaps were included in this trial. Perfusion of the cutaneous part of the flap was determined by measuring a fluorescent oxygen sensor foil covering the flap's skin surface with a handheld fluorescence-microscope. The sensor contains a reservoir of oxygen that is consumed by the tissue, which corresponds to the perfusion status of a flap. Measurements were done before explantation, after successful anastomosis and 1 day after surgery. Additionally, flap perfusion was qualitatively evaluated by contrast-enhanced ultrasound (CEUS) in 13 out of 15 patients. Ultrasound examinations were carried out with a high resolution linear probe after an intravenous bolus injection of 2.4 ml SonoVue® within the first 14 days after surgery., Results: Out of the 15 harvested and transplanted flaps, 3 showed microcirculatory problems on the first postoperative day. All complications were detected by LROI prior to clinical signs. For LROI, we were able to confirm the threshold slope value of 0.3 for differentiating between well perfused and compromised flaps as suggested in our previous study. CEUS showed qualitatively detectable bone perfusion in the 13 measured flaps. 2 flaps that were lost on the second and third postoperative day were also lost for CEUS control. The flap survival rate was 87%, and the complication rate was 33%., Conclusion: LROI has been proven to deliver reproducible objective results for monitoring cutaneous flaps. In addition, CEUS is a promising method for evaluating the microcirculation of the deeper parts (such as bone) of osseocutaneous flaps. Both methods supplement each other, thus allowing the monitoring of all levels of osseocutaneous flaps.

The reliable detection of cervical lymph node (LN) metastases is the planning basis of a selective neck dissection for patients with oral squamous cell carcinoma (OSCC). The aim of this study was to evaluate whether contrast-enhanced ultrasound (CEUS) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) together are able to improve the preoperative characterisation of LNs. A time intensity curve analysis has been performed using CEUS and DCE-MRI for ten LNs, where one LN has been examined per patient. The studied LNs consist of five with and five without metastases. In CEUS the mean time to peak (TTP) was 18 s (range 13-29 s, standard deviation (SD) ± 7 s) for benign and 12 s (range 9-16 s, SD ± 4 s) for malignant LNs. In DCE-MRI the mean TTP was 27 s (range 18-36 s, SD ± 9 s) for benign and 21 s (range 18-27 s, SD ± 5 s) for malignant LNs. Moreover, the relative signal change with respect to reference tissue was significantly higher for LNs with than for those without metastases in both CEUS and DCE-MRI. A combination of imaging morphology, CEUS and DCE-MRI might be a promising method for a reliable differentiation of benign and malignant LNs.