Soft Reconstruction Kernels Improve HCC Imaging on a Photon-Counting Detector CT.

RATIONALE AND OBJECTIVES: Hepatocellular carcinoma (HCC) is the only tumor entity that allows non-invasive diagnosis based on imaging without further histological proof. Therefore, excellent image quality is of utmost importance for HCC diagnosis. Novel photon-counting detector (PCD) CT improves image quality via noise reduction and higher spatial resolution, inherently providing spectral information. The aim of this study was to investigate these improvements for HCC imaging with triple-phase liver PCD-CT in a phantom and patient population study focusing on identification of the optimal reconstruction kernel. MATERIALS AND METHODS: Phantom experiments were performed to analyze objective quality characteristics of the regular body and quantitative reconstruction kernels, each with four sharpness levels (36-40-44-48). For 24 patients with viable HCC lesions on PCD-CT, virtual monoenergetic images at 50 keV were reconstructed using these kernels. Quantitative image analysis included contrast-to-noise ratio (CNR) and edge sharpness. Three raters performed qualitative analyses evaluating noise, contrast, lesion conspicuity, and overall image quality. RESULTS: In all contrast phases, the CNR was highest using the kernels with a sharpness level of 36 (all p < 0.05), with no significant influence on lesion sharpness. Softer reconstruction kernels were also rated better regarding noise and image quality (all p < 0.05). No significant differences were found in image contrast and lesion conspicuity. Comparing body and quantitative kernels with equal sharpness levels, there was no difference in image quality criteria, neither regarding in vitro nor in vivo analysis. CONCLUSION: Soft reconstruction kernels yield the best overall quality for the evaluation of HCC in PCD-CT. As the image quality of quantitative kernels with potential for spectral post-processing is not restricted compared to regular body kernels, they should be preferred.

Photon-counting detector CT improves quality of arterial phase abdominal scans: A head-to-head comparison with energy-integrating CT.

PURPOSE: Photon-counting detector (PCD)-CT is expected to have a substantial impact on oncologic abdominal imaging. We compared subjective and objective image quality between PCD-CT and conventional energy-integrating detector (EID-)CT arterial phase abdominal scans. METHODS: This study included 84 patients undergoing both types of abdominal CT. EID-CT scans were acquired with a tube voltage of 100 kVp. With PCD-CT, acquired with 120-kVp, we reconstructed polychromatic T3D images and virtual monoenergetic images (VMIs) in 10-keV intervals from 40 to 90 keV. Quantitative image analysis included noise and contrast-to-noise ratio (CNR) of hepatic vessels, kidney cortex, and hypervascular liver lesions to liver parenchyma. Three raters used a 5-point Likert scale for qualitative image analysis of image noise and contrast, lesion conspicuity, and overall image quality. Radiation dose exposure (CT dose index) was compared between the two CT types. RESULTS: Mean CT dose index and effective dose were respectively 18 % and 26 % lower with PCD-CT versus EID-CT. Compared with EID-CT, CNRs of kidney cortex and vessel to liver parenchyma were significantly higher in PCD-CT VMIs at energies ≤ 60 keV and in polychromatic T3D images (p < 0.004). Overall image quality of PCD-CT VMIs at 50 and 60 keV was rated as significantly better (p < 0.01) than the EID-CT images (inter-reader agreement alpha = 0.80). Lesion conspicuity was significantly better in low-keV VMIs (p < 0.03) and worse in > 70-keV VMIs. CONCLUSIONS: With low-keV VMI, PCD-CT yields significantly improved objective and subjective quality of arterial phase oncological imaging compared with EID-CT. This advantage may translate into higher diagnostic confidence and lower radiation dose protocols.

Natural language processing of radiology reports to investigate the effects of the COVID-19 pandemic on the incidence and age distribution of fractures.

OBJECTIVE: During the COVID-19 pandemic, the number of patients presenting in hospitals because of emergency conditions decreased. Radiology is thus confronted with the effects of the pandemic. The aim of this study was to use natural language processing (NLP) to automatically analyze the number and distribution of fractures during the pandemic and in the 5 years before the pandemic. MATERIALS AND METHODS: We used a pre-trained commercially available NLP engine to automatically categorize 5397 radiological reports of radiographs (hand/wrist, elbow, shoulder, ankle, knee, pelvis/hip) within a 6-week period from March to April in 2015-2020 into "fracture affirmed" or "fracture not affirmed." The NLP engine achieved an F1 score of 0.81 compared to human annotators. RESULTS: In 2020, we found a significant decrease of fractures in general (p < 0.001); the average number of fractures in 2015-2019 was 295, whereas it was 233 in 2020. In children and adolescents (p < 0.001), and in adults up to 65 years (p = 0.006), significantly fewer fractures were reported in 2020. The number of fractures in the elderly did not change (p = 0.15). The number of hand/wrist fractures (p < 0.001) and fractures of the elbow (p < 0.001) was significantly lower in 2020 compared with the average in the years 2015-2019. CONCLUSION: NLP can be used to identify relevant changes in the number of pathologies as shown here for the use case fracture detection. This may trigger root cause analysis and enable automated real-time monitoring in radiology.

A Hybrid Reporting Platform for Extended RadLex Coding Combining Structured Reporting Templates and Natural Language Processing.

Structured reporting is a favorable and sustainable form of reporting in radiology. Among its advantages are better presentation, clearer nomenclature, and higher quality. By using MRRT-compliant templates, the content of the categorized items (e.g., select fields) can be automatically stored in a database, which allows further research and quality analytics based on established ontologies like RadLex® linked to the items. Additionally, it is relevant to provide free-text input for descriptions of findings and impressions in complex imaging studies or for the information included with the clinical referral. So far, however, this unstructured content cannot be categorized. We developed a solution to analyze and code these free-text parts of the templates in our MRRT-compliant reporting platform, using natural language processing (NLP) with RadLex® terms in addition to the already categorized items. The established hybrid reporting concept is working successfully. The NLP tool provides RadLex® codes with modifiers (affirmed, speculated, negated). Radiologists can confirm or reject codes provided by NLP before finalizing the structured report. Furthermore, users can suggest RadLex® codes from free text that is not correctly coded with NLP or can suggest to change the modifier. Analyzing free-text fields took 1.23 s on average. Hybrid reporting enables coding of free-text information in our MRRT-compliant templates and thus increases the amount of categorized data that can be stored in the database. This enhances the possibilities for further analyses, such as correlating clinical information with radiological findings or storing high-quality structured information for machine-learning approaches.

Workflow-centred open-source fully automated lung volumetry in chest CT.

AIM: To develop a robust open-source method for fully automated extraction of total lung capacity (TLC) from computed tomography (CT) images and to demonstrate its integration into the clinical workflow. MATERIALS AND METHODS: Using only open-source software, an algorithm was developed based on a region-growing method that does not require manual interaction. Lung volumes calculated from reconstructions with different kernels (TLCCT) were assessed. To validate the algorithm calculations, the results were correlated to TLC measured by pulmonary function testing (TLCPFT) in a subgroup of patients for which this information was available within 3 days of the CT examination. RESULTS: A total of 288 patients were analysed retrospectively. Manual review revealed poor segmentation results in 13 (4.5%) patients. In the validation subgroup, the correlation between TLCCT and TLCPFT was r=0.87 (p<0.001). Measurements showed excellent agreement between the two reconstruction kernels with an intraclass correlation coefficient (ICC) of 0.99. Calculation of the volumes took an average of 5 seconds (standard deviation: 3.72 seconds). Integration of the algorithm into the departments of the PACS environment was successful. A DICOM-encapsulated PDF document with measurements and an overlay of the segmentation results was sent to the PACS to allow the radiologists to detect false measurements. CONCLUSIONS: The algorithm developed allows fast and fully automated calculation of lung volume without any additional input from the radiologist. The algorithm delivers excellent segmentation in >95% of cases with significant positive correlations between lung volume on CT and TLC on PFT.

Evaluation of treatment response to enzyme replacement therapy with Velaglucerase alfa in patients with Gaucher disease using whole-body magnetic resonance imaging.

OBJECTIVE: This was a retrospective data analysis to evaluate the treatment response to enzyme replacement therapy (ERT) with Velaglucerase alfa using whole-body magnetic resonance imaging (MRI). MATERIALS AND METHODS: A baseline and follow-up MRI were performed on 18 Gaucher Type 1 patients at an interval of 11.6 months. The MRI score systems determined the Bone-Marrow-Burden (BMB) score, the Düsseldorf-Gaucher score (DGS), and the Vertebra-Disc-Ratio (VDR). The Severity Score Index Type 1 (GD-DS3) was also assessed. RESULTS: The baseline MRI medians were: BMB, 7.00; DGS, 3.00; and VDR: 1.70; while, the follow-up MRI medians were: BMB, 7.00; DGS, 3.00; and VDR: 1.73. The baseline GD-DS3 median was 2.40 (BMB excl.: 0.50) and the follow-up median was 2.00 (BMB excl.: 0.50). There was weak statistical significance with the Wilcoxon signed-rank test for the DGS (p=0.034) and GD-DS3 (p=0.047) between both MRIs. CONCLUSION: Velaglucerase alfa therapy is a effective long-term treatment for Gaucher Type 1 patients who are newly diagnosed or switching therapies. Measurements with whole-body MRI and an objective scoring system were reliable tools for detecting early stage bone marrow activity. Further research is needed to evaluate the "Booster-Effect" of Velaglucerase alfa therapy in Gaucher skeletal disease.

Evaluation of Bone Marrow Infiltration in Non-Neuropathic Gaucher Disease Patients with Use of Whole-Body MRI--A Retrospective Data Analysis.

PURPOSE: To evaluate whole-body magnetic resonance imaging (WB-MRI) for the assessment of bone marrow infiltration in patients with confirmed Gaucher disease type 1 under long-term enzyme replacement therapy (ERT). MATERIALS AND METHODS: This retrospective data analysis included 38 patients in two subgroups. Group A: 10 females, 9 males, 15-29 years, mean age 22 years and Group B: 11 females, 8 males, 29-77 years, mean age 49 years, all treated with alglucerase or imiglucerase for at least 12.5 years. Whole-body MRI was carried out in all patients using a standard MRI protocol. Two radiologists assessed all MR images retrospectively with the use of three different MRI score systems: The bone marrow burden (BMB) score, the Düsseldorf-Gaucher score (DGS) and the vertebra disc ratio (VDR). As a clinical component, severity score index type 1 (GD-DS3) was determined. RESULTS: In both groups the MR scores showed low to moderate pathologic levels but no statistically significant difference was found between both groups. The median scores in group A/group B were 7.00/9.00 for the BMB score (p=0.07), 4.00/3.00 for the DGS score (p=0.062) and 1.54/1.62 for the VDR score (p=0.267). The GD-DS3 score was statistically significantly different between both groups (1.6/3.9, p=0.000) and osseous Gaucher disease complications were only found in group B. CONCLUSION: Bone marrow involvement and typical clinical manifestations are reduced to a minimum, when ERT starts immediately after the confirmed diagnosis of Gaucher disease type 1. The applied MR scores are useful markers to control bone marrow infiltration under enzyme replacement therapy in older patients. Pathologic MR scores in young patients may reflect postponed fat conversion of the juvenile bone marrow. This issue has to be examined in further studies. KEY POINTS: Whole-body MRI is valuable for the staging of Gaucher disease type 1. Osseous complications are reduced to a minimum in early treated patients. MR score systems have to be adjusted in young Gaucher patients.

Morphologic assessment of thoracic deformities for the preoperative evaluation of pectus excavatum by magnetic resonance imaging.

OBJECTIVE: To assess whether MRI is a suitable modality for the preoperative assessment and quantification of pectus excavatum. METHODS: A total of 69 patients (57 male, 12 female; median age 15 years, range 5-35 years) with pectus excavatum were evaluated preoperatively using standardized MRI sequences on 1.5- and 3-Tesla systems (T2-HASTE/inspiration and expiration, T1-VIBE, T2-TRUFI free-breathing, T2-BLADE). The MR sequences were analysed for quality semiquantitatively. The Haller index, correction index, sternal rotation angle and asymmetry index were assessed; correlations between these indices and changes in inspiration and expiration were evaluated. RESULTS: T2-HASTE was the best sequence to assess pectus excavatum morphology, with a higher quality at 3 T than at 1.5 T. All indices could be assessed in every patient. A total of 37 patients had a symmetric deformity, 32 patients an asymmetric deformity. The Haller index correlated significantly (p < 0.001) with the correction index, both becoming higher in expiration. The asymmetry index correlated with the sternal rotation angle (p < 0.001) and did not change significantly in expiration (p = 0.28). CONCLUSIONS: Thoracic MRI is suitable for the preoperative evaluation of patients with pectus excavatum. An exact morphologic assessment is possible without radiation exposure as well as the determination of several indices to quantify the deformities.

Application unit for the administration of contrast gases for pulmonary magnetic resonance imaging: optimization of ventilation distribution for (3) He-MRI.

PURPOSE: MRI of lung airspaces using gases with MR-active nuclei ((3) He, (129) Xe, and (19) F) is an important area of research in pulmonary imaging. The volume-controlled administration of gas mixtures is important for obtaining quantitative information from MR images. State-of-the-art gas administration using plastic bags (PBs) does not allow for a precise determination of both the volume and timing of a (3) He bolus. METHODS: A novel application unit (AU) was built according to the requirements of the German medical devices law. Integrated spirometers enable the monitoring of the inhaled gas flow. The device is particularly suited for hyperpolarized (HP) gases (e.g., storage and administration with minimal HP losses). The setup was tested in a clinical trial (n = 10 healthy volunteers) according to the German medicinal products law using static and dynamic ventilation HP-(3) He MRI. RESULTS: The required specifications for the AU were successfully realized. Compared to PB-administration, better reproducibility of gas intrapulmonary distribution was observed when using the AU for both static and dynamic ventilation imaging. CONCLUSION: The new AU meets the special requirements for HP gases, which are storage and administration with minimal losses. Our data suggest that gas AU-administration is superior to manual modes for determining the key parameters of dynamic ventilation measurements.

Chronic thromboembolic pulmonary hypertension (CTEPH) - potential role of multidetector-row CT (MD-CT) and MR imaging in the diagnosis and differential diagnosis of the disease.

Chronic thromboembolic pulmonary hypertension (CTEPH) can be defined as pulmonary hypertension (resting mean pulmonary arterial pressure of 25 mm Hg or more determined at right heart catheterization) with persistent pulmonary perfusion defects. It is a rare, but underdiagnosed disease with estimated incidences ranging from 0.5% to 3.8% of patients after an acute pulmonary embolism (PE), and in up to 10% of those with a history of recurrent PE. CTEPH is the only form of pulmonary hypertension that can be surgically treated leading to normalization of pulmonary hemodynamics and exercise capacity in the vast majority of patients. The challenges for imaging in patients with suspected CTEPH are fourfold: the imaging modality should have a high diagnostic accuracy with regard to the presence of CTEPH and allow for differential diagnosis. It should enable detection of patients suitable for PEA with great certainty, and allow for quantification of PH by measuring pulmonary hemodynamics (mPAP and PVR), and finally, it can be used for therapy monitoring. This overview tries to elucidate the potential role of ECG-gated multidetector CT pulmonary angiography (MD-CTPA) and MR imaging, and summarizes the most important results that have been achieved so far. Generally speaking, ECG-gated MD-CTPA is superior to MR in the assessment of parenchymal and vascular pathologies of the lung, and allows for the assessment of cardiac structures. The implementation of iodine maps as a surrogate for lung perfusion enables functional assessment of lung perfusion by CT. MR imaging is the reference standard for the assessment of right heart function and lung perfusion, the latter delineating typical wedge-shaped perfusion defects in patients with CTEPH. New developments show that with MR techniques, an estimation of hemodynamic parameters like mean pulmonary arterial pressure and pulmonary vascular resistance will be possible. CT and MR imaging should be considered as complementary investigations providing comprehensive information in patients with CTEPH.

[Teleradiology - update 2014]. / Teleradiologie - Update 2014.

Due to economic considerations and thanks to technological advances there is a growing interest in the integration of teleradiological applications into the regular radiological workflow. The legal and technical hurdles which are still to be overcome are being discussed in politics as well as by national and international radiological societies. The European Commission as well as the German Federal Ministry of Health placed a focus on telemedicine with their recent eHealth initiatives. The European Society of Radiology (ESR) recently published a white paper on teleradiology. In Germany §3 section 4 of the Röntgenverordnung (RöV, X-ray regulations) and DIN 6868-159 set a framework in which teleradiology can also be used for primary reads. These possibilities are already being used by various networks and some commercial providers across Germany. With regards to cross-border teleradiology, which currently stands in contrast to the RöV, many issues remain unsolved.

Effect of kernels used for the reconstruction of MDCT datasets on the semi-automated segmentation and volumetry of liver lesions.

PURPOSE: To evaluate the effect of different reconstruction kernels on the semi-automated segmentation of liver lesions in MDCT. MATERIALS AND METHODS: A total 62 liver lesions were measured by three independent radiologists with the semi-automated segmentation software Oncology-Prototype (Fraunhofer MEVIS, Siemens Healthcare, Germany) using MDCT datasets (3-mm slice thickness, 2-mm increment) reconstructed with standard, soft and detailed kernels (Philips B, A and D). To ensure objective measurements, only lesions with satisfactory initial segmentation were included, and manual correction was not used. The effective diameter and volume were recorded for each lesion. Segmentation in the soft and detailed kernel datasets was performed by copying the initial seed's position from the standard kernel dataset. RESULTS: The mean effective lesion diameter was 19.9 ±â€Š9.7 mm using the standard kernel. Comparing the three kernels, no significant differences were found. The mean difference was 1% ±â€Š6% for the standard kernel compared to the soft kernel, 3% ±â€Š13% for the standard kernel vs. the detailed kernel and 2% ±â€Š9% for the soft kernel compared to the detailed kernel. The intra-class correlation coefficients were > 0.96 in all cases. CONCLUSION: The semi-automated segmentation and volumetry of liver lesions shows reliable measurements regardless of the kernel used for reconstruction of the MDCT dataset. KEY POINTS: ► Semi-automated segmentation and volumetry of liver lesions is reliable regardless of the kernel used for reconstruction of the MDCT dataset. ► Until today the gold standard for the evaluation of tumor response has been unidimensional manual measurement. ► Volumetric measurements could improve the assessment of tumor growth.

[IT systems in radiology and IT systems for radiologists]. / IT-Systeme in der Radiologie und IT-Systeme für den Radiologen.

Radiology plays an important role in introduction and use of information technology (IT) systems in the daily clinical routine. The radiology information system (RIS) and picture archiving and communication system (PACS) are the main systems used in a digital radiology department. In this article the basic principles and functions of these systems and trends in development are described.

Endovascular treatment of symptomatic true-lumen collapse of the downstream aorta after open surgery for acute aortic dissection type A.

AIM: The aim of the present study was to evaluate the outcome of endovascular treatment of true-lumen collapse (TLC) of the downstream aorta after open surgery for acute aortic dissection type A (AADA). METHODS: Retrospective, observational study with follow-up of 16 ± 7.6 months. From April 2010 to January 2012, 89 AADA-patients underwent aortic surgery. Out of these, computed tomography revealed a TLC of the downstream aorta in 13 patients (14.6%). They all received additional thoracic endovascular aortic repair (TEVAR) in consequence of malperfusion syndromes. RESULTS: In all 13 TLC-patients, dissection after AADA-surgery extended from the aortic arch to the abdominal aorta and malperfusion syndromes occurred. Remodeling of the true-lumen was achieved by TEVAR with complemental stent disposal in abdominal and iliac arteries in all cases. One patient died on the third postoperative day due to intracerebral hemorrhage. Another patient, who presented under severe cardiogenic shock died despite AADA-surgery and TEVAR-treatment. Thirty-day mortality was 15.4% in TLC-patients (N = 2/13). In the follow-up period, 3 patients required additional aortic stents after the emergency TEVAR procedures. After 20 weeks, a third patient died secondary to malperfusion due to false-lumen recanalization. Therefore, late mortality was 23.1%. CONCLUSION: After proximal aortic repair for AADA, early postoperative computed tomography should be demanded in all patients to exclude a TLC of the descending aorta. Mortality is still substantial in these patients despite instant TEVAR application. Thus, in case of TLC and malperfusion syndrome of the downstream aorta, TEVAR should be performed early to alleviate or even prevent ischemic injury.

[Irreversible image compression in radiology. Current status]. / Irreversible Bilddatenkompression in der Radiologie. Aktueller Status.

Due to increasing amounts of data in radiology methods for image compression appear both economically and technically interesting. Irreversible image compression allows markedly higher reduction of data volume in comparison with reversible compression algorithms but is, however, accompanied by a certain amount of mathematical and visual loss of information. Various national and international radiological societies have published recommendations for the use of irreversible image compression. The degree of acceptable compression varies across modalities and regions of interest.The DICOM standard supports JPEG, which achieves compression through tiling, DCT/DWT and quantization. Although mathematical loss due to rounding up errors and reduction of high frequency information occurs this results in relatively low visual degradation.It is still unclear where to implement irreversible compression in the radiological workflow as only few studies analyzed the impact of irreversible compression on specialized image postprocessing. As long as this is within the limits recommended by the German Radiological Society irreversible image compression could be implemented directly at the imaging modality as it would comply with § 28 of the roentgen act (RöV).

[Registration and monitoring of radiation exposure from radiological imaging]. / Erfassung und Monitoring der radiologischen Strahlenexposition.

Strategies for reducing radiation exposure are an important part of optimizing medical imaging and therefore a relevant quality factor in radiology. Regarding the medical radiation exposure, computed tomography has a special relevance. The use of the integrating the healthcare enterprise (IHE) radiation exposure monitoring (REM) profile is the upcoming standard for organizing and collecting exposure data in radiology. Currently most installed base devices do not support this profile generating the required digital imaging and communication in medicine (DICOM) dose structured reporting (SR). For this reason different solutions had been developed to register dose exposure measurements without having the dose SR object.Registration and analysis of dose-related parameters is required for constantly optimizing examination protocols, especially computed tomography (CT) examinations based on the latest research results in order to minimize the individual radiation dose exposure from medical imaging according to the principle as low as reasonably achievable (ALARA).

Comparison of fluoroscopy-guided Pull-type percutaneous radiological gastrostomy (Pull-type-PRG) with conventional percutaneous radiological gastrostomy (Push-type-PRG): clinical results in 253 patients.

OBJECTIVES: To analyze the clinical results and complications of fluoroscopy guided internal-external Pull-type percutaneous radiological gastrostomy (Pull-type-PRG) and conventional external-internal percutaneous radiological gastrostomy (Push-type-PRG). METHODS: A total of 253 patients underwent radiological gastrostomy between January 2002 and January 2010. Data were collected retrospectively from radiology reports, Chart review of clinical notes, procedure reports, discharge summaries and subsequent hospital visits. Statistical analysis was performed to compare the two methods for gastrostomy with respect to peri-interventional aspects and clinical results. RESULTS: 128 patients received the Pull-type-PRG whereas the other 125 patients were served with the Push-type-PRG. Indications for gastrostomy were similar in these two groups. The most frequent indications for the both methods were stenotic oesophageal tumors or head/neck tumors (54.7% in Pull-type-PRG, 68% in Push-type-PRG). Gastrostomy procedures were successful in 98.3% in Pull-type-PRG compared to 92% in Push-type-PRG. There was no procedure-related mortality. Compared to Push-type-PRG, the peri-interventional complication rate was significantly reduced in Pull-type-PRG (14.8% versus 34.4%, P = 0.002). CONCLUSIONS: Compared to the external-internal Push-type-PRG, the internal-external Pull-type-PRG showed a high primary success rate and a decreased incidence of peri-interventional complications.

Klatskin tumour: meticulous preoperative work-up and resection rate.

BACKGROUND: Surgery represents the only potentially curative treatment of hilar cholangiocarcinoma (hilCC). It may be suggested that meticulous preoperative work-up in Asian countries leads to higher resection rates. METHOD: One hundred and eighty-two patients treated in our department between 1998 and 2008 were included in an analysis based on our prospectively recorded database. Among them, 75 % had a percutaneous transhepatic cholangiography as part of their diagnostic work-up. A total of 160 patients underwent explorative surgery and 123 patients were resected (77 % of patients undergoing exploration, 68 % of all patients). RESULTS: Ninety-one percent of the patients were diagnosed to have Bismuth III and IV tumours. En-bloc resection of the tumour and the adjacent liver including segment 1 was the standard procedure in 109 of these patients, while hilar resection was performed in 14 patients. Upon tumour resection, hospital mortality was 5.7 %. Five-year survival in patients without surgery or with mere exploration was 0 %, after resection it reached 26 %. Patients with R 1 resection experienced longer survival than patients without resection (p < 0.001). Right and left hemihepatectomies were performed with identical frequency resulting in identical survival. Lymph node involvement proved to be the only significant predictor of prognosis (p = 0.006). CONCLUSION: Resection should be performed whenever possible since even after palliative resection survival is substantially increased compared to patients without resection. Meticulous preoperative work-up may contribute to a high resection rate in patients with hilCC by providing additional information allowing the surgeon to perform more aggressive approaches.