Image-Guided Percutaneous Biopsy for Pancreatic Lesions: 10-Year Experience in a Tertiary Cancer Center.

INTRODUCTION: Image-guided biopsy is an important tool in the diagnosis of solid pancreatic masses. This study aims to evaluate the accuracy and complications associated with this procedure. METHODS: We conducted a retrospective cohort study of all patients referred to interventional radiology for pancreatic biopsy at our institution from July 2004-July 2015. Two radiologists independently reviewed the images, technical aspects, and clinical characteristics. RESULTS: A total of 82 patients underwent pancreatic biopsy using a combination of computed tomography (CT) and/or ultrasound guidance. Mean age was 67.8 years with 56% males. Most lesions were located in the head (63.4%), followed by the tail (19.5%), and the body (17.1%). The procedures were performed using the anterior (79.3%), lateral (7.3%), or posterior (13.4%) approach, with direct access in 85.4% of the patients and indirect access (transgastric or transhepatic) in 14.6% of cases. Core biopsies were obtained in 81.7% of cases, and fine needle aspiration was performed in 18.3% of cases. Needle size varied from 18-22 gauge (median 20 gauge). The median number of samples collected was 3 (range 1-8). A conclusive result was obtained in 82.9% of cases. There were 9 (11%) patients with minor complications: minor bleeding, pain, and inadvertent bowel puncture with no clinical repercussion. There were no deaths or major complications. CONCLUSION: Percutaneous image-guided pancreatic mass biopsy can be performed safely with excellent accuracy. Our results are comparable with endoscopic biopsy/aspiration, and percutaneous biopsy may be used as an alternative, particularly at institutions where endoscopy facilities are limited.

Evaluation of automatic image quality assessment in chest CT - A human cadaver study.

PURPOSE: The evaluation of clinical image quality (IQ) is important to optimize CT protocols and to keep patient doses as low as reasonably achievable. Considering the significant amount of effort needed for human observer studies, automatic IQ tools are a promising alternative. The purpose of this study was to evaluate automatic IQ assessment in chest CT using Thiel embalmed cadavers. METHODS: Chest CT's of Thiel embalmed cadavers were acquired at different exposures. Clinical IQ was determined by performing a visual grading analysis. Physical-technical IQ (noise, contrast-to-noise and contrast-detail) was assessed in a Catphan phantom. Soft and sharp reconstructions were made with filtered back projection and two strengths of iterative reconstruction. In addition to the classical IQ metrics, an automatic algorithm was used to calculate image quality scores (IQs). To be able to compare datasets reconstructed with different kernels, the IQs values were normalized. RESULTS: Good correlations were found between IQs and the measured physical-technical image quality: noise (ρ=-1.00), contrast-to-noise (ρ=1.00) and contrast-detail (ρ=0.96). The correlation coefficients between IQs and the observed clinical image quality of soft and sharp reconstructions were 0.88 and 0.93, respectively. CONCLUSIONS: The automatic scoring algorithm is a promising tool for the evaluation of thoracic CT scans in daily clinical practice. It allows monitoring of the image quality of a chest protocol over time, without human intervention. Different reconstruction kernels can be compared after normalization of the IQs.

Software solutions alone cannot guarantee useful radiology requests.

Background The availability of clinical information and a pertinent clinical question can improve the diagnostic accuracy of the imaging process. Purpose To examine if an electronic request form forcing referring clinicians to provide separate input of both clinical information and a clinical question can improve the quality of the request. Material and Methods A total of 607 request forms in the clinical worklists for a computed tomography (CT) scan of the thorax, the abdomen or their combination, were examined. Using software of our own making, we examined the presence of clinical information and a clinical question before and after the introduction of a new, more compelling order method. We scored and compared the quality of the clinical information and the clinical question between the two systems and we examined the effect on productivity. Results Both clinical information and a clinical question were present in 76.7% of cases under the old system and in 95.3% under the new system ( P < 0.001). Individual characteristics of the clinical information and the clinical question however, with the exception of incompleteness, showed little improvement under the new system. There was also no significant difference between the two systems in the number of requests requiring further search. Conclusion The introduction of electronic radiology request forms compelling referring clinicians to provide separate input of clinical information and a clinical question provides only limited benefit to the quality of the request. Raising awareness among clinicians of the importance of a well-written request remains essential.

Correlation of clinical and physical-technical image quality in chest CT: a human cadaver study applied on iterative reconstruction.

BACKGROUND: The first aim of this study was to evaluate the correlation between clinical and physical-technical image quality applied to different strengths of iterative reconstruction in chest CT images using Thiel cadaver acquisitions and Catphan images. The second aim was to determine the potential dose reduction of iterative reconstruction compared to conventional filtered back projection based on different clinical and physical-technical image quality parameters. METHODS: Clinical image quality was assessed using three Thiel embalmed human cadavers. A Catphan phantom was used to assess physical-technical image quality parameters such as noise, contrast-detail and contrast-to-noise ratio (CNR). Both Catphan and chest Thiel CT images were acquired on a multislice CT scanner at 120 kVp and 0.9 pitch. Six different refmAs settings were applied (12, 30, 60, 90, 120 and 150refmAs) and each scan was reconstructed using filtered back projection (FBP) and iterative reconstruction (SAFIRE) algorithms (1,3 and 5 strengths) using a sharp kernel, resulting in 24 image series. Four radiologists assessed the clinical image quality, using a visual grading analysis (VGA) technique based on the European Quality Criteria for Chest CT. RESULTS: Correlation coefficients between clinical and physical-technical image quality varied from 0.88 to 0.92, depending on the selected physical-technical parameter. Depending on the strength of SAFIRE, the potential dose reduction based on noise, CNR and the inverse image quality figure (IQF(inv)) varied from 14.0 to 67.8%, 16.0 to 71.5% and 22.7 to 50.6% respectively. Potential dose reduction based on clinical image quality varied from 27 to 37.4%, depending on the strength of SAFIRE. CONCLUSION: Our results demonstrate that noise assessments in a uniform phantom overestimate the potential dose reduction for the SAFIRE IR algorithm. Since the IQF(inv) based dose reduction is quite consistent with the clinical based dose reduction, an optimised contrast-detail phantom could improve the use of contrast-detail analysis for image quality assessment in chest CT imaging. In conclusion, one should be cautious to evaluate the performance of CT equipment taking into account only physical-technical parameters as noise and CNR, as this might give an incomplete representation of the actual clinical image quality performance.