PACS Image Research Articles

Photon-counting CT urogram: optimal acquisition potential (kV) determination for virtual noncontrast creation.

To quantitatively and qualitatively compare the degree of iodine removal in the collecting system from PCCT urographic phase-derived virtual noncontrast (VNC) images obtained at 140 kV versus 120 kV. A retrospective PACS search identified adult patients (>18 years) who underwent a PCCT urogram for hematuria from 4/2022 to 4/2023 with available urographic phase-derived VNC images in PACS. Tube voltage (120kV, 140kV), body mass index, CTDIvol, dose length product (DLP), and size-specific dose estimate (SSDE) were recorded. Hounsfield Unit (HU) in both renal pelvises and the urinary bladder on urographic-derived VNC were recorded. Three radiologists qualitatively assessed the degree of iodine removal (renal pelvis, urinary bladder) and diagnostic confidence for urinary stone detection. Continuous variables were compared for 140 kV versus 120 kV with the Wilcoxon rank sum test. A p<.05 indicated statistical significance. 63 patients (34 male; median (Q1, Q3) age: 30 (26, 34) years; 140kV/120kV: 30 patients/33 patients) were included. BMI, CTDIvol, DLP, and SSDE were not different for 140kV and 120kV (all p>.05). Median (Q1, Q3) collecting system HU (renal pelvis and bladder) was 0.9 (-3.6, 4.4) HU at 140kV and 10.5 (3.6, 26.7) HU at 120kV (p=.04). Diagnostic confidence for urinary calculi was 4.6 [1.1] at 140kV and 4.1 [1.4] at 120kV (p=.005). Diagnostic confidence was 5/5 (all readers) in 82.2% (74/90) at 140kV and 59.6% (59/99) at 120kV (p<.001). PCCT urographic phase-derived VNC images obtained at 140kV had better collecting system iodine removal than 120kV with similar patient radiation exposure. With excellent PCCT urographic phase iodine removal at 140kV, consideration can be made to utilize a single-phase CT urogram in young patients.

Dynamic endoluminal contrast enhanced ultrasound (CEUS) for display of drainages in inflammatory abdominal fluid collections1.

To evaluate the additive clinical value of endoluminal contrast enhanced ultrasound (CEUS) after interventional placement of drainages in abdominal fluid collections. Examination of 30 patients using a 1-6 MHz convex probe (Resona 7, Mindray) to locate the fluid collection in B-Mode. Additionally, dynamic endoluminal CEUS with 1 ml sulphur-hexafluoride microbubbles was performed to measure the extent of the percutaneously drained abscesses. Independent assessment of dynamically stored images in PACS in DICOM format. Correlation to reference imaging using computed tomography (CT). A total of 30 patients were examined (17 m, 19-78 years, mean 56.1 years). Drainages were positioned in the liver in 15 cases, in the pelvis after kidney transplantation in 4 cases, close to the spleen in 1 case, and in the abdomen in 10 cases. In all cases abscesses showed marginal hyperaemia with reactive septations in CEUS. The drainage position was assessed by means of B-mode in all cases first and then by CEUS. In 4 cases CEUS showed a fistula to the pleura, in 5 cases to the peritoneum, in 2 cases to the intestine, in 5 cases to the biliary tract, corresponding to the CT. In 2 cases there was a hint of an anastomotic leakage after intestinal anastomosis, which was reliably detected by CT. The drainage was removed in 11 cases within a period of 2 to 5 days after CEUS control, in 9 cases within a period of 5 to 10 days. Another operation was necessary in 3 cases. A new drainage was placed in 2 cases. The required amount of ultrasound contrast medium is 1 ml endoluminally diluted to 9 ml sodium chloride. CEUS facilitates the exact localization and characterization of inflammatory abdominal fluid collections. Furthermore, possible fistulas can be detected that cannot be seen with conventional ultrasound.

Three-Dimensional Quantitative Analysis of Chronic Obstructive Pulmonary Lesions on CT Images

In this paper, the three-dimensional segmentation of pulmonary honeycomb lesions and the function of image biomarkers are integrated into a quantitative analysis module of the lung, and integrated into the PACS image diagnosis workstation for the quantitative analysis of doctors. It is difficult to segment honeycomb lesions in lung CT images because of its diffuse and blurred edges, but it has good texture characteristics. Based on this feature, this paper converts honeycomb lesions into a texture classification problem. Firstly, the lung parenchyma is extracted by automatic threshold segmentation and region growing method, and then the lung parenchyma is divided into several small regions according to the texture by watershed method. Then, according to the texture characteristics of each small area, the trained support vector machine is used to classify. Finally, the correlation between gray level and spatial position of slice data is used to correct the classification results, so as to reduce false positive areas. In order to expand the study of imaging biomarkers of chronic lung diseases to more extensive major diseases, a sample database was established for a wide range of multiple lesions. Through feature extraction and feature analysis of multiple lesions in database, potential feature differences can be excavated, which lays a solid foundation for further study of image biomarkers of multiple lesions.

Peak Signal-to-Noise Ratio Evaluation of Server Display Monitors and Client Display Monitors in a Digital Subtraction Angiography Devices

This study evaluated the PSNR of the server display monitor and client display monitor of the DSA system. The signal is acquired and imaged during the surgery and stored in the PACS server. After that, distortion of the original signal is an important problem in the process of observation on the client monitor. There are many problems such as noise generated during compression and image storage/transmission in PACS, information loss during image storage and transmission, and deterioration in image quality when outputting medical images from a monitor. The equipment used for the experiment in this study was P's DSA. We used two types of monitors in our experiment, one is P’s company Resolution 1280×1024 pixel monitor and the other is W’s company resolution 1536×2048 pixel monitor. The PACS Program used MARO-view, and for the experiment, a PSNR measurement program using Visual C++ was implemented and used. As a result of the experiment, the PSNR value of the kidney angiography image was 26.958dB, the PSNR value of the lung angiography image was 28.9174 dB, the PSNR value of the heart angiography image was 22.8315dB, and the PSNR value of the neck angiography image was 37.0319 dB, and the knee blood vessels image showed a PSNR value of 43.2052 dB, respectively. In conclusion, it can be seen that there is almost no signal distortion in the process of acquiring, storing, and transmitting images in PACS. However, it suggests that the image signal may be distorted depending on the resolution and performance of each monitor. Therefore, it will be necessary to evaluate the performance of the monitor and to maintain the performance.

Abstract No. 482 Utility of touchless image navigation in interventional radiology procedures

Intraprocedural image review during interventional radiology (IR) procedures is common, but current practice requires the operator to either leave the sterile field to use a computer or to direct an assistant while observing. An emerging technology platform (TIPSO; NZ Technologies, Vancouver, Canada) enables ergonomic touchless image interaction at bedside by utilizing 3D motion sensing. This study assesses the technology’s applicability in daily practice and identifies procedural steps to which the technology may contribute. The technology was evaluated in IR procedures that typically involve substantial intraprocedural image review. After each case, the operator completed a survey that records usability data on: i) the type of procedure and imaging interaction; ii) the frequency with which the technology and its specific functions were engaged; and, iii) workflow parameters. The operator also rated the technology’s impact in factors that influence patient outcomes using a 7-point Likert scale [1-most negatively; 4-neutral; 7-most positively]. Data were collected in n = 11 cases (bronchial artery embolization, uterine fibroid embolization, and pulmonary embolism (PE) thrombectomy) for reviewing images in PACS, CT and digital subtraction angiography. The technology was used 5.0 ± 3.4 times/case, most commonly for device navigation (n = 11; 3.8 ± 2.5 times/case), followed by preprocedural setup (n = 6; 1.2 ± 0.4 times/case), and device deployment (n = 1; 2 times). The technology was employed mostly for scrolling (n = 11), followed by changing series (n = 5), and magnification and window/level adjustment (n = 2). Operators rated a Likert score as: 6.7 ± 0.5 in understanding of the patient’s anatomy; 6.0 ± 1.4 in precision of device navigation; 6.0 ± 1.4 in overall workflow; and, 6.6 ± 0.8 in operator’s cognitive focus. Particularly, the technology was useful by enabling bedside image review in emergent cases (i.e., PE) for a prompt determination of an actionable step. Consistent use of the technology was seen in various cases, with a favorable rating for the impact in improving outcomes. Continuing studies will determine the role of touchless image navigation for routine use in IR.

Incidence of Distal Embolization during Peripheral Intervention using the NAV-6 Embolic Protection System

Purpose: To compare the rates of embolic debris (ED) generation during lower extremity arterial interventions and evaluate the safety and efficacy of the using an embolic protection device (EPD). Methods: This was a single-center retrospective review of 111 patients (114 vessels) having undergone peripheral arterial intervention with the use of an EPD (Emboshield NAV-6 device). A database was created through review of the electronic health record and images in PACS. The presence of ED was determined through visual inspection after retrieval of the device or from filling defects identified during digital subtraction angiography with the device deployed. Descriptive statistics were used to report the demographic and clinical information. Relative frequencies of debris generation were determined for vessel type, trans-atlantic inter-society consensus (TASC) classification, and type of intervention. Differences in frequencies between groups weer evaluated with the Chi-square test, and associations were examined using the logistic regression analysis. Results: Of the 114 vessels treated, 16 (14%) demonstrated true distal embolization (DE) past the filter basket and 58 (51%) demonstrated generation of ED as determined by filling of the filter basket. This was significantly higher in patients undergoing atherectomy (70%) compared with those undergoing thrombolysis (38%) or angioplasty with or without stenting (29%) (P &lt; 0.001). Of those patients undergoing atherectomy, laser atherectomy had the lowest rate of DE (26%) compared with either orbital (67%) or directional atherectomy (57%) (P &lt; 0.05). In regression analysis, atherectomy was the only factor with significant association with detection of ED (odds ratio: 4.52, P &lt; 0.0001). There was no statistically significant difference in the frequency of debris generated based on vessel type or TASC classification. Conclusion: The frequency of ED is higher in patients undergoing atherectomy versus patients undergoing lysis or percutaneous transluminal balloon angioplasty with or without stenting. Laser atherectomy has a lower frequency of debris generation when compared to either orbital or directional atherectomy.

핵의학 일반영상 검사업무 오류개선 활동에 따른 환자 만족도

핵의학과에서 시행되는 일반 영상 검사는 수검자의 검사 접수로부터 의사의 판독까지의 과정 동안 오류가 발생된다. 이러한 오류는 최종단계인 의사 판독 시에 확인되어 재검사나 추가촬영, 결과의 재분석, 그리고 PACS 영상의 수정등의 내용을 영상실 검사 담당자에게 지시한다. 이러한 과정을 거쳐 얻어진 결과는 검사에서부터 판독까지의 시간 지연을 초래하고 또한 추가검사가 발생될 경우 환자 만족도와 병원의 신뢰도가 하락하게 된다. 따라서 영상 검사의 접수부터 결과 확정까지 발생되는 오류를 개선하여 수검자들의 불만 감소에 따른 환자 만족도 증가와 근무자들의 업무 효율 증가를 목적으로 한다. 2008년 3월부터 12월까지 9개월간 서울아산병원 핵의학과 일반 영상 검사를 하는 수검자의 검사 오류를 분석하여 2009년 1월부터 12월까지 12개월간 1차 개선 활동으로 검사 절차서의 재 확립 및 검사 업무기술서 작성, 2010년 1월부터 6월까지 6개월간 2차 개선 활동으로 Pre-filtering & Post-Filtering, 2010년 7월부터 10월까지 3개월간 3차 개선 활동 Cross-Check와 스티커 제작 및 부착 실시 이후 검사 오류 건수를 수집하여 비교하였다. 연도별 오류 건 수는 92건에서 1차, 2차 개선 후 32건, 3차 개선 후 46건으로 나타났고, 검사자에 의한 오류는 전체 오류원인의 94.6%이던 것이 74.3%로 감소되었다. 핵의학 일반 영상 검사는 다양한 검사의 종류와 서로 다른 전처치 및 결과산출, 영상의 구성, PACS 전송 영상의 차이로 인하여 검사자의 실수가 발생될 가능성이 높기 때문에 이를 줄이기 위한 개선 활동이 지속되어야 하며 각 영상실 담당자들의 지속적인 Cross-Check와 판독실의 Confirm 과정을 통하여 개인별 편차를 줄여나가야 할 것이다. To n the field of nuclear medicine, with regard to checking regular patients, from the moment they register up to the doctor's diagnosis, the person in charge of the checks can find errors in the diagnosis, reexamine, reanalyze the results or save images to PACS. Through this process, the results obtained from the readings are delayed due to checks and additional tests which occur in hospitals, causing patient satisfaction and affected reliability. Accordingly, the purpose is to include visual inspection of the results to minimize error, improve efficiency and increase patient satisfaction. Nuclear medicine and imaging tests from examines at Asan Medical Center, Seoul, from March 2008 to December 2008, were analyzed for errors. The first stage, from January 2009 to December 2009, established procedures and know-how. The second stage from January 2010 until June 2010 conducted Pre-and Post-filtering assessment, and the third stage from July 2010 until October 2010 consisted of cross-checks and attaching stickers and comparing error cases. Of 92 errors, the 1st, 2nd and 3rd stage had 32 cases, and there were 46 cases after the 4th stage, with the overall errors reduced by 74.3% from 94.6%. In the field of general nuclear medicine, where various kinds of checks are performed according to the patient's needs, analysis, image composition, differing images in PACS, etc, all have the potential for mistakes to be made. In order to decrease error rates, the image can continuously Cross-Check and Confirm diagnosis.

Hyperdense middle cerebral artery sign in multidetector computed tomography: Definition, occurrence, and reliability analysis

The hyperdense middle cerebral artery sign (HMCAS) is one of the early changes seen on the computed tomography in acute ischemic stroke of MCA territory. To evaluate the reliability of subjective evaluation of HMCAS on CT performed at multidetector CT (MDCT) and evaluated in the Picture Archiving Communication Systems, to define objective criteria for HMCAS and to find out if there are any predictors for the occurrence of HMCAS. CTs of 121 consecutive patients (mean age of 70 years) treated with thrombolytic therapy were retrospectively evaluated by two neuroradiologists both subjectively and objectively with respect to HMCAS. HMCAS was subjectively found in 32% of study population. The interobserver and intraobserver agreement were substantial (K value of 0.69 and 0.80, respectively) and increased to almost perfect (K value of 0.86) when the reader provided with clinical information. The HMCAS was found twice as often in male patients. Patients with HMCAS were three years younger than those whose baseline CT did not show HMCAS. A 100% sensitivity achieved when objective criteria were defined as combination of MCA attenuation >or= 46 HU and MCA ratio > 1.2 (using oval ROIs) and MCA attenuation >or= 50 HU and MCA ratio of > 1.4 (using pixel sized ROIs). Performing CT examinations on MDCT and assessment of the images in PACS might have contributed to improvement of the reliability of evaluating HMCAS on CT by enabling an objective evaluation of this sign with measurements of attenuation value in the course of MCA using oval or pixel sized ROIs as well as estimation of MCA ratio.

On the Economic Role of RIS/PACS in Healthcare

The integration of electronic patient data records with digital images in PACS is the only way today to provide high-quality clinical services. Such integration enables clinicians to access both systems' data reliably and consistently, as part of their regular working environment. We present a general framework for capturing the actual tangible and intangible benefits of RIS/PACS implementation at a major hospital. Prior to the implementation, we looked at 150,000 studies in terms of charges and revenues collected, and for a sample we identified report turn-around times (TAT) and process bottlenecks. We repeated these inquiries after the RIS/PACS implementation. In addition, we used a survey instrument to measure the changes in the satisfaction levels of radiologists, technology staff, and referring physicians. We found a phenomenon 63% year-long learning rate that was observed after the systems were implemented. During that period, TAT shrunk by 80%, indicating that most of the benefits of RIS/PACS take time and added effort to be fully realized. The billing process became more authentic and reliable as all preps, procedures and exams could be captured, and lost studies rates have decreased from 10% to less that 1%. We documented a steady increase in revenue per procedure of more than $3 per procedure per month. On top of the above, the satisfaction level of both referring physicians and employees went up dramatically from around 3 to 6 in a seven-point Likert scale! We also present some operational recommendations resulting from an econometric study, and documented and elaborated on the virtual tools now available for more accurate, easy to use teaching purposes. Future paths are process bottleneck identification for continuous improvement, and improved scheduling models for both patients and staff. Our results may lead to fuller utilization of RIS/PACS functionality, to a significant return on investment (ROI), and to improved patient care and acceptance by referring physicians.

Utilizing data grid architecture for the backup and recovery of clinical image data

Grid Computing represents the latest and most exciting technology to evolve from the familiar realm of parallel, peer-to-peer and client-server models. However, there has been limited investigation into the impact of this emerging technology in medical imaging and informatics. In particular, PACS technology, an established clinical image repository system, while having matured significantly during the past ten years, still remains weak in the area of clinical image data backup. Current solutions are expensive or time consuming and the technology is far from foolproof. Many large-scale PACS archive systems still encounter downtime for hours or days, which has the critical effect of crippling daily clinical operations. In this paper, a review of current backup solutions will be presented along with a brief introduction to grid technology. Finally, research and development utilizing the grid architecture for the recovery of clinical image data, in particular, PACS image data, will be presented. The focus of this paper is centered on applying a grid computing architecture to a DICOM environment since DICOM has become the standard for clinical image data and PACS utilizes this standard. A federation of PACS can be created allowing a failed PACS archive to recover its image data from others in the federation in a seamless fashion. The design reflects the five-layer architecture of grid computing: Fabric, Resource, Connectivity, Collective, and Application Layers. The testbed Data Grid is composed of one research laboratory and two clinical sites. The Globus 3.0 Toolkit (Co-developed by the Argonne National Laboratory and Information Sciences Institute, USC) for developing the core and user level middleware is utilized to achieve grid connectivity. The successful implementation and evaluation of utilizing data grid architecture for clinical PACS data backup and recovery will provide an understanding of the methodology for using Data Grid in clinical image data backup for PACS, as well as establishment of benchmarks for performance from future grid technology improvements. In addition, the testbed can serve as a road map for expanded research into large enterprise and federation level data grids to guarantee CA (Continuous Availability, 99.999% up time) in a variety of medical data archiving, retrieval, and distribution scenarios.

Comparative Study in the Femoral Anteversion measured by CT and MR Imaging as a PACS Image Viewer

Comparative Study in the Femoral Anteversion measured by CT and MR Imaging as a PACS Image Viewer

Measurement of Femoral Anteversion in the PACS Image Viewer

Measurement of Femoral Anteversion in the PACS Image Viewer

A review of compression methods for medical images in PACS

As an introduction to Section C2 (medical imaging) of track C (Images and PACS) of MIE ’97, an appropriate and timely topic concerns the coding for the transmission of medical images in PACS. Speed limitations of existing networks along with the explosive growth of image modalities with extremely high volume outputs have combined to make the issue of medical image coding one of the key considerations in the design of future PACS systems. Both lossless and lossy compression schemes are reviewed and compared, and the compression demands are presented of the main digital medical image modalities.

IS&amp;C implementation of an image workstation

The Image Save & Carry (IS & C) 5-inch magneto-optical disk system was introduced to a PACS image workstation so as to exchange digital image data between two independent PACS modules. The results showed that it was possible to connect two different PACS modules by off-line data transmission. Also, the IS & C standard software proved to be of high speed read/write performance for several data files on an image workstation. However, when the IS & C is implemented to the high resolution real-time digital radiography system, an image compression standard will be required to expand its capacity.

41. PACS における画像の検討 : 第 1 報 CRT 画像と CR フィルムの評価(管理・計測技術-3 画像管理 PACS)

41. PACS における画像の検討 : 第 1 報 CRT 画像と CR フィルムの評価(管理・計測技術-3 画像管理 PACS)

41. PACS における画像の検討 : 第 1 報 CRT 画像と CR フィルムの評価(第 47 回総会学術大会一般研究発表予稿)

41. PACS における画像の検討 : 第 1 報 CRT 画像と CR フィルムの評価(第 47 回総会学術大会一般研究発表予稿)

42. PACS における画像の検討 : 第 2 報圧縮画像の評価(管理・計測技術-3 画像管理 PACS)

42. PACS における画像の検討 : 第 2 報圧縮画像の評価(管理・計測技術-3 画像管理 PACS)

42. PACS における画像の検討 : 第 2 報 圧縮画像の評価(第 47 回総会学術大会一般研究発表予稿)

42. PACS における画像の検討 : 第 2 報 圧縮画像の評価(第 47 回総会学術大会一般研究発表予稿)