CT Department Research Articles

NICE guidance in the rapid access chest pain clinic: does it work?

Abstract Background Rapid Access Chest Pain Clinics (RACPC) were developed following the publication of the National Service Framework for Coronary Heart Disease in 2000(1). The National Institute for Health and Care Excellence (NICE) produces guidelines for the management of patients with recent onset chest pain of suspected cardiac origin(2). In 2016 the guidance was updated and recommended the use of CT coronary angiography (CTCA) as the initial investigation for patients with chest pain which was typical or atypical of angina. Adherence to the guideline may be dependent upon factors such as local availability of CT scanners and clinician preference. The RACPC in this tertiary centre is nurse-run with no medical involvement. There is good engagement with the CT department and in July 2017 the NICE guidance was adopted in the clinic. Purpose To evaluate the use of CTCA as the first line investigation for patients with typical or atypical chest pain. Methods Data from all patients reviewed in the clinic between 01/07/2017 and 31/12/2023 were prospectively collected, entered into a database, and then retrospectively analysed. The data were organised into 3 groups: patients with typical chest pain; atypical pain and those with non-cardiac sounding chest pain. The number of patients in each group who underwent a CTCA, and the outcome of the scan were evaluated. The CT scans were categorised as showing significant coronary artery disease (CAD), non-obstructive CAD, no CAD, or as inconclusive. The outcome of patients who had a positive CTCA was also recorded. Results 2986 patients were reviewed in the RACPC in the above period. 14.2% of patients presented with typical pain, 47.4% with atypical pain, and 30.6% had non-cardiac pain. The remaining patients presented with other symptoms such as breathlessness. CTCA was used as the first investigation in the majority of patients with typical or atypical pain, unless alternative investigations or management were deemed to be more clinically appropriate. In 59.5% of typical and 78.5% of atypical presentations, the CT scan showed no CAD, or non-significant CAD. There was a low incidence of positive scans in both groups, however patients with typical pain were more likely to have significant CAD (Table). All patients who had a CTCA indicating significant CAD, were referred for invasive angiography. 88.0% of typical presentations, and 64.0% of those with atypical pain, underwent revascularisation. No patient who underwent invasive angiography was found to have normal coronary arteries. Conclusion Atypical pain is the most frequent presentation in the RACPC, however the majority of these patients, and most of those with typical pain, do not have significant CAD. Careful assessment and the use of CTCA as the initial investigation, enable the identification of those patients who need invasive angiography. This is a cost-effective strategy which also reduces risk and radiation exposure for patients.

Quality Assurance and Quality Monitoring in Pet - CT Department in a Tertiary Care Corporate Hospital, Pune

Quality Assurance and Quality Monitoring in Pet - CT Department in a Tertiary Care Corporate Hospital, Pune

Creating a Longitudinal HCV Care Cascade for Persons With HIV/HCV Coinfection in Selected HIV Clinics Using Data to Care Methods.

Highly effective direct-acting antiviral (DAA) treatments for hepatitis C have led to strategic goals promoting hepatitis C virus (HCV) cure particularly in focus populations including persons with HIV/HCV coinfection. Implementing treatment more broadly requires both clinic-level and public health approaches such as those inherent in Data to Care (D2C) originally developed to improve the treatment cascade for persons with HIV (PWH). We used D2C methods to characterize and improve HCV treatment for persons with HIV/HCV coinfection among 11 HIV clinics in Connecticut cities with high PWH prevalence. Providers who were local champions in HCV treatment were recruited to participate along with clinic data staff and were key to quality improvement via practice transformation. We developed a methodology whereby clinic-generated lists of PWH receiving care from 2009 to 2018 were matched by CT Department of Public Health (DPH) against the state-wide HCV surveillance system. The resultant coinfection list was reviewed by clinical staff who designated HCV treatment status, enabling creation of individual clinic-level HCV treatment cascades. Data from DPH, especially current residency and deaths, enabled better characterization and allowed for refinement of longitudinal cascades. There were 1,496 patients with HIV/HCV coinfection. Sustained virologic response (SVR) rates varied by clinic (range, 44%-100%) with an aggregate SVR rate of 71% in September 2020. SVR rates improved during the project through a combination of increased treatment initiation/completion as well as data clean-up including serial updates of patient treatment status. Lack of treatment initiation was associated with being female (odds ratio [OR] = 2.18) and not having HIV viral suppression (OR = 3.24).

Characterization of Incidental Liver Lesions: Comparison of Multidetector CT versus Ultrasonography

Background: Due to recent advancements in imaging techniques, as well as the widespread use of routine medical exams and screenings, incidental LL are now more frequently discovered by US. Physicians must decide whether to simply follow up when incidental LL are discovered in the US or to order additional imaging tests for lesion classification. The goal of our study was to identify LL using MDCT and US. Methods and Results: A total of 50 participants were selected from a variety of male and female patients with abdominal pain and suspected liver diseases, and received a CT triphasic scan and US at the Royal Care International Hospital, Ibn Alhaitham Diagnostic Center, Alfaisal Specialized Hospital, and the Department of Diagnostic Radiology in the CT department of Sudan from April 2018 to May 2020. The results of the ultrasound scanning (liver lesions and related findings) performed on patients before the CT scanning indicated that ascites+ liver lesions was predominant (48.6%). The incidental liver lesions that take peripheral nodular enhancement by MDCT when contrast media is injected, were liver metastases (30%), hemangioma (14%), and HCC (10%). Liver cysts represent 10(20%) of the total cases of lesions that were non-enhanced by CT, with a few cases of liver cirrhosis (2%), hepatosplenomegaly (2%), and cyst + hepatitis (2%). We found a significant relationship between peripheral nodular enhancement for liver lesions by MDCT and non-enhancing liver lesions (P=0.001). Conclusion: The US and CT scan findings have a statistically significant relationship (P≤0.017). Contrast-enhanced CT performs better at diagnosing liver lesions than does standard US.

Optimization of CT Protocols for Newborn Patients by Ingenuity 128, Philips. A Phantom Study

Purpose: To evaluate the impact of CT scan protocol parameters on patient dose and image quality for optimization of protocols for newborn patients.
 Materials and methods: Three anatomical areas (chest, abdomen and combined chest + abdomen area) of a newborn PH-50 Newborn Whole-Body Phantom (Kyoto Kagaku Co, LTD, Japan) were scanned on Ingenuity 128 CT scanner (Philips) using different scan parameters. The values of weighted CT dose index (CTDIvol) and dose length product (DLP) were used as dose characteristics and the noise of CT image was chosen to estimate the image quality. The noise was determined in the soft tissues in the areas of shoulder girdle and diaphragm in images with the reconstruction kernel B, as well as in lung tissue of lung apices for images with the reconstruction kernel YC for chest and chest + abdomen; and in soft tissues (for reconstruction kernel B) in the area of the diaphragm for abdomen.
 Results: The analysis of the impact of tube voltage and dose right index (DRI) on dose characteristics and image quality made it possible to determine the optimal parameters of CT protocols for selected CT department: chest – 80 kV at DRI -– 19, abdomen – 100 kV at DRI – 22, chest + abdomen – 120 kV at DRI – 22. These protocol parameters provide an effective dose of newborn patients – 1.4, 1.7 and 2,8 mSv for chest, abdomen and chest + abdomen scans, respectively.
 Conclusion: The impact of different scan parameters (tube voltage and DRI) of chest, abdomen and chest + abdomen protocols on patient dose and image noise was evaluated. The study allowed setting optimized protocol parameters to improve the image quality.

Evaluation of Liver Changes in Type-2 Diabetes Mellitus Patients using Computed Tomography

There is an association between hypertension, non-alcoholic fatty liver, and diabetes mellitus. Diabetic patients commonly have fatty liver and heart problems. Objective: To evaluate the adverse effects of diabetes on the liver, and to determine the association between diabetes and metabolic associated fatty liver disease using Computed Tomography. Methods: It was a cross-sectional study conducted on 50 diabetic patients using convenient sampling method. The research was carried out in CT Department of Radiology of Tertiary care hospital in Gujranwala, Pakistan. Males and females between the ages of 30-80 who had undergone abdominal CT scans were included in this study. A written consent form was also signed by patients. This study was conducted over 4 months from December 2021 to March 2022. Data were entered and analyzed using SPSS version 20.0. Results: The current study revealed that male diabetic patients have more chances to have non-alcoholic fatty liver disease 33(66%) than females 17(34%). The diabetic patients of in senior age group (50-60) years were most commonly affected by 27(54%) with metabolic-associated fatty liver disease. According to findings diabetic patients frequently had fatty liver disease 22(44%) and fatty liver disease along with cardiovascular disease was 11(22%). Some other findings with less occurrence of non-alcoholic fatty liver disease were hypertension and hyperlipidemia 7(14%). Conclusion: In conclusion, diabetic patients are more common to be related with fatty liver disease. There was strong connection between diabetes mellitus and fatty liver disease. Elderly patients are more commonly affected.

What the Baby Formula and Medical Contrast Material Shortages Have in Common: Insights and Recommendations for Managing the Iodinated Contrast Media Shortage.

The impact of supply chain and supply chain logistics, including personnel directly and indirectly related to the movement of supplies, has come to light in a variety of industries since the global COVID-19 pandemic. Acutely, the experience with baby formula and iodinated contrast material exposes key vulnerabilities to supply chains. The rather sudden diminished availability of iodinated contrast material has forced health care systems to engage in more judicious use of product through catalyzing the adoption of behaviors that had been recommended and deemed reasonable prior to the shortage. The authors describe efforts at a large, academic safety net county health system to conserve iodinated contrast media by optimizing contrast media use in the CT department and changing ordering patterns of referring providers. Special attention is given to opportunities to conserve contrast material in cardiothoracic imaging, including low kV and dual-energy CT techniques. A values-based leadership philosophy and collaboration with key stakeholders facilitate effective response to the critical shortage and rapid deployment of iodinated contrast media conservation strategies. Last, while the single-supplier model is efficient and cost-effective, its application to critically necessary services such as health care must be questioned considering disruptions related to the COVID-19 pandemic. Keywords: CT, Intravenous Contrast Agents, CT-Spectral Imaging (Dual Energy) ©RSNA, 2022.

Spontaneous Pneumomediastinum in COVID-19 Pneumonia: A Rare Occurence.

Spontaneous pneumomediastinum with COVID pneumonia is a rare occurrence with or without accompanying subcutaneous emphysema or pneumothorax. The aim of this study was to establish relation of this complication to severity of lung disease and its clinical outcome. The study was conducted for a period of seven months from April to October 2020 in the CT Department of Armed Forces Institute of Radiology and Imaging (AFIRI), Rawalpindi, Pakistan. All COVID positive patients having spontaneous pneumomediastinum on high resolution CT (HRCT) chest were included (n=14). These patients were assessed for severity of lung disease as per CT severity score (CTSS), and were followed up for their clinical outcome. All patients with spontaneous pneumomediastinum had moderate to severe degree of COVID pneumonia; mortality in patients with pneumomediastinum was 50%; and was seen in those patients who had greater severity of lung disease as per the CTSS. Key Words: Spontaneous, Pneumomediastinum, COVID, Pneumothorax, Subcutaneous, Emphysema.

Connecticut’s Veterans-Directed Care Program Outcomes Compared to HCBS Waiver Participants: HCBS CAHPS Results

Connecticut (CT) Veterans Directed Home and Community Based Services Program (VDC) is an innovative Veterans Administration (VA) services option providing veterans at risk of institutionalization with person-centered consumer-directed long-term services and supports at home. Funded by an Administration for Community Living grant, the CT Department of Aging and Disability Services partnered with the VA, the five CT Area Agencies on Aging, and UConn Health Center on Aging (UConn). UConn researchers conducted the Consumer Assessment of Healthcare Providers and Systems in Home and Community Based Services (HCBS CAHPS) survey with VDC participants (n=36) from October 2019 through March 2020. The standardized, validated HCBS CAHPS survey, which Connecticut administers to individuals in most CT Medicaid HCBS programs, is a universal, cross-disability tool to assess/improve the quality of HCBS programs. Analyses compared VDC participants’ program experiences to survey results from individuals in the Connecticut Home Care Program (CHCP) (for older adults) (n=629), Personal Care Assistance (PCA) (n=282), and Acquired Brain Injury (ABI) (n=327) waiver programs. Notably, more VDC participants (91%) knew who their support broker was, compared to CHCP, ABI, and PCA (82%, 79%, and 72%, respectively) who knew their case manager; 91% of VDC participants gave their support broker the highest rating, compared to 66% to 74% of participants in other programs who rated their case manager. This study provides strong evidence that the CT VDC program is positively impacting veterans and that the AAAs and support brokers are effectively helping them receive the HCBS they need in a consumer-directed way.

OD140 - Dosimetric evaluation to medical workers operating in a PET/ CT department after the use of in house production of Ga-68 peptides

OD140 - Dosimetric evaluation to medical workers operating in a PET/ CT department after the use of in house production of Ga-68 peptides

A case-control study of airborne dissemination of bacteria during CT colonography.

The COVID-19 pandemic has highlighted the importance of aerosol spread of infection. We have conducted a study to detect bacterial contamination of room surfaces and room air during CT colonography and confirm the efficacy of room disinfection procedures carried out between examinations. Systematic sampling of the CT examination couch and horizontal surfaces 1 m and 3 m from the couch was performed before and after patient examinations. A 1 m3 sample of room air was obtained during patient examinations. Samples were processed using routine laboratory methods. A case-control study design was used (30 CT colonography and 30 routine body CT scans). Evidence of airborne dissemination of bacteria was detected in >30% of CT colonography examinations and <10% of control examinations (p = 0.01). No pathogenic bacteria were detected in surface samples taken before patient examinations. The room disinfection policy in use in our CT department is effective in eliminating pathogenic bacteria from surfaces in the patient environment. CT colonography causes contamination of room air with enteric bacteria in a significant proportion of cases. CT colonography may possibly be an aerosol-generating procedure. Larger-scale investigation is needed to fully evaluate this potential infection risk.

Upper tract imaging modality to investigate haematuria: cancer detection rates and changing guidelines

BackgroundTo assess the imaging modalities used to investigate both visible haematuria and non-visible haematuria along with their detection rate of malignancy at two hospitals and the corresponding radiological workload produced.MethodsA retrospective study was conducted across two hospitals. All CT urograms and ultrasound scans investigating haematuria in the outpatient setting over a 12-month period were evaluated.ResultsThe detection rate for upper tract urothelial cancer with visible haematuria was 0.97% and for renal cell carcinoma was 0.64%. Of all the CT urograms performed for non-visible haematuria 4.9% had suspicious findings but none of these represents an underlying malignancy. Of all the ultrasound scans performed for either visible or non-visible haematuria, none were shown to have an underlying malignancy. The detection rate was thus zero for an upper tract urinary cancer or renal cell carcinoma in the non-visible haematuria group. A CT urogram was performed in 27% and 67% of cases in each respective hospital to further investigate non-visible haematuria. CT urography makes up 2.3% and 5.2% of each hospitals overall respective workload in the CT department. CT urography to investigate non-visible haematuria could be replaced by ultrasound in low-risk patients.ConclusionsRadiological investigations are a limited resource and better rationalisation of upper tract imaging is needed in the setting of haematuria. Risk stratification of patients would be of benefit to help prevent a significant delay in timely diagnostics for higher risk individuals presenting with haematuria.

Capacity management of CT department with service time differences and emergency nonpreemptive priority

In the presence of different service times of regular patients and nonpreemptive priority of emergency patients at the same day, this paper considers an advance appointment-scheduling problem of medical resources in which a finite amount of same-day service capacity should be allocated to different patients. This booking problem is modeled as a dynamic programming (DP) problem. The structural properties of DP model analytically reveal a booking limit policy. The booking limit numbers of regular patients do not monotonically increase with their revenues because of the service time differences. A numerical analysis is provided to test the performance of our booking limit policy by comparing polices in previous studies. Simulation results show that our policy provides a positive improvement in terms of the total reward of the service system, even when patients do not have perfect adherence to appointments (e.g., patient no-shows and unpunctuality). The numerical experiments demonstrate that the dedicated medical resource cannot improve emergency patients’ access to service but deteriorated their direct waiting time.

The Prevalence of Coronary Artery Anomalies in Children with Congenital Heart Disease

Background and purposes: Coronary artery anomalies (CAA), although rare in the general population, are common in patients with congenital heart disease (CHD). CAA can be the cause of sudden cardiac death; thus, the childhood diagnosis of CAA is essential in patients suffering from CHD. The present study aimed to investigate the prevalence of CAAs in pediatric patients with CHD in Iran. Materials and Methods: We recruited children with CHD (one day to 21 years old), who were referred to the CT Department of Shahid Rajaei Hospital (Tehran, Iran) to undergo CT angiography (CTA) for various reasons between 2011 and 2013. We recorded age, gender, and underlying heart diseases, as well as the CTA findings, reported by a radiologist and a cardiologist. We classified CAAs using the most commonly used classification of CAA based on anatomical considerations. Results: Among a total of 219 patients with CHD, 112 (51.1%) were male, and 107 (48.9%) were female with the mean age of 3.5 ± 2.4 years. The prevalence of CAAs was 8.7% (19 patients) with no significant difference based on gender (P-value &gt;0.05). All 19 patients had CAAs of origin; the most common CAAs were anomalous origin of right coronary artery (RCA) from left sinus (31.6%) and anomalous origin of left main coronary artery (LMCA) from pulmonary artery (ALCAPA) (21.0%), respectively. Conclusion: We observed a high prevalence of CAA in children with CHD, which emphasizes the importance of raising awareness about CAAs and improving the screening methods in the pediatric population suffering from CHD.

219 The Effect of Introducing In-house Radiographers Out of Hours on Door to CT Times for FAST Positive Patients

Abstract Background Stroke is a leading cause of death and disability in Ireland with up to 7,000 people hospitalised following a stroke annually (IHF/HSE 2016). Every minute in which a large vessel ischaemic stroke is left untreated equates to the average patient losing 1.9 million neurons (Saver, 2006). With the introduction of out of hours in-house radiographers our aim was to look at how this impacted on the service of care to FAST positive patients who present to our Emergency Department. Stroke is a medical emergency where urgent assessment and treatment can lead to improved survival and reduced disability. Methods To assess the impact of the introduction of in-house radiographers out of hours we compared door to CT times of FAST positive patients who presented to ED out of hours pre and post the introduction of in-house radiographers. We took the first 30 FAST calls following the introduction of the in-house radiographers and compared those times to the last 30 FAST calls prior to their introduction. Results Preliminary results have shown that the introduction of in-house radiographers has reduced the median time spent in the Emergency Department times prior to CT imaging. Current median door to CT times prior to the introduction of in-house radiographers was 27 minutes, the median door to CT time post introduction of in-house radiographers is 21 minutes, however full results are still awaited. Conclusion The introduction of in-house radiographers out of hours has led to a quicker transition of patients from the Emergency Department to the CT department thus reducing door to CT times.

Preventing Burnout in the Face of Growing Patient Volumes in a Busy Outpatient CT Suite: A Technologist Perspective

CT technologists, like radiologists, are at risk of increased stress and burnout due to ever increasing clinical and workload demands. To mitigate these issues, radiology facilities need to be prepared to actively address and resolve issues that impact the technologist satisfaction. At our institution, a Process Improvement Committee was formed to identify and alleviate workplace stressors faced by CT technologists. As a result of the initiative, our CT department has evolved into a technologist-driven department in which experienced and effective technologists play a large role in fostering efficient and patient-centered care, while feeling empowered to function as leaders in their work environment. In this article, a senior CT technologist provides a first-hand account of the process changes from the technologist's perspective, focusing on strategies for establishing a supportive system that allows technologists to thrive in providing patient-centered care even in the busiest of clinical contexts.

Abstract TP460: Recognizing Large Vessel Occlusions Earlier in the Stroke Alert Process

Background: As an Agency for Healthcare Administration (AHCA) Comprehensive Stroke Center we were looking for ways to decrease our door to groin puncture time for patients that had Large Vessel Occlusions (LVO) requiring mechanical thrombectomy. We found patients were often making two trips to the CT scanner. First for their plain brain CT to rule out blood and then for a CT Angiogram and CT Perfusion scan if it appeared the patient was having a Large Vessel Occlusion (LVO). Our mean groin puncture time for mechanical thrombectomy was 116 minutes in 2015. Purpose: To recognize the signs and symptoms of a LVO and save time by completing the plain brain CT scan, the CT Angiogram, and the CT Perfusion scan on the same trip to the CT department. Method: Our vascular neurologist reviewed the signs and symptoms of Large Vessel Occlusions utilizing V.A.N. (vision, aphasia, neglect) criteria with the Emergency Room Physicians, the Emergency Room Nurses, the Clinical Resource Nurses as well as all Emergency Medical Services (EMS) personnel. Lectures were given as well as hands on demonstrations. Telemedicine was asked to see the patient upon arrival in the ambulance bay to observe for LVO as well. Mock codes were run on both campuses with success. Results: Initially all stroke alerts were getting CT Angiograms and CT Perfusions completed regardless of whether they were VAN positive. However, after we reviewed all the false positives the number of patients actually getting these scans decreased to those that truly needed them. EMS now feels comfortable and competent calling LVO’s in the field. As do the Emergency Room physicians. As a result of these patients getting their required scans in one trip to the CT department, our door to groin puncture time has decreased from 116 minutes to a mean of 56 minutes. Conclusion: In conclusion, we found that adopting the utilization of VAN criteria to recognize LVO’s has decreased the mean door to groin puncture time for mechanical thrombectomy allowing for sooner return of circulation to the brain and improving patient outcomes.

Point of care creatinine testing in diagnostic imaging: A feasibility study within the outpatient computed tomography setting

IntroductionAlthough the risks associated with iodinated contrast administration are acknowledged to be very low, screening of kidney function prior to administration is still standard practice in many hospitals. This study has evaluated the feasibility of implementing a screening form in conjunction with point of care (PoC) creatinine testing as a method to manage the risks of post contrast acute kidney injury (PC-AKI) within the CT imaging pathway. MethodOver an eight-week period 300 adult outpatients attending a UK CT department for contrast-enhanced scans were approached. Participants completed a screening questionnaire for co-morbidities linked to kidney dysfunction and consented to have a PoC and laboratory creatinine tests. Comparison was made against with previous baseline blood tests obtained within the preceding 3 months, as required by the study site. Participants were also invited to attend for follow up PoC and laboratory bloods tests at 48–72 h. Results14 patients (4.7%) had a scan-day eGFR below 45mL/min/1.73m2, all identified through screening. The majority of patients (n=281/300; 93.7%) fell in the same risk category based on previous and scan-day blood results. Six PoC test failures were recorded on the scan day. The constant error between the Abbott i-STAT PoC scan-day measurements and the laboratory scan-day measurements was -3.71 (95% CI: -6.41 to -0.50). Five patients had an elevated creatinine (≥25% from baseline) post contrast administration, but no instances of PC-AKI (≥50% from baseline) were identified. ConclusionPoC creatinine testing is a practical method of ensuring renal function and is feasible in the radiology environment.

A Stitch in Time Saves 1.9 Million: How Advanced Imaging Solutions in Neuroradiology can Improve Outcomes for Stroke Patients

Stroke is the leading cause of disability in Canada and the third leading cause of death. Every year there are over 50,000 new strokes, with nearly 14,000 of cases resulting in death. For every minute delay in treating a stroke, the patient loses 1.9 million brain cells, and for each hour in which treatment does not occur, the brain loses as many neurons as it does in almost 3.6 years of normal aging. Thus, it is vital that the patient receives revascularization therapy as soon as possible. Despite this knowledge, there is still an inefficient use of time between stroke onset to revascularization. Advanced image solutions are urgently needed to shorten the door to treatment time, save more brain cells and improve patient outcomes. Currently, the stroke team relies on CT to detect blood, ischemia, occlusion or stenosis and assess brain tissue at risk. This step in the workflow can delay revascularization therapy by up to 60 minutes. Our multidisciplinary research team is working with a vendor engineering team to 1) improve the image quality of the Philips Allura c-arm cone-beam CT (XperCT) and 2) develop specialized stroke imaging software. The goal is to improve the imaging capabilities of the angiography suite so that it can provide the same essential imaging as standard CT, allowing patients to forgo a visit to CT and go straight to the angio-suite for treatment, shortening the door to puncture time by up to 60 minutes. Thus far, we have improved the image quality of cone-beam CT by utilizing a specialized aluminum filter and reconstruction algorithms designed to reduce bone-beam hardening effects. Our current stroke imaging protocol consists of the standard non-enhanced XperCT ‘mask’ image, followed by a unique dual-phase enhanced XperCT. The dual-phase scan consists of two modified XperCT acquisitions with the c-arm performing a propeller scan 220 degrees in each direction around the patient’s head during IV injection of a contrast bolus (80 cc). The scans are 10 seconds apart, and result in volumetric images of early and late brain perfusion phases. The specialized stroke analysis software then performs a subtraction of these two phases to highlight any brain regions of delayed filling. Using a quality assessment questionnaire, the unenhanced and perfusion XperCT scans acquired in the angio-suite were evaluated by an experienced radiologist and compared to unenhanced and perfusion images acquired in CT. Results demonstrated that the image quality improvements and new stroke imaging software can provide the necessary diagnostic information, in the angio-suite, immediately before revascularization therapy. This includes the detection or exclusion of blood, ischemia, occlusion or stenosis and tissue at risk. Limitations with this process do exist. For example, patient motion between the scans can interfere with the subtraction process. Additionally, although the cone-beam CT images are sufficient for diagnosis, the XperCT quality still has inferior contrast and spatial resolution compared to a standard CT perfusion. Currently, stroke patients must first visit the CT department for imaging to confirm a large vessel occlusion before going to the angiography suite for mechanical thromectomy treatment. Preliminary results from our efforts to improve cone-beam CT image quality and develop specialized stroke image analysis software demonstrate that diagnostic-quality imaging can be acquired using a c-arm in the angio-suite, allowing patients to bypass CT and come straight to the angio-suite for imaging and immediate treatment. Although image quality improvement work continues, this one-stop-stroke-shop approach promises to reduce diagnosis time, save more brain cells and improve patient outcomes.

Three-dimensional computed tomography analysis and clinical application of sacroiliac screw placement

Objective: To evaluate the possibility of transverse sacroiliac screw placement in different segments of the sacrum. Methods: Data of 80 pelvic CT scans (slice thickness ≤1.0 mm) archived in CT department of the Third Hospital of Hebei Medical University from September 2016 to October 2017 were retrospectively collected. Mimics software was used to rebuild the pelvis three-dimensional model. According to whether the sacral 1(S(1)) segment could place the transverse sacroiliac screws or not, all the sacrums were divided into normal group (n=55) and dysmorphic group (n=25). Simulation the S(1), sacral 2(S(2)) transverse sacroiliac screw placement in 3-Matic software. Analysis whether there was any difference in maximum diameter and length of S(2) transverse sacroiliac screw between the normal group and the dysmorphic group. The pelvic CT data of the dysmorphic group were measured, and the optimal tilt angle and length of the oblique S(1) screw were obtained. The feasibility of transverse sacroiliac screw insertion in sacral 3(S(3)) segment was evaluated.t-test, rank sum test, and χ(2) test was used to analyze data, respectively. Results: In the dysmorphic group, the largest diameter of the S(1) transverse screw was (4.9±1.6)mm, and the normal group was (13.6±3.6)mm (t=-15.07, P=0.00). In the dysmorphic group, the largest diameter of S(2) transverse screw was (13.8±3.0)mm, and was (12.4±2.2)mm in the normal group(t=2.11, P=0.04). There was no significant difference in the length of S(2) transverse sacroiliac screw between the two groups (t=0.47, P=0.64). In the dysmorphic group, the anterior vertebral height of S(1) was (23.1±4.0)mm, which was significantly higher than that of the normal group ((14.1±4.2)mm)(t=9.01, P=0.00). The angle of S(1)S(2) in the dysmorphic group was 10.9°(3.8°, 17.6°), which was significantly larger than that of the normal group (2.0°(1.0°, 2.0°) (Z=-4.03, P=0.00). In the dysmorphic group, the incline angle of the oblique S(1) sacroiliac screw was (35.6±6.2)°, the anteversion angle was (37.2±4.4)°, and the mean screw length was (90.2±4.7)mm. In the dysmorphic group, the placement rate of S(3) transverse sacroiliac screw was 48.0%, and that of the normal sacral group was 9.1%. Conclusions: There is often dysmorphic in the sacrum in patients with large S(1) anterior vertebral height and S(1)S(2) angle. Sacral dysmorphic patients with posterior pelvic ring injury may be treated with S(1) pedicle oblique sacroiliac screws. S(3) transverse sacroiliac screws should be carefully placed, especially for the absence of sacral dysmorphic in patients.