Early after Discharge cardiac CT for low risk chest pain: The ED-CT study.

OBJECTIVES: An accelerated diagnostic pathway is created to aid the management of low risk patients presenting to the emergency room with chest pain. Records are taken of patient outcomes and factors influencing physician decision making between inpatient invasive angiography versus early outpatient cardiac CT angiography. METHODS: A cohort study at 30 days post discharge is undertaken over 1 year. Differences are observed between a population of patients who underwent early outpatient CT and a population of ambulatory haemodynamically stable patients who underwent inpatient fluoroscopic angiography. RESULTS: 369 underwent CT (F = 46%), 37 underwent angiography (F = 30%). Median outpatient CT was at 14 days. At 30 days 0 patients suffered mortality or myocardial infarction. 11% were recommended for invasive angiography. 2% of CT patients underwent coronary revascularisation. Median calcium score was 0. 20% of the CT population were commenced on high potency statin, or had their pre-existing statin dose intensified. Calcium score affected a composition of statin commencement, angiography, and revascularisation (OR 59, p < 0.001). Age, troponin, vascular disease, previous coronary revascularisation appeared to influence choice between CCTA and invasive angiography. CONCLUSION: An accelerated diagnostic pathway for outpatient cardiac CT for chest pain resulted in no mortality or myocardial infarction, with a low level of downstream testing and coronary revascularisation. ADVANCES IN KNOWLEDGE: At a median time to CCTA of 14 days post discharge from the emergency department there is no effect on patient major adverse cardiac events.

CT coronary angiography and COVID-19: inpatient use in acute chest pain service.

OBJECTIVES: CT coronary angiography (CTCA) is a well-validated clinical tool in the evaluation of chest pain. In our institution, CTCA availability was increased in January 2020, and subsequently, expanded further to replace all exercise testing during the COVID-19 pandemic. Our objective was to assess the impact of increased utilisation of CTCA on length of stay in patients presenting with chest pain in the prepandemic era and during the COVID-19 pandemic. METHODS: Study design was retrospective. Patients referred for cardiology review between October 2019 and May 2020 with chest pain and/or dyspnoea were broken into three cohorts: a baseline cohort, a cohort with increased CTCA availability and a cohort with increased CTCA availability, but after the national lockdown due to COVID-19. Coronary angiography and revascularisation, length of stay and 30-day adverse outcomes were assessed. RESULTS: 513 patients (35.3% female) presented over cohorts 1 (n=179), 2 (n=182), and 3 (n=153). CTCA use increased from 7.8% overall in cohort 1% to 20.4% in cohort 3. Overall length of stay for the patients undergoing CTCA decreased from a median of 4.2 days in cohort 1 to 2.5 days in cohort 3, with no increase in 30 days adverse outcomes. Invasive coronary angiogram rates were 45.8%, 39% and 34.2% across the cohorts. 29.6% underwent revascularisation in cohort 1, 15.9% in cohort 2 and to 16.4% in cohort 3. CONCLUSIONS: Increased CTCA availability was associated with a significantly reduced length of stay both pre-COVID-19 and post-COVID-19 lockdown, without any increase in 30-day adverse outcomes.

A Business Analytics Software Tool for Monitoring and Predicting Radiology Throughput Performance.

Business analytics (BA) is increasingly being utilised by radiology departments to analyse and present data. It encompasses statistical analysis, forecasting and predictive modelling and is used as an umbrella term for decision support and business intelligence systems. The primary aim of this study was to determine whether utilising BA technologies could contribute towards improved decision support and resource management within radiology departments. A set of information technology requirements were identified with key stakeholders, and a prototype BA software tool was designed, developed and implemented. A qualitative evaluation of the tool was carried out through a series of semi-structured interviews with key stakeholders. Feedback was collated, and emergent themes were identified. The results indicated that BA software applications can provide visibility of radiology performance data across all time horizons. The study demonstrated that the tool could potentially assist with improving operational efficiencies and management of radiology resources.

Comparison of intensive versus standard hemodialysis central venous catheter dysfunction protocol using rt-PA: a quality assurance initiative.

PURPOSE: Catheter locking solutions such as recombinant tissue plasminogen activator (rt-PA) are used to treat and prevent clotting of hemodialysis (HD) catheters during HD treatments and the interdialytic period. However, evidence to guide the use of rt-PA for catheter dysfunction is limited. METHODS: We evaluated outcomes using two catheter dysfunction protocols in a cohort of consecutive prevalent dialysis patients (Jan 2013 to Sep 2014) undergoing HD with a tunneled catheter. In the intensive protocol, rt-PA was administered to all catheters based on blood flow and/or line reversal. In the standard protocol, rt-PA administration was based only on blood flow. The primary outcome was the rate of rt-PA use for catheter malfunction (rt-PA treatment days/1000 total line days; [TLD]). Secondary outcomes included the cost of rt-PA/TLD and the rate of catheter-related bacteremia. RESULTS: There were 26 and 35 patients managed by the intensive and standard protocols, respectively. The rate of rt-PA use was 52/1000 TLD (intensive) versus 39/1000 TLD (standard) (rate ratio 1.30, 95% CI 1.12-1.52 CI, p<0.001). The rate of bacteremia was 0.43 and 0.22/1000 TLD for the intensive and standard protocols, respectively (p = 0.491). The cost of rt-PA was CDN $5.58 and CDN $6.15 per TLD for the intensive protocol and standard protocol groups (p<0.001). CONCLUSIONS: Managing catheter dysfunction based on line reversal and blood flow as opposed to only blood flow was associated with a higher rate of rt-PA use, but at a reduced overall cost.

Pattern of Investigation Reflects Risk Profile in Emergency Medical Admissions.

Demand for hospital resources may increase over time; we have examined all emergency admissions (51,136 episodes) from 2005 to 2013 for underlying trends and whether resource utilization and clinical risk are correlated. We used logistic regression of the resource indicator against 30-day in-hospital mortality and adjusted this risk estimate for other outcome predictors. Generally, resource indicators predicted an increased risk of a 30-day in-hospital death. For CT Brain the Odds Ratio (OR) was 1.37 (95% CI: 1.27, 1.50), CT Abdomen 3.48 (95% CI: 3.02, 4.02) and CT Chest, Thorax, Abdomen and Pelvis 2.50 (95% CI: 2.10, 2.97). Services allied to medicine including Physiotherapy 2.57 (95% CI: 2.35, 2.81), Dietetics 2.53 (95% CI: 2.27, 2.82), Speech and Language 5.29 (95% CI: 4.57, 6.05), Occupational Therapy 2.65 (95% CI: 2.38, 2.94) and Social Work 1.65 (95% CI: 1.48, 1.83) all predicted an increased risk. The in-hospital 30-day mortality increased with resource utilization, from 4.7% (none) to 27.0% (five resources). In acute medical illness, the use of radiological investigations and allied professionals increased over time. Resource utilization was calibrated from case complexity/30-day in-hospital mortality suggesting that complexity determined the need for and validated the use of these resources.

Neoadjuvant crizotinib in advanced inflammatory myofibroblastic tumour with ALK gene rearrangement.

BACKGROUND: Inflammatory myofibroblastic tumours (IMTs) are rare sarcomas that were first described in the lung. They are composed of myofibroblastic mesenchymal spindle cells accompanied by an inflammatory infiltrate of plasma cells. Complete resection is the treatment of choice. There is currently no standard treatment for inoperable or recurrent disease. Expression of ALK protein triggered by ALK gene rearrangement at chromosome 2p23 has been found in 36%-60% of IMTs. CASE REPORT: We report a rapid early response to crizotinib as neoadjuvant therapy, enabling surgical excision of a large ALK-translocated IMT, which resulted in complete disease clearance. To the best of our knowledge, this is the first case in the literature of a patient with IMT in whom crizotinib was used successfully in the neoadjuvant or curative setting.

18F-FDG-PET/CT is of limited value in primary staging of early stage cervical cancer.

PURPOSE: To assess the clinical benefit of 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography (18F-FDG-PET/CT) in evaluating pelvic lymph nodes in patients with early stage cervical cancer (FIGO stage 1a­1b1), who have magnetic resonance imaging (MRI)-defined lymph node negative disease, with histopathologic results as the reference standard. MATERIALS AND METHODS: We assessed one hundred and seventy nine sequential 18F-FDG-PET/CT scans in women with newly diagnosed cervical carcinoma between January 2009 and September 2011. 47 of these patients had early stage disease (FIGO stage 1a­1b1) with no suspicious lymph nodes on MRI. 18F-FDG-PET/CT images were analyzed and histopathological findings (pelvic lymph node resection) served as the reference standard. RESULTS: The median age of patients was 48 (range 22­86) years. 66 % had squamous histotype. Median number of nodes dissected per patient was 21 (range 8­47), 2 of 47 patients had nodal metastases (4.25 %). All patients in this group had no suspicious lymph nodes on 18F-FDG-PET/CT. Overall patient based sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 18F-FDG-PET/CT for detection of nodal disease were 0 %, 100 %, 0 %, 96 %, and 96 % respectively. CONCLUSION: Pathologic validation of 18F-FDG-PET/CT imaging demonstrates little value for 18F-FDG-PET/CT in patients with early stage (FIGO stage 1a­1b1) MRI-defined lymph node negative cervical carcinoma. Since the likelihood of metastatic nodal disease is very low in women with stage 1a­1b1 cervical cancer, we believe that 18F-FDG-PET/CT should not have a role in the routine pre-treatment evaluation of these women.

The utility of deformable image registration for small artery visualisation in contrast-enhanced whole body MR angiography.

PURPOSE: An investigation was carried out into the effect of three image registration techniques on the diagnostic image quality of contrast-enhanced magnetic resonance angiography (CE-MRA) images. METHODS: Whole-body CE-MRA data from the lower legs of 27 patients recruited onto a study of asymptomatic atherosclerosis were processed using three deformable image registration algorithms. The resultant diagnostic image quality was evaluated qualitatively in a clinical evaluation by four expert observers, and quantitatively by measuring contrast-to-noise ratios and volumes of blood vessels, and assessing the techniques' ability to correct for varying degrees of motion. RESULTS: The first registration algorithm ('AIR') introduced significant stenosis-mimicking artefacts into the blood vessels' appearance, observed both qualitatively (clinical evaluation) and quantitatively (vessel volume measurements). The two other algorithms ('Slicer' and 'SEMI'), based on the normalised mutual information (NMI) concept and designed specifically to deal with variations in signal intensity as found in contrast-enhanced image data, did not suffer from this serious issue but were rather found to significantly improve the diagnostic image quality both qualitatively and quantitatively, and demonstrated a significantly improved ability to deal with the common problem of patient motion. CONCLUSIONS: This work highlights both the significant benefits to be gained through the use of suitable registration algorithms and the deleterious effects of an inappropriate choice of algorithm for contrast-enhanced MRI data. The maximum benefit was found in the lower legs, where the small arterial vessel diameters and propensity for leg movement during image acquisitions posed considerable problems in making accurate diagnoses from the un-registered images.

MRI in acutely ill medical patients in an Irish hospital: influence on outcomes and length of hospital stay.

PURPOSE: MRI is an important diagnostic tool for acute medical admissions. Its relevance to in-hospital mortality and length of stay (LOS) has been examined at St James's Hospital in Dublin, Ireland. METHODS: All patients admitted for medical emergencies from 2010 through 2012 were studied (18,534 episodes); any relationship between an MRI request, underlying diagnosis on any in-hospital death, and LOS was examined. Logistic regression with generalized estimating equations, adjusted for correlated observations (readmissions), odds ratio estimates, and zero-truncated Poisson regression for LOS were used. RESULTS: MRI procedures were requested in 8.6% of episodes. The in-hospital mortality rate was significantly higher when MRI was performed (7.8% vs 4.6%, P < .001). The unadjusted odds ratio for in-hospital death during that episode was 1.74 (95% confidence interval, 1.26-2.37; P < .001) compared with episodes without MRI. The hospital stay for those MRI episodes was longer (median, 9.1 days; interquartile range, 4.0-26.8 days) than for non-MRI episodes (median, 5.8 days; interquartile range, 2.2-12.2; P < .001). Each unit increase in MRI waiting time (cutoffs set at 0, 1, 3, 7, and 14 days) gave an estimated increase of 1.12 days in hospital LOS, adjusted for illness severity and comorbidities. CONCLUSIONS: MR imaging identified in a subgroup of emergency patients at higher risk of an in-hospital death. These patients have longer LOS attributable in part to procedure wait times, not merely to illness severity or comorbidities.

Positron emission tomography/computed tomography imaging in Merkel cell carcinoma: a study of 270 scans in 97 patients at the Dana-Farber/Brigham and Women's Cancer Center.

BACKGROUND: Merkel cell carcinoma (MCC) is a rare and lethal cutaneous neuroendocrine carcinoma. Imaging is crucial for accurate staging, which remains a strong predictor of survival, as well as earlier detection of recurrence and progression, which are common despite aggressive management. There is no consensus on the role of initial and subsequent imaging for MCC. OBJECTIVE: We sought to evaluate the use of 2-fluoro-[(18)F]-deoxy-2-D-glucose (FDG)-positron emission tomography (PET)/computed tomography (CT) in the management of MCC. METHODS: In all, 270 FDG-PET/CT studies were performed in 97 patients with pathology-proven MCC at the Dana-Farber/Brigham and Women's Cancer Center, Boston, Mass, from August 2003 to December 2010. RESULTS: FDG-PET/CT scans were obtained as part of the initial (61 scans in 61 patients) and subsequent (209 scans in 79 patients) treatment strategies. MCCs were FDG-avid with a mean maximum standardized uptake value of primary lesions of 6.5 (range 1.3-12.9) and a mean maximum standardized uptake value of regional and distant metastases of 7.2 (range 1.5-9.9). FDG-PET/CT upstaged 16% of patients who underwent baseline scans. FDG-PET/CT studies showed that bone and bone-marrow metastases were more common than previously reported, and were often undetected by CT. LIMITATIONS: Our study is limited by its retrospective design, and potential referral bias associated with a tertiary care center. CONCLUSIONS: FDG-PET/CT performed as part of the initial management strategy tended to upstage patients with more advanced disease. FDG-PET/CT performed as part of the subsequent treatment strategy identified metastatic disease, particularly in bone/bone marrow, which was not seen on CT. FDG-PET/CT imaging is a valuable staging and restaging tool in MCC management.

Neurosyphilis presenting with unusual hippocampal abnormalities on magnetic resonance imaging and positron emission tomography scans: a case report.

INTRODUCTION: The incidence of neurosyphilis has declined markedly since the introduction of penicillin therapy. While there are a number of case reports in the literature of neurosyphilis causing focal decreased 18F-fluorodeoxyglucose uptake on positron emission tomography/computed tomography scans, to the best of our knowledge this is the first published report of neurosyphilis presenting with intensely increased 18F-fluorodeoxyglucose uptake in the hippocampus. CASE PRESENTATION: A 55-year-old Caucasian man presented to our facility with acute collapse against a background of memory difficulties over the previous six months. The results of his initial physical examination were normal. He scored 24 out of 30 on the Montreal Cognitive Assessment test. A magnetic resonance imaging scan of his brain revealed high T2 signal intensity and atrophy within the right frontal area in addition to high T2 signal intensity in the bilateral mesial temporal areas. Blood and cerebrospinal fluid analysis revealed an active syphilis infection. An 18F-fluorodeoxyglucose positron emission tomography brain scan showed intensely increased 18F-fluorodeoxyglucose uptake limited to the head of the right hippocampus. He responded to penicillin treatment with an improvement in his cognition, which was further reflected in a complete resolution of the findings previously seen on magnetic resonance imaging and 18F-fluorodeoxyglucose positron emission tomography scans. CONCLUSIONS: Diagnosis of neurosyphilis can be difficult, as many patients are either asymptomatic or present with non-specific symptoms such as memory disturbance or seizures. This report highlights the importance of considering neurosyphilis in the differential diagnosis when mesiotemporal changes are seen on magnetic resonance imaging or 18F-fluorodeoxyglucose positron emission tomography scans.

Pediatric 99mTc-MDP bone SPECT with ordered subset expectation maximization iterative reconstruction with isotropic 3D resolution recovery.

PURPOSE: To perform a preliminary evaluation of the image quality of pediatric technetium 99m ((99m)Tc) methylene diphosphonate (MDP) bone single photon emission computed tomography (SPECT) by using iterative reconstruction-ordered subset expectation maximization with three-dimensional resolution recovery (OSEM-3D)-and to assess whether any improvements with use of this technique could lead to a reduction in patient dose or a shortening in imaging time. MATERIALS AND METHODS: Institutional advisory board approval was obtained for this investigation. Fifty (99m)Tc-MDP SPECT studies of the spine were evaluated (36 female and 14 male patients; mean age, 15.5 years). Each study was acquired by using a dual-detector camera, with each detector rotating 360°. By using filtered back projection (FBP) and OSEM-3D, images were reconstructed from data generated by both detectors. Likewise, OSEM-3D was used to reconstruct data from a single detector simulating half the administered radiopharmaceutical activity. Two nuclear medicine physicians, blinded to the patient data, reviewed the images for image quality in four different categories by using a four-point scale: artifacts (category 1), lesions (category 2), noise (category 3), and image sharpness (category 4). RESULTS: Compared with FBP, images reconstructed by using OSEM-3D with one or two detectors showed significant improvement in image quality with regard to lesion detection, noise level, and image sharpness (P < .02, .01, and .001, respectively). With OSEM-3D, no significant differences were observed when either one or two detectors were used. CONCLUSION: Improved image quality of skeletal SPECT with either a 50% reduction in radiation dose or a 50% reduction in acquisition time or combination of the two can be achieved by using OSEM-3D.

Pediatric 99mTc-DMSA SPECT performed by using iterative reconstruction with isotropic resolution recovery: improved image quality and reduced radiopharmaceutical activity.

PURPOSE: To compare two methods of reconstructing technetium 99m (99mTc) dimercaptosuccinic acid (DMSA) renal single photon emission computed tomographic (SPECT) data--ordered subset expectation maximization with three-dimensional resolution recovery (OSEM-3D) and filtered back projection (FBP)--in children in terms of improving image quality and reducing the radiopharmaceutical activity and radiation dose. MATERIALS AND METHODS: The institutional review board approved this retrospective study and waived the requirement for informed patient consent. Fifty sequential pediatric patient 99mTc-DMSA SPECT studies of 98 kidneys were retrospectively analyzed by using a dual-detector gamma camera. FBP reconstruction with data from both detectors was compared with OSEM-3D reconstruction with half the gamma photon counts (ie, data from only one detector). Two nuclear medicine physicians blinded to the patients' medical histories and reconstruction techniques evaluated the studies. Scores for image quality, renal size, and relative function were compared by using paired t tests. Total scores for renal cortical defects were compared by using the Wilcoxon signed rank test. The kappa coefficient was calculated as an indicator of the concordance between the OSEM-3D and FBP reconstruction methods. RESULTS: Image quality was significantly enhanced with OSEM-3D (P < .001, paired t test). Cortical defects were identified better on OSEM-3D images than on FBP images. Of the 98 kidney SPECT studies analyzed, 19 showed identical cortical defects and 75 showed none at both OSEM-3D and FBP. In four kidneys, OSEM-3D depicted cortical defects that were not seen with FBP. No significant difference in relative renal function between the two methods was observed (P = .973). CONCLUSION: Compared with FBP, OSEM-3D yielded superior image quality in the evaluation of 99mTc-DMSA renal SPECT data, with the potential for markedly reduced radiation doses and/or shorter scanning times for patients.

Clinical, radiographic, and biochemical characterization of multiple myeloma patients with osteonecrosis of the jaw.

PURPOSE: Osteonecrosis of the jaw (ONJ) has been reported in patients with a history of aminobisphosphonate use. This study was conducted in order to define ONJ clinically and radiographically and gain insights into its pathophysiology. EXPERIMENTAL DESIGN: Eleven multiple myeloma (MM) patients with ONJ were included in the study. Patients underwent clinical, biochemical, radiographic, and molecular profiling. Ten MM patients on aminobisphosphonates without ONJ and five healthy volunteers were used as controls for biochemical and molecular studies. RESULTS: MM patients with ONJ were treated with either pamidronate (n = 3), zoledronate (n = 4), or both agents sequentially (n = 4) for a mean of 38.7 months. Radiographic studies showed bone sclerosis and fragmentation on plain films and computerized tomography. Quantitative regional analysis of NaF-PET and FDG-PET scans confirmed an increased standardized uptake value (SUVmax) in areas of ONJ. The target to background ratio of SUVmax was significantly greater for NaF-PET compared with FDG-PET scan. Biochemical bone marker data and transcriptional profiling studies showed that genes and proteins involved in osteoblast and osteoclast signaling cascades were significantly down-regulated in patients with ONJ. CONCLUSIONS: ONJ was associated with a mean duration of 38.7 months of aminobisphosphonate exposure. Radiographic and functional imaging confirmed sites of clinically established ONJ. Gene and protein studies are consistent with altered bone remodeling, evidenced by suppression of both bone resorption and formation.

Acute varicella infection mimics recurrent Hodgkin's disease on F-18 FDG PET/CT.

We report a case where acute varicella infection, chickenpox, mimics the findings of recurrent Hodgkin disease on F-18 FDG PET/CT. A 28-year-old man with a history of Hodgkin disease in remission had fatigue, pyrexia, and a raised ESR. His F-18 FDG PET/CT, performed to exclude lymphoma recurrence, demonstrated FDG-avid lymphadenopathy and increased FDG uptake in his spleen. A day later he developed the generalized rash of acute varicella infection. This was managed with valacyclovir. Repeat F-18 FDG PET/CT done 1 month later showed no evidence of FDG-avid disease. In this patient the stimulation of an immune response by the acute viral infection mimics recurrent lymphoma.

Intracranial stab wound: a case report.

OBJECTIVE: Intracranial stab wounds are relatively uncommon, as the adult skull usually provides an effective barrier to penetration. We present an interesting case of a penetrating intracranial stab wound with several important teaching points. CLINICAL PRESENTATION: A 44-year-old man presented to the emergency department with a 1.2-cm stab wound to the left temporal area. His initial Glasgow Coma Score was 14/15. Computerized tomography of his brain revealed a left temporal lobe haemorrhage and contusion. Magnetic resonance images of his brain revealed a linear haematoma extending from his left temporal lobe into the left middle cerebellar peduncle, consistent with a penetrating injury. He was managed conservatively with intravenous antibiotics and made an excellent recovery. Three weeks after injury, he had mild residual problems with recall and attention. CONCLUSION: Several leaning points exist in this case. Firstly, as stab wounds to the brain frequently present as apparently innocuous facial or scalp lacerations, a high index of suspicion is needed to prevent these injuries presenting with serious late infective complications. Secondly, reports of similar cases in the literature suggest that stab wounds to the temporal region are associated with a high morbidity and mortality. This case demonstrates that a patient with an injury such as this can occasionally make a good functional recovery. Finally, this case highlights the advantage of magnetic resonance imaging over computerized tomography in patients with these injuries once it has been established that there is no residual intracranial metal fragment prior to magnetic resonance imaging. In this case, the entire wound tract was only evident on magnetic resonance imaging and not on the initial computerized tomography scans.

An interactive taxonomy of MR imaging sequences.

Discerning an underlying structure in the array of magnetic resonance (MR) imaging sequences and acronyms available is a bewildering task. Attempts have been made to present standard taxonomies of MR imaging sequences, primarily on the basis of their underlying physics. Despite this, it is difficult to usefully incorporate given taxonomies into routine clinical knowledge. The links, differences, and similarities among sequences are multidimensional and too complex for tabular presentation on the printed page. The authors present an interactive taxonomy of MR imaging sequences. With this graphical interface, the user can explore the changing relationships among a wide range of sequence types as they are viewed from different perspectives and through different associations, working through a natural learning process.