Cardiac functional imaging

During the last 20 years, cardiac imaging has drastically evolved. Positron emission tomography (PET), fast three-dimensional (3D) imaging with the latest generations of echocardiography & multi-detector computed tomography (CT), stress perfusion assessed by magnetic resonance imaging (MRI), blood flow analysis using four-dimensional (4D) flow MRI, all these techniques offer new trends for optimal noninvasive functional cardiac imaging. Dynamic functional imaging is obtained by acquiring images of the heart at different phases of the cardiac cycle, allowing assessment of cardiac motion, function, and perfusion. Between CT and Cardiac MRI (CMR), CMR has the best temporal resolution, which is suitable for functional imaging while cardiac CT provides higher spatial resolution with isotropic data that have an identical resolution in the three dimensions of the space. The latest generations of CT scanners enable whole heart assessment in one beat, offering also an acceptable temporal resolution with the possibility to display the images in a dynamic mode. Another rapidly growing technique using functional and molecular imaging for the assessment of biological and metabolic pathways is the PET using radio-labeled tracers. Meanwhile, the oldest cardiac imaging tool with doppler ultrasound technology has never stopped evolving. Echocardiography today performs 3D imaging, stress perfusion, and myocardial strain assessment, with high temporal resolution. It still is the first line and more accessible exam for the patient. These different modalities are complementary and may be even combined into PET-CT or PET-MRI. The ability to combine the functional/molecular data with anatomical images may implement a new dimension to our diagnostic tools.     

PET/CT in the management of differentiated thyroid cancer

The standard treatment of differentiated thyroid cancer (DTC) consists of surgery followed by iodine-131 (¹³¹I) administration. Although the majority of DTC has a very good prognosis, more aggressive histologic subtypes convey a worse prognosis. Follow-up consists of periodically measurements of serum thyroglobulin, thyroglobulin antibodies and neck ultrasound and ¹²³I/¹³¹I whole-body scan. However, undifferentiated thyroid tumors have a lower avidity for radioiodine and the ability of DTC to concentrate ¹³¹I may be lost in metastatic disease. Positron emission tomography (PET)/computed tomography (CT) has been introduced in the evaluation of patients with thyroid tumors and the 2-[18F]-fluoro-2-deoxyd-glucose (¹⁸F-FDG) has been largely validated as marker of cell's metabolism. According to the 2015 American Thyroid Association guidelines, ¹⁸F-FDG PET/CT is recommended in the follow-up of high-risk patients with elevated serum thyroglobulin and negative ¹³¹I imaging, in the assessment of metastatic patients, for lesion detection and risk stratification and in predicting the response to therapy. It should be considered that well-differentiated iodine avid lesions could not concentrate ¹⁸F-FDG, and a reciprocal pattern of iodine and ¹⁸F-FDG uptake has been observed. Beyond ¹⁸F-FDG, other tracers are available for PET imaging of thyroid tumors, such as Iodine-124 (¹²⁴I), ¹⁸F-tetrafluoroborate and Gallium-68 prostate-specific membrane antigen. Moreover, the recent introduction of PET/MRI, offers now several opportunities in the field of patients with DTC. This review summarizes the evidences on the role of PET/CT in management of patients with DTC, focusing on potential applications and on elucidating some still debating points.     

Multiparametric imaging of breast cancer: An update of current applications

Imaging plays an indispensable role in the diagnosis and treatment of breast cancer. Several new imaging tools are currently being developed for clinical use to improve diagnostic performance and tumor response evaluation. Abbreviated magnetic resonance imaging (MRI) allows shortening scanning time without penalizing diagnostic performances. Ultrafast dynamic contrast-enhanced MRI is a new approach that provides kinetic information and helps identify breast lesions developed in breast with marked background parenchymal enhancement. Intravoxel incoherent motion and kurtosis are parameters of diffusion-weighted imaging (DWI) that bring useful information in breast cancer. High-resolution DWI, allows morphological assessment of lesions without using a contrast agent. High-resolution breast positron emission tomography provides detailed metabolic information on small breast cancer. Photoacoustic imaging utilizes hemoglobin as an intrinsic contrast agent and depicts fine -branching structure of the tumor vessels related to cancer. It is important that experts in breast imaging understand the advantages and limitations of these new techniques in order to offer optimal imaging to each patient.     

Functional imaging in thyroid cancer patients with metastases and therapeutic implications

Functional imaging plays a central role in the management of thyroid cancer patients.In patients with a differentiated thyroid cancer (DTC), radioactive iodine (RAI) is used mostly with a therapeutic intent, either post-operatively or as the first line systemic treatment in patients with known structural disease. A whole body scan is performed a few days after the RAI administration, and this procedure is very sensitive to detect all tumor foci with RAI uptake. PET/CT with ¹⁸F-FDG complements the use of RAI at the initial evaluation of patients with high-risk DTC, during follow-up in those with rising serum thyroglobulin levels over time, for the work-up of patients with documented structural disease and for assessing the efficacy of focal or systemic treatment modalities. ¹⁸F-FDG uptake is a prognostic indicator in all these clinical conditions. A dosimetric approach with ¹²⁴I PET/CT showed encouraging results.Several functional imaging modalities are currently available for medullary thyroid carcinoma (MTC) patients. ¹⁸F-FDG-PET/CT may be sensitive in MTC patients with high FDG uptake that signals aggressive disease. ¹⁸F-DOPA is the most sensitive imaging technique to visualize small tumor foci, and is also highly specific in patients with a known MTC, but should be complemented by a CT scan of the chest and by a MRI of the liver to detect small metastases.     

Deep Learning to Predict Mortality After Cardiothoracic Surgery Using Preoperative Chest Radiographs

BackgroundThe Society of Thoracic Surgeons Predicted Risk of Mortality (STS-PROM) estimates mortality risk only for certain common procedures (eg, coronary artery bypass or valve surgery) and is cumbersome, requiring greater than 60 inputs. We hypothesized that deep learning can estimate postoperative mortality risk based on a preoperative chest radiograph for cardiac surgeries in which STS-PROM scores were available (STS index procedures) or unavailable (non–STS index procedures).MethodsWe developed a deep learning model (CXR-CTSurgery) to predict postoperative mortality based on preoperative chest radiographs in 9283 patients at Massachusetts General Hospital (MGH) having cardiac surgery before April 8, 2014. CXR-CTSurgery was tested on 3615 different MGH patients and externally tested on 2840 patients from Brigham and Women’s Hospital (BWH) having surgery after April 8, 2014. Discrimination for mortality was compared with the STS-PROM using the C-statistic. Calibration was assessed using the observed-to-expected ratio (O/E ratio).ResultsFor STS index procedures, CXR-CTSurgery had a C-statistic similar to STS-PROM at MGH (CXR-CTSurgery: 0.83 vs STS-PROM: 0.88; P = .20) and BWH (0.74 vs 0.80; P = .14) testing cohorts. The CXR-CTSurgery C-statistic for non–STS index procedures was similar to STS index procedures in the MGH (0.87 vs 0.83) and BWH (0.73 vs 0.74) testing cohorts. For STS index procedures, CXR-CTSurgery had better calibration than the STS-PROM in the MGH (O/E ratio: 0.74 vs 0.52) and BWH (O/E ratio: 0.91 vs 0.73) testing cohorts.ConclusionsCXR-CTSurgery predicts postoperative mortality based on a preoperative CXR with similar discrimination and better calibration than the STS-PROM. This may be useful when the STS-PROM cannot be calculated or for non–STS index procedures.     

Non-invasive diagnosis of severe alcoholic hepatitis: Usefulness of cross-sectional imaging

PurposeTo describe the computed tomography (CT) and magnetic resonance imaging (MRI) features of severe acute alcoholic hepatitis (SAAH) and estimate the capabilities of CT and MRI in differentiating SAAH from alcoholic cirrhosis and non-alcoholic steato-hepatitis (NASH) cirrhosis.Materials and methodsFifty patients with pathologically proven SAAH (SAAH group) who underwent CT or MRI examinations up to 30 days before or 15 days after liver biopsy between January 2008 and June 2018 were retrospectively included. There were 31 men and 29 women with a mean age of 52 ± 9 (SD) years (range: 33–67 years). Imaging features of the SAAH group were compared to those obtained in two control groups including 62 patients with alcoholic cirrhosis without acute alcoholic hepatitis (control group 1) and 19 patients with NASH cirrhosis (control group 2) by two independent radiologists blinded to the final diagnosis. Univariate analyses were performed to compare imaging characteristics between the three groups, followed by diagnostic performance analysis for the diagnosis of SAAH of the main CT features.ResultsHeterogeneous steatosis was significantly more frequent in SAAH group than in the control groups (41/50; 82% vs. 7/62; 10% and 1/19; 5% in control groups 1 and 2, respectively for reader 1 and 34/50; 68% vs. 8/62; 13% and 1/19; 5% in control groups 1 and 2, respectively for reader 2; both P = 0.01). Transient perfusion disorders were more frequent in SAAH group than in the control groups (35/50; 70% vs. 12/62; 21% and 5/19; 26% in control groups 1 and 2, respectively for reader 1 and 39/50; 78% vs. 14/62; 23% and 13/19; 6% in control groups 1 and 2, respectively for reader 2; both P = 0.01). The combination of these two findings yielded 100% specificity (45/45; 95% CI: 92–100) for readers 1 and 2 for the diagnosis of SAAH vs. alcoholic cirrhosis and NASH cirrhosis.ConclusionThe imaging features of SAAH are specific and mainly associate transient heterogeneous steatosis and liver perfusion disorders. CT/MRI may be useful to differentiate SAAH from alcoholic cirrhosis and NASH cirrhosis.     

Magnetic resonance imaging of patients with lateral epicondylitis: Relationship between pain and severity of imaging features in elbow joints

ObjectiveThe aim of this study was to determine the inter- and intra-observer reliabilities of magnetic resonance imaging (MRI) for the diagnosis of lateral epicondylitis, to examine whether degree of common extensor tendon (CET) injury is related to other elbow abnormalities on MRI, and to investigate the correlation between elbow abnormalities on MRI and patients' symptoms.MethodsFifty-one patients (32 women and 19 men; mean age: 50 years (range, 22–63)) with a diagnosis of lateral epicondylitis were included in the study. The average duration of symptoms was 2.3 years. MRI scoring system was used to grade the CET injuries and associated injuries in the elbow joint. Three independent radiologists retrospectively reviewed MRI images. Inter- and intra-observer reliabilities for diagnosing lateral epicondylitis were calculated using kappa statistics, and Spearman's rank correlation analysis was used to analyze relationships between degree of CET injury and the associated abnormalities of elbow joints. Statistical relations were considered significant for p values of <0.05. In addition, using Spearman's rank correlation analysis, CET injuries and associated abnormalities of elbow joints were correlated with clinical symptoms using visual analog scale pain scores.ResultsVarious degrees of CET injuries were found in total of 51 patients. Radial collateral ligament and lateral ulnar collateral ligament (RCL/LCL) was the most common accompanying elbow abnormality other than CET injuries. Inter- and intra-observer agreements of CET and RCL/LUCL injuries on MRI were excellent. There were significant correlation between degrees of CET and RCL/LUCL injuries (correlation coefficient r = 0.667, p < 0.01) and between degree of RCL/LUCL injuries and visual analog 11-point pain box scale (VAS) scores (correlation coefficient r = 0.478, p = 0.033).ConclusionMRI showed excellent inter- and intra-observer reliabilities for the evaluation of lateral epicondylitis. In addition to common extensor tendinopathy, RCL/LUCL abnormality was the most common accompanying finding and degree of RCL/LUCL injuries positively correlated with degree of CET injuries. Furthermore, degree of RCL/LUCL injuries positively correlates with severity of pain.Level of evidenceLevel IV, Diagnostic study.     

Joint Position Paper of the Working Group of Pacing and Electrophysiology of the French Society of Cardiology (SFC) and the Société française d’imagerie cardiaque et vasculaire diagnostique et interventionnelle (SFICV) on magnetic resonance imaging in patients with cardiac electronic implantable devices

Magnetic resonance imaging (MRI) has become the reference imaging for the management of a large number of diseases. The number of MR examinations increases every year, simultaneously with the number of patients receiving a cardiac electronic implantable device (CEID). A CEID was considered an absolute contraindication for MRI for years. The progressive replacement of conventional pacemakers and defibrillators by MR-conditional CEIDs and recent data on the safety of MRI in patients with “MR-nonconditional” CEIDs have progressively increased the demand for MRI in patients with a CEID. However, some risks are associated with MRI in CEID carriers, even with “MR-conditional” devices because these devices are not “MR-safe”. A specific programing of the device in “MR-mode” and monitoring patients during MRI remain mandatory for all patients with a CEID. A standardized patient workflow based on an institutional protocol should be established in each institution performing such examinations. This joint position paper of the Working Group of Pacing and Electrophysiology of the French Society of Cardiology and the Société française d’imagerie cardiaque et vasculaire diagnostique et interventionnelle (SFICV) describes the effect and risks associated with MRI in CEID carriers. We propose recommendations for patient workflow and monitoring and CEID programming in MR-conditional, “MR-conditional nonguaranteed” and MR-nonconditional devices.     

Redefining “low risk”: Outcomes of surgical aortic valve replacement in low-risk patients in the transcatheter aortic valve replacement era

ObjectivesGuidelines suggest aortic valve replacement (AVR) for low-risk asymptomatic patients. Indications for transcatheter AVR now include low-risk patients, making it imperative to understand state-of-the-art surgical AVR (SAVR) in this population. Therefore, we compared SAVR outcomes in low-risk patients with those expected from Society of Thoracic Surgeons (STS) models and assessed their intermediate-term survival.MethodsFrom January 2005 to January 2017, 3493 isolated SAVRs were performed in 3474 patients with STS predicted risk of mortality <4%. Observed operative mortality and composite major morbidity or mortality were compared with STS-expected outcomes according to calendar year of surgery. Logistic regression analysis was used to identify risk factors for these outcomes. Patients were followed for time-related mortality.ResultsWith 15 observed operative deaths (0.43%) compared with 55 expected (1.6%), the observed:expected ratio was 0.27 for mortality (95% confidence interval [CI], 0.14-0.42), stroke 0.65 (95% CI, 0.41-0.89), and reoperation 0.50 (95% CI, 0.42-0.60). Major morbidity or mortality steadily declined, with probabilities of 8.6%, 6.7%, and 5.2% in 2006, 2011, and 2016, respectively, while STS-expected risk remained at approximately 12%. Mitral valve regurgitation, ventricular hypertrophy, pulmonary, renal, and hepatic failure, coronary artery disease, and earlier surgery date were residual risk factors. Survival was 98%, 91%, and 82% at 1, 5, and 9 years, respectively, superior to that predicted for the US age-race-sex–matched population.ConclusionsSTS risk models overestimate contemporary SAVR risk at a high-volume center, supporting efforts to create a more agile quality assessment program. SAVR in low-risk patients provides durable survival benefit, supporting early surgery and providing a benchmark for transcatheter AVR.     

Is the skin microbiota a modifiable risk factor for breast disease?: A systematic review

PurposeHigh prevalence, unreliable risk discrimination and poor clinical outcomes are observed in malignant and benign breast diseases (BD). The involvement of microbial communities in the development of BD has become topical, and distal influences of microbial dysregulation in the breast have been well established. Despite advances, the role of the breast skin microbiota in BD remains unclear. Interactions between the skin microbiota and the underlying mucosal immune system are complex. In homeostasis, the skin offers a physical barrier protecting underlying breast tissue from skin commensals and noxious environmental triggers. Our review aims to illuminate the role of the skin microbiota in the development of BD.MethodsAdhering to the PRISMA protocol, a systematic review was conducted utilising the Medline and Embase search engines.ResultsThrough a comprehensive search of the last ten years, twenty-two studies satisfied the inclusion criteria. Proteobacteria, Firmicutes, Actinobacteria and Bacteroidetes were identified as the most prevalent phyla of both breast tissue and skin in healthy controls and BD. High abundance of skin commensals, specifically some species of Staphylococcus, have been linked in breast cancer and metastases. Similarly, dysregulated microbial abundance is also seen in inflammatory and implant-associated BD. These findings raise the hypothesis that the skin microbiota plays a role in tissue homeostasis and may contribute to a range of breast pathologies. Several mechanisms of microbial transfer to underlying tissue have been proposed, including retrograde transfer through ductal systems, breakdown of the skin barrier, and migration through nipple-aspirate fluid.ConclusionOur review provides preliminary insights into the skin microbiota as a modifiable risk factor for BD. This raises opportunities for future studies in antimicrobials/probiotics as an adjunct to, or replacement of surgery; a diagnostic and/or prognostic tool for BD; and the possibility of conditioning the microbiota to manage BD.     

Cost-effectiveness of abbreviated-protocol MRI screening for women with mammographically dense breasts in a national breast cancer screening program

IntroductionMagnetic resonance imaging (MRI) has shown the potential to improve the screening effectiveness among women with dense breasts. The introduction of fast abbreviated protocols (AP) makes MRI more feasible to be used in a general population. We aimed to investigate the cost-effectiveness of AP-MRI in women with dense breasts (heterogeneously/extremely dense) in a population-based screening program.MethodsA previously validated model (SiMRiSc) was applied, with parameters updated for women with dense breasts. Breast density was assumed to decrease with increased age. The base scenarios included six biennial AP-MRI strategies, with biennial mammography from age 50–74 as reference. Fourteen alternative scenarios were performed by varying screening interval (triennial and quadrennial) and by applying a combined strategy of mammography and AP-MRI. A 3% discount rate for both costs and life years gained (LYG) was applied. Model robustness was evaluated using univariate and probabilistic sensitivity analyses.ResultsThe six biennial AP-MRI strategies ranged from 132 to 562 LYG per 10,000 women, where more frequent application of AP-MRI was related to higher LYG. The optimal strategy was biennial AP-MRI screening from age 50–65 for only women with extremely dense breasts, producing an incremental cost-effectiveness ratio of € 18,201/LYG. At a threshold of € 20,000/LYG, the probability that the optimal strategy was cost-effective was 79%.ConclusionPopulation-based biennial breast cancer screening with AP-MRI from age 50–65 for women with extremely dense breasts might be a cost-effective alternative to mammography, but is not an option for women with heterogeneously dense breasts.     

Position paper on stress cardiac MRI in chronic coronary syndrome: Endorsed by the Société Française de Radiologie (SFR) the Société Française d’Imagerie CardioVasculaire (SFICV) and the Société Française de Cardiologie (SFC)

This position paper was intended to update the former consensus between the French Societies of Radiology and Cardiology about the use of stress cardiac magnetic resonance imaging (MRI) in chronic coronary syndrome published in 2009. The Delphi method was used to build the present consensus. This expert panel consensus includes recommendations for indications, procedure with patient preparation, stress inducing drugs, acquisition protocol, interpretation and risk stratification by stress MRI.     

Association between background parenchymal enhancement and tumor response in patients with breast cancer receiving neoadjuvant chemotherapy

PurposeTo analyze the relationships between background parenchymal enhancement (BPE) of the contralateral healthy breast and tumor response after neoadjuvant chemotherapy (NAC) in women with breast cancer.Materials and methodsA total of 228 women (mean age, 47.6 years ± 10 [SD]; range: 24–74 years) with invasive breast cancer who underwent NAC were included. All patients underwent breast magnetic resonance imaging (MRI) before and after NAC and 127 patients underwent MRI before, during (after the 4th cycle of NAC) and after NAC. Quantitative semi-automated analysis of BPE of the contralateral healthy breast was performed. Enhancement level on baseline MRI (baseline BPE) and MRI after chemotherapy (final BPE), change in enhancement rate between baseline MRI and final MRI (total BPE change) and between baseline MRI and midline MRI (early BPE change) were recorded. Associations between BPE and tumor response, menopausal status, tumor phenotype, NAC type and tumor stage at diagnosis were searched for. Pathologic complete response (pCR) was defined as the absence of residual invasive cancer cells in the breast and ipsilateral lymph nodes.ResultsNo differences were found in baseline BPE, final BPE, early and total BPE changes between pCR and non-pCR groups. Early BPE change was higher in non-pCR group in patients with stages 3 and 4 breast cancers (P = 0.019) and in human epidermal growth factor receptor 2 (HER2)-negative patients (P = 0.020).ConclusionEarly reduction of BPE in the contralateral breast during NAC may be an early predictor of loss of tumor response, showing potential as an imaging biomarker of treatment response, especially in women with stages 3 or 4 breast cancers and in HER2 – negative breast cancers.     

Bladder endometriosis: Preoperative MRI analysis with assessment of extension to ureteral orifices

PurposeThe purpose of this study was to retrospectively evaluate the performance of magnetic resonance imaging (MRI) in locating endometriosis implants within the bladder wall with assessment of ureteral orifice extension using surgical findings as standard of reference.Materials and methodsMRI examinations of 39 consecutive women (mean age: 31.2 ± 5.5 [SD] years; age range: 22–42 years) operated in 3 university hospitals for bladder endometriosis over a 6-year period were reviewed by 2 independent readers. Interobserver agreement was assessed using Kappa tests. Results of consensus reading were used to calculate sensitivity, specificity and accuracy of MRI for the diagnosis, location and extent of endometriosis implants using surgical findings as the standard of reference.ResultsMean bladder repletion volume was 134 ± 110 [SD] mL (range: 21–479 mL). The mean largest endometriosis implant diameter was 30 ± 7 [SD] mm (range: 19–41 mm). On MR images, 34/39 (87%) endometriosis implants were present in the two anterior thirds of the dome (k = 0.45), 31/39 (79%) extended or were present in the posterior third pouch (k = 0.92) and 25/39 (64%) extended into the bladder base (k = 0.84) with sensitivities of 100% (31/31; 95% confidence interval [CI]: 89–100%), 100% (30/30; 95% CI: 88–100%) and 90% (19/21; 95% CI: 69–98%), respectively, specificities of 83% (5/6, 95% CI: 36–100), 88% (7/8, 95% CI: 47–100%), 87% (13/15; 95% CI: 52–96), respectively and accuracies of 97% (36/37, 95% CI: 86–100%), 97% (37/38; 95% CI: 86–100%), and 89% (32/36; 95% CI: 74–97%), respectively. In 9 (9/25; 36%) patients with bladder base involvement, a zero distance was reported between endometriosis implants and ureteral orifices, all but one presenting with low-to-moderate bladder volumes. In the two patients who needed ureteral resection-reimplantation, ureteral dilation was associated with a zero distance. External adenomyosis was reported in 26/39 (66%) patients (k = 0.94).ConclusionA dedicated preoperative MRI work-up for bladder endometriosis helps accurately depict and locate endometriosis implants. Adequate bladder filling is needed to improve appropriate estimate of the distance between endometriosis implants and ureteral orifices to better predict requirement of ureteral resection-reimplantation.     

Diagnostic accuracy of ultrasonography for occult femoral neck fracture

BackgroundA delay in the diagnosis and treatment of an occult femoral neck fracture (OFNF) can negatively affect the subsequent quality of life. We investigated the diagnostic accuracy of ultrasonography for OFNF in patients confirmed with this condition by magnetic resonance imaging (MRI), and compared these results with other clinical findings.MethodsNinety-four outpatients aged above 70 years with acute hip pain but without radiographic abnormal findings who were suspected of having an occult femoral neck fracture (11 men and 83 women with a mean age of 81.8 ± 6.0 years) were enrolled. Both ultrasonography and MRI were performed in all cases within 24 h. The ultrasonographic distance between the anterior aspect of the femoral neck and the anterior joint capsule (ultrasound joint swelling) was measured.ResultsBy MRI findings, 27 patients were assigned to an occult femoral neck fracture (OFNF) group (1 man, 26 women) and 67 patients to a non-OFNF group (10 men, 57 women). The mean ultrasound joint swelling in both groups was 7.53 ± 1.52 mm and 3.45 ± 0.89 mm, respectively (p = 0.006, 95% CI, 3.58–4.59). A cut-off value of 5.3 mm showed a sensitivity of 0.96 (0.89–0.96) and a specificity of 0.98 (0.92–1.00).ConclusionsUltrasonography shows very high diagnostic accuracy for occult femoral neck fracture. This modality can thus contribute to initial bed-side examinations for this condition in patients over 70 years with acute hip pain.     

CT and MRI features of sclerosing angiomatoid nodular transformation of the spleen: A report of 18 patients with pathologic correlation

PurposeThe purpose of this study was to describe the computed tomography (CT) and magnetic resonance imaging (MRI) features of sclerosing angiomatoid nodular transformation (SANT) of the spleen and correlate imaging features with those obtained at histopathologic analysis.Materials and methodsA total of 18 patients (9 men, 9 women; mean age, 42.2 ± 10.7 [standard deviation (SD)] years; range, 23–59 years) with histopathologically confirmed SANT were retrospectively evaluated. The presenting symptoms, gross pathologic changes, and histopathologic and correlative immunohistochemical results were recorded. CT (n = 8) and MRI (n = 12) features were analyzed by two radiologists and included number, size, shape, boundary, attenuation, signal intensity, and enhancement patterns.ResultsSeventeen patients (17/18; 94%) had a single SANT without specific clinical symptoms and one patient (1/18; 6%) had multiple SANTs with left-upper-quadrant bloating and pain. The largest lesion diameter exceeded 3 cm. On plain CT images, SANTs were slightly hypoattenuating in seven patients (7/8; 88%), isoattenuating in one patient (1/8; 13%), and contained calcification in two patients (2/8; 25%). On T2-weighted MR images, SANTs displayed hypointensity in ten patients (10/12; 83.3%), isointensity in one patient (1/12; 8%) and hyperintensity in one patient (1/12; 8%). On T2-weighted images, stellate or scattered fibrous scars were observed in all patients (12/12; 100%). On diffusion-weighted images, SANTs appeared as heterogenous or homogeneous hypointense in 12 patients (12/12; 100%). Compared to out-of-phase images, SANTs displayed decreased local signal intensity on in-phase images in 12 patients (12/12; 100%). On enhanced CT and MRI images, SANTs had clear boundaries (17/18; 94%), oval (7/18; 39%) or lobular (7/18; 39%) shape, displayed progressive centripetal enhancement (18/18; 100%), spoke-wheel pattern (14/18; 78%), nodular enhancement (11/18; 61%), or delayed enhancement of central fibrous scar (9/18; 50%).ConclusionsSANT of the spleen predominantly manifests as a solid, single, oval or lobular, and well-defined lesion with a fibrous scar and occasional calcification. Typical enhancement characteristics include progressive and centripetal enhancement, spoke-wheel pattern, nodular enhancement, and delayed enhancement of central fibrous scar. Hypointensity on T2- and diffusion-weighted images are due to hemosiderin deposition and fibrous tissue.     

An updated model of hydrocephalus in sheep to evaluate the performance of a device for ambulatory wireless monitoring of cerebral pressure through shunts

BackgroundCerebrospinal fluid (CSF) diversion by shunts is the most common surgical treatment for hydrocephalus. Though effective, shunts are associated with risk of dysfunction leading to multiple surgical revisions, affecting patient quality-of-life and incurring high healthcare costs. There is a need for ambulatory monitoring systems for life-long assessment of shunt status. The present study aimed to develop a preclinical model assessing the feasibility of our wireless device for continuous monitoring of cerebral pressure in shunts.MethodsWe first adapted a previous hydrocephalus model in sheep, which used an intracisternal kaolin injection. Seven animals were used to establish the model, and 1 sheep with naturally dilated ventricles was used as control. Hydrocephalus was confirmed by clinical examination and brain imaging before inserting the ventriculoperitoneal shunts and the monitoring device allowing continuous measurement of the pressure through the shunt for a few days in 3 sheep. An external ventricular drain was used as gold standard.ResultsOur results showed that a reduction in kaolin dose associated to postoperative management was crucial to reduce morbidity and mortality rates in the model. Ventriculomegaly was confirmed by imaging 4 days after injection of 75 mg kaolin into the cisterna magna. For the implanted sheep, recordings revealed high sensitivity of our sensor in detecting fluctuations in cerebral pressure compared to conventional measurements.ConclusionsThis proof-of-concept study highlights the potential of this preclinical model for testing new shunt devices.     

Perioperative Anemia and Transfusions and Late Mortality in Coronary Artery Bypass Patients

BackgroundPerioperative anemia and transfusions are associated with adverse operative outcomes after coronary artery bypass graft surgery (CABG). Their individual association with long-term outcomes is unclear.MethodsPatients aged 65 years and older who had undergone CABG and were in The Society of Thoracic Surgeons (STS) Adult Cardiac Surgery Database (n = 504,596) from 2011 to 2018 were linked to Centers for Medicare and Medicaid Service data to assess long-term survival. The association of intraoperative anemia defined by intraoperative nadir hematocrit (nHct) and red blood cell (RBC) transfusions, and their interactions, on long-term mortality were assessed with Kaplan-Meier estimates and multivariable Cox regression. Restricted cubic splines were used to explore the association between nHct as a continuous variable and long-term mortality.Results258,398 on-pump CABG STS Adult Cardiac Surgery Database patients surviving the perioperative period were linked to Centers for Medicare and Medicaid Service claims files. Per World Health Organization criteria, 41% had preoperative anemia. Mean intraoperative nHct was 24%; RBC transfusion rate was 43.7%. Univariable analysis associated both RBC transfusion and lower nHct with worse survival. Lower nHct was only marginally associated with risk-adjusted mortality: adjusted hazard ratio (AHR) 1.04 (95% CI, 1.01-1.06) and 1.07 (95% CI, 1.00-1.14) at nHct 20% and at nHct 14%, respectively. RBC transfusion was associated with significantly higher adjusted mortality irrespective of timing of transfusion: AHR intraoperative 1.21 (95% CI, 1.18-1.27); AHR postoperative 1.26 (95% CI, 1.22-1.30); AHR both 1.46 (95% CI, 1.40-1.52) and across all levels of nHct. RBC transfusion was not associated with improved survival at any level of nHct.ConclusionsAmong Medicare CABG patients, RBC transfusions were associated with increased risk-adjusted late mortality across all levels of nHct whereas intraoperative anemia was only marginally so. Tolerance of lower intraoperative nHct than currently accepted may be preferable to transfusions.     

Diagnostic performance of sacroiliac joint MRI and added value of spine MRI to detect active spondyloarthritis

PurposeTo investigate the diagnostic performance of sacroiliac joint (SIJ) magnetic resonance imaging (MRI) and the incremental value of spine MRI to “predict” clinical disease activity in patients with axial spondyloarthritis (axSpA).Materials and methodsThis cross-sectional study included adult patients with known axSpA according to the SpondyloArthritis International Society (ASAS) classification criteria, radiological arm. MRI disease activity was scored semi-quantitatively for SIJ and total spine MRI in each patient. Two cut-off levels (≥ 1.3 and ≥ 2.1) for ankylosing spondylitis disease activity score with C-reactive protein (ASDAS-CRP) were considered for clinical disease activity categorization. MRI scores were first evaluated individually. Then, SIJ score was combined with the score from a spine segment (lumbar, cervical, thoracic or total spine) to build a bi-parametric model using a classification tree. Receiver operating characteristic (ROC) curves were constructed to evaluate the classification performance according to disease activity category of these models.ResultsForty-four patients (30 men, 14 women; mean age, 37 years ± 10 [SD] [range: 17–64 years]) with a mean disease duration of 5 years ± 8 (SD) (range: 0–35 years) were included. Thirty-six patients (36/44; 82%) had ASDAS-CRP ≥ 1.3 and 27 patients (27/44; 61%) had ASDAS-CRP ≥ 2.1. The most frequently involved spinal segment was mid-thoracic (T7-T8). The SIJ MRI score was an informative model to identify active axSpA (AUC ≥ 0.7, regardless of the cut-off level on ASDAS-CRP). Performance of bi-parametric models based on “SIJ + thoracic spine” (for detecting patients with ASDAS-CRP ≥ 1.3) or “SIJ + total spine” (for detecting patients with ASDAS-CRP ≥ 2.1) outperformed that of the individual SIJ score (P < 0.05).ConclusionThe combination of MRI of the SIJ and spine allows to accurately discriminate between active and inactive axSpA, outperforming SIJ MRI alone.     

Artificial intelligence in emergency radiology: A review of applications and possibilities

Artificial intelligence (AI) applications in radiology have been rising exponentially in the last decade. Although AI has found usage in various areas of healthcare, its utilization in the emergency department (ED) as a tool for emergency radiologists shows great promise towards easing some of the challenges faced daily. There have been numerous reported studies examining the application of AI-based algorithms in identifying common ED conditions to ensure more rapid reporting and in turn quicker patient care. In addition to interpretive applications, AI assists with many of the non-interpretive tasks that are encountered every day by emergency radiologists. These include, but are not limited to, protocolling, image quality control and workflow prioritization. AI continues to face challenges such as physician uptake or costs, but is a long-term investment that shows great potential to relieve many difficulties faced by emergency radiologists and ultimately improve patient outcomes. This review sums up the current advances of AI in emergency radiology, including current diagnostic applications (interpretive) and applications that stretch beyond imaging (non-interpretive), analyzes current drawbacks of AI in emergency radiology and discusses future challenges.