Standard Imaging Modality Research Articles

Abstract LB036: Clinical value of 18F-FDG-PET compared with CT scan in the detection of nodal and distant metastasis in urothelial carcinoma or bladder cancer

Abstract Computed tomography (CT) scan is the standard imaging modality for staging patients with urothelial carcinoma (UC) or bladder cancer (BC). Despite negative staging prior to surgery, 20-30% of patients have lymph node (LN) metastasis. Surgery for BC and UC has high morbidity and preoperative staging is vital. Value of 18F-fluorodeoxyglucose positron emission tomography (18F-FDG-PET) in staging UC and BC is debatable. We report a large series comparing 18F-FDG-PET with CT. We retrospectively reviewed 90 patients diagnosed with UC or BC who underwent surgery or confirmatory biopsy that were staged with both CT and 18F-FDG-PET between 2015 and 2020. 78 patients staged with CT and 18F-FDG-PET had formal pelvic LN dissection. 21 patients had neoadjuvant chemotherapy (NAC). 18F-FDG-PET reports for positive sites were qualitative, with 18F-FDG avid sites considered positive. On CT, enlarged LN by RECIST criteria 1.1 (>10 mm) and other qualitative findings suggesting metastasis were considered positive. Histopathological findings from surgical specimens or image guided biopsy were considered gold standard in comparison to imaging reports. 18F-FDG-avid or enlarged pelvic LNs with surgically proven nodal metastasis were considered true positives. Performance characteristics of 18F-FDG-PET and CT including sensitivity, specificity, positive predictive value (PPV) and negative predictive value (PPV) were calculated. Metastatic pelvic LN were confirmed histologically in 18/78 (23.1%) patients. Sensitivity, specificity, PPV and NPV of CT for detecting pelvic LN metastases were 27.8% (95% CI:10.7-53.6%), 96.7% (95% CI:87.5-99.4%), 71.4% (95% CI:30.3-94.9%) and 81.7% (95% CI:70.4-89.5%) respectively. Sensitivity, specificity, PPV and NPV of 18F-FDG-PET for detecting pelvic LN metastases were 50.0% (95% CI:26.8-73.2%), 88.3% (95% CI:76.8-94.8%), 56.3% (95% CI:30.6-79.2%) and 85.5% (95% CI:73.7-92.7%) respectively. 11/90 (12.2%) patients had 18F-FDG-PET suggestive of distant metastases. 10 (90.9%) of these 11 patients had image guided biopsy of these 18F-FDG-PET-positive sites confirming metastases. Pre-operative staging with 18F-FDG-PET identified metastatic disease in 4/85 (4.7%) patients which were occult on CT. This retrospective study suggested that 18F-FDG-PET may be more sensitive than CT for detecting pelvic LN metastases. 4/85 (4.7%) patients avoided cystectomy due to 18F-FDG-PET diagnosed metastases which were not reported on CT. Further research involving randomised controlled trials comparing the diagnostic yield of 18F-FDG-PET and CT in detecting nodal and distant metastasis in UC or BC is warranted to confirm our findings. Citation Format: Oliver Oey, Pravin Viswambaram, Jeremy Ong, Richard Gauci, Ronny Low, Dickon Hayne. Clinical value of 18F-FDG-PET compared with CT scan in the detection of nodal and distant metastasis in urothelial carcinoma or bladder cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr LB036.

Up around the bend: progress and promise of intravascular imaging in neurointerventional surgery

Endovascular treatment in peripheral and coronary circulations has been greatly advanced with the aid of intravascular imaging such as optical coherence tomography (OCT) and intravascular ultrasound (IVUS).1 2 Studies have...

3D whole-brain metabolite imaging to improve characterization of low-to-intermediate grade gliomas.

MRI is the standard imaging modality used for diagnosis, treatment planning, and post-treatment management of gliomas. Contrast-enhanced T1-weighted (CE-T1w) MRI is used to plan biopsy and radiation for grade IV gliomas but is less effective for grade II and III gliomas (i.e., low-to-intermediate grade gliomas) which may have minimal or no enhancement. Magnetic resonance spectroscopic imaging (MRSI) is an advanced MRI technique that has been shown, to improve diagnostic yield of biopsy and target delineation for grade IV glioma. The purpose of this study is to determine if MRSI can improve characterization and tissue sampling of low-to-intermediate grade gliomas. Prospective grade II and grade III glioma patients were enrolled to undergo whole brain high-resolution MRSI prior to tissue sampling. Choline/N-acetyl-aspartate (Cho/NAA) maps were overlaid on anatomic imaging and imported into stereotactic biopsy software. Patients were treated with standard-of-care surgery and radiation. Volumes of spectroscopically abnormal tissue were generated and compared with anatomic imaging and areas of enhancing recurrence on follow-up imaging. Ten patients had pathologic diagnosis of grade II (n = 4) or grade III (n = 6) with a median follow-up of 27.3 months. Five patients had recurrence, and regions of recurrence were found to overlap with metabolically abnormal regions on MRSI at the time of diagnosis. MRSI in low-to-intermediate grade glioma patients is predictive of areas of subsequent recurrence. Larger studies are needed to determine if MRSI can be used to guide surgical and radiation treatment planning in these patients.

ROLE OF CT SCAN OF PARANASAL AIR SINUSES FOR DIAGNOSTIC EVALUATION OF SINONASAL PATHOLOGY IN A TERTIARY CARE HOSPITAL IN EASTERN INDIA.

This study aims to evaluate the sensitivity and specicity of CT in diagnosis of sinonasal diseases along with the spectrum of Paranasal sinus diseases oncomputerized tomography (CT) and correlate their clinical and histopathological ndings. 40patients who have undergone endoscopic sinus surgery, their relevant histopathological and surgical reports are included in Radiodiagnosis department of Nil Ratan Sircar Medical College. Chronic sinusitis has 100% sensitivity,94% specicity, 96% positive predictive value (PPV) and 100% negative predictive value (NPV). For fungal sinusitis the sensitivity was 66%,specicity was 97.4%, PPV 66% and NPV 97.4%. Polyps have sensitivity of 90.9%, specicity of 94%, PPV 90% and NPV 100% Benign neoplasms have sensitivity of 100%, specicity of 100%, PPV 100% and NPV 100%. CT may be used as gold standardimaging modality for evaluating the PNS diseases.

Impact of Multiparametric Stone Measurement in Noncontrast Computer Tomography on Ureterorenoscopic Stone Removal

Purpose: Low-dose computer tomography (NCCT) is the standard imaging modality for patients with acute flank pain with a suspicion of urolithiasis. The stone size is usually measured 2D by a radiologist. We compared 3D stone measurement using different windows to the 2D measurement and evaluated the clinical impact on ureterorenoscopic stone removal (URS). Methods: One hundred sixty-four patients (201 stones) with a preoperative NCCT, following a URS within 4 weeks, were included in this study. Stone location, number and size of stones, operating time, and laser lithotripsy were documented. Stones were measured in 3D using bone and soft tissue window. The maximum diameter was compared to the radiological report. The U test, Kruskal-Wallis, and regression were used for statistical analyses. Results: Almost two-thirds (64.68%; 130 stones) of stone measurements in 3D with the bone window were lower than the radiologist reports in 2D. One-third (34.83%; 70 stones) of stone measurements were higher and 0.5% (1 stone) reported the same size. Using the 3D soft tissue window, 81.09% (163 stones), 17.91% (37 stones), and 1% (2 stones) of stones were measured bigger, smaller, or had the same measurement results, respectively. In the clinical setting, we could calculate a cutoff for laser lithotripsy at a maximum stone diameter of 5.70 mm (p < 0.01) with the 3D and 6.01 mm with the 2D measurements, respectively, and found a significant correlation between maximum stone diameter and operating time (p < 0.01) and number of stones and operating time (p < 0.01 with and p = 0.02 without laser). Conclusion: 3D stone measurement with bone window seems to be more accurate than 2D measurement, but 2D is sufficient for planning stone treatment.

Endovascular treatment in anterior circulation stroke beyond 6.5 hours after onset or time last seen well: results from the MR CLEAN Registry

BackgroundRandomised controlled trials with perfusion selection have shown benefit of endovascular treatment (EVT) for ischaemic stroke between 6 and 24 hours after symptom onset or time last seen well. However,...

Contrast-Enhanced Ultrasound for Evaluation of Pleural Effusion: A Pictorial Essay.

B-mode ultrasound (B-US) is the standard imaging modality to evaluate pleural effusion. The value of B-US for assessing the malignancy of a pleural effusion (PE) is limited. For this purpose, computed tomography (CT) and thoracoscopy are the methods of choice to evaluate an effusion. The aim of this Pictorial Essay is to demonstrate contrast-enhanced ultrasound (CEUS) as a method in addition to B-US and CT for the evaluation of PE taking into account the clinical background. The characteristic patterns of pleural pathologies, effusion morphology, and associated lung parenchymal consolidations are presented.

Fetal brain MRI: how it added to ultrasound diagnosis of fetal CNS anomalies-1 year experience

BackgroundCentral nervous system (CNS) anomalies are the most commonly diagnosed abnormalities of all fetal malformations and are usually primarily discovered on routine prenatal ultrasonography (US). Fetal magnetic resonance imaging (MRI) is a non-invasive technology with high soft tissue contrast that is documented to increase the diagnostic accuracy for detection of fetal brain anomalies.The aim of our study is to analyze the value of adding magnetic resonance imaging (MRI) of the fetal brain to antenatal ultrasound in the diagnosis of fetal central nervous system (CNS) anomalies.ResultsWe diagnosed various CNS anomalies including twelve cases with infra- and supra-tentorial arachnoid cysts, six cases had Dandy-Walker malformation (DWM) and its variants, 1 case with mega cisterna magna, 2 cases of holoprosencephaly, 1 case of hydranencephaly, 2 cases with supratentorial hydrocephalus, 1 case of craniopharyngioma, 6 cases with corpus callosum (CC) agenesis, 1 case of extradural hematoma, and 8 cases with Meckel-Gruber syndrome (MGS). MRI diagnosis confirmed the ultrasound finding, without additional information in 23 cases (57.5%%), added an extra finding in 11 cases (27.5%), differentiated between 2 pathologies in 3 cases (7.5%), and changed the diagnosis in 3 cases (7.5 %).The 40 pregnancies resulted in 27 births (67.5%), 2 died directly after birth (5%), 7 terminations (17.5%), and 4 intrauterine fetal deaths (IUFD) (10 %).ConclusionUltrasound is the gold standard imaging modality for anomaly scan in the second and third trimesters; however, MRI of the fetal brain might be a clinically valuable complement especially when ultrasound examination is inconclusive due to maternal obesity, severe oligohydramnios, or in complicated cases with unclear diagnosis.

Advanced Imaging Techniques for Radiotherapy Planning of Gliomas.

Simple SummaryConventional magnetic resonance imaging (MRI) sequences have known limitations in target delineation for radiation treatment (RT) planning of cerebral gliomas. Advanced physiology-based MRI techniques and radionuclide imaging techniques, including positron emission tomography (PET) with amino acid radiopharmaceuticals, may increase the specificity for glioma tissue characterization. Our work aims to provide a comprehensive review of the advanced MRI and PET imaging modalities that can complement conventional MRI for RT planning of gliomas. A detailed overview of their basic principles and clinical results is given based on the most updated literature.The accuracy of target delineation in radiation treatment (RT) planning of cerebral gliomas is crucial to achieve high tumor control, while minimizing treatment-related toxicity. Conventional magnetic resonance imaging (MRI), including contrast-enhanced T1-weighted and fluid-attenuated inversion recovery (FLAIR) sequences, represents the current standard imaging modality for target volume delineation of gliomas. However, conventional sequences have limited capability to discriminate treatment-related changes from viable tumors, owing to the low specificity of increased blood-brain barrier permeability and peritumoral edema. Advanced physiology-based MRI techniques, such as MR spectroscopy, diffusion MRI and perfusion MRI, have been developed for the biological characterization of gliomas and may circumvent these limitations, providing additional metabolic, structural, and hemodynamic information for treatment planning and monitoring. Radionuclide imaging techniques, such as positron emission tomography (PET) with amino acid radiopharmaceuticals, are also increasingly used in the workup of primary brain tumors, and their integration in RT planning is being evaluated in specialized centers. This review focuses on the basic principles and clinical results of advanced MRI and PET imaging techniques that have promise as a complement to RT planning of gliomas.

Rectal MRI after neoadjuvant chemoradiation therapy: a pictorial guide to interpretation.

Magnetic resonance imaging (MRI) is the current reference standard imaging modality for restaging rectal cancer after neoadjuvant chemoradiation and is used to guide clinical management decisions. This pictorial essay provides an illustrative atlas of the key MRI features used to assess rectal cancer after treatment. MRI findings of residual tumor including non-mucinous, mucinous, and signet-ring cell adenocarcinoma subtypes are correlated with histopathology. Imaging appearances of treatment changes that mimic residual tumor in the setting of confirmed pathological complete response at resection are illustrated. Treatment complications are also shown. Knowledge of these imaging findings and their importance may help radiologists comply with all elements of the structured reporting templates proposed by the Rectal Cancer Disease Focused Panel of the Society of Abdominal Radiology and by the European Society of Gastrointestinal and Abdominal Radiology.

Pulmonary Embolism in High-Risk Patients: How to Select Standard Imaging and Management Strategy?

Objective: To describe the use of computed tomography pulmonary angiography (CTPA) for diagnostic purposes and percutaneous catheter-directed thrombolysis (PCDT) as a treatment choice for high-risk pulmonary embolism (PE) patients. Methods: This case report describes a case of an elderly female presented with dyspnea, cough, fever, and chest pain. No significant medical history was identified. Results: CTPA was conducted and showed multiple thrombus with significant stenosis in several branches of pulmonary artery. Initial anticoagulation was administered without delay. Patient then underwent PCDT to remove the thrombus. No post intervention symptom and systemic complications were noted. Conclusions: Computed tomography pulmonary angiography is useful as the standard imaging modality to help evaluating suspected pulmonary embolism. Percutaneous catheter-directed thrombolysis is indicated to treat high-risk patients with high risk of bleeding.

Ferumoxytol-enhanced magnetic resonance angiography provides comparable vascular conspicuity to CT angiography in dogs with intrahepatic portosystemic shunts.

Computed tomography angiography (CTA) is currently the gold standard imaging modality for anatomically characterizing canine hepatic vascular anomalies; with conventional, gadolinium-enhanced MR angiography being less frequently utilized. However, both imaging modalities are limited by a brief, first pass peak of contrast medium in the vasculature that necessitates precisely timed image acquisition. A long-acting purely intravascular magnetic resonance imaging (MRI) contrast agent, ferumoxytol, offers the potential to reduce complexity of magnetic resonance angiography (MRA) protocol planning by ensuring diagnostic contrast medium concentration in all the vessels that are targeted for imaging. Aims of this prospective, pilot, methods comparison study were to develop an optimized MRA protocol using ferumoxytol in dogs with hepatic vascular anomalies, perform a dose escalation trial to compare image quality with four-dose regimens of ferumoxytol, and compare accuracy of vascular anatomic depiction based on the gold standard of CTA. Six dogs (10.7-36.1kg) with portosystemic shunts (four intrahepatic left divisional shunts and two intrahepatic right divisional shunts) were recruited for inclusion in the study. A dose-escalation trial was performed to compare image quality at four incremental dose levels of ferumoxytol (1, 2, 3, and 4mg/kg) and to compare the accuracy of vascular anatomic detection to CTA. Ferumoxytol contrast-enhanced MRA (CE-MRA) at 4mg/kg provided similar conspicuity of normal and abnormal vasculature compared to CTA with a minimal decrease in spatial resolution. Findings indicated that ferumoxytol holds promise for comprehensive, single breath hold CE-MRA of all abdominal vessels in dogs with portosystemic shunts. Background information provided in this study can be used to support development of other future applications such as intracranial and cardiac MRA, real-time imaging, flow quantification, and potentially sedated MRI imaging.

Detection of clustered anomalies in single-voxel morphometry as a rapid automated method for identifying intracranial aneurysms.

Unruptured intracranial aneurysms (UIAs) are prevalent neurovascular anomalies which, in rare circumstances, rupture to cause a catastrophic subarachnoid haemorrhage. Although surgical management can reduce rupture risk, the majority of UIAs exist undiscovered until rupture. Current clinical practice in the detection of UIAs relies heavily on manual radiological review of standard imaging modalities. Recent computer-aided UIA diagnoses can sensitively detect and measure UIAs within cranial angiograms but remain limited to low specificities whose output also requires considerable radiologist interpretation not amenable to broad screening efforts. To address these limitations, we have developed a novel automatic pipeline algorithm which inputs medical images and outputs detected UIAs by characterising single-voxel morphometry of segmented neurovasculature. Once neurovascular anatomy of a specified resolution is segmented, correlations between voxel-specific morphometries are estimated and spatially-clustered outliers are identified as UIA candidates. Our automated solution detects UIAs within magnetic resonance angiograms (MRA) at unmatched 86% specificity and 81% sensitivity using 3 min on a conventional laptop. Our approach does not rely on interpatient comparisons or training datasets which could be difficult to amass and process for rare incidentally discovered UIAs within large MRA files, and in doing so, is versatile to user-defined segmentation quality, to detection sensitivity, and across a range of imaging resolutions and modalities. We propose this method as a unique tool to aid UIA screening, characterisation of abnormal vasculature in at-risk patients, morphometry-based rupture risk prediction, and identification of other vascular abnormalities.

A Clinical and Radiological study of Intracranial Aneurysms in Alexandria University Hospitals

Intracranial aneurysms (IA) represent focal dilatation in a cerebral artery due to weakness in the intima layer.Unruptured intracranial aneurysms (UIA) have a prevalence of 3.2% of general population, being more common above 30 years and a female to male ratio of 3:1. They are either discovered incidentally or may present with visual complain, headache, stroke or cranial nerve palsy. (1)Rupture of IA leads to devastating subarachnoid hemorrhage (SAH) which has an incidence of 9 per 100 000 person-years and is associated with high morbidity and mortality.(2) Several grading scores have been used to predict development of complication and outcome of SAH such as Hunt and Hess Classification, World Federation of Neurosurgeons (WFNS) grading scale, modified Fisher score and VASOGRADE scale. (3)Aneurysmal size was the first determinant of rupture risk, where larger aneurysms carry greater probability of rupture. Recent studies have demonstrated that small aneurysms are responsible for 30-40% of all SAH. Other aneurysm characteristics as neck diameter, aneurysm width, height, parent artery diameter, aspect ratio (AR) and size ratio play a major role in prediction of rupture. (4)IAs can be classified according to rupture status, location, size and type (saccular, fusiform, dissecting and blister aneurysms) (5)Detection of IAs done using CT angiography or magnetic resonance angiography, however digital subtraction angiography (DSA) remains the gold standard imaging modality (6)

Detection of Tumor Multifocality in Resectable Intrahepatic Cholangiocarcinoma: Defining the Optimal Pre-operative Imaging Modality

BackgroundMultiple tumor foci (MTF) in intrahepatic cholangiocarcinoma (ICC), including satellitosis and true multifocality, is a known negative prognostic factor and can inform pre-operative decision-making. Lack of standardized pre-operative liver staging practices may contribute to undiagnosed MTF and poor outcomes. We sought to investigate the sensitivity of different cross-sectional imaging modalities for MTF at our institution. MethodsWe identified n = 52 patients with ICC who underwent curative-intent resection from 2004 to 2017 in a multidisciplinary hepato-pancreato-biliary cancer program. Timing and modality of pre-operative imaging were recorded. Blinded review of imaging was performed and modalities were evaluated for false-negative rate (FNR) in detecting MTF, satellitosis, and true multifocality. ResultsForty-one (79%) patients underwent CT and 20 (38%) underwent MRI prior to hepatectomy. MTF was pre-operatively identified in six (12%) patients. An additional seven patients had MTF discovered on final surgical pathology, despite a median interval from CT/MRI to surgery of 20 days. On blinded review the FNR of MRI compared to CT for multifocality was 0% vs. 38%, 50% vs 80% for satellitosis, and 22% vs 46% for MTF as a whole. ConclusionCT is inadequate for pre-operative diagnosis of MTF in resectable ICC, even when performed within 30 days of hepatectomy. We recommend liver-protocol MRI as the standard pre-operative imaging modality in non-metastatic ICC.

A Concise Review of the Multimodality Imaging Features of Renal Cell Carcinoma

The evaluation of renal cell carcinoma (RCC) is routinely performed using the multimodality imaging approach, including ultrasonography, computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET). Ultrasonography is the most frequently used imaging modality for the initial diagnosis of renal masses. The modality of choice for the characterization of the renal mass is multiphasic CT. Recent advances in CT technology have led to its widespread use as a powerful tool for preoperative planning, reducing the need for catheter angiography for the evaluation of vascular invasion. CT is also the standard imaging modality for staging and follow-up. MRI serves as a problem-solving tool in selected cases of undefined renal lesions. Newer MRI techniques, such as arterial spin labeling and diffusion-weighted imaging, have the potential to characterize renal lesions without contrast media, but these techniques warrant further investigation. PET may be a useful tool for evaluating patients with suspected metastatic disease, but it has modest sensitivity in the diagnosis and staging of RCC. The newer radiotracers may increase the accuracy of PET for RCC diagnosis and staging. In summary, the main imaging modality used for the characterization, staging, and surveillance of RCC is multiphasic CT. Other imaging modalities, such as MRI and PET, are used for selected indications.

Interatrial septal aneurysm mimicking an atrial myxoma on multiparametric cardiovascular magnetic resonance imaging

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Interatrial septal aneurysm (IASA) appears as a localised saccular deformity usually detected during routine echocardiography or stroke evaluation. Imaging hallmarks are &amp;gt;15mm prolapsing motion across the interatrial septum (IAS) and identical content to blood-pool, which are in contrast to this patient. Clinical case An 81-year-old asymptomatic man underwent transesophageal echocardiographic (TEE) right atrial mass assessment revealing a well-circumscribed, mobile mass attached to the interatrial septum suggestive of myxoma. Given previously-excised renal cell carcinoma, gadolinium contrast-enhanced cardiovascular magnetic resonance (CMR) imaging was performed for mass characterisation. Mass signal intensity (SI) was distinct to blood-pool, in keeping with mass content not being blood. Cine imaging revealed an isointense, mobile mass (Figure 1, Video 1) attached to the fossa ovalis. The mass was of intermediate SI isointense to myocardium on T1-weighted, and bright and hyperintense on T2-weighted imaging. First-pass perfusion (Video 2) and early enhancement imaging demonstrated a hypointense, non-perfusing mass. The mass hyperenhanced on late enhancement imaging excluding the differential of thrombus. Imaging findings were entirely consistent with atrial myxoma. Intraoperatively, the excised mass was actually confirmed as an IASA with exquisitely tight neck. Discussion This is the first case of IASA mimicking atrial myxoma on CMR imaging. We postulate that it behaved like a non-perfusing mass as its uniquely narrow neck resulted in extremely slow flow in and out. This permitted minimal blood with contrast entry which remained ‘trapped’ within, resulting in distinct SI to blood pool, and late hyperenhancement. Left atrial pressures forced the mass into the right atrium, preventing typical lateral IASA motion. Conclusion The diagnosis of IASA is best established with TEE while CMR imaging is the reference standard imaging modality for tissue characterization. It is vital to be able to identify and differentiate such entities to avoid misdiagnosis of an IASA as a cardiac myxoma or a malignant cardiac tumour. Nevertheless, we recognize the presence of limitation of imaging in this extraordinary case. Abstract Figure 1

M1a prostate cancer: Results of a Dutch multidisciplinary consensus meeting.

ObjectivesTo determine the consensus of a Dutch multidisciplinary expert panel on the diagnostic evaluation and treatment of de novo and recurrent metastatic prostate cancer (PCa) limited to non‐regional lymph nodes (M1a) in daily clinical practice.Materials and methodsThe panel consisted of 37 Dutch specialists from disciplines involved in the management of M1a PCa (urology, medical and radiation oncology, radiology, and nuclear medicine). We used a modified Delphi method consisting of two voting rounds and a consensus meeting (video conference). Consensus (good agreement) was defined as the situation in which ≥ 75% of the panelists chose the same option.ResultsConsensus existed for 57% of the items. The panel agreed that prostate‐specific membrane antigen positron emission tomography/computed tomography (PSMA‐PET/CT) is the most appropriate standard imaging modality to identify de novo (100%) and recurrent (97%) M1a PCa. Androgen deprivation therapy (ADT) combined with radiotherapy to the prostate ± the M1a lesion(s) was most frequently considered an option for de novo M1a PCa. For M1a as recurrent disease, ADT alone, deferring treatment, or local radiotherapy to the M1a lesion(s) were judged to be the most important treatment options. However, no specific indications for treatment choice in relation to disease characteristics could be formulated.ConclusionsThe Dutch consensus panel preferred PSMA‐PET/CT as the standard diagnostic modality to detect M1a PCa. Although potential treatment options were identified, explicit recommendations could not be formulated. This might (partly) be explained by the absence of high‐level clinical evidence in this subset of patients. Further research is, therefore, strongly encouraged.

Imaging for Pediatric Blunt Abdominal Trauma With Different Prediction Rules: Is the Outcome the Same?

Computerized tomography (CT) of the abdomen and pelvis is the standard imaging modality to diagnose intra-abdominal injury (IAI). Clinicians must weigh the risk-benefit of CT compared with the degree of clinical suspicion for an IAI. Pediatric Emergency Care Applied Research Network (PECARN), Streck, and blunt abdominal trauma in children (BATiC) prediction rules have been published to help guide evaluation of these patients. Pediatric Emergency Care Applied Research Network uses history and physical examination findings, whereas Streck and BATiC use examination plus laboratory and imaging findings. At the time of the study, there was not a protocol that was more routinely sited. Our goal was to compare these different prediction rules. This was a retrospective electronic chart review of all children younger than 18 years presenting for either level 1 or 2 trauma activations at our pediatric emergency department (ED) between June 1, 2015, to June 30, 2017. Charts were manually reviewed for a mechanism concerning for abdominal trauma, and demographic data, history and physical examination findings, laboratory and imaging results per prediction rules, and revisits in 7 days were collected.The prediction rules were applied to all charts that had all data necessary. For study purposes, a score of zero for PECARN and Streck, and score of ≤5 for modified BATiC (mBATiC) were defined as "low risk." Patients with no CT, negative CT, and no new injury found on revisit were classified as "no IAI identified," and patients with positive CT or revisit with injury found as "IAI identified." The results were compared via Fisher exact test. A total of 249 patients met the inclusion criteria with a median age of 12 years. Of the low-risk patients, 119 (98.7%) of 121 in PECARN group, 21 (100%) of 21 in Streck, and 48 (85.7%) of 56 in mBATiC group had no IAI identified. None of the low-risk patients required any intra-abdominal intervention. No missed IAI was identified during revisit review. Negative predictive values of all 3 rules were significant for PECARN, Streck, and mBATiC (98.35%, 100%, and 85.71%, respectively). Overall, 27 patients had positive CT results for IAI. The PECARN and Streck rules have high negative predictive values to predict low-risk patients who do not require CT. When laboratory studies are not obtained, PECARN is an effective means of excluding IAI for low-risk patients. When laboratory tests were obtained, the Streck rule performed well. Overall, the results are similar to the past individual studies done on each individual rule. History and physical examination findings are of high importance in pediatric trauma. This study supports limited imaging when no abnormal findings are present in children with blunt torso trauma. This is the only study found in the literature that has compared 3 different prediction rules.

Long-term fundus fluorescence angiography and real-time diagnosis of retinal diseases in non-human primate-animal models

Fluorescein angiography (FA) is a standard imaging modality for evaluating vascular abnormalities in retina-related diseases, which is recognized as the major cause of vision loss. Long-term and real-time fundus angiography is of great importance in preclinical research, nevertheless remaining big challenges up to present. In this study, we demonstrate that long-term fluorescence imaging of retinal vessels is enabled through a kind of fluorescent nanoagents, which is made of small-sized (hydrodynamic diameter: ∼ 3 nm) silicon nanoparticles (SiNPs) featuring strong fluorescence, robust photostability, lengthened blood residency and negligible toxicity. In particular, the presented SiNPs-based nanoagents are capable of imaging retinal capillaries in ∼ 10 min, which is around 10-fold longer than that (∼ 1 min) of fluorescein sodium (FS, known as the most widely used contrast agents for FA in clinic). Taking cynomolgus macaques as non-human primate-animal model, we further demonstrate the feasibility of real-time diagnosis of retinal diseases (e.g., age-related macular degeneration (AMD)) through dynamic monitoring of vascular dysfunction.