Initial Scan Research Articles

Audit comparing inclusion of key criteria in reporting of initial staging MRI scans for rectal cancer with ARGANZ/Australia Cancer Council recommended template

Audit comparing inclusion of key criteria in reporting of initial staging MRI scans for rectal cancer with ARGANZ/Australia Cancer Council recommended template

Abstract C149: Efficacy and safety of entrectinib in patients (pts) with locally advanced/metastatic NTRK or ROS1 fusion-positive (fp) solid tumors, not evaluable for the primary endpoint of STARTRK-2

Abstract Background: Oncogenic alterations can drive the formation and progression of various solid tumor types. Entrectinib is a potent, CNS-active tyrosine kinase inhibitor that has previously demonstrated clinical activity in pts with NTRK- or ROS1-fp solid tumors in an integrated analysis of three phase I/II trials (ALKA-372-001 [EudraCT 2012-000148-88]; STARTRK-1 [NCT02097810]; STARTRK-2 [NCT02568267]). We present data from a previously unpublished cohort of pts from STARTRK-2, who were deemed non-evaluable for the primary endpoint, including a subset of pts who had non-measurable disease at baseline. Methods: Adult pts with locally advanced/metastatic NTRK- or ROS1-fp solid tumors who received ≥1 dose of entrectinib but were considered non-evaluable for the primary endpoint of the STARTRK-2 study were included in our analyses. Pts were considered non-evaluable due to having: non-measurable disease by RECIST v1.1 at baseline per the investigator’s assessment, an Eastern Cooperative Oncology Group performance status ≥3, a history/concomitant presence of another malignancy, or dual oncogenic alterations. Tumor responses were assessed by blinded independent central review (BICR) by RECIST v1.1, at Week 4 and every 8 weeks thereafter for ≥12 months from initial on-study scan. Endpoints assessed include: objective response rate (ORR) and duration of response (DoR) by BICR, treatment duration and safety. Results: The analysis population comprised 37 pts with solid tumors, including 19 (51.4%) with non-small cell lung cancer; 16 pts had NTRK-fp and 21 had ROS1-fp tumors. The median duration of follow-up was 52.3 months. The median age was 57 years (range 15–81) and 54% (n=20) of pts were female. The ORR by BICR was 37.8% (n/N=14/37; 95% confidence interval [CI] 22.5–55.2), including three pts with a complete response and 11 pts with a partial response. The median DoR was 35.3 months (95% CI 14.5–45.7). In the subset of pts with non-measurable disease at baseline per investigator (n=15; 41%), the median duration of follow-up was 54.3 months; the ORR by BICR was 46.7% (n/N=7/15; 95% CI 21.3–73.4) and the median DoR was 45.7 months (95% CI 45.7–not reached). The median treatment duration was 12.8 months (range 0.1–56.1) for the main analysis population (N=37) and 46.5 months (range 0.4–56.1) for the subset of pts with non-measurable disease at baseline (n=15). The safety profile (N=37) was consistent with previous reports from the integrated analysis; 32 pts (86.5%) had a treatment-related adverse event (most were Grade 1–2), without an unanticipated toxicity, and there were no treatment-related deaths. Conclusions: Entrectinib has demonstrated clinically meaningful activity and a manageable safety profile in pts with NTRK- or ROS1-fp solid tumors who were deemed non-eligible for the primary endpoint in the STARTRK-2 study. These data suggest a potential clinical benefit with entrectinib in a group of pts who are usually excluded from clinical trials, reinforcing the need for molecular testing for all pts to optimize treatment decisions. Citation Format: Stephen V Liu, Marc Peeters, Myung-Ju Ahn, Jessica J Lin, Yuichiro Ohe, Chung Cheung Thomas Yau, Walter Bordogna, Stuart Osborne, Sven Schwemmers, Harald Zeuner, Koichi Goto. Efficacy and safety of entrectinib in patients (pts) with locally advanced/metastatic NTRK or ROS1 fusion-positive (fp) solid tumors, not evaluable for the primary endpoint of STARTRK-2 [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr C149.

Subsequent welding of mild steel in the pipeline industry: mechanical, wear and microstructure characteristics

In this work, an attempt was made to join MS IS2062 using a combination of gas tungsten arc welding (GTAW) and shielded metal arc welding (SMAW) processes using various welding parameters to get the best weldability. An initial scanning electron microscope study was conducted to determine the microstructure of the sample. In addition to measuring and correlating microstructures and welding parameters, mechanical properties like tensile strength and microhardness are also measured. Here, friction force (FF) and specific wear rate (SWR) were carried out to analyse the tribological behaviour of the weld joint. It was found that the weld MS IS2062 by subsequent welding achieved 15% and 5% higher yield strength and 5% and 4% harder than SMAW and GTAW. Pull-off and cracks were found in the tensile fracture image, and changes in grain boundaries have been observed in the microstructural study. The contact pressure shows the greatest influence on roughness and FF; at the same time, velocity influences the SWR, as found in the experimental results. The subsequent welding process was performed with good stabilisation by balancing between the SMAW and GTAW welding, and to obtain superior properties, we must optimise our results and choose the best possible method.

Reduction in retinal microvascular perfusion during migraine attacks.

To determine if there are changes in structure and function of the retinal vasculature during and between migraine attacks using optical coherence tomography angiography (OCTA). Migraine attacks commonly include visual symptoms, but the potential role of the retina in these symptoms is not well understood. OCTA is a rapid, non-invasive imaging technique that is used to visualize the retinal microvasculature with high spatial resolution in a clinical setting. In this study we used OCTA to quantify different features of the retinal vasculature in patients with migraine during and between attacks, as well as in healthy controls (HCs). We performed a prospective cohort study of 37 patients with migraine with aura (MA) (median [interquartile range, IQR] age of 37 [14] years, 86% female) and 30with migraine without aura (MO) (median [IQR] age of 37 [17] years, 77% female) and 20 HCs (median [IQR] age of 35 [7] years, 50% female). Macular OCTA scans were obtained for all participants for the interictal analysis. In 12 MA and eight MO, scans were captured both during and outside of migraine attacks and five HCs had initial and repeat scans. In addition to analyzing the morphology of the foveal avascular zone, we calculated the vessel flux index (VFI), which is an indicator of retinal perfusion and conventional metrics (such as vessel area density) in the foveal and parafoveal regions. There was a significant difference in the parafoveal VFI in the ictal state between the groups (p = 0.009). During migraine attacks there was a significant reduction in the parafoveal region VFI in MA (-7%, 95% confidence interval [CI] -10% to -4%; p = 0.006) and MO (-7%, 95% CI -10% to -3%; p = 0.016) from their interictal baseline as compared to the change between repeat scans in HCs (2%, 95% CI -3% to 7%). Interictally, there was a mean (standard deviation [SD]) 13% (10%) (p = 0.003) lower blood perfusion in the MA group as compared to the MO group in the foveal region (mean [SD] 0.093 [0.023] vs. 0.107 [0.021], p = 0.003). Interictal analysis also revealed higher circularity in the superficial foveal avascular zone in the MA group compared with the MO group (mean [SD] 0.686 [0.088] vs. 0.629 [0.120], p = 0.004). In addition, interictal analysis of the patients with MA or MO and unilateral headache showed increased retinal vascular parameters consistent with greater perfusion in the eye ipsilateral to the side of the pain as compared with the contralateral eye. These results indicate that perfusion is reduced in MA and MO in the parafoveal retina during the ictal period. Interictally, the foveal retina in MA has reduced perfusion when compared to the foveal retina in MO. Patients with unilateral headache showed interictal asymmetry of retinal perfusion between eyes. These results indicate that changes in retinal perfusion could be a part of migraine pathophysiology, and that distinct retinal vascular signatures identified with OCTA could represent biomarkers for migraine.

A Novel 2D/3D X-ray Microscopy Alignment and Inspection Solution for Thermocompression Bonding (TCB) in a Highly Integrated Flip Chip Fan-Out Wafer Level Package (FO-WLP)

As packaging drives to extend the capabilities of Moore’s Law via heterogenous integration, numerous bonding technologies have emerged as potential pathways, allowing for integration of both a variety of devices in the lateral space as well as vertical integration of chips via stacking. As vertical integration on interposer becomes more complex due to shrinking CDs and increasing die layers, alignment and shape control in the bonding process becomes critical. Thermocompression bonding (TCB) is particularly well-suited for larger die, where localized reflow allows a better control of chip gap height and tilt throughout the bonding process. TCB systems require both high accuracy and repeatability in all dimensions to provide a reliable system in package. While a 2D system can provide a plan view assessment of a single bond layer between two chips, it falls short in characterizing the critical z-dimension in a highly integrated chip stacking scenario. Therefore a robust solution is needed for both system alignment validation in the x,y plane as well as a capability to explore gap height and bump quality/buried issues in high aspect ratio TSV. This paper will explore an x-ray application of a stacked 15-layer die-to-interposer structure to qualitatively validate overall health of the TSV (bond, pad, fill) via a nondestructive volumetric method as well as quantitatively evaluate stacked die for via/ball/pad alignment to determine overall alignment shift during the bonding process. In the test vehicle for a flip chip FO-WLP process flow first presented by IMEC, a silicon (Si) bridge is utilized to connect the logic and through-package via dies with a bump pitch of 20µm for the logic die interconnect. This is done by carefully aligning the logic dies on the carrier and then placing the through-package dies aligned to the carrier and logic dies. In the final step, a high accuracy placement and stacking TCB tool attaches the Si bridge. To perform an accurate assessment for bump alignment and bond quality, an initial high-resolution 3D x-ray scan is performed on a 1.5mm3 region of interest with over 2,000 individual projections at a 1.4µm voxel resolution with a 4x objective, taking approximately two hours. The dataset is put through a deep-learning algorithm which generates an AI model. This model is then applied to a faster scan of 15 minutes with a 1.4µm voxel resolution for the same field of view (FOV) on a nearby array and the data is collected and processed. To verify alignment of the entire sample, data is collected on the tightest pitch (in this case 20µm) oriented in both the vertical (x) and horizontal (y) plane in the through-silicon via (TSV) region. The z-plane is analyzed and processed by computer vision algorithms, and individual interconnects are then quantified and sorted for solder height (z), width (x,y) and TSV misalignment (deviation from expected center, x1y1 → x2y2). To validate the model, a high-resolution uncorrected 20h scan and a 15min scan based on deep learning are collected for the same region of interest (ROI). The data is comparable. Furthermore, the global misalignment data between both datasets demonstrates similar misalignment propagating through the 15-layer stack.

Pediatric posterior reversible encephalopathy syndrome: Can MR imaging features predict outcomes in non-oncologic patients?

PurposeIdentify MR features predictive of poor outcomes in non-oncologic pediatric PRES. MethodA six-year search of all non-oncologic pediatric patients with clinical and MR features of PRES was performed. Modified Rankin scores were used to classify clinical outcomes into good versus poor, then clinical and MR features were compared among groups. Univariate and multivariate analysis was performed to identify MR predictors of poor outcomes for various imaging features, and p-values < 0.05 were considered statistically significant. ResultsOne hundred and forty-one patients (mean age 10.1 ± 3.0 years, male to female ratio 1:1.1) were included. Clinically, nephrotic syndrome (p = 0.03), focal deficits (p = 0.04), longer hospitalization (p < 0.001), and mechanical ventilation (p < 0.001) were significantly associated with poor outcomes. Univariate analysis revealed that deep grey matter nuclei (OR = 5.29, 95 % CI: 1.6–18.0) and cerebellar edema patterns (OR = 3.49, 95 % CI: 1.3–9.5), cytotoxic edema (OR = 63.6, 95 % CI:16.5–244.2), hemorrhage (OR = 16.58, 95 % CI: 4.3–64.2), and severe PRES patterns (OR = 11.0, 95 % CI: 3.5–34.7) on MR were all significantly associated with poor outcomes (p-values = 0.008 and 0.014, <0.001, <0.001, and < 0.001, respectively). This remained true for cytotoxic edema (OR = 84.26, 95 % CI: 17.3–410.9, p-value < 0.001) and hemorrhage (OR = 44.56, 95 % CI: 6.9–289.7, p-value < 0.001) on multivariate analysis. ConclusionDiffusion restriction and hemorrhage on initial MR scans were the two independent predictors of poor outcomes in non-oncologic pediatric patients.

Semi-automatic miniature specimen testing method to characterize the plasticity and fracture properties of metals

Miniature-testing is essential to characterize the plastic response of materials for which the extraction of conventional full-size specimens is impossible. Examples are weld regions with high property gradients or electronic circuit components. Here, we present the design of a novel testing system for miniature specimens. After inserting the specimens with wedge-shaped shoulders, the system carries out the clamping, initial geometry scanning, and mechanical testing with digital image correlation in an automated manner. The automation prevents the accidental damaging of the miniature specimens during manual handling and adds to the robustness of the overall procedure. It is shown that the experiments with miniature specimens extracted from DP600 steel and aluminum 7075-T6 are highly reproduceable. More importantly, they lead to the same plasticity and fracture properties as experiments on conventional ten-times larger full-size specimens. A correction procedure accounting for the surface roughness, white layer and heat affect zone induced through wire EDM is provided. In addition to developing and validating the new experimental technique, it is applied to characterize a 22MnB4 rod material and stainless steel 316 L foil.

Mitigating mental health and wellbeing challenges among young populations: A scan of youth-led initiatives across Canada to inform psychosocial program development

Youth across Canada are developing creative initiatives that address blind spots and inadequacies in youth mental health services and support, yet few have been formally documented. This study fills this gap, compiling and distilling learnings from youth-led initiatives about the approaches and spaces they have created to support the mental health and wellbeing needs of their peers. Using a decolonizing framework, a systematic scan of the grey literature was conducted to identify youth-led initiatives across Canada. A total of 107 youth-led initiatives were included and information regarding their governance structure, mission, delivery of their programs, and definition of mental health and wellbeing was collected and thematically analyzed using an intersectionality lens. Three important themes were identified that ground the work of youth-led initiatives: 1) Facilitating education, capacity building and access to resources, 2) Ensuring inclusive spaces for healing and social support, and 3) Fostering diversity and pride. The unique narratives, values and approaches projected in youth-led initiatives offer important insights regarding what youth want, and emphasize the importance of engaging youth in the design and development of mental health and wellbeing policies, services, and strategies to improve their responsiveness and cultural safety.

Abstract 15869: Antiarrhythmic Effects of Mesenchymal Stromal Cells in a Post-Infarct Swine Model of Ventricular Tachycardia

Introduction: Mesenchymal Stromal Cells (MSC) reduce scar burden in models of ischemic cardiomyopathy. It is unknown whether MSCs exert antiarrhythmic effects. Hypothesis: MSCs reduce inducibility of monomorphic VT (mmVT) or prolong VT cycle length by ≥20 msec in a post-infarct swine model of VT. Methods: Two groups of 8 Yorkshire Swine underwent a 180-minute occlusion of the LAD. Group 1 (n=8) pigs underwent initial MRI scan, electrophysiology study (EPS), and 3D electroanatomic mapping (EAM) with injection of open-label MSCs (200M cells) around the borderzone of the infarct, using a NOGA Myostar catheter (J&amp;J) guided by EAM. Group 1 pigs had repeat EAM, and final EPS 8 weeks later. Group 2 pigs (n=8) were randomized between placebo and MSC and underwent sequential MSC injections (100M cells/procedure), 7 weeks apart, followed by final EPS and MRI 7 weeks later. Scar% = total scar/myocardial mass (grams). Results: MmVT was induced in 5 of 8 (62.5%) at initial EPS (i-EPS) in Group 1 pigs and 3 of 8 (37.5%) at final EPS (f-EPS). In Group 2 all 4 MSC-treated swine had inducible mmVT during i-EPS but only 2 had mmVT at f-EPS. Overall, 9 of 12 MSC-treated pigs had mmVT initially and 5 of 12 pigs had mmVT at f-EPS (p=0.12). For MSC-treated pigs with persistently inducible mmVT (Groups 1 &amp; 2), the baseline VT CL increased in all pigs by ≥20msec and increased from 216 ± 17 msec initially to 274 ± 35 msec at f-EPS (p = 0.001). In Group 1, Scar% was unchanged (22.2±1.6% to 20.5±2.1%) after single MSC treatment (p=0.17). In Group 2 MSC-treated pigs, Scar% decreased from 25.8±2.0% to 17.9±0.6% after 2 MSC treatments (p=0.014). In pigs with mmVT at i-EPS, the scar% was 24.4±1.2%, compared with 19.3±2.0% in pigs without i-EPS inducible mmVT (p=0.025). In pigs with mmVT at f-EPS, scar% was 22.5±1.8% compared with 18.1±1.6% in pigs without mmVT at f-EPS (p=0.048). Placebo-treated pigs showed no change in scar% (22.5±2.6% to 22.4±2.9%, p=0.44) and no change in VT inducibility (3 of 4 pigs at i-EPS and f-EPS). Conclusions: This study demonstrates that MSC injection reduced myocardial scar and either suppressed induction of VT or prolonged VT cycle length, consistent with an antiarrhythmic effect. Lower scar burden was associated with non-inducibility of VT, either at baseline or final EPS.

Functional to structural plasticity in unilateral sudden sensorineural hearing loss: neuroimaging evidence

A cortical plasticity after long-duration single side deafness (SSD) is advocated with neuroimaging evidence while little is known about the short-duration SSDs. In this case-cohort study, we recruited unilateral sudden sensorineural hearing loss (SSNHL) patients and age-, gender-matched health controls (HC), followed by comprehensive neuroimaging analyses. The primary outcome measures were temporal alterations of varied dynamic functional network connectivity (dFNC) states, neurovascular coupling (NVC) and brain region volume at different stages of SSNHL. The secondary outcome measures were pure-tone audiograms of SSNHL patients before and after treatment. A total of 38 SSNHL patients (21 [55%] male; mean [standard deviation] age, 45.05 [15.83] years) and 44 HC (28 [64%] male; mean [standard deviation] age, 43.55 [12.80] years) were enrolled. SSNHL patients were categorized into subgroups based on the time from disease onset to the initial magnetic resonance imaging scan: early- (n = 16; 1-6 days), intermediate- (n = 9; 7-13 days), and late- stage (n = 13; 14-30 days) groups. We first identified slow state transitions between varied dFNC states at early-stage SSNHL, then revealed the decreased NVC restricted to the auditory cortex at the intermediate- and late-stage SSNHL. Finally, a significantly decreased volume of the left medial superior frontal gyrus (SFGmed) was observed only in the late-stage SSNHL cohort. Furthermore, the volume of the left SFGmed is robustly correlated with both disease duration and patient prognosis. Our study offered neuroimaging evidence for the evolvement from functional to structural brain alterations of SSNHL patients with disease duration less than 1 month, which may explain, from a neuroimaging perspective, why early-stage SSNHL patients have better therapeutic responses and hearing recovery.

Longitudinal follow-up of incidental renal calculi on computed tomography.

Measuring small kidney stones on CT is a time-consuming task often neglected. Volumetric assessment provides a better measure of size than linear dimensions. Our objective is to analyze the growth rate and prognosis of incidental kidney stones in asymptomatic patients on CT. This retrospective study included 4266 scans from 2030 asymptomatic patients who underwent two or more nonenhanced CT scans for colorectal screening between 2004 and 2016. The DL software identified and measured the volume, location, and attenuation of 883 stones. The corresponding scans were manually evaluated, and patients without follow-up were excluded. At each follow-up, the stones were categorized as new, growing, persistent, or resolved. Stone size (volume and diameter), attenuation, and location were correlated with the outcome and growth rates of the stones. The stone cohort comprised 407 scans from 189 (M: 124, F: 65, median age: 55.4years) patients. The median number of stones per scan was 1 (IQR: [1, 2]). The median stone volume was 17.1mm3 (IQR: [7.4, 43.6]) and the median peak attenuation was 308 HU (IQR: [204, 532]. The 189 initial scans contained 291stones; 91 (31.3%) resolved, 142 (48.8%) grew, and 58 (19.9) remained persistent at the first follow-up. At the second follow-up (for 27 patients with 2 follow-ups), 14/44 (31.8%) stones had resolved, 19/44 (43.2%) grew and 11/44 (25%) were persistent. The median growth rate of growing stones was 3.3mm3/year, IQR: [1.4,7.4]. Size and attenuation had a moderate correlation (Spearman rho 0.53, P < .001 for volume, and 0.50 P < .001 for peak attenuation) with the growth rate. Growing and persistent stones had significantly greater maximum axial diameter (2.7 vs 2.3mm, P =.047) and peak attenuation (300 vs 258 HU, P =.031) CONCLUSION: We report a 12.7% prevalence of incidental kidney stones in asymptomatic adults, of which about half grew during follow-up with a median growth rate of about 3.3mm3/year.

Cardiac sympathetic "morbidity" might reflect the neurobiology of early Parkinson's disease.

An appropriate extracranial biomarker that delineates endophenotypes of Parkinson's disease (PD) at an early stage and reflects the neurodegenerative process is lacking. An evaluation of myocardial sympathetic nerve terminals could be a good candidate. This study aimed to explore subtypes of PD patients that showed cardiac catecholaminergic vesicular defect and their characteristics. This study included 122 early drug-naïve PD patients who were followed for approximately 4-5years. All patients were examined with 18F-N-(3-fluoropropyl)-2beta-carbon ethoxy-3beta-(4-iodophenyl) nortropane positron-emission tomography and 123I-meta-iodobenzylguanidine myocardial scintigraphy. Cardiac scans were reexamined two or three times. Patients were subgrouped into the sympathetic denervated group at the initial scan, those without evidence of denervated myocardium in the first and subsequent scans, and the converters whose myocardium was initially normal but became impaired in the subsequent scans. Cognition in 99 patients was initially assessed with neuropsychological tests. Any associations between cardiac denervation subtypes and presynaptic dopamine transporter densities were investigated. Cognitive status relevant to cardiac sympathetic denervation status was evaluated. This study found that cross-sectional comparisons of presynaptic monoamine transporter availability with a predefined order of cardiac denervation groups revealed parallel degeneration. A quadratic correlation between cardiac catecholamine capacity and cognition was observed. This association was interpreted to reflect the early neurobiology of PD. An observed cardiac catecholaminergic gradient was to mirror the central neurobiology of early PD.

SAT521 Predictive Value of Tumor Volumetrics in Patients with Medullary Thyroid Cancer

Abstract Disclosure: N. Behairy: None. S. Gubbi: None. M.G. Pascoal: None. A. Bharadwaj: None. E.C. Wright: None. T. Abijo: None. N. Uttarkar Vikram: None. P. Veeraraghavan: None. C. Cochran: None. J. Glod: None. J. Klubo-Gwiezdzinska: None. Predictive Value of Tumor Volumetrics in Patients with Medullary Thyroid Cancer Background Medullary thyroid cancer (MTC) is a rare endocrine malignancy that can present either as a sporadic disease or as a part of inherited autosomal dominant multiple endocrine neoplasia type 2A (MEN2A) and 2B (MEN2B) syndromes. There is limited data on the prognostic value of the tumor volume (TV) doubling time (TVDT) in patients with sporadic and familial MTC. Therefore, the goal of this study was to examine the association between TVDT and disease-specific survival (DSS) in patients with metastatic MTC. Material and Methods This cohort study included patients with metastatic MTC for whom at least 3 follow-up CT/MRI scans revealed ≥2 measurable lesions and up to the 5 largest lesions in each affected organ were analyzed. The tumor volumes were measured in 2 dimensions (2D) per standard practice reporting and 3 dimensions (3D) using an ellipsoid formula. The average TVDT of all measured lesions in each organ with metastatic deposits was calculated using a previously reported formula. Calcitonin (Ct-DT) and CEA doubling times (CEA-DT) were assessed using the American Thyroid Association Guidelines calculator. The association between DSS and TVDT, Ct-DT, and CEA-DT was tested using Cox regression. Correlations were assessed using a Spearman correlation coefficient. The study was approved by the Institution Review Board. Results The study cohort consisted of 51 patients (27 women, 53%) with age at the initial scan 24 ± 17 years and an average primary tumor size of 3.3±2.0 cm. Seven patients presented with sporadic MTC, 12 with MEN2A and 32 with MEN2B. During a follow-up of 8.0±4.3 years, 28/51 (55%) patients had disease progression and required systemic or local therapies and 9/51 (18%) patients died. A total of 456 scans were analyzed documenting that the organs with the most rapid TVDT were neck masses in 25/51 (49%), liver metastases in 16/51 (31%), lung nodules in 7/51 (14%) and prostate lesions in 3/51 (6%) patients. There was a strong correlation between 2D and 3D TVDT (r = 0.96) as well as between Ct-DT and CEA-DT (r = 0.82). However, the correlation between 2D TVDT and Ct-DT and CEA-DT were low (r = 0.45 for both). The DSS hazard ratios (HR) for DT &amp;lt;1 year compared to ≥3 years were 8.2 (1.5-45.4) for 2D TVDT, 8.7 (1.6-48.2) for 3D TVDT, 15.9 (1.72-146.7) for Ct-DT, and 11.72 (2.0-68.7) for CEA-DT. DSS was not associated with either familial or sporadic etiology of MTC (p = 0.38), gender (p = 0.12), or age at initial scan (p = 0.85). Conclusions Apart from Ct-DT and CEA-DT, TVDT is a valuable prognostic factor in metastatic MTC. Given a strong correlation between 2D and 3D TVDT, standard 2D-based TVDT measurements might be used as an easily obtained and clinically feasible prognostic marker of DSS in MTC patients. Presentation Date: Saturday, June 17, 2023

Impact of forced diuresis at two different time points on pelvic imaging in prostatic carcinoma with 68Ga-PSMA PET/CT.

We compared diagnostic quality of 68Ga-PSMA PET/CT imaging focused on the pelvic structures using two furosemide protocols in two different groups of patients. A total of 55 patients with prostate cancer were retrospectively enrolled in the study. Out of 55, 31 patients were in group 1 (median age: 66 years, Range 44-78 years) in which furosemide injection was given after completion of whole-body 68Ga-PSMA PET/CT scan and 24 patients were in group 2 (median age: 63.5 years, range: 50-82 years) in which it was given along with the 68Ga-PSMA injection. In both groups, an initial time point scan (T0 scan) and a delayed time point scan (T1scan) were done. The images were analyzed qualitatively as well as quantitatively. Quantitatively there was no statistically significant difference between the SUVmax and T:B of prostatic lesion and seminal vesicle invasion (SVI) in both the groups at two time points (P > 0.05). Early furosemide injection caused a washout of the urinary bladder radiotracer concentration in significantly higher number of patients in group 2 (62.5% vs. 6.45% patients, P < 0.001). There was significant clearance of radiotracer activity from the ureters in group 2 (SUVmax: 9.28 vs. 3.09, P = 0.002). The simultaneous furosemide and 68Ga-PSMA injection can reduce the urinary excretion of the tracer and improve the diagnostic confidence of prostatic lesion, SVI and lymph nodal metastasis, along with reducing the scanning time and radiation burden, making this protocol an effective alternative to the present protocol of delayed furosemide injection.

Systematic review of research barriers, facilitators, and stakeholders in long-term care and geriatric settings, and a conceptual mapping framework to build research capacity

BackgroundOlder adults are underrepresented in research. Heterogeneity of research processes in this population, specifically in long-term care (LTC) and geriatric acute care (GAC), is not well described and may impede the design, planning, and conduct of research. In this study, we identified, quantified, and mapped stakeholders, research stages, and transversal themes of research processes, to develop a mapping framework to improve research capacity by better characterizing this heterogeneity.MethodsMulticomponent mixed methods study. An environmental scan was used to initiate a preliminary framework. We conducted a systematic literature search on processes, barriers, and methods for clinical research in GAC and LTC to extract and update stakeholders, research stages, and themes. Importance and interactions of elements were synthesized via heatmaps by number of articles, mentions, and content intersections.ResultsFor our initial framework and environmental scan, we surveyed 24 stakeholders. Of 9277 records, 68 articles were included in our systematic review and allowed us to identify 12 stakeholders, 13 research stages, 17 transversal themes (either barriers, facilitators, general themes, or recommendations), and 1868 intersections. Differences in relative importance between LTC and GAC emerged for stakeholders (staff, managers vs. caregivers, ethics committees), and for research stages (funding, facility recruitment vs. ethics, individual recruitment). Crucial themes according to specific stakeholders were collaboration for the research team; communication, trust, and human resources for managers; heterogeneity for patients and residents. A heatmap framework synthesizing vital stakeholders and themes per research stage was generated.ConclusionsWe identified and quantified the interactions between stakeholders, stages, and themes to characterize heterogeneity in LTC and GAC research. Our framework may serve as a blueprint to co-construct and improve each stage of the research process.

Lesion Expansion in Gnathic Fibrous Dysplasia: Natural History, Indicators of Progression, and Response to Bisphosphonates.

Fibrous dysplasia (FD) is characterized by expansile fibro-osseous lesions that may occur in association with endocrinopathies as part of McCune-Albright syndrome (MAS). Craniofacial FD is a significant source of morbidity and most commonly involves the gnathic bones. There is a critical need to understand the natural history and risk factors for gnathic FD progression to develop preventative trials and identify candidates for intervention. The purpose of this study was to characterize gnathic FD lesion expansion and to identify risk factors associated with lesion growth. Patients with gnathic FD and serial CT imaging were evaluated. Volumetric analyses of CT scans were performed using MIM Encore software. Generalized mixed model analysis was used to account for intra-subject correlation, with FD lesion volume as the dependent variable. In addition to age, effects of MAS-associated endocrinopathies, sex, disease severity, and bisphosphonate treatment were evaluated. A total of 104 total lesions in 52 patients were characterized longitudinally. Median age at initial scan was 8.8 years (range 3.4-18.8), and median age at final scan was 16.8 years (range 6.9-33.4 years). The median number of scans per subject was 4 (range 2-14). FD lesion volume increased with age (2.50 cm3 /yr, 95% confidence interval [CI] 1.95-3.04, p < 0.001). However, lesion expansion rate decreased over time (-0.05 cm3 /yr, 95% CI -0.07 to 0.04, p < 0.001). Mandibular lesions tended to expand at a greater rate than maxillary lesions (p < 0.001). Growth hormone excess was associated with accelerated expansion rate (p = 0.002). Other MAS-associated endocrinopathies, pubertal status, sex, weight, lesion density, disease severity, and bisphosphonate treatment were not associated with lesion volume or expansion. Gnathic FD lesion expansion is most rapid in younger children and declines as patients approach adulthood. The availability of quantitative natural history data will guide clinicians in identifying patients who are candidates for medical and surgical interventions and clinical trials for preventative therapies. Published 2023. This article is a U.S. Government work and is in the public domain in the USA.

Isolated Tears of the Superior Fascicle of Anterior Talofibular Ligament Can Be Identified on MRI: A Cadaveric Study

Category: Sports; Ankle Introduction/Purpose: Vega et al. describe two components of the anterior talofibular ligament(ATFL), including the intracapsular superior fascicle(sATFL) and the extracapsular inferior fascicle(iATFL). Based on this anatomic distinction, ankle “microinstability” describes instability arising from injury to the sATFL alone. Because the sATFL resides within the ankle joint, synovial fluid limits its healing, potentially leading to pain and subjective ankle instability without a positive anterior drawer exam. Since physical examination is unreliable for microinstability, arthroscopic examination is considered the gold standard for diagnosing sATFL injury. A noninvasive approach for diagnosis would be ideal; however, the efficacy of MRI in detecting injury to the sATFL is not understood. Therefore, we aimed to assess whether MRI could identify the sATFL as an independent structure and diagnose an isolated sATFL tear. Methods: Fourteen mid-tibia cadaveric specimens (7 males, age: 33-78 years) with neutral alignment and no history of trauma or previous surgery were included in the study. A board-certified foot and ankle orthopedic surgeon dissected the lateral ankle ligament complex to confirm the independent presence of the sATFL and the iATFL. After initial dissection, all specimens underwent a clinical MRI scan sequence, and two musculoskeletal radiologists with &gt; 15 years of experience read the images in consensus to identify the sATFL. Half of the specimens were randomly assigned to undergo bisection of the sATFL. All 14 specimens underwent a second MRI scan, and the same radiologists assessed the images while blinded to the sATFL condition. The percentage of specimens with identifiable sATFL during the initial MRI scan and identifiable injury of the sATFL during the second scan were calculated. Results: A total of 14 specimens were dissected down to the lateral ligament complex. The ATFL was observed as a two- fascicle(sATFL and iATFL) ligament in all 14 specimens. A gap between both fascicles was observed. The fibular insertion of the sATFL was located just distal to the fibular insertion of the anterior tibiofibular ligament. In contrast, the fibular insertion of the iATFL was located between the insertion of the sATFL and the fibular tip. In the initial MRI scans, radiologists identified both the sATFL and the iATFL in 10/14(71.4%) specimens. The distinction between the two fascicles was not possible in the other four specimens. In the second set of MRI scans, radiologists correctly identified 6/7(85.7%) specimens that underwent sATFL bibisection and 7/7(100%) specimens with intact sATFL. Conclusion: Our cadaveric dissection confirmed the presence of two distinct fascicles of the ATFL in all specimens. While the radiologists could only identify the discrete bundles of the sATFL and iAFTL in 71.4% of intact specimens, they distinguished the bisected sATFL in 6 out of 7 specimens. These findings suggest that MRI can be a potential tool for diagnosing microinstability. Since microinstability frequently involves intraarticular pathology, performing MRI can be considered if patients experience subjective ankle instability and pain but without signs of ankle laxity on clinical examination.

Assessing the Appropriateness of Repeat MRI Scan Requests Within a Foot and Ankle Department

Category: Other Introduction/Purpose: With diagnostic resources often in great demand, it is important to ensure clinicians request investigations appropriately. Unnecessary radiological investigations are costly and delay patient care. This study aimed to assess the incidence and appropriateness of repeat MRI scans being requested in a single foot and ankle unit, to identify areas which can be improved. Methods: This was a retrospective analysis of 1322 scans between October-2019 to October-2022. We included all patients who had a diagnostic MRI scan requested after being assessed in our foot-and-ankle clinics. Assessments were made on the proportion of repeat scans, the seniority of requester, the indications put forward for the repeat scan, the modality of patient assessment (telephone vs face-to-face appointment), and the impact on patient management. A scan was considered a repeat, if the same anatomical location was scanned within a 3-year period. Scans were deemed appropriate if they were: part of a clinical trial, for tumour/infection/stress-fracture monitoring, for new trauma, pre-operative planning, following agreement in MDT discussions, or following significant changes in clinical symptoms. We expected that scans should ideally only be requested where the result is expected to influence management and that a scan should not be repeated without evidence of change in clinical symptoms (unless for monitoring). Results: Over the 3-year period, 6.5% of MRI scans performed were considered repeat scans. The average time between initial and repeat scans was 13.1±8.6months (range 1-33 months). 88% of patients had only one repeat scan. The majority(58%) of repeat scans were requested by non-senior clinicians. In total, 47/85(55%) scans were deemed appropriate. 75% of the patients in this cohort had been assessed face-to-face. Twenty of these scans were repeated for significant change in clinical symptoms and 50% meaningfully influenced management plans. Conversely, 38/85(45%) repeat scans did not have strong clinical indications. The majority(80%) of these were requested by non- senior clinicians and 50% were requested after a telephone review. From the scans requested by the non-senior clinicians, none(0%) had a meaningfully influence on patients’ management plans. Conclusion: This study highlights that although repeat MRI scans were not common, they seldom influenced patient management unless there was a meaningful change in patient symptoms. MRI scans were more likely to influence management when initiated by senior clinicians and following a face-to-face assessment. In order to streamline patient care and reduce unnecessary investigations we propose a protocol to guide the requesting of repeat scans. This protocol includes identifying significant symptomatic change, in-person review, and senior clinician or multi-disciplinary input when a repeat scan is being considered.

A case of disappearing amyloid on technetium pyrophosphate scan

Technetium-99mm pyrophosphate (Tc-PYP) scintigraphy is a highly accurate non-invasive method for the diagnosis of transthyretin (ATTR) cardiac amyloidosis. Prognosis for this disease is improved following treatment with the transthyretin (TTR) stabilizer tafamidis. Although tafamidis slows disease progression, its effects on myocardial amyloid and Tc-PYP uptake remain unclear. We present a patient with ATTR cardiac amyloidosis who had a strongly positive initial Tc-PYP scan, with a dramatic decrease in Tc-PYP uptake on repeat scan after 3 years of tafamidis treatment. However, myocardial biopsy showed persistent diffuse amyloid deposits. This case highlights the need for further studies regarding the utility of serial Tc-PYP scans in monitoring the progress of ATTR cardiomyopathy.

Milestones in CT: Past, Present, and Future.

In 1971, the first patient CT examination by Ambrose and Hounsfield paved the way for not only volumetric imaging of the brain but of the entire body. From the initial 5-minute scan for a 180° rotation to today's 0.24-second scan for a 360° rotation, CT technology continues to reinvent itself. This article describes key historical milestones in CT technology from the earliest days of CT to the present, with a look toward the future of this essential imaging modality. After a review of the beginnings of CT and its early adoption, the technical steps taken to decrease scan times-both per image and per examination-are reviewed. Novel geometries such as electron-beam CT and dual-source CT have also been developed in the quest for ever-faster scans and better in-plane temporal resolution. The focus of the past 2 decades on radiation dose optimization and management led to changes in how exposure parameters such as tube current and tube potential are prescribed such that today, examinations are more customized to the specific patient and diagnostic task than ever before. In the mid-2000s, CT expanded its reach from gray-scale to color with the clinical introduction of dual-energy CT. Today's most recent technical innovation-photon-counting CT-offers greater capabilities in multienergy CT as well as spatial resolution as good as 125 μm. Finally, artificial intelligence is poised to impact both the creation and processing of CT images, as well as automating many tasks to provide greater accuracy and reproducibility in quantitative applications.