Search

Objective: The aim of this study was to describe the surgeon's ability to accurately predict the margin following resection of colorectal liver metastases (CRLMs)., Background: The decision to resect CRLM is based on the surgeon's ability to predict tumor-free resection margins. However, to date, no study has evaluated the accuracy of surgeon margin prediction., Methods: In this single-institution prospective study, the operating attending and fellow independently completed a preoperative and postoperative questionnaire describing their expected resection margin in 100 consecutive cases (200 assessments) of CRLM resections. In cases with multiple metastases, the closest margin was assessed as the margin of interest for the primary outcome. Surgeon assessments were compared with the gold-standard histopathologic assessment., Results: After excluding aborted cases, 190 preoperative and 190 postoperative assessments from 95 cases were included in the analysis. The pathologic margin was noted to be wide (≥1 cm), 1 mm to 1 cm, narrow (<1 mm), and positive in 28 (29.5%), 55 (57.9%), 5 (5.3%), and 7 (7.4%) cases, respectively. The 88 cases with negative margins were all predicted to be negative. None of the cases with positive margins were predicted to be positive. Ninety-one (48%) preoperative and 104 (55%) postoperative predictions were accurate. The sensitivity of predicting a margin <1 mm was 8.3% preoperatively and 16.7% postoperatively. The positive predictive value for preoperative and postoperative predictions of margin <1 mm was 18.2% and 26.7%, respectively., Conclusions: Surgeons are inaccurate at predicting positive and close surgical margins following resection of CRLM. A predicted close margin should not necessarily preclude resection., Competing Interests: A.C.W. consults for Biosapien and Histosonics and received honorarium for teaching by Medtronic and AstraZeneca. J.A.D.’s spouse is employed by American Regent Pharmaceuticals. The remaining authors report no conflicts of interest., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

There are few studies on the severity and prognosis of patients infected with the severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) omicron variant. From January 11, 2022 to January 25, 2022, 181 patients were infected with the SARS-CoV-2 omicron variant in a single hospital in Korea. The initial clinical characteristics were investigated through the COVID-19 basic investigation form. Outcomes were reviewed using medical records. The median age of the patients was 57 years (range 1-90), and 95 patients (52.5%) were male. None were re-infected with SARS-CoV-2, and 127 (70.2%) were fully vaccinated (boosted or within 6 months after second vaccination). Forty-two patients (23.2%) were asymptomatic. Among symptomatic patients, the frequency of symptoms was as follows: cough (37.0%), sore throat (33.7%), and fever (30.4%). In terms of disease severity, 168 (92.8%) patients did not require supplemental oxygen, 6 (3.3%) required low-flow oxygen, 5 (2.8%) required high-flow oxygen, and 2 (1.1%) died. Four of the five individuals who required high-flow oxygen and the two who died were not vaccinated. Most of the patients who contracted the SARS-CoV-2 omicron variant exhibited mild clinical features; however, severe clinical features including mortality were encountered among individuals who were not vaccinated., Competing Interests: The authors have no potential conflicts of interest to disclose., (© Copyright: Yonsei University College of Medicine 2022.)

Purpose: Lymph node metastasis (LNM) drastically reduces survival after resection of intrahepatic cholangiocarcinoma (IHC). Optimal treatment is ill defined, and it is unclear whether tumor mutational profiling can support treatment decisions., Experimental Design: Patients with liver-limited IHC with or without LNM treated with resection ( N = 237), hepatic arterial infusion chemotherapy (HAIC; N = 196), or systemic chemotherapy alone (SYS; N = 140) at our institution between 2000 and 2018 were included. Genomic sequencing was analyzed to determine whether genetic alterations could stratify outcomes for patients with LNM., Results: For node-negative patients, resection was associated with the longest median overall survival [OS, 59.9 months; 95% confidence interval (CI), 47.2-74.31], followed by HAIC (24.9 months; 95% CI, 20.3-29.6), and SYS (13.7 months; 95% CI, 8.9-15.9; P < 0.001). There was no difference in survival for node-positive patients treated with resection (median OS, 19.7 months; 95% CI, 12.1-27.2) or HAIC (18.1 months; 95% CI, 14.1-26.6; P = 0.560); however, survival in both groups was greater than SYS (11.2 months; 95% CI, 14.1-26.6; P = 0.024). Node-positive patients with at least one high-risk genetic alteration ( TP53 mutation, KRAS mutation, CDKN2A/B deletion) had worse survival compared to wild-type patients (median OS, 12.1 months; 95% CI, 5.7-21.5; P = 0.002), regardless of treatment. Conversely, there was no difference in survival for node-positive patients with IDH1/2 mutations compared to wild-type patients., Conclusions: There was no difference in OS for patients with node-positive IHC treated by resection versus HAIC, and both treatments had better survival than SYS alone. The presence of high-risk genetic alterations provides valuable prognostic information that may help guide treatment., (©2021 American Association for Cancer Research.)

Background: There is limited information describing the presenting characteristics and dynamic clinical changes in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection diagnosed in the early phase of illness. This study is a case series of patients with coronavirus disease 2019 (COVID-19) admitted to 11 hospitals in Korea., Methods: Patients with confirmed SARS-CoV-2 infection by positive polymerase chain reaction (PCR) testing of respiratory specimens by active surveillance that were finally discharged between February 20 and April 30, 2020 were included. Patients were classified into mild and non-mild groups on initial admission according to oxygen demand and Sequential Organ Failure Assessment score, and the mild group was followed up and subgrouped into non-aggravation and aggravation groups., Results: A total of 161 patients with SARS-CoV2 infection were enrolled. Among the mild group of 136 patients, 11.7% of patients experienced clinical aggravation during hospitalization, but there was no initial clinical parameter on admission predicting their aggravation. Fever (odds ratio [OR], 4.56), thrombocytopenia (OR, 12.87), fever (OR, 27.22) and lactate dehydrogenase (LDH) > 300 U/L (OR, 18.35), and CRP > 1 mg/dL (OR, 11.31) significantly indicated aggravation in the 1st, 2nd, 3rd, and 4th 5-day periods, respectively. PCR positivity lasted for a median of 22 days and 32 days after the onset of illness in the non-aggravation and aggravation groups, respectively., Conclusion: Old age was associated with early severe presentation. Clinical aggravation among asymptomatic or mild patients could not be predicted initially but was heralded by fever and several laboratory markers during the clinical course., Competing Interests: The authors have no potential conflicts of interest to disclose., (© 2020 The Korean Academy of Medical Sciences.)

The Neumann problem on an ellipsoid in R n asks for a function harmonic inside the ellipsoid whose normal derivative is some specified function on the ellipsoid. We solve this problem when the specified function on the ellipsoid is a normalized polynomial (a polynomial divided by the norm of the normal vector arising from the definition of the ellipsoid). Specifically, we give a necessary and sufficient condition for a solution to exist, and we show that if a solution exists then it is a polynomial whose degree is at most the degree of the polynomial giving the specified function. Furthermore, we give an algorithm for computing this solution. We also solve the corresponding generalized Neumann problem and give an algorithm for computing its solution.

Acceleration of dynamic 2D (T 2 Mapping) and 3D hyperpolarized 13 C MRI acquisitions using the balanced steady-state free precession sequence was achieved with a specialized reconstruction method, based on the combination of low rank plus sparse and local low rank reconstructions. Methods were validated using both retrospectively and prospectively undersampled in vivo data from normal rats and tumor-bearing mice. Four-fold acceleration of 1-2 mm isotropic 3D dynamic acquisitions with 2-5 s temporal resolution and two-fold acceleration of 0.25-1 mm 2 2D dynamic acquisitions was achieved. This enabled visualization of the biodistribution of [2- 13 C]pyruvate, [1- 13 C]lactate, [ 13 C,  15 N 2 ]urea, and HP001 within heart, kidneys, vasculature, and tumor, as well as calculation of high resolution T 2 maps., (Copyright © 2018 Elsevier Inc. All rights reserved.)

With the translation of metabolic MRI with hyperpolarized 13 C agents into the clinic, imaging approaches will require large volumetric FOVs to support clinical applications. Parallel imaging techniques will be crucial to increasing volumetric scan coverage while minimizing RF requirements and temporal resolution. Calibrationless parallel imaging approaches are well-suited for this application because they eliminate the need to acquire coil profile maps or auto-calibration data. In this work, we explored the utility of a calibrationless parallel imaging method (SAKE) and corresponding sampling strategies to accelerate and undersample hyperpolarized 13 C data using 3D blipped EPI acquisitions and multichannel receive coils, and demonstrated its application in a human study of [1- 13 C]pyruvate metabolism., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Superior mesenteric artery (SMA) syndrome refers to the constellation of symptoms that are associated with intermittent obstruction of the duodenum due to vascular compression. We present a case of SMA-like syndrome related to variant mesenteric venous drainage in the setting of normal aortomesenteric angle (AMA) and borderline reduced aortomesenteric distance (AMD)., (Copyright © 2017 Elsevier Inc. All rights reserved.)

The purpose of this work was to study the anatomic and metabolic changes that occur with tumor progression, regression and recurrence in a switchable MYC-driven murine breast cancer model. Serial 1 H MRI and hyperpolarized [1- 13 C]pyruvate metabolic imaging were used to investigate the changes in tumor volume and glycolytic metabolism over time during the multistage tumorigenesis. We show that acute de-induction of MYC expression in established tumors results in rapid tumor regression and significantly reduced glycolytic metabolism as measured by pyruvate-to-lactate conversion. Moreover, cancer recurrences occurring at the tumor sites independently of MYC expression were observed to accompany markedly increased lactate production., (Copyright © 2017 Elsevier Inc. All rights reserved.)

The goal of this project was to develop and apply techniques for T 2 mapping and 3D high resolution (1.5mm isotropic; 0.003cm 3 ) 13 C imaging of hyperpolarized (HP) probes [1- 13 C]lactate, [1- 13 C]pyruvate, [2- 13 C]pyruvate, and [ 13 C, 15 N 2 ]urea in vivo. A specialized 2D bSSFP sequence was implemented on a clinical 3T scanner and used to obtain the first high resolution T 2 maps of these different hyperpolarized compounds in both rats and tumor-bearing mice. These maps were first used to optimize timings for highest SNR for single time-point 3D bSSFP acquisitions with a 1.5mm isotropic spatial resolution of normal rats. This 3D acquisition approach was extended to serial dynamic imaging with 2-fold compressed sensing acceleration without changing spatial resolution. The T 2 mapping experiments yielded measurements of T 2 values of >1s for all compounds within rat kidneys/vasculature and TRAMP tumors, except for [2- 13 C]pyruvate which was ~730ms and ~320ms, respectively. The high resolution 3D imaging enabled visualization the biodistribution of [1- 13 C]lactate, [1- 13 C]pyruvate, and [2- 13 C]pyruvate within different kidney compartments as well as in the vasculature. While the mouse anatomy is smaller, the resolution was also sufficient to image the distribution of all compounds within kidney, vasculature, and tumor. The development of the specialized 3D sequence with compressed sensing provided improved structural and functional assessments at a high (0.003cm 3 ) spatial and 2s temporal resolution in vivo utilizing HP 13 C substrates by exploiting their long T 2 values. This 1.5mm isotropic resolution is comparable to 1 H imaging and application of this approach could be extended to future studies of uptake, metabolism, and perfusion in cancer and other disease models and may ultimately be of value for clinical imaging., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Purpose: To develop a compressed sensing (CS) acceleration method with a high spectral bandwidth exploiting the spatial-spectral sparsity of MR spectroscopic imaging (MRSI)., Methods: Accelerations were achieved using blip gradients during the readout to perform nonoverlapped and stochastically delayed random walks in kx -ky -t space, combined with block-Hankel matrix completion for efficient reconstruction. Both retrospective and prospective CS accelerations were applied to (13) C MRSI experiments, including in vivo rodent brain and liver studies with administrations of hyperpolarized [1-(13) C] pyruvate at 7.0 Tesla (T) and [2-(13) C] dihydroxyacetone at 3.0 T, respectively., Results: In retrospective undersampling experiments using in vivo 7.0 T data, the proposed method preserved spectral, spatial, and dynamic fidelities with R(2) ≥ 0.96 and ≥ 0.87 for pyruvate and lactate signals, respectively, 750-Hz spectral separation, and up to 6.6-fold accelerations. In prospective in vivo experiments, with 3.8-fold acceleration, the proposed method exhibited excellent spatial localization of metabolites and peak recovery for pyruvate and lactate at 7.0 T as well as for dihydroxyacetone and its metabolic products with a 4.5-kHz spectral span (140 ppm at 3.0 T)., Conclusions: This study demonstrated the feasibility of a new CS approach to accelerate high spectral bandwidth MRSI experiments. Magn Reson Med 76:369-379, 2016. © 2016 Wiley Periodicals, Inc., (© 2016 Wiley Periodicals, Inc.)

Magnetic resonance imaging is an inherently signal-to-noise-starved technique that limits the spatial resolution, diagnostic image quality and results in typically long acquisition times that are prone to motion artefacts. This limitation is exacerbated when receive coils have poor fit due to lack of flexibility or need for padding for patient comfort. Here, we report a new approach that uses printing for fabricating receive coils. Our approach enables highly flexible, extremely lightweight conforming devices. We show that these devices exhibit similar to higher signal-to-noise ratio than conventional ones, in clinical scenarios when coils could be displaced more than 18 mm away from the body. In addition, we provide detailed material properties and components performance analysis. Prototype arrays are incorporated within infant blankets for in vivo studies. This work presents the first fully functional, printed coils for 1.5- and 3-T clinical scanners.

A calibrationless parallel imaging technique developed previously for (1)H MRI was modified and tested for hyperpolarized (13)C MRI for applications requiring large FOV and high spatial resolution. The technique was demonstrated with both retrospective and prospective under-sampled data acquired in phantom and in vivo rat studies. A 2-fold acceleration was achieved using a 2D symmetric EPI readout equipped with random blips on the phase encode dimension. Reconstructed images showed excellent qualitative agreement with fully sampled data. Further acceleration can be achieved using acquisition schemes that incorporate multi-dimensional under-sampling., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Purpose: A chemical shift separation technique for hyperpolarized (13) C metabolic imaging with high spatial and temporal resolution was developed. Specifically, a fast three-dimensional pulse sequence and a reconstruction method were implemented to acquire signals from multiple (13) C species simultaneously with subsequent separation into individual images., Theory and Methods: A stack of flyback echo-planar imaging readouts and a set of multiband excitation radiofrequency pulses were designed to spatially modulate aliasing patterns of the acquired metabolite images, which translated the chemical shift separation problem into parallel imaging reconstruction problem. An eight-channel coil array was used for data acquisition and a parallel imaging method based on nonlinear inversion was developed to separate the aliased images., Results: Simultaneous acquisitions of pyruvate and lactate in a phantom study and in vivo rat experiments were performed. The results demonstrated successful separation of the metabolite distributions into individual images having high spatial resolution., Conclusion: This method demonstrated the ability to provide accelerated metabolite imaging in hyperpolarized (13) C MR using multichannel coils, tailored readout, and specialized RF pulses., (© 2014 Wiley Periodicals, Inc.)

Purpose: A calibrationless parallel imaging reconstruction method, termed simultaneous autocalibrating and k-space estimation (SAKE), is presented. It is a data-driven, coil-by-coil reconstruction method that does not require a separate calibration step for estimating coil sensitivity information., Methods: In SAKE, an undersampled, multichannel dataset is structured into a single data matrix. The reconstruction is then formulated as a structured low-rank matrix completion problem. An iterative solution that implements a projection-onto-sets algorithm with singular value thresholding is described., Results: Reconstruction results are demonstrated for retrospectively and prospectively undersampled, multichannel Cartesian data having no calibration signals. Additionally, non-Cartesian data reconstruction is presented. Finally, improved image quality is demonstrated by combining SAKE with wavelet-based compressed sensing., Conclusion: Because estimation of coil sensitivity information is not needed, the proposed method could potentially benefit MR applications where acquiring accurate calibration data is limiting or not possible at all., (Copyright © 2013 Wiley Periodicals, Inc.)

Al contents have been doped as a sensitizer to improve the luminescent brightness, and the conventional solid state reaction method has been used to synthesize the phosphors. Al doping effects on the microstructures of YVO4:Eu3+ phosphors were measured by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). The luminescent characteristics were characterized by photoluminescence excitation (PLE) and emission (PL) measurements. Incorporation of Al3+ ions into the YVO4:Eu phosphors has greatly enhanced the crystallinity, particle size and hence the luminescence properties and the optimum concentration in Al dopants are found to be 0.05 mol. The photoluminescence intensity of 0.05 mol Al(3+)-doped YVO4:Eu3+ phosphors was improved by a factor of 1.41, in comparison with undoped Y0.95Eu0.05VO4 phosphor. The improvement in photoluminescence properties with Al doping may result from the improved crystallinity and from the enlarged grain sizes inducing lower scattering loss.

Background: The use of skeletal muscle relaxants (SMRs) among older adults is associated with sedation and confusion, which may lead to an increased risk of falls and injuries. SMRs continue to be used among older adults, although they are on the Beers list as drugs to avoid in the elderly., Objective: To investigate the relationship between SMR use and subsequent risk of injury., Methods: This was a retrospective case-control study of members aged 65 years or older enrolled in an integrated health care system. Cases were defined as patients with a documented injury resulting in either a hospitalization or an emergency department or urgent care visit from January 2009 through December 2010. Cases were matched to controls in a 1:4 ratio by age and sex. Patients had to be enrolled and alive on the date of an injury (index date). SMR exposure for all cases and controls was evaluated within 60 days prior to the index date. Conditional logistic regression adjusted for covariates was performed, with risk estimates presented as odds ratios with 95% confidence intervals., Results: From a base population of 322,806 older adults, we identified 27,974 cases of injury and 104,303 matched controls. Among the cases, 365 (1.30%) used an SMR; among the controls, 801 (0.77%) used an SMR in the 60 days prior to the index date. After adjustment for demographic and clinical covariates, risk of injury was significantly increased for patients using an SMR compared to no use (OR 1.32, 95% CI 1.16-1.50; p < 0.001). Carisoprodol was associated with an increased risk of injury (OR 1.73, 95% CI 1.04-2.88; p = 0.036), as were methocarbamol (OR 1.42, 95% CI 1.16-1.75; p = 0.001) and cyclobenzaprine (OR 1.22, 95% CI 1.02-1.45; p = 0.029)., Conclusions: Older adults using SMRs have an increased risk of injury. These findings provide evidence to support current recommendations to avoid the use of SMRs in elderly patients.

The development of hyperpolarized technology utilizing dynamic nuclear polarization (DNP) has enabled the rapid measurement of (13)C metabolism in vivo with very high SNR. However, with traditional DNP equipment, consecutive injections of a hyperpolarized compound in an animal have been subject to a practical minimum time between injections governed by the polarization build-up time, which is on the order of an hour for [1-(13)C]pyruvate. This has precluded the monitoring of metabolic changes occurring on a faster time scale. In this study, we demonstrated the ability to acquire in vivo dynamic magnetic resonance spectroscopy (MRS) and 3D magnetic resonance spectroscopic imaging (MRSI) data in normal rats with a 5 min interval between injections of hyperpolarized [1-(13)C]pyruvate using a prototype, sub-Kelvin dynamic nuclear polarizer with the capability to simultaneously polarize up to 4 samples and dissolve them in rapid succession. There were minimal perturbations in the hyperpolarized spectra as a result of the multiple injections, suggesting that such an approach would not confound the investigation of metabolism occurring on this time scale. As an initial demonstration of the application of this technology and approach for monitoring rapid changes in metabolism as a result of a physiological intervention, we investigated the pharmacodynamics of the anti-cancer agent dichloroacetate (DCA), collecting hyperpolarized data before administration of DCA, 1 min after administration, and 6 min after administration. Dramatic increases in (13)C-bicarbonate were detected just 1 min (as well as 6 min) after DCA administration., (Copyright © 2013 Elsevier Inc. All rights reserved.)

We are reporting a rare chronic irritating, incapacitating skin condition that can be controlled by radiation treatment. We would like to add this case to the world literature.

Salmonella typhi splenic abscesses are a very rare complication of typhoid fever. Splenectomy is the standard surgical treatment for these lesions. But these days, with improvements in imaging techniques, percutaneous drainage of splenic abscesses has been demonstrated to be one of the alternative treatment in selected cases. We report the case of a 7 year-old male, who presented with Salmonella typhi in blood and urine cultures, and a 1: 320 in O titer of Widal test. Ultrasound and computed tomography showed a single splenic abscess, 3 cm in diameter. He was treated with antibiotics, but the symptoms were not relieved. Thus we performed the percutaneous drainage of the splenic abscess under ultrasound guidance. A culture of the aspirated material was positive for Salmonella typhi, and the boy's condition improved. We think that percutaneous drainage of a single lesion was an excellent alternative to surgery, particularly because our patient was young and spleen conservation was desirable.