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Tomography: a Journal for Imaging Research

Henry R Haley, Nathan Shen, Tonela Qyli, Johanna M Buschhaus, Matthew Pirone, Kathryn E Luker, Gary D Luker
Bone constitutes the most common site of breast cancer metastases either at time of presentation or recurrent disease years after seemingly successful therapy. Bone metastases cause substantial morbidity, including life-threatening spinal cord compression and hypercalcemia. Given the high prevalence of patients with breast cancer, health-care costs of bone metastases (>$20,000 per episode) impose a tremendous economic burden on society. To investigate mechanisms of bone metastasis, we developed femoral artery injection of cancer cells as a physiologically relevant model of bone metastasis...
June 2018: Tomography: a Journal for Imaging Research
Nicholas S Burris, Ana Paula S Lima, Michael D Hope, Karen G Ordovas
S ubclinical systolic and diastolic left ventricular (LV) dysfunction has been reported in previous echocardiographic studies on congenital bicuspid aortic valve (BAV). Patients with BAV commonly undergo evaluation with magnetic resonance imaging, and feature-tracking cardiovascular magnetic resonance (CMR-FT) is an emerging technique that assesses myocardial strain using standard cine sequences. This study investigated differences in myocardial strain between patients with BAV with preserved ejection fraction (EF) and controls using CMR-FT...
March 2018: Tomography: a Journal for Imaging Research
Inbal E Biton, Noa Stettner, Ori Brener, Ayelet Erez, Alon Harmelin, Joel R Garbow
Inflammatory bowel disease (IBD) is characterized by a chronic flaring inflammation of the gastrointestinal tract. To determine disease activity, the inflammatory state of the colon should be assessed. Endoscopy in patients with IBD aids visualization of mucosal inflammation. However, because the mucosa is fragile, there is a significant risk of perforation. In addition, the technique is based on grading of the entire colon, which is highly operator-dependent. An improved, noninvasive, objective magnetic resonance imaging (MRI) technique will effectively assess pathologies in the small intestinal mucosa, more specifically, along the colon, and the bowel wall and surrounding structures...
March 2018: Tomography: a Journal for Imaging Research
Mansour Mustafa, Dhruv Patel, Lily Shen, Anita Shetty, Robert Mansberg
A 38-year-old woman with Hodgkin lymphoma was referred for staging fludeoxyglucose (18 F) positron emission tomography/computed tomography (FDG PET/CT) that showed widespread intensely FDG-avid disease in multiple nodal stations above the diaphragm and spleen and extranodal involvement in the lungs and vertebral bodies. She underwent chemotherapy and radiotherapy. Progress FDG PET/CT 5 months later showed significant metabolic and anatomic response. Repeat FDG PET/CT 1 month later was highly suspicious of recurrent disseminated FDG-avid lymphoma in multiple nodal stations above and below the diaphragm, spleen, multiple bones, and lungs...
March 2018: Tomography: a Journal for Imaging Research
Paul E Kinahan, Darrin W Byrd, Brian Helba, Kristen A Wangerin, Xiaoxiao Liu, Joshua R Levy, Keith C Allberg, Karthik Krishnan, Ricardo S Avila
A challenge in multicenter trials that use quantitative positron emission tomography (PET) imaging is the often unknown variability in PET image values, typically measured as standardized uptake values, introduced by intersite differences in global and resolution-dependent biases. We present a method for the simultaneous monitoring of scanner calibration and reconstructed image resolution on a per-scan basis using a PET/computed tomography (CT) "pocket" phantom. We use simulation and phantom studies to optimize the design and construction of the PET/CT pocket phantom (120 × 30 × 30 mm)...
March 2018: Tomography: a Journal for Imaging Research
Faris Durmo, Jimmy Lätt, Anna Rydelius, Silke Engelholm, Sara Kinhult, Krister Askaner, Elisabet Englund, Johan Bengzon, Markus Nilsson, Isabella M Björkman-Burtscher, Thomas Chenevert, Linda Knutsson, Pia C Sundgren
The aim was to evaluate volume, diffusion, and perfusion metrics for better presurgical differentiation between high-grade gliomas (HGG), low-grade gliomas (LGG), and metastases (MET). For this retrospective study, 43 patients with histologically verified intracranial HGG (n = 18), LGG (n = 10), and MET (n = 15) were chosen. Preoperative magnetic resonance data included pre- and post-gadolinium contrast-enhanced T1-weighted fluid-attenuated inversion recover, cerebral blood flow (CBF), cerebral blood volume (CBV), fractional anisotropy, and apparent diffusion coefficient maps used for quantification of magnetic resonance biometrics by manual delineation of regions of interest...
March 2018: Tomography: a Journal for Imaging Research
Andreas Pohlmann, Kathleen Cantow, Till Huelnhagen, Dirk Grosenick, Joāo Dos Santos Periquito, Laura Boehmert, Thomas Gladytz, Sonia Waiczies, Bert Flemming, Erdmann Seeliger, Thoralf Niendorf
Diagnosis of early-stage acute kidney injury (AKI) will benefit from a timely identification of local tissue hypoxia. Renal tissue hypoxia is an early feature in AKI pathophysiology, and renal oxygenation is increasingly being assessed through T2 *-weighted magnetic resonance imaging (MRI). However, changes in renal blood volume fraction (BVf) confound renal T2 *. The aim of this study was to assess the feasibility of intravascular contrast-enhanced MRI for monitoring renal BVf during physiological interventions that are concomitant with variations in BVf and to explore the possibility of correcting renal T2 * for BVf variations...
December 2017: Tomography: a Journal for Imaging Research
Esmaeil Enjilela, Ting-Yim Lee, Jiang Hsieh, Amol Murjoomdar, Errol Stewart, Mark Dekaban, Feng Su, Aaron So
Radiation dose of computed tomography liver perfusion imaging can be reduced by collecting fewer x-ray projections in each gantry rotation, but the resulting aliasing artifacts could affect the hepatic perfusion measurement. We investigated the effect of projection undersampling on the assessment of hepatic arterial blood flow (HA BF) in hepatocellular carcinoma (HCC) when dynamic contrast-enhanced (DCE) liver images were reconstructed with filtered backprojection (FBP) and compressed sensing (CS). DCE liver images of a patient with HCC acquired with a 64-row CT scanner were reconstructed from all the measured projections (984-view) with the standard FBP and from one-third (328-view) and one-fourth (246-view) of all available projections with FBP and CS...
December 2017: Tomography: a Journal for Imaging Research
Patrick Virtue, Michael Lustig
In Fourier-based medical imaging, sampling below the Nyquist rate results in an underdetermined system, in which a linear reconstruction will exhibit artifacts. Another consequence is lower signal-to-noise ratio (SNR) because of fewer acquired measurements. Even if one could obtain information to perfectly disambiguate the underdetermined system, the reconstructed image could still have lower image quality than a corresponding fully sampled acquisition because of reduced measurement time. The coupled effects of low SNR and underdetermined system during reconstruction makes it difficult to isolate the impact of low SNR on image quality...
December 2017: Tomography: a Journal for Imaging Research
Kyle M Jones, Carol A Stuehm, Charles C Hsu, Phillip H Kuo, Mark D Pagel, Edward A Randtke
Performing chemical exchange saturation transfer (CEST) magnetic resonance imaging (MRI) in lung tissue is difficult because of motion artifacts. We, therefore, developed a CEST MRI acquisition and analysis method that performs retrospective respiration gating. Our method used an acquisition scheme with a short 200-millisecond saturation pulse that can accommodate the timing of the breathing cycle, and with saturation applied at frequencies in 0.03-ppm intervals. The Fourier transform of each image was used to calculate the difference in phase angle between adjacent pixels in the longitudinal direction of the respiratory motion...
December 2017: Tomography: a Journal for Imaging Research
Frederick W Damen, Alycia G Berman, Arvin H Soepriatna, Jessica M Ellis, Stephen D Buttars, Kristiina L Aasa, Craig J Goergen
In vivo imaging has provided a unique framework for studying pathological progression in various mouse models of cardiac disease. Although conventional short-axis motion-mode (SAX MM) ultrasound and cine magnetic resonance imaging (MRI) are two of the most prevalent strategies used for quantifying cardiac function, there are few notable limitations including imprecision, inaccuracy, and geometric assumptions with ultrasound, or large and costly systems with substantial infrastructure requirements with MRI. Here we present an automated 4-dimensional ultrasound (4DUS) technique that provides comparable information to cine MRI through spatiotemporally synced imaging of cardiac motion...
December 2017: Tomography: a Journal for Imaging Research
Lena Trinh, Emelie Lind, Pernilla Peterson, Jonas Svensson, Lars E Olsson, Sven Månsson
Chemical shift-encoded imaging (CSEI) is the most common magnetic resonance imaging fat-water separation method. However, when high spatial resolution fat fraction (FF) images are desired, CSEI might be challenging owing to the increased interecho spacing. Here, 3 T2 -based methods have been assessed as alternative methods for obtaining high-resolution FF images. Images from the calf of 10 healthy volunteers were acquired; FF maps were then estimated using 3 T2 -based methods (2- and 3-parameter nonlinear least squares fit and a Bayesian probability method) and CSEI for reference...
September 2017: Tomography: a Journal for Imaging Research
Christian Østergaard Mariager, Per Mose Nielsen, Haiyun Qi, Marie Schroeder, Lotte Bonde Bertelsen, Christoffer Laustsen
This study investigated a simple method for calculating the single-kidney glomerular filtration rate (GFR) using dynamic hyperpolarized 13 C-urea magnetic resonance (MR) renography. A retrospective data analysis was applied to renal hyperpolarized 13 C-urea MR data acquired from control rats, prediabetic nephropathy rats, and rats in which 1 kidney was subjected to ischemia-reperfusion. Renal blood flow was determined by the model-free bolus differentiation method, GFR was determined using the Baumann-Rudin model method...
September 2017: Tomography: a Journal for Imaging Research
Matthew D Garrett, Ted K Yanagihara, Randy Yeh, Guy M McKhann, Michael B Sisti, Jeffrey N Bruce, Sameer A Sheth, Adam M Sonabend, Tony J C Wang
Glioblastoma is the most common adult central nervous system malignancy and carries a poor prognosis. Disease progression and recurrence after chemoradiotherapy are assessed via serial magnetic resonance imaging sequences. T2-weighted fluid-attenuated inversion recovery (FLAIR) signal is presumed to represent edema containing microscopic cancer infiltration. Here we assessed the prognostic impact of computerized volumetry of FLAIR signal in the peri-treatment setting for glioblastoma. We analyzed pre- and posttreatment FLAIR sequences of 40 patients treated at the Columbia University Medical Center between 2011 and 2014, excluding those without high-quality FLAIR imaging within 2 weeks before treatment and 60 to 180 days afterward...
September 2017: Tomography: a Journal for Imaging Research
Mette Hauge Lauritzen, Peter Magnusson, Christoffer Laustsen, Sadia Asghar Butt, Jan Henrik Ardenkjær-Larsen, Lise Vejby Søgaard, Olaf B Paulson, Per Åkeson
We evaluated the use of hyperpolarized 13 C magnetic resonance imaging (MRI) in an open-chest rat model of myocardial infarction to image regional changes in myocardial metabolism. In total, 10 rats were examined before and after 30 minutes of occlusion of the left anterior descending coronary artery using hyperpolarized [1-13 C]pyruvate. Cardiac metabolic images of [1-13 C]pyruvate and its metabolites [1-13 C]lactate, [1-13 C]alanine, and [13 C]bicarbonate were obtained before and after ischemia. Significant reduction in the [1-13 C]alanine and [1-13 C]lactate signals were observed in the ischemic region post ischemia...
September 2017: Tomography: a Journal for Imaging Research
Antonio Fernández-Baldera, Charles R Hatt, Susan Murray, Eric A Hoffman, Ella A Kazerooni, Fernando J Martinez, MeiLan K Han, Craig J Galbán
Small airways disease (SAD) is one of the leading causes of airflow limitations in patients diagnosed with chronic obstructive pulmonary disease (COPD). Parametric response mapping (PRM) of computed tomography (CT) scans allows for the quantification of this previously invisible COPD component. Although PRM is being investigated as a diagnostic tool for COPD, variability in the longitudinal measurements of SAD by PRM has been reported. Here, we show a method for correcting longitudinal PRM data because of non-pathological variations in serial CT scans...
September 2017: Tomography: a Journal for Imaging Research
Nicholas S Burris, Benjamin A Hoff, Ella A Kazerooni, Brian D Ross
Thoracic aortic aneurysm is a common and lethal disease that requires regular imaging surveillance to determine timing of surgical repair and prevent major complications such as rupture. Current cross-sectional imaging surveillance techniques, largely based on computed tomography angiography, are focused on measurement of maximal aortic diameter, although this approach is limited to fixed anatomic positions and is prone to significant measurement error. Here we present preliminary results showing the feasibility of a novel technique for assessing change in aortic dimensions, termed vascular deformation mapping (VDM)...
September 2017: Tomography: a Journal for Imaging Research
Mikin Patel, Danial Jilani, Aytekin Oto, Pritesh Patel
Gastrointestinal stromal tumor (GIST) frequently metastasizes to the liver, and conventional staging computed tomography (CT) protocols use multiphasic contrast enhancement for detection of hepatic lesions. We evaluated the sensitivity of arterial phase CT imaging for hepatic GIST metastases compared with that of standard (portal venous [PV]) phase imaging. We conducted a retrospective review of patients who presented with hepatic GIST metastases identified on staging CT examinations between 2005 and 2015. Arterial and PV phase CT images were randomized and reviewed by 2 radiologists blinded to clinical history, correlative imaging, and number of controls...
June 2017: Tomography: a Journal for Imaging Research
Sina Straub, Julian Emmerich, Heinz-Peter Schlemmer, Klaus H Maier-Hein, Mark E Ladd, Matthias C Röthke, David Bonekamp, Frederik B Laun
We propose an alternative processing method for quantitative susceptibility mapping of the prostate that reduces artifacts and enables better visibility and quantification of calcifications and other lesions. Three-dimensional gradient-echo magnetic resonance data were obtained from 26 patients at 3 T who previously received a planning computed tomography of the prostate. Phase images were unwrapped using Laplacian-based phase unwrapping. The background field was removed with the V-SHARP method using tissue masks for the entire abdomen (Method 1) and masks that excluded bone and the rectum (Method 2)...
June 2017: Tomography: a Journal for Imaging Research
Yafang Xu, Steffen Ringgaard, Christian Østergaard Mariager, Lotte Bonde Bertelsen, Marie Schroeder, Haiyun Qi, Christoffer Laustsen, Hans Stødkilde-Jørgensen
Magnetic resonance imaging (MRI) is increasingly the method of choice for rapid stroke assessment in patients and for guiding patient selection in clinical trials. The underlying metabolic status during stroke and following treatment is recognized as an important prognostic factor; thus, new methods are required to monitor local biochemistry following cerebral infarction, rapidly and in vivo. Hyperpolarized MRI with the tracer [1-13 C]pyruvate enables rapid detection of localized [1-13 C]lactate production, which has recently been shown in patients, supporting its translation to assess clinical stroke...
June 2017: Tomography: a Journal for Imaging Research
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