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Tomography: a Journal for Imaging Research

Brian J Nguyen, Aman Khurana, Brendon Bagley, Andrew Yen, Richard K J Brown, Jadranka Stojanovska, Michael Cline, Mitchell Goodsitt, Sebastian Obrzut
Virtual reality (VR) systems can offer benefits of improved ergonomics, but their resolution may currently be limited for the detection of small features. For detection of lung nodules, we compared the performance of VR versus standard picture archiving and communication system (PACS) monitor. Four radiologists and 1 novice radiologist reviewed axial computed tomography (CTs) of the thorax using standard PACS monitors (SM) and a VR system (HTC Vive, HTC). In this study, 3 radiologists evaluated axial lung-window CT images of a Lungman phantom...
December 2018: Tomography: a Journal for Imaging Research
Keith A Cauley, Samuel W Fielden
Multiple sclerosis (MS) is a progressive neurodegenerative disease, affecting 1 million Americans and 2.5 million people globally. Although the diagnosis is made clinically, imaging plays a major role in diagnosing and monitoring disease progression and treatment response. Magnetic resonance imaging (MRI) has proven sensitive in imaging MS lesions, but the characterization offered by routine clinical MRI remains qualitative and with discrepancies between imaging and clinical findings. We investigated the ability of digital analysis of noncontrast head computed tomography (CT) images to detect global brain changes of MS...
December 2018: Tomography: a Journal for Imaging Research
Deepa Shetty, Dhruv Patel, Ken Le, Chuong Bui, Robert Mansberg
The novel Gallium-68 prostate-specific membrane antigen (PSMA)-bis [2-hydroxy-5-(carboxyethyl)benzyl] ethylenediamine-diacetic acid positron emission tomography (PET) tracer is increasingly used in the evaluation of prostate cancer, particularly in the detection of recurrent disease. However, PSMA is expressed in nonprostatic tissues, as well as in other pathologic conditions. Here we illustrate such interpretive pitfalls with relevant images that one may encounter while reporting PSMA PET/CT. This study aims to show variation in physiological distribution of PSMA activity and uptake in various benign and neoplastic disorders that may be misinterpreted as prostatic metastatic disease...
December 2018: Tomography: a Journal for Imaging Research
Faris Durmo, Anna Rydelius, Sandra Cuellar Baena, Krister Askaner, Jimmy Lätt, Johan Bengzon, Elisabet Englund, Thomas L Chenevert, Isabella M Björkman-Burtscher, Pia C Sundgren
We investigated multivoxel proton magnetic resonance spectroscopy (1 H-MRS) biometrics for preoperative differentiation and prognosis of patients with brain metastases (MET), low-grade glioma (LGG) and high-grade glioma (HGG). In total, 33 patients (HGG, 14; LGG, 9; and 10 MET) were included. 1 H-MRS imaging (MRSI) data were assessed and neurochemical profiles for metabolites N-acetyl aspartate (NAA) + NAAG(NAA), Cr + PCr(total creatine, tCr), Glu + Gln(Glx), lactate (Lac), myo-inositol(Ins), GPC + PCho(total choline, tCho), and total lipids, and macromolecule (tMM) signals were estimated...
December 2018: Tomography: a Journal for Imaging Research
Linda Knutsson, Anina Seidemo, Anna Rydhög Scherman, Karin Markenroth Bloch, Rita R Kalyani, Mads Andersen, Pia C Sundgren, Ronnie Wirestam, Gunther Helms, Peter C M van Zijl, Xiang Xu
Dynamic glucose-enhanced (DGE) imaging uses chemical exchange saturation transfer magnetic resonance imaging to retrieve information about the microcirculation using infusion of a natural sugar (D-glucose). However, this new approach is not yet well understood with respect to the dynamic tissue response. DGE time curves for arteries, normal brain tissue, and cerebrospinal fluid (CSF) were analyzed in healthy volunteers and compared with the time dependence of sampled venous plasma blood glucose levels. The arterial response curves (arterial input function [AIF]) compared reasonably well in shape with the time curves of the sampled glucose levels but could also differ substantially...
December 2018: Tomography: a Journal for Imaging Research
Koshino Kazuhiro, Rudolf A Werner, Fujio Toriumi, Mehrbod S Javadi, Martin G Pomper, Lilja B Solnes, Franco Verde, Takahiro Higuchi, Steven P Rowe
Even as medical data sets become more publicly accessible, most are restricted to specific medical conditions. Thus, data collection for machine learning approaches remains challenging, and synthetic data augmentation, such as generative adversarial networks (GAN), may overcome this hurdle. In the present quality control study, deep convolutional GAN (DCGAN)-based human brain magnetic resonance (MR) images were validated by blinded radiologists. In total, 96 T1-weighted brain images from 30 healthy individuals and 33 patients with cerebrovascular accident were included...
December 2018: Tomography: a Journal for Imaging Research
Dženan Zukić, Darrin W Byrd, Paul E Kinahan, Andinet Enquobahrie
Multicenter clinical trials that use positron emission tomography (PET) imaging frequently rely on stable bias in imaging biomarkers to assess drug effectiveness. Many well-documented factors cause variability in PET intensity values. Two of the largest scanner-dependent errors are scanner calibration and reconstructed image resolution variations. For clinical trials, an increase in measurement error significantly increases the number of patient scans needed. We aim to provide a robust quality assurance system using portable PET/computed tomography "pocket" phantoms and automated image analysis algorithms with the goal of reducing PET measurement variability...
September 2018: Tomography: a Journal for Imaging Research
Tyler J Bradshaw, Gengyan Zhao, Hyungseok Jang, Fang Liu, Alan B McMillan
This study evaluated the feasibility of using only diagnostically relevant magnetic resonance (MR) images together with deep learning for positron emission tomography (PET)/MR attenuation correction (deepMRAC) in the pelvis. Such an approach could eliminate dedicated MRAC sequences that have limited diagnostic utility but can substantially lengthen acquisition times for multibed position scans. We used axial T2 and T1 LAVA Flex magnetic resonance imaging images that were acquired for diagnostic purposes as inputs to a 3D deep convolutional neural network...
September 2018: Tomography: a Journal for Imaging Research
Jingwen Yao, Dan Ruan, Catalina Raymond, Linda M Liau, Noriko Salamon, Whitney B Pope, Phioanh L Nghiemphu, Albert Lai, Timothy F Cloughesy, Benjamin M Ellingson
Amine chemical exchange saturation transfer (CEST) echoplanar imaging (EPI) provides unique pH and amino acid MRI contrast, enabling sensitive detection of altered microenvironment properties in various diseases. However, CEST contrast is sensitive to static magnetic field (B0 ) inhomogeneities. Here we propose 2 new B0 correction algorithms for use in correcting pH-weighted amine CEST EPI based on k-means clustering and Lorentzian fitting of CEST data: the iterative downsampling estimation using Lorentzian fitting and the 2-stage Lorentzian estimation with 4D polynomial fitting...
September 2018: Tomography: a Journal for Imaging Research
Abubakr Eldirdiri, Stefan Posse, Lars G Hanson, Rie B Hansen, Pernille Holst, Christina Schøier, Annemarie T Kristensen, Helle Hjorth Johannesen, Andreas Kjaer, Adam E Hansen, Jan Henrik Ardenkjaer-Larsen
Here, we developed a symmetric echo-planar spectroscopic imaging (EPSI) sequence for hyperpolarized 13 C imaging on a clinical hybrid positron emission tomography/magnetic resonance imaging system. The pulse sequence uses parallel reconstruction pipelines to separately reconstruct data from odd-and-even gradient echoes to reduce artifacts from gradient imbalances. The ramp-sampled data in the spatiotemporal frequency space are regridded to compensate for the chemical-shift displacements. Unaliasing of nonoverlapping peaks outside of the sampled spectral width was performed to double the effective spectral width...
September 2018: Tomography: a Journal for Imaging Research
Lotte Bonde Bertelsen, Per Mose Nielsen, Haiyun Qi, Christian Østergaard Mariager, Jakob Lindhardt, Christoffer Laustsen
Numerous patient groups receive >1 medication and as such represent a potential point of improvement in today's healthcare setup, as the combined or cumulative effects are difficult to monitor in an individual patient. Here we show the ability to monitor the pharmacological effect of 2 classes of medications sequentially, namely, 2,4-dinitrophenol, a mitochondrial uncoupler, and dichloroacetate, a pyruvate dehydrogenase kinase inhibitor, both targeting the oxygen-dependent energy metabolism. We show that although the 2 drugs target 2 different metabolic pathways connected ultimately to oxygen metabolism, we could distinguish the 2 in vivo by using hyperpolarized [1-13 C]pyruvate magnetic resonance imaging...
September 2018: Tomography: a Journal for Imaging Research
Phillip H Kuo, Carol Stuehm, Scott Squire, Kevin Johnson
The recent report of the existence of meningeal lymphatic vessels (MLVs) in human and nonhuman primates used both histology and magnetic resonance imaging (MRI). Many questions about the physiology and function of these lymphatic vessels remain unanswered. Through the combination of appropriately positioned saturation bands and time-of-flight angiography sequences, MRI can resolve direction of flow within vessels without the use of exogenous contrast agent. Six healthy volunteers underwent high-resolution MRI of the MLVs running alongside the superior sagittal sinus to determine the direction of the lymphatic flow...
September 2018: Tomography: a Journal for Imaging Research
Richard K J Brown, Sean Petty, Stephanie O'Malley, Jadranka Stojanovska, Matthew S Davenport, Ella A Kazerooni, Daniel Fessahazion
Magnetic resonance imaging (MRI) is an extremely useful tool for the detection and characterization of numerous pathologic processes. Although patients can benefit from the use of MRI, claustrophobia is a major issue in some cases. This fear alone can lead to cancellation of the scanning procedure in some cases and the need for conscious sedation in others. Patient anxiety during the scan can also lead to increased motion-related artifacts on the images with associated degradation of the diagnostic quality of the study...
September 2018: Tomography: a Journal for Imaging Research
Liang Wen, Xinan Shi, Liping He, Dan Han
Here, we investigated the diagnostic performance of manganese (Mn)-enhanced magnetic resonance imaging (MEMRI) in colorectal cancer (CRC). The ability of CRC cell lines SW620 and SW480 to uptake Mn was evaluated and compared with a normal colon cell using MEMRI. Subcutaneous xenografts in nude mice underwent MRI examination at tumor sizes of 5, 10, and 15 mm. Contrast enhancement was compared between gadolinium (Gd)- and Mn-enhanced MRI. SW620 and SW480 cell lines took up more Mn2+ than normal cells, resulting in 4...
June 2018: Tomography: a Journal for Imaging Research
Jennifer Saunders, Mel Cusi, Hans Van der Wall
It has not been easy to identify mechanical failure of the sacroiliac joint (SIJ) with traditional imaging. The integrated model of function (Lee and Vleeming, 1998) suggests that under normal circumstances, form and force closure combined contribute to sacral nutation and "locking" the SIJ for optimal load transfer. This model is supported by clinical evidence and scintigraphic findings that contribute to successful therapy in 80% of cases. Single-photon emission computed tomography and x-ray computed tomography (SPECT-CT), a hybrid device, was used in a study of 1200 patients (64% female and 36% male patients with an average age of 42 years; range, 15-78 years) with a clinical diagnosis of SIJ incompetence (pelvic girdle pain syndrome)...
June 2018: Tomography: a Journal for Imaging Research
Alexandra M Foust, Rukya M Ali, Xuan V Nguyen, Amit Agrawal, Luciano M Prevedello, Eric C Bourekas, Daniel J Boulter
The presence of a single nodal metastasis has significant prognostic and treatment implications for patients with head and neck cancer. This study aims to investigate whether dual-energy computed tomography (DECT)-derived iodine content and spectral attenuation curve analysis can improve detection of nodal metastasis in oropharyngeal carcinoma. Eight patients with newly diagnosed oropharyngeal squamous cell carcinoma and pathologically proven nodal metastatic disease (n = 13 metastatic nodes; n = 16 nonmetastatic nodes) who underwent contrast-enhanced DECT of the neck were retrospectively evaluated...
June 2018: Tomography: a Journal for Imaging Research
Trung N T Le, Heeseung Lim, Amanda M Hamilton, Katie M Parkins, Yuanxin Chen, Timothy J Scholl, John A Ronald
Glioblastoma multiforme (GBM) is the most common primary brain tumor, with most patients dying within 15-18 months of diagnosis despite aggressive therapy. Preclinical GBM models are valuable for exploring GBM progression and for evaluating new therapeutics or imaging approaches. The rat C6 glioma model shares similarities with human GBM, and application of noninvasive imaging enables better study of disease progression. Here, multiparametric magnetic resonance imaging (mpMRI) and bioluminescence imaging (BLI) were applied to characterize longitudinal development of orthotopic luciferase-expressing C6 tumors...
June 2018: Tomography: a Journal for Imaging Research
Heeseung Lim, Mohammed Albatany, Francisco Martínez-Santiesteban, Robert Bartha, Timothy J Scholl
This study presents the first longitudinal measurement of the intracellular/extracellular pH gradient in a rat glioma model using noninvasive magnetic resonance imaging. The acid-base balance in the brain is tightly controlled by endogenous buffers. Tumors often express a positive pH gradient (pHi - pHe ) compared with normal tissue that expresses a negative gradient. Alkaline pHi in tumor cells increases activity of several enzymes that drive cellular proliferation. In contrast, acidic pHe is established because of increased lactic acid production and subsequent active transport of protons out of the cell...
June 2018: Tomography: a Journal for Imaging Research
Jeremy R Burt, Michael Valente, Ali Agha, Kimberly Beavers, Joseph Limback, Michael Fiorino, Rebecca Vicenti, Fiona Tissavirasingham, Khurram Butt, Andrew R Crofton
Prenatal ultrasonography in the early third trimester showed an unusual branching pattern of the right aortic arch. Echocardiography performed 4 h after birth showed the right aortic arch with mirror-image branching, patent ductus arteriosus, and patent foramen ovale. Because the location of the ductus arteriosus was unclear on echocardiography, cardiovascular magnetic resonance imaging was performed 3 days after birth. Advanced techniques including contrast-enhanced time-resolved magnetic resonance angiography and 3D time-of-flight magnetic resonance angiography allowed accurate diagnosis of a vascular ring comprising ascending and descending aorta, right aortic arch with mirror-image branching, and diverticulum of Kommerell giving rise to a left ligamentum arteriosum...
June 2018: 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
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