Search

Introduction and objectives: patients with long, sequential and diffuse coronary lesions who undergo a percutaneous coronary intervention remain at a high risk of suffering cardiovascular events despite the improved safety and efficacy of the new drug-eluting stents. The objective of this study was to analyze the utility of SyncVision/iFR-guided revascularization (SyncVision version 4.1.0.5, Philips Volcano, Belgium) in this type of lesions. Methods: Randomized, multicenter, controlled, and open-label trial designed to compare SyncVision/iFR-guided and angiography-guided revascularizations in patients with long, sequential or diffuse significant angiographic coronary stenosis (ClinicalTrials.gov identifier: NCT04283734). A total of 100 patients will be randomized (1:1, no stratification). The primary endpoint is the average length of the stent implanted. The secondary endpoint is a composite of cardiac death, myocardial infarction, definitive or probable stent thrombosis, new target lesion revascularization or new target lesion failure; and the presence of residual ischemia as seen on single-photon emission computed tomography at the 6-month follow-up. Patients will be followed for 12 months after the procedure. Results: The trial is currently in the recruitment phase, and it has already recruited the first 7 patients. We expect to complete the recruitment phase by February 2021 and the follow-up by February 2022. Conclusions: The iLARDI study is the first randomized trial to assess the potential utility of SyncVision-guided revascularization in long, sequential and diffuse coronary lesions.

Background Intravascular ultrasound (IVUS) provides endoluminal views and cross-sectional images of carotid arteries but lacks overview of vascular territory provided by angiography. Co-registration of IVUS with angiographic images may provide the potential to navigate both imaging modalities in a synchronous manner. The objective of this study is to evaluate the feasibility and accuracy of co-registering both imaging modalities in the carotid vasculature of the neck. Methods Fourteen patients with 15 cervical carotid artery lesions underwent angiography and subsequent treatment. In each case, an IVUS catheter was advanced to the target lesion and a reference angiography sequence was acquired. This was followed by an electrocardiography-triggered fluoroscopy sequence that was initiated upon IVUS catheter pullback. IVUS data collected during pullback were registered with fluoroscopy and evaluated for error and clinical usability. Results A total of 32 landmarks were identified that demonstrated reasonable agreement during IVUS–angiography co-registration. There was a mean registration error distance of 3.36 mm (SD 2.82 mm) between targets. The longitudinal extent and severity of the disease through the target segment could be easily evaluated after co-registration. Conclusion Semiautomatic tracking and co-registration of angiography and IVUS is a new technology and has the potential to increase the use of IVUS in carotid disease and to proivde the opportunity to optimize procedural outcomes.

Intravascular imaging using both intravascular ultrasound (IVUS) and optical coherence tomography (OCT) have become important tools in the Interventional Cardiologists armamentarium. However, in some centers, intravascular imaging is not widely employed. A number of reasons for this may exist, including lack of training in the use of intravascular imaging. Co-registration with angiography may be a helpful tool for those beginning to use both IVUS and OCT in the cath lab, and may reduce the learning curve associated with its use. For experienced operators, co-registration can shorten procedure time and lessen contrast use which may be particularly important when performing complex or multivessel PCI. As a research tool, co-registration can allow for accurate comparison of interval intravascular images. In this review, we will discuss how to acquire co-registered images using both IVUS and OCT systems, and the potential advantages of this technology over non-co-registered images, and indeed angiography alone.

We reviewed the role of multiparametric magnetic resonance imaging (MP-MRI) and methods of MRI guided biopsy including in-bore, cognitive fusion, and software-based fusion. MP-MRI has been developed, optimized, and studied as a means of improving prostate cancer detection beyond the standard evaluation that utilizes digital rectal examinations and serum prostate specific antigen (PSA). MP-MRI has been proven to be an excellent diagnostic imaging modality that improves prostate cancer detection and risk stratification by guiding biopsy samples. The co-registration between MRI and ultrasound has allowed for software-based fusion which enables office-based biopsy procedures while still benefiting from the detailed prostate characterization of MRI. MP-MRI/ultrasound fusion guided biopsy has been studied in detail as this technology has been developed, tested, and validated in the past decade. The imaging to pathology correlation supporting the use of MP-MRI/ultrasound fusion is well documented in the literature. As the indication for the use of prostate MP-MRI becomes more widespread, it is important to continue to evaluate the correlation between imaging and pathologic findings.

Automation of downstream analysis may offer many potential benefits to routine histopathology. One area of interest for automation is in the scoring of multiple immunohistochemical markers to predict the patient's response to targeted therapies. Automated serial slide analysis of this kind requires robust registration to identify common tissue regions across sections. We present an automated method for co-localized scoring of Estrogen Receptor and Progesterone Receptor (ER/PR) in breast cancer core biopsies using whole slide images. Regions of tumor in a series of fifty consecutive breast core biopsies were identified by annotation on H&E whole slide images. Sequentially cut immunohistochemical stained sections were scored manually, before being digitally scanned and then exported into JPEG 2000 format. A two-stage registration process was performed to identify the annotated regions of interest in the immunohistochemistry sections, which were then scored using the Allred system. Overall correlation between manual and automated scoring for ER and PR was 0.944 and 0.883, respectively, with 90% of ER and 80% of PR scores within in one point or less of agreement. This proof of principle study indicates slide registration can be used as a basis for automation of the downstream analysis for clinically relevant biomarkers in the majority of cases. The approach is likely to be improved by implantation of safeguarding analysis steps post registration. © 2016 International Society for Advancement of Cytometry.

Prostate magnetic resonance imaging (MRI) allows the detection and treatment planning of clinically significant cancers. However, indolent cancers, e.g., those with Gleason scores 3+3, are not readily distinguishable on MRI. Thus an image-guided biopsy is still required before proceeding with a radical treatment for aggressive tumors or considering active surveillance for indolent disease. The excision of the prostate as part of radical prostatectomy treatments provides a unique opportunity to correlate whole-mount histology slices with MRI. Through a careful spatial alignment of histology slices and MRI, the extent of aggressive and indolent disease can be mapped on MRI which allows one to investigate MRI-derived features that might be able to distinguish aggressive from indolent cancers. Here, we introduce a framework for the 3D spatial integration of radiology and pathology images in the prostate. Our approach, first, uses groupwise-registration methods to reconstruct the histology specimen prior to sectioning, and incorporates the MRI as a spatial constraint, and, then, performs a multi-modal 3D affine and deformable alignment between the reconstructed histology specimen and the MRI. We tested our approach on 15 studies and found a Dice similarity coefficient of 0.94±0.02 and a urethra deviation of 1.11±0.34 mm between the histology reconstruction and the MRI. Our robust framework successfully mapped the extent of disease from histology slices on MRI and created ground truth labels for characterizing aggressive and indolent disease on MRI.

The efficacy of an IVUS-guided stent implantation strategy to improve acute results and clinical outcome has been described previously. OCT is another technique which allows high-resolution intracoronary imaging. However, the use of invasive imaging modalities to guide PCI has, as yet, played a limited role in current clinical practice. This may be partly explained by the expertise required for interpretation and clinical decision making. We present a novel technology which enables real-time co-registration of OCT images with angiography. This will simplify matching cross-sectional images to their geographic position on the angiogram, thereby facilitating imaging-guided PCI.

There is an expanding research interest in high-grade gliomas because of their significant population burden and poor survival despite the extensive standard multimodal treatment. One of the obstacles is the lack of individualized monitoring of tumor characteristics and treatment response before, during and after treatment. We have developed a two-stage semi-automatic method to co-register MRI scans at different time points before and after surgical and adjuvant treatment of high-grade gliomas. This two-stage co-registration includes a linear co-registration of the semi-automatically derived mask of the preoperative contrast-enhancing area or postoperative resection cavity, brain contour and ventricles between different time points. The resulting transformation matrix was then applied in a non-linear manner to co-register conventional contrast-enhanced T-1-weighted images. Targeted registration errors were calculated and compared with linear and non-linear co-registered images. Targeted registration errors were smaller for the semi-automatic non-linear co-registration compared with both the non-linear and linear co-registered images. This was further visualized using a three-dimensional structural similarity method. The semi-automatic non-linear co-registration allowed for optimal correction of the variable brain shift at different time points as evaluated by the minimal targeted registration error. This proposed method allows for the accurate evaluation of the treatment response, essential for the growing research area of brain tumor imaging and treatment response evaluation in large sets of patients. Copyright (c) 2016 John Wiley & Sons, Ltd.

OBJECTIVES We present our experience with a novel method for real time co-registration of intravascular ultrasound (IVUS) and coronary angiography. BACKGROUND A major limitation of the current practice of concomitant use of coronary angiography and IVUS is that the locations of the acquired IVUS images are not correlated with their exact locations on the vessel roadmap obtained by coronary angiography. METHODS Phantoms simulating the coronary tree were used to test the accuracy and potential of co-registration. Subsequently we examined patients who underwent IVUS during cardiac catheterization. Analysis and feasibility were performed in 42 arteries of 36 patients. RESULTS The statistical validation in phantoms resulted in a co-registration accuracy of 1.12 mm. The length measurement on an angiogram resulted in an accuracy of 0.38 mm. Co-registration in patients was successful in all cases and four categories were assisted by 1(bad) to 5 (good) grading. Accuracy (the co-registration precision in pointing at the exact corresponding location): 4.8±0.41; Ease of use and workflow: 4.74±0.44; Stent landing zone detection and evaluation: 4.58±0.5; Stent landing zone length and diameter measurement: 4.94±0.23. The co-registration error was estimated as no more than 1 mm. CONCLUSION In this pilot study, we found that the novel IVUS and coronary angiography co-registration method is accurate, easy to use, fast and user-friendly. This method precludes the need to use motorized automated pull back device.

Integration of angiographic co-registration (ACR) with optical coherence tomography (OCT) leads to significant changes in PCI strategy. ACR with OCT allows complete integration of all available data-points to aid decision making. Randomized clinical trials comprehensively evaluating the impact of OCT with ACR to improve clinical outcomes are ongoing.

Image fusion software enables technetium(99m)-methylene diphosphonate (Tc(99m)-MDP) bone scan images to be co-registered with CT scan or MRI, allowing greater anatomical discrimination. We examined the role of bone scan images co-registered with CT scan or MRI in the investigation of patients presenting with axial spinal pain and/or limb pain. One hundred and thirty-nine consecutive patients were examined, and thereafter investigated with CT scan, MRI, and/or dynamic plain films. At this point diagnosis (pathology type and anatomical site) and treatment intention were declared. The co-registered Tc(99m)-MDP bone scan images were then studied, after which diagnosis (pathology type and anatomical site) and treatment intention were re-declared. This data were then analysed to determine whether the addition of co-registered bone scan images resulted in any change in diagnosis or treatment intention. The most significant change in diagnosis was pathology type (10%). Anatomical site changed markedly without overlap of the pre and post-isotope fields in 5%, and with overlap in 10%. Treatment intention had a major change in 3.6% and minor change in 8.6%. In the two groups where there was (i) no obvious pathology after full pre-isotope investigation, or (ii) a spinal fusion under suspicion, addition of the bone scan information led to a major change in the pathology and/or anatomical localisation in 18% and 19%, respectively. The addition of co-registered Tc(99m)-MDP bone scan images offers significant diagnostic assistance, particularly in the difficult diagnostic groups where a failed spinal fusion may be the suspected pain generator, or when no pain generator can otherwise be found.

We present a new clinically practical method for online co-registration of 3D quantitative coronary angiography (QCA) and intravascular ultrasound (IVUS) or optical coherence tomography (OCT). The workflow is based on two modified commercially available software packages. Reconstruction steps are explained and compared to previously available methods. The feasibility for different clinical scenarios is illustrated. The co-registration appears accurate, robust and induced a minimal delay on the normal cath lab activities. This new method is based on the 3D angiographic reconstruction of the catheter path and does not require operator's identification of landmarks to establish the image synchronization.

The latest version of Leksell GammaPlan (LGP) is equipped with Digital Imaging and Communication in Medicine (DICOM) image-processing functions including image co-registration. Diagnostic magnetic resonance imaging (MRI) taken prior to Gamma Knife treatment is available for virtual treatment pre-planning. On the treatment day, actual dose planning is completed on stereotactic MRI or computed tomography (CT) (with a frame) after co-registration with the diagnostic MRI and in association with the virtual dose distributions. This study assesses the accuracy of image co-registration in a phantom study and evaluates its usefulness in clinical cases. Images of three kinds of phantoms and 11 patients are evaluated. In the phantom study, co-registration errors of the 3D coordinates were measured in overall stereotactic space and compared between stereotactic CT and diagnostic CT, stereotactic MRI and diagnostic MRI, stereotactic CT and diagnostic MRI, and stereotactic MRI and diagnostic MRI co-registered with stereotactic CT. In the clinical study, target contours were compared between stereotactic MRI and diagnostic MRI co-registered with stereotactic CT. The mean errors of coordinates between images were < 1 mm in all measurement areas in both the phantom and clinical patient studies. The co-registration function implemented in LGP has sufficient geometrical accuracy to assure appropriate dose planning in clinical use.

The use of coronary computed tomography angiography (CTA) co-registration with real-time fluoroscopy during chronic total occlusion (CTO) percutaneous coronary intervention (PCI) has received limited study. We examined the clinical and angiographic characteristics and outcomes of 12 consecutive

Surgical resection of spinal tumors involves complex reconstructive procedures. The stability and integrity of the surgical construct are evaluated with multidetector computed tomography (MDCT). As coregistration, or fusion, of different imaging modalities, especially positron emission tomography/computed tomography (PET/CT), is common practice, we sought to determine if this technique could be applied to sequential, postoperative MDCT studies of the spine. Herein, we demonstrate that by utilizing the Hermes workstation, co-registration of MDCT spine studies can be performed. This technique allows sequential MDCT examinations of the post-operative spine to be viewed together as one study and may aid in evaluation of the position and integrity of the surgical construct over time. Further study and refinement of this technique will be necessary before clinical implementation.

Aims: To study the validity of a co-registration method for postimplantation computed tomography (CT) images for localizing the location of an intracranial deep brain stimulator. Methods: Three-dimensional reconstruction images of postimplantation CTs were co-registered with preoperative CTs by stereotactic planning software and used to localize 18 leads in the subthalamic nuclei of 10 patients with Parkinson’s disease. Our conventional method using superimposition of sagittal postimplantation magnetic resonance (MR) images were employed as a comparison. Results: The co-registered CT images separately visualized four individual contacts; on the other hand, the MR superimposition method demonstrated the leads as a group of no MR signal areas. Although laterality of the distal contact did not differ between two methods, the distal contact was located more anteriorly and inferiorly by the MR superimposition method than by the CT co-registration method. Conclusion: The CT co-registration method is superior to MR in visualizing deep brain stimulation contacts and resolves problems of MR safety in patients treated with a neurostimulator.

The purpose of our study was to assess the diagnostic value of multi-modal imaging through co-registration of short tau inversion recovery (STIR) and diffusion-weighted imaging (DWI) MRI with 18FDG-PET/CT in T and N staging of head and neck tumours. 25 patients with head and neck squamous cell carcinoma who had undergone MRI and PET/CT before treatment were retrospectively evaluated. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of PET/CT, MRI and their combined use were assessed in T and N staging. Histopathology and follow-up imaging results were used as the gold standard. In assessing trans-compartmental extensions, PET-MRI showed 93 % sensitivity, 88 % specificity, 94 % PPV, and 88 % NPV, as compared to the 94 and 53 % sensitivity, 75 and 75 % specificity, 89 and 82 % PPV, and 86 and 43 % demonstrated by MRI and PET, respectively. In the identification of pathological lymph nodes, PET-MRI showed 92 % sensitivity, 89 % specificity, 96 % PPV, and 89 % NPV, whereas PET/CT displayed 72 % sensitivity, 89 % specificity, 95 % PPV and 53 % NPV. The corresponding figures for DWI and STIR sequences were 84 and 100 % sensitivity, 67 and 56 % specificity, 88 and 86 % PPV, and 60 and 100 % NPV, respectively. Multi-modal imaging assessment of co-registered MRI and PET/CT images provides more accurate results for trans-compartmental extensions in T and N staging than the individual techniques alone.

Background MR reconstruction of virtual 3 dimensional volumes are routinely used to demonstrate cardiac malformations, particularly the complex geometric relationships between the great arteries and cardiac chambers. However, because of the need to signal average over multiple heart beats, rendering fast moving structures such as atrioventricular (AV) and semilunar valves has been limited. Echocardiography has sufficient frame rates to acquire images of moving valves in real-time 3d volumes.

This paper presents a review of 3D reconstruction of coronary arteries based on the co-registration of Intravascular Ultrasound (IVUS) and coronary angiogram. This method has been proposed to ease the process of diagnosis and treatment for coronary artery disease, which is highlighted as a global disease. The purpose of this paper is to provide an introduction and understanding of the works that have been done. This paper consists of an introduction, importance of 3D coronary artery, registration process, background of IVUS and coronary angiogram, and a brief description about previous works.

Background: Repeat Gamma Knife stereotactic radiosurgery (GKSR) procedures are becoming common, especially for brain metastases. It is important to identify tumors requiring treatment at repeat GKSR and it can be challenging to distinguish treated tumors, tumor progression and new tumors. Using the image co-registration tool within the Leksell Gamma Plan software, we developed a technique to aid in the identification of tumors needing treatment. Objectives: The objective was to explore a new co-registration technique to identify tumors requiring treatment at repeat GKSR procedures. Methods: Ten patients who underwent repeat GKSR for brain metastases were identified. Contrast-enhanced volumetric T1 magnetic resonance images (MRI) from the previous GKSR were co-registered with the new images and the resulting two-color format image was used to evaluate tumor status. Results: Using the co-registered images, tumors were characterized as: resolved, regressed, stable, larger or new. Overall, 13.6% of tumors completely resolved, 26.2% regressed, 13.1% remained stable, while 7.9% progressed. Thirty-nine percent of tumors were new. Conclusions: The co-registration technique makes clinically relevant changes conspicuous on MRI. It distinguishes between tumors potentially requiring treatment and those that have been treated successfully. It can be used with tumors other than metastases and for evaluating tumor response at follow-up.

Interpreting complex paediatric body MRI studies requires the integration of information from multiple sequences. Image processing software, some freely available, allows the radiologist to use simple and rapid post-processing techniques that may aid diagnosis. We demonstrate the use of fusion and subtraction post-processing techniques with examples from four areas of application: enterography, oncological imaging, musculoskeletal imaging and MR fistulography.

Aims: To demonstrate the feasibility and potential usefulness of an offline fusion of matched optical coherence tomography (OCT) and intravascular ultrasound (IVUS)/virtual histology (IVUS-VH) images. Methods and results: A total of nine matched OCT, IVUS, and IVUS-VH cross-sections were fused according to a methodology described in this report. On the basis of the fused images, an OCT-IVUS-VH tissue classification algorithm is proposed taking into account the individual strength of both techniques. Conclusions: Offline fusion of co-registered IVUS and OCT is feasible and combines the strengths of both imaging modalities, potentially improving the diagnostic accuracy of plaque characterisation.

The correlation of multiple in vivo imaging modalities with graded whole-mount histology ideally requires co-registration with appropriately quantified accuracy. This work presents a framework for the co-registration of multiple in vivo prostate images with histology as a composition of pair wise registrations. This work also proposes a methodology for the measurement of the accuracy of these registrations based on a composition of target registration errors calculated from homologous landmarks in registered pairs of images. Preliminary results from the implementation of components of the framework are reported.

Dyssynchronous myocardial contraction can be treated with surgical implant of a pacing device. Integrated information of coronary anatomy and mechanical delay may be extremely beneficial to success of the implant but it is not available in current cardiac imaging modalities. The objective of this study is to investigate the feasibility of a point-merge co-registration approach to overcome the limitation. This study shows that our method is a reliable and fast tool useful not only to attain optimal left ventricular implantation site but also to better select patients that undergo cardiac resynchronization therapy.

Background: Single photon emission computed tomography (SPECT) following injection of radiotracer during a seizure is known as ictal SPECT. Comparison of an ictal SPECT study to a baseline or interictal study can aid identification of a seizure focus. Case presentation: A young woman with encephalitis and refractory seizures underwent brain SPECT during a period of frequent seizure-like episodes, and during a seizure-free period. A focal area of increased radiotracer uptake present only when she was experiencing frequent seizure-like episodes was originally localized to the brainstem, but with later computerized co-registration of SPECT to MRI, was found to lie outside the brain, in the region of the sphenoid sinus. Conclusion: Low-resolution SPECT images present difficulties in interpretation, which can be overcome through co-registration to higher-resolution structural images.

We studied the physiological changes in animal model tumors by co-registration of near-infrared spectroscopy and MRI. T2 weighted and Gd-DTPA enhanced MRI images correlate with changes observed in Hb, HbO2 and water concentrations measured by near-infrared spectroscopy.

Intravascular Ultrasound (IVUS) can be used for percutaneous coronary interventions (PCI) guidance. Accurate anatomic co-registration of IVUS images with the angiogram could facilitate stent ‘landing zone’ selection. We evaluated the accuracy of a new system for co-registration of IVUS images

To investigate if cone beam CT (CBCT) can be used to estimate the delivered dose in head and neck intensity-modulated radiotherapy (IMRT).15 patients (10 without replan and 5 with replan) were identified retrospectively. Weekly CBCT was co-registered with original planning CT. Original high-dose clinical target volume (CTV1), low-dose CTV (CTV2), brainstem, spinal cord, parotids and external body contours were copied to each CBCT and modified to account for anatomical changes. Corresponding planning target volumes (PTVs) and planning organ-at-risk volumes were created. The original plan was applied and calculated using modified per-treatment volumes on the original CT. Percentage volumetric, cumulative (planned dose delivered prior to CBCT + adaptive dose delivered after CBCT) and actual delivered (summation of weekly adaptive doses) dosimetric differences between each per-treatment and original plan were calculated.There was greater volumetric change in the parotids with an average weekly difference of between -4.1% and -27.0% compared with the CTVs/PTVs (-1.8% to -5.0%). The average weekly cumulative dosimetric differences were as follows: CTV/PTV (range, -3.0% to 2.2%), ipsilateral parotid volume receiving ≥26 Gy (V26) (range, 0.5-3.2%) and contralateral V26 (range, 1.9-6.3%). In patients who required replan, the average volumetric reductions were greater: CTV1 (-2.5%), CTV2 (-6.9%), PTV1 (-4.7%), PTV2 (-11.5%), ipsilateral (-10.4%) and contralateral parotids (-12.1%), but did not result in significant dosimetric changes.The dosimetric changes during head and neck simultaneous integrated boost IMRT do not necessitate adaptive radiotherapy in most patients.Our study shows that CBCT could be used for dose estimation during head and neck IMRT.