Advances In Computed Tomography Imaging Research Articles

A Comprehensive Review of Advancements in Diagnostic Imaging: Unveiling Oral Cavity Malignancies Using Computed Tomography.

Early detection of oral cavity malignancies is essential for improving treatment outcomes and patient survival rates. Diagnostic imaging, particularly computed tomography (CT), plays a pivotal role in the early identification and detailed assessment of these malignancies. This comprehensive review explores the advancements in CT imaging and its application in diagnosing oral cavity cancers. It discusses the anatomy and physiology of the oral cavity, the clinical characteristics of common malignancies, and the principles and protocols of CT imaging. The review highlights the diagnostic features of oral malignancies on CT, including distinguishing benign from malignant lesions and staging criteria. Emerging technologies, such as higher-resolution imaging, integration with other modalities, and the potential of artificial intelligence, are examined for their role in enhancing diagnostic accuracy. The clinical implications, challenges, and future directions in the use of CT imaging for oral cavity malignancies are also discussed. This review underscores the importance of continued research and technological advancements in optimizing the use of CT for early detection and effective management of oral cavity cancers.

Advanced CT Imaging, Radiomics, and Artificial Intelligence to Evaluate Immune Checkpoint Inhibitors’ Effects on Metastatic Renal Cell Carcinoma

Advances in the knowledge of renal cell carcinoma (RCC)’s oncogenesis have led to the development of new therapeutic approaches, such as immune checkpoint inhibitors (ICIs), which have improved the clinical outcomes of metastatic RCC (mRCC) patients. Our literature search led to a series of studies that were divided into four subcategories: RECIST criteria, radiomics and artificial intelligence, atypical response patterns, and body composition. These studies provide novel and promising data aimed at improving patient management and clinical outcomes, further strengthening the concept of precision medicine. Radiomics and artificial intelligence allow us to obtain—in a non-invasive fashion—a multitude of data that cannot be detected with the naked eye, offering potential advantages that might help to predict the response to treatments and possibly improve patients’ outcomes through a personalized therapeutic approach. The purpose of this literature review is to describe the available evidence on the role of computed tomography (CT) in evaluating and predicting ICIs’ effects on mRCC patients by applying radiomics and artificial intelligence.

Effective dose and radiation risk under 640-slice abdominal computed tomography examination without contrast medium injection

Medical imaging plays a crucial role in modern medicine. In order to provide fast and accurate medical diagnosis, computed tomography (CT) is a commonly used tool in radiological examinations, and 640-slice CT is the most advanced CT imaging modality. To evaluate the radiation dose and the risk under 640-slice abdominal CT examination. Examinations were performed using a 640-slice CT scanner on an Alderson-Rando anthropomorphic phantom. The used scanning acquisition parameters were the same as those used on abdominal examination without contrast medium injection in clinical practice. To measure the absorbed doses, optically stimulated luminescence dosimeters (OSLDs) were put into liver, stomach, bladder, gonads, colon, small intestine, bone marrow, and skin. According to the 1990 Recommendations of the International Commission on Radiological Protection (ICRP Publication 60), the calculated effective doses received from this examination were 0.90 mSv in males and 0.89 mSv in females. According to the 2007 Recommendations of the International Commission on Radiological Protection (ICRP Publication 103), the calculated effective dose received from this examination was 0.83 mSv in both sexes. Radiation doses obtained from the abdominal 640-slice CT examination are lower than the yearly cumulative doses received from natural radiation, revealing there is no deterministic effect and radiation risk is relatively low; therefore, this CT examination is considered safe.

Should Primary Stroke Centers Perform Advanced Imaging?

Should Primary Stroke Centers Perform Advanced Imaging?

Advanced CT and MR Imaging of the Posttreatment Head and Neck.

Advances in MR and computed tomography (CT) techniques have resulted in greater fidelity in the assessment of treatment response and residual tumor on one hand and the assessment of recurrent head and neck malignancies on the other hand. The advances in MR techniques primarily are related to diffusion and perfusion imaging which rely on the intrinsic architecture of the tissues and organ systems. The techniques exploit the density of the cellular architecture; and the vascularity of benign and malignant lesions which in turn affect the changes in the passage of contrast through the vascular bed. Dual-energy CT and CT perfusion are the major advances in CT techniques that have found significant applications in the assessment of treatment response and tumor recurrence.

New advances in CT imaging of pancreas diseases: a narrative review.

Computed tomography (CT) plays a pivotal role as a diagnostic tool in many diagnostic and diffuse pancreatic diseases. One of the major limits of CT is related to the radiation exposure of young patients undergoing repeated examinations. Besides the standard CT protocol, the most recent technological advances, such as low-voltage acquisitions with high performance X-ray tubes and iterative reconstructions, allow for significant optimization of the protocol with dose reduction. The variety of CT tools are further expanded by the introduction of dual energy: the production of energy-selective images (i.e., virtual monochromatic images) improves the image contrast and lesion detection while the material-selective images (e.g., iodine maps or virtual unenhanced images) are valuable for lesion detection and dose reduction. The perfusion techniques provide diagnostic and prognostic information lesion and parenchymal vascularization and interstitium. Both dual energy and perfusion CT have the potential for pushing the limits of conventional CT from morphological evaluation to quantitative imaging applied to inflammatory and oncological diseases. Advances in post-processing of CT images, such as pancreatic volumetry, texture analysis and radiomics provide relevant information for pancreatic function but also for the diagnosis, management and prognosis of pancreatic neoplasms. Artificial intelligence is promising for optimization of the workflow in qualitative and quantitative analyses. Finally, basic concepts on the role of imaging on screening of pancreatic diseases will be provided.

A Web-based Decision Tool to Estimate Subarachnoid Hemorrhage Risk in Emergency Department Patients.

Subarachnoid hemorrhage (SAH) from a leaking aneurysm is a neurological emergency. SAH patients often present with headache—a common chief complaint among emergency department patients. If unrecognized, 70% of the patients with re-bleeds die and one third are left with neurological deficits. Therefore, it is critical to distinguish the signs and symptoms of SAH from benign causes of headache, perform the appropriate diagnostic tests and treat in a timely manner in order to reduce the disability and mortality associated with this condition. In patients with suspected SAH, traditional diagnostic strategies in the emergency department employ non-contrast computed tomography (CT) of the brain to detect blood in the subarachnoid space followed by lumbar puncture if there is a high clinical probability of aneurysmal bleed without any evidence of blood on CT scan. While the older generation CT scanners were less sensitive to blood detection in the subarachnoid space, recent advances in CT imaging have resulted in sensitivity approaching 100% for detection of blood in the subarachnoid space specifically within six hours of symptom onset. Therefore, the benefit of lumbar puncture is controversial when performed within the first six hours of symptom onset. Despite this, lumbar puncture is still commonly performed in the emergency department, exposing patients to unnecessary procedural risks. The objective of this research study is to develop a web-based risk calculator that estimates the risk of SAH based on time to emergency department presentation after symptom onset, physical findings and imaging characteristics with the goal of reducing unnecessary lumbar punctures in the emergency department. In this technical report, we describe the prototype calculator, the mathematical basis of the model and provide a link to the web-based prototype. In the future, we will refine the prototype, make it user-friendly to physicians, staff and patients and study its benefits in the emergency department.

Abstract W P327: Quantitative Localization and Predictive Performance of Intracranial Hemorrhage

Background and Purpose: Current studies of association between intracranial hemorrhage (ICH) localization and stroke severity present conflicting evidence. Using advanced registration techniques on computed tomography (CT) scans, we provide detailed quantification of ICH location and its association with stroke outcomes. Methods: We analyzed 111 scans from 111 patients enrolled in the MISTIE (Minimally Invasive Surgery plus recombinant-tissue plasminogen activator for Intracerebral Evacuation) trial. We registered CT scans to a CT template, estimated a 3-dimensional map of where ICH engagement occurs, and derived regions predictive of 2 severity scores: the National Institutes of Health Stroke Scale (NIHSS) and Glasgow Coma Scale (GCS) scores. We compared the prediction performance of these regions compared to using location information determined by human readers using the adjusted R2 from linear regression models. Results: In this sample, ICH is primarily located in deep brain nuclei and lobar white matter, including the superior corona radiata and the thalamus (Figure 1), is related to severity scores. The prediction performance was twice as good for the image-based model compared to the reader-based model (adjusted R2: 0.254 vs. 0.129 for NIHSS, 0.214 vs. 0.069 for GCS). Conclusions: Measures of ICH location and engagement using advanced CT imaging processing provide finer, more quantitative, and more predictive anatomic information than that provided by expert human readers. These findings suggest that important anatomic relationships may play biologically plausible roles in determining the severity of a particular ICH and can be estimated using this analytic platform.

Advances in CT imaging for urolithiasis.

Urolithiasis is a common disease with increasing prevalence worldwide and a lifetime-estimated recurrence risk of over 50%. Imaging plays a critical role in the initial diagnosis, follow-up and urological management of urinary tract stone disease. Unenhanced helical computed tomography (CT) is highly sensitive (>95%) and specific (>96%) in the diagnosis of urolithiasis and is the imaging investigation of choice for the initial assessment of patients with suspected urolithiasis. The emergence of multi-detector CT (MDCT) and technological innovations in CT such as dual-energy CT (DECT) has widened the scope of MDCT in the stone disease management from initial diagnosis to encompass treatment planning and monitoring of treatment success. DECT has been shown to enhance pre-treatment characterization of stone composition in comparison with conventional MDCT and is being increasingly used. Although CT-related radiation dose exposure remains a valid concern, the use of low-dose MDCT protocols and integration of newer iterative reconstruction algorithms into routine CT practice has resulted in a substantial decrease in ionizing radiation exposure. In this review article, our intent is to discuss the role of MDCT in the diagnosis and post-treatment evaluation of urolithiasis and review the impact of emerging CT technologies such as dual energy in clinical practice.

Thoracoscopic or Open Surgery for Pulmonary Metastasectomy: An Observer Blinded Study

Video-assisted thoracic surgery (VATS) resection of pulmonary metastases has long been questioned because radiologically undetected parenchymal lesions may be missed when bimanual palpation is restricted to the portholes. Technology, however, has improved and advanced VATS resections are now performed routinely worldwide. This prompted us to conduct a prospective observer-blinded study on pulmonary metastasectomy. Eligible patients with oligometastatic pulmonary disease on computed tomography (CT) underwent high-definition VATS, with digital palpation by 1 surgical team and subsequent immediate thoracotomy during the same anesthesia by a different surgical team, with bimanual palpation and resection of all palpable nodules. Preoperative CT evaluations and surgical results were blinded. Primary endpoints were number and histopathology of detected nodules. During a 3-year period 89 consecutive patients, with newly developed nodules suspicious of lung metastases from previous cancers in colon-rectum (n=59), kidney (n=15), and other malignancies (n=15) were included, with a total of 140 suspicious nodules visible on CT. During VATS, 122 nodules were palpable (87%). All nodules were identified during thoracotomy, where 67 additional and unexpected nodules were also identified; 22 were metastases (33%), 43 (64%) were benign lesions, and 2 (3%) were primary lung cancers. In patients operated for nodules suspicious of lung metastases, a substantial number of additional nodules were detected during thoracotomy despite advancements in CT imaging and VATS technology. Many of these nodules were malignant and would have been missed if VATS was used exclusively. Consequently, we considered VATS inadequate if the intention is to resect all pulmonary metastases during surgery.

Status of Direct Conversion Detectors for Medical Imaging With X-Rays

Imaging detectors for medical X-ray and computed tomography (CT) applications have undergone many improvements and technology changes over time. But most (dynamic) detectors sold in this field still rely on indirect conversion, using scintillators and photodiodes to convert the X-ray quanta ultimately into electrical signals. Direct conversion detectors promise very high spatial resolution and high signal-to-noise ratios. Some direct conversion materials may allow for counting or even energy resolving detection of the X-ray quanta. Based on this, for example spectrally resolving CT systems are becoming an interesting option for the next decade. This contribution highlights the requirements of advanced medical X-ray and CT imaging and reviews examples of status and progress in the field. The emphasis is on the direct conversion sensors for pixelated detectors, but considerations on read-out concepts and on associated challenges such as interconnects will also be presented. Finally, the most burning issues, such as count rate limitations and polarization effects, will be discussed from an application point of view.

Acute Stroke Triage to Intravenous Thrombolysis and Other Therapies with Advanced CT or MR Imaging: Pro MR Imaging

In this article and the companion piece, two sets of experts present their views on the use of computed tomography (CT) or magnetic resonance (MR) imaging to select patients with acute stroke to undergo available reperfusion therapies. Specifically, in this article, two neurologists provide the clinical background and motivation behind the use of advanced imaging in stroke triage—most notably with regard to major clinical trials—to extend the time window for intravenous thrombolysis beyond the currently recommended 3-hour window after stroke. To date, these trials have focused almost exclusively on the use of MR imaging and MR angiography to determine patient eligibility. In this article, the authors compare the MR and CT methods of triage. In the companion article, three neuroradiologists expand on the benefits and limitations of advanced CT imaging in stroke evaluation and offer their perspective on which modality to choose and why.

Acute Stroke Triage to Intravenous Thrombolysis and Other Therapies with Advanced CT or MR Imaging: Pro CT

Max Wintermark, MD Howard A. Rowley, MD Michael H. Lev, MD A s outlined by Kohrmann and Schellinger in their pro magnetic resonance (MR) imaging article, the two primary goals of acute stroke imaging are to distinguish ischemic stroke from intracranial hemorrhage (ICH) and to select ischemic stroke patients for reperfusion therapies. In this article, we too will focus on ischemic stroke imaging. Although our focus remains on nonhemorrhagic stroke with respect to the advantages of advanced computed tomography (CT) over advanced MR imaging in stroke evaluation in all comers, we wish to underscore that CT angiography is becoming increasingly important in the evaluation of patients with ICH, as it has the ability to depict underlying vascular malformations, such as aneurysms, that could warrant immediate surgery. Moreover, the detection of active contrast material extravasation at CT angiography (the recently described spot sign) also has predictive value with regard to both hematoma growth (1,2) and mortality (3). This spot sign has the potential, in future clinical trials, to be used to select patients with ICH who are eligible for factor VIIa therapy. To our knowledge, there is no MR counterpart for the CT angiography spot sign. Also, MR studies can be difficult to perform in patients with ICH, as they are often critically ill and require mechanical support and intensive monitoring; furthermore, there is a need for extremely rapid assessment and triage, given the potential risks of herniation, intracranial hypertension, and death. CT remains an available, affordable, and— for stroke triage—accurate modality.

Calcium Scoring and Contrast-Enhanced CT Angiography

Computed tomography (CT) technology has emerged as the most promising imaging modality for the noninvasive evaluation of the coronary circulation. Of the CT-based approaches, multidetector-row computed tomography (MDCT) and to a lesser extent electron beam computed tomography offer the potential of providing not only data on the spatial extent and burden of coronary calcium content, but also angiographic data, and plaque composition characteristics with the potential for prediction of susceptibility to future cardiovascular events. A number of studies have now confirmed that CT-based assessment of the presence and amount of coronary artery calcium provides incremental prognostic information over traditional risk factors in patients with coronary artery disease and can be employed to refine risk stratification in both asymptomatic and symptomatic subjects. With the advent of several recent advances in CT imaging, it is now possible to provide high resolution (sub-millimeter, isotropic voxels) images of the coronary arteries obtained rapidly with iodinated contrast injected peripherally. MDCT is currently the preferred modality for noninvasive contrast angiography of the coronary arteries by most groups, with a new generation of 64-slice scanners promising to further improve the results of this technique. MDCT-derived angiographic information in conjunction with coronary calcium scoring and plaque characterization has the potential of replacing invasive angiography, as it potentially could provide better global assessment of risk.

Cross-sectional imaging in Crohn disease.

The role of cross-sectional imaging in the diagnosis of Crohn disease has expanded with recent technologic advances in computed tomography (CT) and magnetic resonance (MR) imaging that allow rapid acquisition of high-resolution images of the intestines. To acquire images of diagnostic quality, administration of a fairly large amount of intraluminal contrast agent prior to examination and scanning with intravenous contrast material injection are necessary. Both CT and MR imaging are reported to have a sensitivity of over 95% for the detection of Crohn disease; however, they may not allow early diagnosis. Colonoscopy and conventional enteroclysis studies are indicated for patients with early-stage disease. At more advanced stages, CT and MR imaging can help identify and characterize pathologically altered bowel segments as well as extraluminal lesions (eg, fistulas, abscesses, fibrofatty proliferation, increased vascularity of the vasa recta, mesenteric lymphadenopathy). These modalities can also clearly depict inflammatory lesion activity and conditions that require elective gastrointestinal surgery, thereby aiding in treatment planning. In the clinical setting, CT is currently the imaging modality of choice at most institutions; however, it is expected that MR imaging will soon play a comparable role. CT or MR imaging should be included in a comprehensive evaluation of patients with Crohn disease, along with conventional imaging and clinical and laboratory tests.