Computed body tomography.

Only the surface of the diagnostic possibilities inherent in CT imaging has been scratched. Solic organ pathology is readily visible in most instances by computed tomography. With further extension of present knowledge and development of newer contrast agents, the ability of computed body tomography to image a wide range of diseases appears almost limitless.     

Computed tomography of the heart: Initial experience

Computed tomography (CT) provides non-invasive diagnosis of cardiac lesions by direct demonstration of the myocardium and the individual cavities of the heart. The potential role of CT scanning in the detection and quantitation of acute myocardial infarction has been previously investigated in experimental animals. Initial experience in assessing 10 patients admitted with recent infarction on biochemical and electrocardiographic evidence is reported. Intravenous infusion of iodinated contrast agents produced contrast enhancement either of the rim or diffusely through the myocardium in the area of infarct, as sited electrocardiographically. Patients with coronary artery bypass grafts and hypertrophic cardiomyopathy have also been studied by this method. Cardiac CT with intravenous administration of contrast may have an important role in the future in assessment and follow-up of ischaemic heart disease.     

Computed tomography of talocalcaneal coalition: imaging techniques

The diagnosis of symptomatic talocalcaneal coalition requires an imaging study that demonstrates precise anatomic detail. Computed tomography affords the best method for the diagnosis. This essay reviews the computed tomographic anatomy of talocalcaneal coalitions in several projections and stresses the routine use of the angled coronal and direct sagittal projections.     

Computed tomography perfusion imaging in acute stroke

The development of thrombolytic and neuroprotective agents for the treatment of acute stroke has created an imperative for improved imaging techniques in the assessment of acute stroke. Five cases are presented to illustrate the value of perfusion CT in the evaluation of suspected acute stroke. To obtain the perfusion data, a rapid series of images was acquired without table movement following a bolus of contrast medium. Cerebral blood flow, cerebral blood volume and mean transit time were determined by mathematically modelling the temporal changes in contrast enhancement in the brain and vascular system. Pixel-by-pixel analysis allowed generation of perfusion maps. In two cases, CT-perfusion imaging usefully excluded acute stroke, including one patient in whom a low-density area on conventional CT was subsequently proven to be tumour. Cerebral ischaemia was confirmed in three cases, one with an old and a new infarction, one with a large conventional CT abnormality but only a small perfusion defect, and one demonstrating infarct and penumbra. Perfusion CT offers the ability to positively identify patients with non-haemorrhagic stroke in the presence of a normal conventional CT, to select those cases where thrombolysis is appropriate, and to provide an indication for prognosis.     

Simultaneous whole body 18F-fluorodeoxyglucose positron emission tomography magnetic resonance imaging for evaluation of pediatric cancer: Preliminary experience and comparison with 18F-fluorodeoxyglucose positron emission tomography computed tomography

AIM: To describe our preliminary experience with simultaneous whole body ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography and magnetic resonance imaging (PET-MRI) in the evaluation of pediatric oncology patients.METHODS: This prospective, observational, single-center study was Health Insurance Portability and Accountability Act-compliant, and institutional review board approved. To be eligible, a patient was required to: (1) have a known or suspected cancer diagnosis; (2) be under the care of a pediatric hematologist/oncologist; and (3) be scheduled for clinically indicated ¹⁸F-FDG positron emission tomography-computed tomography (PET-CT) examination at our institution. Patients underwent PET-CT followed by PET-MRI on the same day. PET-CT examinations were performed using standard department protocols. PET-MRI studies were acquired with an integrated 3 Tesla PET-MRI scanner using whole body T1 Dixon, T2 HASTE, EPI diffusion-weighted imaging (DWI) and STIR sequences. No additional radiotracer was given for the PET-MRI examination. Both PET-CT and PET-MRI examinations were reviewed by consensus by two study personnel. Test performance characteristics of PET-MRI, for the detection of malignant lesions, including FDG maximum standardized uptake value (SUVmax) and minimum apparent diffusion coefficient (ADCmin), were calculated on a per lesion basis using PET-CT as a reference standard.RESULTS: A total of 10 whole body PET-MRI exams were performed in 7 pediatric oncology patients. The mean patient age was 16.1 years (range 12-19 years) including 6 males and 1 female. A total of 20 malignant and 21 benign lesions were identified on PET-CT. PET-MRI SUVmax had excellent correlation with PET-CT SUVmax for both benign and malignant lesions (R = 0.93). PET-MRI SUVmax > 2.5 had 100% accuracy for discriminating benign from malignant lesions using PET-CT reference. Whole body DWI was also evaluated: the mean ADCmin of malignant lesions (780.2 + 326.6) was significantly lower than that of benign lesions (1246.2 + 417.3; P = 0.0003; Student’s t test). A range of ADCmin thresholds for malignancy were evaluated, from 0.5-1.5 × 10^-3 mm²/s. The 1.0 × 10^-3 ADCmin threshold performed best compared with PET-CT reference (68.3% accuracy). However, the accuracy of PET-MRI SUVmax was significantly better than ADCmin for detecting malignant lesions compared with PET-CT reference (P < 0.0001; two-tailed McNemar’s test).CONCLUSION: These results suggest a clinical role for simultaneous whole body PET-MRI in evaluating pediatric cancer patients.     

Computed tomography angiography: state-of-the-art imaging using multidetector-row technology

Multidetector-row computed tomography (MDCT) is an essential diagnostic modality for many clinical algorithms. This is particularly true with regard to the evaluation of cardiovascular disease. As a result of increased image acquisition speed, improved spatial resolution, and greater scan volume, MDCT angiography (computed tomography angiography [CTA]) has become an excellent noninvasive imaging technique, replacing intra-arterial digital subtraction angiography for most vascular territories. The clinical success of CTA depends on precise synchronization of image acquisition with optimal vascular enhancement. As technology continuously evolves, however, this task can be challenging. It remains important to have a fundamental knowledge of the principles behind technical parameters and contrast medium administration. This article reviews these essential principles, followed by an overview of current clinical applications.     

Computed tomography of a carotid body tumor

A patient with a carotid body tumor was evaluated by computed tomography. The tumor demonstrated an enhanced rim and a central lower density. This corresponds to the "eggshell" appearance described angiographically in carotid body tumors.     

Computed body tomography in children: evaluation of 45 patients.

Computed tomographic (CT) body scans from a series of 45 infants and children were reviewed for the indications leading to the examinations, for technical quality of the images, and for diagnostic value of CT scanning. Useful diagnostic information was obtained in 30 of the 39 cases with technically satisfactory images. Individual case reports of CT examinations including findings from other imaging studies demonstrate how CT can interface with other methods to yield additional diagnostic information. Methods of patient preparation and suggested indications for CT body scan examinations of children are presented.     

Computed tomography in the imaging of colonic diverticulitis

Colonic diverticulitis occurs when diverticula within the colon become infected or inflamed. It is becoming an increasingly common cause for hospital admission, particularly in western society, where it is linked to a low fibre diet. Symptoms of diverticulitis include abdominal pain, diarrhoea and pyrexia, however, symptoms are often non-specific and the clinical diagnosis may be difficult. In addition, elderly patients and those taking corticosteroids may have limited findings on physical examination, even in the presence of severe diverticulitis. A high index of suspicion is required in such patients in order to avoid a significant delay in arriving at the correct diagnosis. Imaging plays an important role in establishing an early and correct diagnosis. In the past, contrast enema studies were the principal imaging test used to make the diagnosis. However, such studies lack sensitivity and have limited success in identifying abscesses that may require drainage. Conversely computed tomography (CT) is both sensitive and specific in making a diagnosis of diverticulitis. In addition, it is the imaging technique of choice in depicting complications such as perforation, abscess formation and fistulae. CT-guided drainage of diverticular abscesses helps to reduce sepsis and to permit a one-stage, rather than two-stage, surgical operation. The purpose of this review article is to discuss the role of CT in the imaging of diverticulitis, describe the CT imaging features and complications of this disease, as well as review the impact and rationale of CT imaging and intervention in the overall management of patients with diverticulitis.     

QIBA guidance: Computed tomography imaging for COVID-19 quantitative imaging applications

As the COVID-19 pandemic impacts global populations, computed tomography (CT) lung imaging is being used in many countries to help manage patient care as well as to rapidly identify potentially useful quantitative COVID-19 CT imaging biomarkers. Quantitative COVID-19 CT imaging applications, typically based on computer vision modeling and artificial intelligence algorithms, include the potential for better methods to assess COVID-19 extent and severity, assist with differential diagnosis of COVID-19 versus other respiratory conditions, and predict disease trajectory. To help accelerate the development of robust quantitative imaging algorithms and tools, it is critical that CT imaging is obtained following best practices of the quantitative lung CT imaging community. Toward this end, the Radiological Society of North America's (RSNA) Quantitative Imaging Biomarkers Alliance (QIBA) CT Lung Density Profile Committee and CT Small Lung Nodule Profile Committee developed a set of best practices to guide clinical sites using quantitative imaging solutions and to accelerate the international development of quantitative CT algorithms for COVID-19. This guidance document provides quantitative CT lung imaging recommendations for COVID-19 CT imaging, including recommended CT image acquisition settings for contemporary CT scanners. Additional best practice guidance is provided on scientific publication reporting of quantitative CT imaging methods and the importance of contributing COVID-19 CT imaging datasets to open science research databases.     

Computed tomography of partial growth plate arrest: Initial experience

Twelve growth plates in 11 patients with clinical evidence of partial growth plate tethering underwent thin slice (1.5 mm) axial high resolution computed tomography (CT), or direct coronal CT. The normal epiphyseal plate was readily visualised as a low density layer of soft tissue density between adjacent sclerotic margins of epiphysis and metaphysis. Two growth plates had greater than 50% obliteration and ten had partial obliteration. Our preliminary results show excellent correlation between the CT findings and surgical pathology. We expect that CT will replace polytomography in the operative evaluation of partial growth plate arrest, as it has in our institution.     

Computed tomography imaging of cardiac allograft vasculopathy

Cardiac allograft vasculopathy (CAV) is the main cause of morbidity and mortality beyond 1 year after heart transplantation. Ischemic symptoms are usually not present because of the denervated allograft and diffuse nature of the disease. Patients present with heart failure, ventricular arrhythmia, or sudden cardiac death as a result of advanced CAV. Therefore, clinical evaluation includes routine annual invasive coronary angiography (ICA) and transthoracic echocardiography to screen for CAV. Noninvasive imaging methods for the detection of CAV have not been widely adopted. Computed tomography (CT) permits detection of coronary stenoses and plaque in the nontransplant population. The strength of CT is its high negative predictive value. These attributes predispose CT to a role of a gatekeeper for further invasive testing in heart transplant recipients. We reviewed the available literature on CT evaluation of CAV. Technical challenges (eg, high heart rates, need for contrast and radiation, image quality) specific for patients who have received a heart transplant are emphasized, and solutions, including appropriate protocols and advances through the new CT technology, are summarized. We systematically analyze the results of studies that report the diagnostic performance of cardiac CT for the detection of coronary stenoses compared with ICA. Similar analysis is performed for the comparison between CT and intravascular ultrasound scanning for the detection of nonobstructive CAV. Finally, we suggest future directions in cardiac CT imaging research of CAV.     

Computed tomography imaging of acute neck inflammatory processes

Early diagnosis and management of neck infections and inflammatory processes is a common challenge for emergency and ear, neck and throat physicians, as well as radiologists. Emergency neck infections are diverse in their presentation, ranging from a transient enlargement of a lymph node to a rapidly spreading necrotizing fasciitis. Symptoms and signs, with the clinical history, usually suggest the diagnosis. But complex neck anatomy and sometimes limited physical examination can obscure and delay diagnosis, thus the need for an appropriate imaging exam and correct interpretation. In this pictorial review, we will consider common neck acute inflammatory processes that may be encountered in the emergency room and discuss some of their salient imaging findings.     

NMR-whole body tomography: a new imaging method

NMR tomography (zeugmatography) can provide 2D and true 3D images of the human body. Advantages of this new imaging method in medicine are the possibilities to get both anatomic and functional images at one time without any invasive procedures. Furthermore, NMR has no ionizing radiation hazards. The spacial resolution of NMR tomography ranges between 0.5 and 3.0 mm. Within the next years, NMR tomography will replace several conventional X-ray, CAT scanning and nuclear medicine techniques. This article gives a brief survey of NMR basics and its medical applications.     

Computed tomography imaging of the temporal bone--normal anatomy

This review describes the fundamental anatomical structures of the temporal bone as depicted on high-resolution computed tomography, and the clinical significance of these structures. It is not an encyclopaedic atlas, but provides the junior radiology/otorhinolaryngology resident with sufficient knowledge for interpretation of most of the imaging studies encountered in daily clinical practice.     

Computed tomography in the evaluation of osteosarcoma: experience with 25 cases.

Experience with computed tomography (CT) in 25 patients with histologically proven osteosarcoma is presented. CT was as accurate as conventional radiographic methods in determining the presence of a lesion, but it was definitely superior in defining the extent of disease, particularly intramedullary extension and soft tissue extraosseous tumor component. CT was capable of demonstrating skip metastases in one patient. CT plays a key role in the preoperative evaluation of osteosarcoma patients, particularly when less than radical surgery is planned as primary treatment and when postoperative recurrence is suspected. CT is also useful in assessing the response to therapy in nonsurgical cases. The technique involved in the performance of this examination is discussed.