MDCT of the hand and wrist: beyond trauma.

High-resolution multidetector computed tomography (MDCT) has played a pivotal role in assessing patients following trauma; however, recent advancements in technology including dual-energy CT, as well as multiplanar and three-dimensional (3D) capabilities, are expanding the potential clinical applications of CT to include nontraumatic pathologies. This article will review optimal technical parameters for the creation of MDCT and 3DCT images and illustrate the imaging capabilities of 3DCT imaging for demonstrating nontraumatic hand and wrist pathology.

Anastomotic leak after robot-assisted laparoscopic radical prostatectomy: evaluation with MDCT cystography with multiplanar reformatting and 3D display.

OBJECTIVE: This article reviews the pattern of anastomotic leak after robot-assisted laparoscopic radical prostatectomy (RALRP) on MDCT cystography with multiplanar reformatting and 3D display and discusses key surgical procedures to explain intraperitoneal leak and the incidence and clinical significance of anastomotic leak. CONCLUSION: RALRP is a minimally invasive surgery for localized prostate cancer, and its use has increased recently. Intraperitoneal extension of vesicourethral anastomotic leak after RALRP can occur, which is not associated with radical retropubic prostatectomy. MDCT cystography is a fast and accurate method for detection and evaluation of the extent of anastomotic leak after RALRP.

The elephant trunk procedure for aortic aneurysm repair: an illustrated guide to surgical technique with CT correlation.

OBJECTIVE: The purpose of this article is to provide a comprehensive overview of a relatively new surgical aortic procedure, the elephant trunk technique. In conjunction with information from the literature, a series of illustrations provide a detailed description of the surgical procedure and postoperative appearance with CT correlation. CONCLUSION: This article explains the rationale behind a staged thoracic aortic surgery, describes and illustrates the surgical technique used to perform the elephant trunk procedure and the normal postoperative imaging appearance, and discusses potential complications specific to the elephant trunk procedure.

Internet-based dissemination of educational video presentations: a primer in video podcasting.

OBJECTIVE: Video "podcasting" is an Internet-based publication and syndication technology that is defined as the process of capturing, editing, distributing, and downloading audio, video, and general multimedia productions. The expanded capacity for visual components allows radiologists to view still and animated media. CONCLUSION: These image-viewing characteristics and the ease of widespread delivery are well suited for radiologic education. This article presents detailed information about how to generate and distribute a video podcast using a Macintosh platform.

Internet-based dissemination of educational audiocasts: a primer in podcasting--how to do it.

OBJECTIVE: "Podcasting" is a relatively new Internet-based broadcast technology with unique characteristics that may prove valuable in radiologic education. In this article, we describe the procedure for generating, distributing, and downloading a podcast. CONCLUSION: Podcast technology holds promise as an inexpensive method to rapidly and cost effectively disseminate educational Internet audio broadcasts ("audiocasts").

Volume rendering versus maximum intensity projection in CT angiography: what works best, when, and why.

The introduction and widespread availability of 16-section multi-detector row computed tomographic (CT) technology and, more recently, 64-section scanners, has greatly advanced the role of CT angiography in clinical practice. CT angiography has become a key component of state-of-the-art imaging, with applications ranging from oncology (eg, staging of pancreatic or renal cancer) to classic vascular imaging (eg, evaluation of aortic aneurysms and renal artery stenoses) as well as newer techniques such as coronary artery imaging and peripheral runoff studies. With an average of 400-1000 images in each volume data set, three-dimensional postprocessing is crucial to volume visualization. Radiologists now have workstations that provide capabilities for evaluation of these data sets by using a range of software programs and processing tools. Although different systems have unique capabilities and functionality, all provide the options of volume rendering and maximum intensity projection for image display and analysis. These two postprocessing techniques have different advantages and disadvantages when used in clinical practice, and it is important that radiologists understand when and how each technique should be used.

Adult ureteropelvic junction obstruction: insights with three-dimensional multi-detector row CT.

Ureteropelvic junction obstruction (UPJO) is a benign, congenital condition that remains an enigma in terms of both diagnosis and therapy. On the basis of a series of cases that were referred to the authors in their clinical practice, they found that the unprecedented quality and novel perspectives of multi-detector row computed tomography (CT) with two- and three-dimensional postprocessing allow a comprehensive, single-study assessment of the ureterovascular relationships in UPJO. This topic is important because the causative role of crossing vessels may be questioned on the basis of such studies, and the therapeutic approach may be altered by using precise anatomic images customized to the pathologic features of the individual patient. Although CT images can provide only circumstantial or supportive evidence of the pathophysiology of UPJO, they greatly facilitate therapeutic intervention when it is clinically indicated and may eliminate the need for it in select cases. Careful attention to the postprocessing of CT images may show that the crossing vasculature has no direct relationship to the transition point of the UPJO in many cases.

Minimally invasive thymectomy: the Mayo Clinic experience.

BACKGROUND: The prevalence of minimally invasive thymectomy (MIT) is increasing and may have significant benefit to patients in terms of morbidity and post-operative recovery. Our aim was to review the Mayo Clinic experience of MIT. METHODS: We reviewed data from all MIT cases collected in a prospectively maintained database from January 1995 to February 2015. Data were collected regarding patient demographics, perioperative management and patient outcomes. RESULTS: A total of 510 thymectomies were performed in 20 years. Fifty-six patients underwent MIT (45 video-assisted thoracoscopy, 11 robotic-assisted). The median age was 55 years (range, 23-87 years) with male to female ratio of 25:31. Thymoma was the main pathologic diagnosis in 27/56 patients (48%), with 11/27 (41%) associated with myasthenia gravis (MG), and 16/27 (59%) non-MG. Other pathologies included 1/56 (2%) of each teratoma, lymphoma, lymphangioma, carcinoma and thymolipoma. There were 3/56 (5%) atrophic glands, 4/56 (7%) cysts, 6/56 (11%) benign glands and 11/56 (20%) hyperplastic. Mean blood loss (mL) and operative time (min) were significantly lower in the video-assisted thoracoscopic surgery (VATS) group compared to robotic (65±41 vs. 160±205 mL, P=0.04 and 102±39 vs. 178±53 min, P=0.001, respectively). There was no 30-day mortality. Post-operative morbidity occurred in 7/45 (16%) VATS patients (phrenic nerve palsy 7%, pericarditis 4%, atrial fibrillation 2%, pleural effusion 2%) and 1/11 (9%) robotic (urinary retention requiring self-catheterization). Reoperation was required in 1/3 of VATS patients with phrenic nerve palsy. There was no significant difference in length of hospital stay [VATS 1.5 days (range, 1-4 days) and robotic 2 days (range, 1-5 days) VATS; P=0.05]. Mean follow-up was 18.4 months (range, 1-50.4 months) with no tumor recurrences. CONCLUSIONS: MIT can be performed with low morbidity and mortality. VATS is associated with reduced blood loss, operative times and earlier hospital discharge compared to robotic MIT.

Visitors and content preferences on an educational web site dedicated to clinical body computed tomography: results of a 2001 audit and online survey.

RATIONALE AND OBJECTIVES: To ascertain demographic characteristics and content preferences of visitors to an educational Web site dedicated to clinical body computed tomography (CT). Such information could help determine whether the resource is attaining its educational goals. METHODS: During February 2001, a commercial Internet service measured the number and average length of visits to the site, the domain names of the visitors, and the content most frequently requested. During the same month, a nine-question self-administered user survey was posted on the site's main page. RESULTS: The service reported 19,013 visits during which 98,685 pages of content were viewed. Of the total number of users to visit, 37.9% were from domains outside North America. Helical CT scanning protocols, teaching atlases, CT teaching files, and medical illustrations were the most frequently requested content. Of the 687 visitors responding to the survey, 51.5% were radiologists and 33.5% were radiological technologists. CONCLUSIONS: Radiologists and radiological technologists are the principal visitors to the site. These users prefer to view helical CT scanning protocols and the Web site's core educational material.

Current concepts in multi-detector row CT evaluation of the coronary arteries: principles, techniques, and anatomy.

Cardiac imaging is becoming a practical application of mechanical computed tomography (CT) with the availability of four, eight, and 16 detector row scanners. The role of imaging is progressing from simple determination of the presence of arterial calcifications on nonenhanced scans to demonstration of vascular stenoses on coronary CT angiograms. Optimization of the imaging technique and knowledge of coronary artery anatomy are both important for the development of CT of the heart. Technical factors such as a slow heart rate, a short scanning time, subcentimeter spatial resolution, high temporal resolution, and reconstruction of multiple image data sets at various intervals in the cardiac cycle result in optimal visualization of the coronary arteries. Axial, thin-slab maximum intensity projection, and volume-rendered images are used to display the normal anatomy and anomalies of the coronary arteries. The challenges of CT angiography of the coronary arteries have been partially met and will likely be overcome with continued evolution of the technology.

Multidetector row computed tomography with volume rendering--an aid to understanding pelvic anatomy and disease.

Recent progress in computed tomography (CT) imaging has included multidetector row CT and volume rendering 3-dimensional post processing platforms. The growth in each of these areas has been synergistic and has offered new avenues for the formation and interpretation of diagnostic CT imaging studies. There is untapped added information in a conventional 2-dimensional axial planar pelvis study that may be harnessed with these tools. This article seeks to review the principles and application of these techniques when images of the normal pelvis are obtained. It is hoped the reader will gain insight into the design of such studies and an enhanced appreciation of the anatomic features routinely obtained on conventional CT studies.

Acute non-traumatic maternal illnesses in pregnancy: imaging approaches.

The imaging methods used to obtain diagnostic information for pregnant patients presenting with acute non-traumatic maternal illnesses have been reviewed. Conditions affecting the gastrointestinal tract, urinary tract, uterus, adnexae, central nervous system and chest have been investigated via a variety of imaging methods, which include ultrasound, computed tomography (CT), magnetic resonance imaging (MRI), intravenous pyelography (IVP), angiography and fluoroscopy. The method of choice, application, and safety to the mother and fetus are considered for investigation of each condition.

Multi-detector row and volume-rendered CT of the normal and accessory flow pathways of the thoracic systemic and pulmonary veins.

Multi-detector row computed tomography (CT) and volume rendering can be used as an interpretive aid to present the systemic and pulmonary venous anatomy of the thorax. Both of these venous systems are routinely imaged in clinical practice and are important in interpretation of diagnostic images in health and disease. Multi-detector row CT and three-dimensional volume rendering provide high-quality near-isotropic data (ie, the longitudinal resolution approximates the in-plane resolution). The data sets allow tailored postprocessing to produce images optimized for these vessels, which are often not fully appreciated at planar axial imaging alone. Venous structures of the thorax that can be demonstrated with multi-detector row CT and volume rendering include the jugular veins; the subclavian and brachiocephalic veins; the internal and lateral thoracic veins; the superior and inferior venae cavae; the coronary sinus, the cardiac and pericardiophrenic veins, and vein grafts; the azygos, hemiazygos, and accessory hemiazygos veins; the intercostal veins; the pulmonary veins; and other thoracic veins.

Patterns of collateral pathways in extrahepatic portal hypertension as demonstrated by multidetector row computed tomography and advanced image processing.

Pancreatic neoplasm can compromise the portal vein or its tributaries, resulting in extrahepatic portal hypertension. Collateral channels may develop, usually in a hepatopetal direction. These include gastroepiploic veins, short gastric veins, left gastric vein, left colic veins, and spontaneous splenorenal shunts. We present the spectrum of these collaterals as delineated by multidetector row computed tomography with advanced image processing. Delineation of these collaterals is important before surgery so as to avoid possible uncontrollable bleeding if they are inadvertently disrupted.

A five-step approach to digital image manipulation for the radiologist.

Digital manipulation of images plays a key role in development of multimedia presentations. Five basic steps to digitizing images and preparing them for publication and computer presentation are scanning, correction, editing and labeling, saving files, and producing final output. These steps can be completed with commercially available hardware and image manipulation software (eg, Photoshop). The higher the quality of the original scanned image, the more image data there will be to edit: A good image cannot be created from an inferior scan. The most important functions for properly scanning images are size, resolution, and color. Resolutions of 300 ppi and 72 ppi should be used for print publication and computer presentations, respectively. The higher resolution image has the larger file size. The scanned image should be saved as a TIFF (tagged image file format), which is an uncompressed file type used for printed images. The Joint Photographic Experts Group (JPEG) format compresses the size of the image file but also reduces image quality. The JPEG format is a good choice if a small file size is needed, such as in Web and PowerPoint presentations. If the user needs to save an image as a JPEG file, the image should be edited first and then saved once in JPEG format. With Photoshop, the user can rotate and crop an image; adjust its brightness, contrast, and color; remove unwanted patient information, dust, and scratches; and add text and symbol labels to enhance images for teaching purposes. Digital manipulation can be fast and effective if the user has some basic knowledge and tools.

Modern CT applications in veterinary medicine.

Although computed tomography (CT) is used primarily for diagnosis in humans, it can also be used to diagnose disease in veterinary patients. CT and associated three-dimensional reconstruction have a role in diagnosis of a range of illnesses in a variety of animals. In a sea turtle with failure to thrive, CT showed a nodal mass in the chest, granulomas in the lungs, and a ball in the stomach. CT of a sea dragon with balance and movement problems showed absence of the swim bladder. In a sloth with failure to thrive, CT allowed diagnosis of a coin in the intestine. CT of a puffin with failure to thrive showed a mass in the chest, which was found to be a hematoma. In a smooth-sided toad whose head was tilted to one side and who was circling in that direction, CT showed partial destruction of the temporal bone. CT of a domestic cat with listlessness showed a mass with focal calcification, which proved to be a leiomyosarcoma. CT of a sea otter showed pectus excavatum, which is caused by the animal smashing oysters against its chest. In a Japanese koi with abdominal swelling, CT allowed diagnosis of a hepatoma.