Osteoarthritis--radiology imaging

Osteoarthritis is degenerative arthritis. On radiograms it is characterised with joint place narrowing, subchondral bone sclerosis, and formation of cystic and osteophitic changes.     

Recent advances in MR imaging: FLAIR imaging

Fluid-attenuated inversion recovery (FLAIR) imaging is a technique that increases the sensitivity of magnetic resonance imaging to detect central nervous system (CNS) diseases characterized by an increase in interstitial water content such as brain tumors, cerebral infarcts, and gliotic scars. A role for this technique in subarchnoid disease processes such as hemorrhage and epidermoid tumor is also being revealed.     

Adrenal imaging

The problems inherent in visualizing the adrenal glands are illustrated by the variety of imaging modalities that have been employed. Although urography has been the basic screening examination, one can make a sound argument for CT as the procedure of choice in the evaluation of the patient with suspected adrenal pathology. Angiography, venous sampling, and radionuclide studies continue to have a role in selected problem cases. This article reviews the usefulness of available modalities in the context of the clinical evaluation of adrenal disease.     

Patellofemoral imaging

Imaging of the patella and patellofemoral joint cannot be isolated from imaging of the knee anymore than the function of the patellofemoral joint can be separated from the function of the entire knee. Therefore, the current author will focus on imaging of the patellofemoral joint yet integrate this with the entire knee. Because radiographs and other imaging techniques are adjuncts to the history and physical examination, and specifically an extension of the physical examination, each view or technique must be selected thoughtfully to yield the most useful and accurate information possible. Imaging techniques range from relatively inexpensive to very costly, yet the amount of useful information may not show a positive correlation with the cost. Only by integrating the history, physical examination, and the best imaging techniques can the clinician locate the abnormality, determine its cause, and plan a proper course of treatment. Radiographic imaging of the patellofemoral joint requires attention to detail on the part of the technician and knowledge of these techniques on the part of the clinician who orders and interprets the results. Understanding these concepts will help achieve everyone's goal: high-quality and cost-effective orthopaedic care.     

Scrotal imaging

Color Doppler ultrasound has been the mainstay for the evaluation of the scrotum in a variety of clinical settings. However, ultrasonography results are not always accurate or conclusive. Despite the high cost and limited availability, magnetic resonance imaging with the dynamic contrast-enhanced subtraction technique provides accurate information on morphology as well as blood flow. Infrared scrotal thermography increases accuracy in the diagnosis of varicocele. This article attempts to summarize recent advances in scrotal imaging with regard to testicular and extratesticular disorders.     

1.5 T: intraoperative imaging beyond standard anatomic imaging

Intraoperative high-field MRI with integrated microscope-based neuronavigation is a safe and reliable technique providing immediate intraoperative quality control. Major indications are pituitary tumor, glioma, and epilepsy surgery. Intraoperative high-field MRI provides intraoperative anatomic images at high quality that are up to the standard of pre- and postoperative neuroradiologic imaging. Compared with previous low-field MRI systems used for intraoperative imaging, not only is the image quality is clearly superior but the imaging spectrum is much wider and the intraoperative work flow is improved. Furthermore, high-field MRI offers various modalities beyond standard anatomic imaging, such as magnetic resonance spectroscopy, diffusion tensor imaging, and functional MRI.     

Musculoskeletal imaging in progress: The EOS imaging system

The EOS 2D/3D radio-imaging device (Biospace med, France) can disclose a digital radiographic image of bones with a very low radiation dose. This in turn allows in obtaining a single image of a large field of view, as wide as the full skeleton. The simultaneous capturing of spatially paired AP and lateral X-ray images is also a specificity of EOS imaging, which further provides secondary 3D (volumic) reformation of skeletal images. The main indications of this new imaging technology are assessment and follow-up of balance disorders of the spine and of the lower limbs.     

Novel imaging modalities for lymph node imaging in urologic oncology

Accurate lymph node staging in genitourinary (GU) malignancies is important for planning an appropriate treatment and establishing an accurate prognosis. This article discusses the novel imaging techniques for detection of metastases in various GU malignancies, including prostate, bladder, penile, and testicular cancers. Discussion includes nuclear medicine techniques of (18)F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT), (11)C-choline and (18)F-choline PET/CT, and ProstaScint scanning, as well as sentinel lymph node mapping. Magnetic resonance (MR) techniques include lymphotropic nanoparticle-enhanced MR imaging and diffusion-weighted MR imaging.     

Laparoscopic infrared imaging

A system was developed to determine the potential role of infrared imaging as a tool for localizing anatomic structures and assessing tissue viability during laparoscopic surgical procedures. A camera system sensitive to emitted energy in the midinfrared range (3–5 μm) was incorporated into a two-channel visible laparoscope. Laparoscopic cholecystectomy, dissection of the ureter, and assessment of bowel perfusion were performed in a porcine model with the aid of this infrared imaging system. Inexperienced laparoscopists were asked to localize and differentiate structures before dissection using the visible system and then using the infrared system. Assessment of bowel perfusion was also conducted using each system. Infrared imaging proved to be useful in differentiating between blood vessels and other anatomic structures. Differentiation of the cystic duct and arteries and transperitoneal localization of the ureter were successful in all instances using the infrared system when use of the visible system had failed. This system also permitted assessment of bowel perfusion during laparoscopic occlusion of mesenteric vessels. These initial studies demonstrate that infrared imaging may improve the differentiation and localization of anatomic structures and allow assessment of physiologic parameters such as perfusion not previously attainable with visible laparoscopic techniques. It may thus potentially be a powerful adjunct to laparoscopic surgery. Received: 23 August 1996/Accepted: 14 October 1996     

Cardiac functional imaging

During the last 20 years, cardiac imaging has drastically evolved. Positron emission tomography (PET), fast three-dimensional (3D) imaging with the latest generations of echocardiography & multi-detector computed tomography (CT), stress perfusion assessed by magnetic resonance imaging (MRI), blood flow analysis using four-dimensional (4D) flow MRI, all these techniques offer new trends for optimal noninvasive functional cardiac imaging. Dynamic functional imaging is obtained by acquiring images of the heart at different phases of the cardiac cycle, allowing assessment of cardiac motion, function, and perfusion. Between CT and Cardiac MRI (CMR), CMR has the best temporal resolution, which is suitable for functional imaging while cardiac CT provides higher spatial resolution with isotropic data that have an identical resolution in the three dimensions of the space. The latest generations of CT scanners enable whole heart assessment in one beat, offering also an acceptable temporal resolution with the possibility to display the images in a dynamic mode. Another rapidly growing technique using functional and molecular imaging for the assessment of biological and metabolic pathways is the PET using radio-labeled tracers. Meanwhile, the oldest cardiac imaging tool with doppler ultrasound technology has never stopped evolving. Echocardiography today performs 3D imaging, stress perfusion, and myocardial strain assessment, with high temporal resolution. It still is the first line and more accessible exam for the patient. These different modalities are complementary and may be even combined into PET-CT or PET-MRI. The ability to combine the functional/molecular data with anatomical images may implement a new dimension to our diagnostic tools.     

Pronator quadratus imaging

Our objectives are to review the sonographic features of the pronator quadratus muscle, to explain the major advantages of ultrasonography as compared to other imaging modalities and to identify the clinical applications in routine wrist ultrasound examination.     

Laparoscopic infrared imaging

BACKGROUND: As an adjunct to direct visual imaging, an infrared endoscope was developed to assist in the identification of various anatomic structures and to assess tissue viability during laparoscopic procedures. A camera sensitive to emitted energy in the mid-infrared range (3 to 5 microm) was incorporated into a two-channel visible-light laparoscope. METHODS AND MATERIALS: Laparoscopic procedures were performed in a porcine model, inexperienced laparoscopists being asked to localize and differentiate structures before dissection using the visible-light system and then the infrared system. To determine clinical utility, nine laparoscopic urologic procedures were performed with the assistance of the infrared system. RESULTS: In the clinical evaluation, infrared imaging proved to be useful in differentiating between blood vessels and other anatomic structures. In contrast to the experience with the conventional endoscope, vessel identification, assessment of organ perfusion, and transperitoneal localization of the ureter was successful in all instances using the infrared system. In the porcine model, this system also permitted assessment of bowel perfusion during laparoscopic occlusion of mesenteric vessels and distinguished between the cystic duct and artery. CONCLUSION: Infrared imaging is a potentially powerful adjunct to laparoscopic surgery. It may improve the differentiation and localization of anatomic structures and allow assessment of physiologic features, such as perfusion, not previously attainable with laparoscopic techniques.     

MR imaging of cervical disc disease: value GRASS imaging

Since magnetic resonance imaging (MRI) technology has been greatly improved, MRI for cervical disc disease has become widely used in many facilities. Among non-invasive procedures, MRI is regarded as one of the most useful ones. Conventional myelography, CT myelography, and MRI were performed on 10 patients with cervical disc disease. The authors discussed the correlation between conventional myelography, CT myelography, and MRI as regards their ability to determine the localization and the laterality of disc protrusion and osteophyte. In our MRI study, we use both short-echo (SE) images and GRASS images. The parameters of our GRASS included 5mm-thick sections. TR = 200, TE = 20, and flip angles of 10 degrees. This pulse sequence generates images with high signal cerebrospinal fluid (CSF), resulting in a high-contrast CSF-spinal cord, osteophyte, and disc protrusion. As yet, although it easily shows the localization and laterality of the disc and/or osteophyte, image quality of the GRASS is not yet sufficient to allow us to evaluate detailed deformity of the spinal cord and nerve root. The authors stress the usefulness of this GRASS image for the evaluation of suspected cervical disc disease.