Röntgendiagnostik in der Mund-, Kiefer- und Gesichtschirurgie

Dentomaxillofacial imaging today is based on graded diagnostic algorithms. Basic techniques (e.g. orthopantomography) are used to obtain an overview. Depending on the findings, specific techniques (e.g. occlusal film, conventional tomography or computed cone-beam tomography) are used for detailed assessment, and advanced techniques (e.g. computed tomography and magnetic resonance imaging) for complex questions. Cone-beam computed tomography (CBCT) is a new imaging technology in dentomaxillofacial radiology that is equivalent to conventional computed tomography in terms of diagnostic options and valency in hard tissue diagnostics of the oral and maxillofacial region, while requiring a lower radiation dose. Now widely available, this technology requires detailed discussions on the current state of the art in dentomaxillofacial imaging.     

Neuroimaging in pediatric traumatic head injury: diagnostic considerations and relationships to neurobehavioral outcome.

Contemporary neuorimaging techniques in child traumatic brain injury are reviewed, with an emphasis on computerized tomography (CT) and magnetic resonance (MR) imaging. A brief overview of MR spectroscopy (MRS), functional MR imaging (fMRI), single-photon emission computed tomography (SPECT), and magnetoencephalography (MEG) is also provided because these techniques will likely constitute important neuroimaging techniques of the future. Numerous figures are provided to illustrate the multifaceted manner in which traumatic deficits can be imaged and the role of neuroimaging information as it relates to TBI outcome.     

Functional Imaging of Atherosclerosis to Advance Vascular Biology

Preliminary events leading to the rupture of atherosclerotic plaques or aneurysmal wall expansion undoubtedly are linked to altered and increased metabolism of cells in the vascular wall. To allow in vivo identification of this local activity, imaging techniques such as positron emission tomography (PET) and contrast ultrasonography may be used. However, the use of complementary multimodal imaging methods, such as computed tomography (CT), magnetic resonance imaging (MRI), single photon emission computed tomography (SPECT), etc., can inform about other processes, including vascular wall calcification, haemosiderin deposits, apoptosis and accumulation of activated platelets in the arterial wall. Such techniques may be used as an adjunct in following the evolution of the disease, as well as having crucial roles as molecular and cellular probes of arterial disease. Therefore, functional imaging techniques may be able to help us take more reliable decisions on the need for medical or surgical treatment of arterial disease.     

Diagnostic imaging of osteosarcoma

The diagnosis, treatment planning, and follow-up evaluation of osteosarcoma rely heavily on a variety of imaging techniques. Plain roentgenography, radionuclide bone scanning, computed tomography, and magnetic resonance imaging play important roles in defining local tumor extent, detecting metastatic disease, and monitoring for recurrent tumor. Invasive studies such as angiography are now rarely necessary. In the future, newer imaging modalities, including positron emission tomography, can be expected to become important tools for evaluation of these tumors.     

Lung cancer. Diagnostic tools

Early diagnosis of lung cancer represents the best method for improving survival rates. The diagnostic aids available have improved exponentially on old and new techniques over the past 20 years. The greatest impact has been in computed tomography and positron emission tomography scanning imaging techniques. In the future, these techniques will improve, and others such as monoclonal antibody scans and antisense imaging techniques will certainly further enhance the physician's ability to diagnose earlier, and thereby, treat earlier.     

Contemporary imaging of the renal mass

Contemporary imaging techniques for renal mass evaluation are essential to clinical management and surgical planning. Ultrasonography can be used to distinguish cystic from solid lesions but is less sensitive and accurate in renal mass characterization than computed tomography (CT) and magnetic resonance imaging (MRI). Multiphase CT imaging before and after administration of contrast is the primary imaging modality for characterization and staging of renal lesions. MRI is increasingly used as a problem solving tool. Advanced MRI techniques such as diffusion-weighted imaging and perfusion-weighted imaging are being explored in assessment of renal lesions. These techniques are discussed in this article.     

Nuclear medicine imaging: new radiotracers and future techniques

Nuclear medicine imaging is based upon positron emission tomography (PET) and single photon emission computed tomography (SPECT) imaging. PET and SPECT are widely used in patients with medically refractory partial epilepsy. For clinical purposes, PET is performed using FDG and SPECT is performed using perfusion agents. PET is also used to better understand the pathophysiological mechanisms of epilepsies. New radiotracers are available for PET and SPECT imaging such as (18)F-fluoro-L-Dopa and (123)I-FP-CIT and others are under development. In addition, there are currently new methodological developments combining techniques such as SPECT associated with computed tomography and in the near future PET combined with MRI. This progress will improve the performance of nuclear medicine imaging techniques.     

Intraoperative bone imaging in the treatment of osteoid osteoma of the femoral neck

An osteoid osteoma of the femoral neck in a 7-year-old girl was successfully excised using intraoperative 99mTc bone imaging. Since the nidus of the lesion was not seen with conventional radiography, linear tomography, and computed tomography, these techniques could not be used during surgery to localize the lesion or to indicate when its removal was complete. Postoperative bone imaging demonstrated that avascular necrosis of the femoral head had not occurred.     

Noninvasive management of a dorsal patellar defect

We present the case of a 13-year-old girl with bilateral anterior knee pain in which an unilateral dorsal patellar defect (DDP) was diagnosed. The pathology was extensively assessed with noninvasive imaging techniques including plain radiographs, computed tomography, magnetic resonance imaging, and scintigraphy. Based on the findings, a biopsy could be avoided. The characteristic findings and value of the above-mentioned imaging techniques as well as the differential diagnosis are discussed.     

Advanced imaging of bone macrostructure and microstructure in bone fragility and fracture repair

Research into the molecular and cellular pathways focusing on bone fragility and fracture-healing has led to new potential treatments to aid in fracture-healing. This research has focused on physical as well as biological modes of treatment. As new products and methods are derived, it is essential to develop effective and sensitive noninvasive means by which early changes in the fracture repair process can be detected. Specialized noninvasive and/or nondestructive techniques can provide structural information about local and systemic skeletal health, the propensity to fracture, and the pathophysiology of bone fragility. The methods available to quantitatively assess macrostructure include computed tomography and, particularly, volumetric quantitative computed tomography. Methods for assessing microstructure of trabecular bone include high-resolution computed tomography, microquantitative computed tomography, high-resolution magnetic resonance imaging, and micromagnetic resonance imaging. These new techniques help to illustrate the process of fracture-healing by defining the skeletal response to innovative therapies and assessing biomechanical relationships. This review presents perspectives on the advanced imaging modalities that are currently available and on recent developments that may improve the detection and understanding of bone fragility and fracture-healing.     

Imaging of adrenal masses

PURPOSE OF REVIEW: This review aims to outline recent developments in adrenal imaging and characterization. Controversies in the management of adrenal incidentalomas will be addressed. RECENT FINDINGS: Evaluation of density readings on unenhanced computed tomography and on contrast-enhanced delayed series has tremendously improved the characterization of adrenal masses. Attenuation measurements may, however, vary between different scanner types and may also be influenced by patient factors and the scanning technique. Evaluation of the mean percentage washout for adrenal masses on delayed enhanced computed tomography series is independent of such factors and allows the characterization of adrenal lesions with high sensitivity and specificity. In magnetic resonance imaging, dynamic gadolinium-enhanced and chemical-shift techniques have significantly improved the characterization of adrenal masses. Nuclear medicine studies prove to be useful adjuncts. Controversial reports have been published on the role of positron emission tomography/computed tomography in adrenal imaging. Adrenal venous sampling may allow differentiation of aldosteronoma and idiopathic hyperaldosteronism. SUMMARY: Recent developments in adrenal mass imaging have improved the characterization of adrenal mass lesions. The need for histology sampling of incidentally discovered adrenal masses has been significantly reduced due to the high specificity of these new techniques. Controversies still exist regarding the optimal strategy for hormonal screening of a patient with an incidentally detected adrenal mass.     

Juvenile spondylodiscitis: the value of magnetic resonance imaging: a report of two cases

Two boys presenting with reluctance to sit straight and stand were diagnosed with spondylodiscitis of the lumbar spine. After confirmation of the diagnosis on plain radiographs, computed tomography and magnetic resonance imaging, they were successfully treated with antibiotics and in one case a lumbar orthosis. The use of magnetic resonance imaging is discussed and compared to the other radiological techniques. Magnetic resonance imaging seems to be the most sensitive and specific imaging technique used in the diagnostic process of spondylodiscitis. Computed tomography and technetium bone scan both play a specific part in the process of diagnosis and follow-up.     

Anaesthesia for magnetic resonance imaging/computed tomography

The need for general anaesthesia for magnetic resonance imaging/computed tomography investigations can be reduced by the implementation of structured sedation programmes supervised by anaesthetists. Despite its side-effects, chloral hydrate is still the drug most widely used. Rectal thiopental or intravenous propofol are suggested anaesthetic agents for pre-school children and uncooperative or claustrophobic individuals. Spiral computed tomography scans and ultrafast magnetic resonance imaging shorten immobilization times further. However, functional magnetic resonance imaging and intervention techniques in neuroradiology depend on a motionless patient. A useful strategy for testing anaesthesia equipment has been outlined.     

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.     

Editorial Commentary: Unguided Glenohumeral Injections—Do We Achieve Sufficient Accuracy?

Image-guided (fluoroscopy, ultrasound, computed tomography, magnetic resonance imaging) and unguided glenohumeral injection techniques are frequently used for different diagnostic and therapeutic purposes in clinical practice. Guided injections are highly accurate, reproducible, and more often performed in routine practice. Nevertheless, these techniques are more cost intensive and time consuming, and require special imaging devices. In case of fluoroscopic- or computed tomography–guided injections, radiation exposure of the patient is a disadvantage. In contrast, unguided glenohumeral injection techniques do not have these drawbacks, but rather are based on the precise identification of anatomic landmarks and depend on the experience of the provider. That is the reason they are supposed to be less accurate and less reproducible than guided techniques. But recent studies showed comparable accuracy; therefore, the use of unguided glenohumeral injection techniques should be considered in daily clinical practice in the hands of experienced shoulder arthroscopists.     

Premature partial physeal arrest. Diagnosis by magnetic resonance imaging in two cases

The management of premature physeal arrest requires accurate assessment of not only the location but also the extent of the bar. Numerous imaging techniques are available to evaluate the physis. Multiplanar tomography has proven to be the most precise method. The utility of magnetic resonance imaging (MRI) of physeal bars has not been demonstrated. This article presents MRI results in two cases of physeal bars. MRI provides a means of assessing physeal bar formation with an accuracy approaching that of multiplanar tomography. In certain instances, its efficacy may exceed that of tomography, specifically when the physis cannot be properly oriented for tomographic evaluation, when more planes are desired, and when radiation exposure is thought to be excessive. With improvement of its capabilities and availability (which may also reduce cost), it may become the diagnostic imaging technique of choice.     

Current role of imaging in diagnosing aortic graft infections

Vascular prosthetic graft infection is a rare but serious complication after aortic graft replacement, with high morbidity and mortality rates. Therefore, adequate diagnostics are needed to detect and treat these infections as early as possible. Several imaging modalities provide different diagnostic values for detecting prosthetic graft infection. Previous studies reported on the diagnostic value of ultrasound, computed tomography imaging, magnetic resonance imaging, fluorodeoxyglucose-positron emission tomography, and single-photon emission computed tomography. In addition, adjunctive studies on new and promising techniques to detect prosthetic graft infection (eg, bio-optical imaging and target imaging with nuclear techniques) have also been investigated. This review provides a summary of noninvasive imaging modalities and their diagnostic values in order to evaluate and treat possible vascular graft infections as early as possible.     

Diagnostic imaging techniques in thyroid cancer

With the refinement of fine-needle aspiration, the specific applications of thyroid imaging techniques need to be reevaluated for efficiency and cost containment. No thyroid imaging test should be routinely obtained. Radionuclide scanning is most beneficial in evaluating the functional status of thyroid nodules when fine-needle aspiration is inadequate, the findings are benign, or when there is no discrete nodule that is palpated in an enlarged gland. When fine-needle aspiration is unavailable or unreliable, radionuclide scanning becomes a first-line diagnostic tool. Ultrasonography should be used primarily for identifying a solid component of a cystic nodule, determining the size of nodules on thyroxine suppression that are not easily palpable, or for performing guided fine-needle aspiration. Computerized tomography and magnetic resonance imaging both have a definite role in the evaluation of thyroid tumors. Magnetic resonance imaging is superior to computerized tomography for the evaluation of metastatic, retrotracheal, or mediastinal involvement of large thyroid tumors or goiters. Careful selection of the diagnostic techniques will ensure more accurate diagnosis and reduce unnecessary patient costs in the treatment of thyroid cancer.     

The role of 3-D rotational x-ray imaging in spinal trauma

The most widely used imaging devices in trauma spine surgery are fluoroscopy and computed tomography. Both techniques have their specific pros and cons and expose both patient and operating staff to considerable radiation during image acquisition. Three-dimensional-rotational x-ray imaging (3-DRX) is a relatively new technique in which a C-arm is moved around the patient to allow for an "acquisition run" during which multiple fluoroscopy images are obtained. The images can subsequently be processed on a workstation into a 3-D volume, which can then be manipulated in a similar way to 3-D computed tomography data. The 3-DRX technique combines the advantages of both fluoroscopy and computed tomography: fast visual feedback and high resolution multiplanar reformatted images, respectively, and could be used in an intraoperative setting. In this paper some technical aspects of 3-DRX imaging and its potential role in spinal trauma treatment are presented.