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Imaging Evaluation (imaging + evaluation)
Selected AbstractsScreening women at high risk for breast cancer with mammography and magnetic resonance imaging,CANCER, Issue 9 2005Constance D. Lehman M.D., Ph.D. Abstract BACKGROUND The authors compared the performance of screening mammography versus magnetic resonance imaging (MRI) in women at genetically high risk for breast cancer. METHODS The authors conducted an international prospective study of screening mammography and MRI in asymptomatic, genetically high-risk women age , 25 years. Women with a history of breast cancer were eligible for a contralateral screening if they had been diagnosed within 5 years or a bilateral screening if they had been diagnosed > 5 years previously. All examinations (MRI, mammography, and clinical breast examination [CBE]) were performed within 90 days of each other. RESULTS In total, 390 eligible women were enrolled by 13 sites, and 367 women completed all study examinations. Imaging evaluations recommended 38 biopsies, and 27 biopsies were performed, resulting in 4 cancers diagnosed for an overall 1.1% cancer yield (95% confidence interval [95%CI], 0.3,2.8%). MRI detected all four cancers, whereas mammography detected one cancer. The diagnostic yield of mammography was 0.3% (95%CI, 0.01,1.5%). The yield of cancer by MRI alone was 0.8% (95%CI, , 0.3,2.0%). The biopsy recommendation rates for MRI and mammography were 8.5% (95%CI, 5.8,11.8%) and 2.2% (95%CI, 0.1,4.3%). CONCLUSIONS Screening MRI in high-risk women was capable of detecting mammographically and clinically occult breast cancer. Screening MRI resulted in 22 of 367 of women (6%) who had negative mammogram and negative CBE examinations undergoing biopsy, resulting in 3 additional cancers detected. MRI also resulted in 19 (5%) false-positive outcomes, which resulted in benign biopsies. Cancer 2005. © 2005 American Cancer Society. [source] Design of an MR-compatible piezoelectric actuator for MR elastographyCONCEPTS IN MAGNETIC RESONANCE, Issue 4 2002Kai Uffmann Abstract Magnetic Resonance (MR) elastography is a method for measuring tissue elasticity via phase images acquired with an MR scanner. The propagation of periodic mechanical waves through the tissue can be captured by means of a modified phase contrast sequence. These waves are generated with a mechanical oscillator (actuator) and coupled into the tissue through the skin. The actuator must be capable of generating a sinusoidal excitation with excellent phase and amplitude stability, while not disturbing the MR imaging process. In this work, an actuator based on a piezoelectric principle was developed. Based on the imaging evaluation of several material samples, the housing for the piezoelectric ceramic was constructed of aluminum. Smaller parts of the housing were manufactured from brass and titanium to fulfill the mechanical constraints. A lever was used to transfer the oscillation generated by the piezoelectric ceramic to the point of excitation. The lever amplifies the piezoelectric motion, allowing for a more compact design. Three different lever designs were characterized by an acceleration sensor both outside and inside the magnet. It was shown that the rigidity of the lever, as determined by its material and form, was decisive in determining the resonant frequency of the system and therefore the maximum practical frequency of operation. It was also shown that the motion of the oscillator is unaffected by the electromagnetic fields of the MR imager. The final design can be placed directly in the magnet bore within a few centimeters of the tissue volume to be imaged without generating significant artifacts. An amplitude range of 0,1 mm in the frequency range from 0 to over 300 Hz was achieved, sufficient for performing most MR elastography applications. © 2002 Wiley Periodicals, Inc. Concepts in Magnetic Resonance (Magn Reson Engineering) 15: 239,254, 2002 [source] Magnetic resonance imaging evaluation of 264 horses with foot pain: The podotrochlear apparatus, deep digital flexor tendon and collateral ligaments of the distal interphalangeal jointEQUINE VETERINARY JOURNAL, Issue 4 2007S. DYSON Summary Reasons for performing study: To improve understanding of the interrelationships between injuries of the podotrochlear apparatus and deep digital flexor tendon (DDFT). Hypotheses: There is a difference in frequency of different types of lesions at different anatomical sites of the DDFT. Lesions of the collateral sesamoidean ligament (CSL), distal sesamoidean impar ligament (DSIL), distal interphalangeal (DIP) joint and navicular bursa are seen in association with lesions of the navicular bone. Methods: The magnetic resonance (MR) images of 264 horses with unilateral or bilateral foot pain were analysed and graded. Descriptive statistics were performed to establish the frequency of occurrence of DDFT lesion types at different anatomical levels, and lesions of the CSL, DSIL, navicular bursa, DIP joint and collateral ligaments (CLs) of the DIP joint. A Chi-square test was used to test for a difference in the proportion of navicular bone grades between limbs with and without DDFT lesions at each level, and to compare navicular bone grades for limbs with and without each of DSIL, CSL, navicular bursa or DIP joint lesions. Results: Lesions of the DDFT occurred in 82.6% of limbs, occurring most commonly at the level of the CSL (59.4%) and the navicular bone (59.0%). Core lesions predominated at the level of the proximal phalanx (90.3%), whereas at the level of the CSL and navicular bone core lesions, sagittal splits and dorsal abrasions were most common. There was a positive association between DDFT lesions and navicular bone pathology involving all aspects of the bone. Lesions of the DSIL (38.2% limbs) were more common than those of the CSL (10.5%), but the presence of either was associated with abnormalities of the navicular bone, especially involving the proximal or distal borders and the medulla. Conclusions and clinical relevance: There are close interactions between injuries of the components of the podotrochlear apparatus, the DDFT, the navicular bursa and the DIP joint. Further knowledge about the biomechanical risk factors for injury may have importance for both disease prevention and management. [source] Imaging techniques in the diagnosis and management of rhinosinusitis in childrenPEDIATRIC ALLERGY AND IMMUNOLOGY, Issue 2007F. Triulzi Sinusitis in children is a common problem. The diagnosis of both acute and chronic rhinosinusitis in the pediatric population, should be made first of all clinically, and not on the basis of imaging findings alone. Plain radiography may be used as a screening method for various pathological conditions of sinuses, but computed tomography (CT) remains the study of choice for the imaging evaluation of acute and chronic rhinosinusitis. In acute sinusitis, CT is indicated in patients with symptoms persisting after 10 days of appropriate therapy and in patients with suspected complications (especially in the brain and in the orbit). In addition to CT scanning, magnetic resonance (MR) imaging of the sinuses, orbits, and brain should be performed whenever extensive or multiple complications of sinusitis are suspected. In chronic sinusitis, CT scanning is the ,gold standard' for the diagnosis and the management, because it also provides an anatomic road map, when surgery is required. Nuclear medicine studies and ultrasound are rarely indicated in acute and chronic rhinosinusitis. [source] Magnetic resonance imaging profiles predict clinical response to early reperfusion: The diffusion and perfusion imaging evaluation for understanding stroke evolution (DEFUSE) studyANNALS OF NEUROLOGY, Issue 5 2006Gregory W. Albers MD Objective To determine whether prespecified baseline magnetic resonance imaging (MRI) profiles can identify stroke patients who have a robust clinical response after early reperfusion when treated 3 to 6 hours after symptom onset. Methods We conducted a prospective, multicenter study of 74 consecutive stroke patients admitted to academic stroke centers in North America and Europe. An MRI scan was obtained immediately before and 3 to 6 hours after treatment with intravenous tissue plasminogen activator 3 to 6 hours after symptom onset. Baseline MRI profiles were used to categorize patients into subgroups, and clinical responses were compared based on whether early reperfusion was achieved. Results Early reperfusion was associated with significantly increased odds of achieving a favorable clinical response in patients with a perfusion/diffusion mismatch (odds ratio, 5.4; p = 0.039) and an even more favorable response in patients with the Target Mismatch profile (odds ratio, 8.7; p = 0.011). Patients with the No Mismatch profile did not appear to benefit from early reperfusion. Early reperfusion was associated with fatal intracranial hemorrhage in patients with the Malignant profile. Interpretation For stroke patients treated 3 to 6 hours after onset, baseline MRI findings can identify subgroups that are likely to benefit from reperfusion therapies and can potentially identify subgroups that are unlikely to benefit or may be harmed. Ann Neurol 2006 [source] In vivo microfocal computed tomography and micro,magnetic resonance imaging evaluation of antiresorptive and antiinflammatory drugs as preventive treatments of osteoarthritis in the ratARTHRITIS & RHEUMATISM, Issue 9 2010Michael D. Jones Objective To determine whether treatment with an antiresorptive drug in combination with an antiinflammatory drug reduces periarticular bone and soft tissue adaptations associated with the progression of posttraumatic secondary osteoarthritis (OA). Methods We used in vivo microfocal computed tomography (micro-CT) to map bony adaptations and in vivo micro,magnetic resonance imaging (micro-MRI) to examine joint inflammation in a rat model of surgically induced OA secondary to knee triad injury. We examined the arthroprotective effects of the bisphosphonates alendronate and risedronate and the nonsteroidal antiinflammatory drug (NSAID) meloxicam. Results Micro-CT revealed reduced levels of periarticular trabecular bone loss in animals with knee triad injury treated with the bisphosphonate drugs alendronate or risedronate, or the NSAID meloxicam, compared with untreated animals. Alendronate treatment reduced bony osteophyte development. While risedronate as a monotherapy did not positively impact osteophytogenesis, combination therapy with risedronate and meloxicam reduced osteophyte severity somewhat. Micro-MRI revealed an increased, diffuse water signal in the epiphyses of untreated rats with knee triad injury 8 weeks after surgery, suggestive of a bone marrow lesion,like stimulus. In contrast, meloxicam-treated rats showed a significant reduction in fluid signal compared with both bisphosphonate-treated groups 8 weeks after surgery. Histologic analysis qualitatively confirmed the chondroprotective effect of both bisphosphonate treatments, showing fewer degradative changes compared with untreated rats with knee triad injury. Conclusion Our findings indicate that select combinations of bisphosphonate and NSAID drug therapy in the early stages of secondary OA preserve trabecular bone mass and reduce the impact of osteophytic bony adaptations and bone marrow lesion,like stimulus. Bisphosphonate and NSAID therapy may be an effective disease-modifying drug regimen if administered early after the initial injury. [source] Colour Doppler imaging evaluation of blood flow parameters in the ophthalmic artery in acute and chronic phases of optic neuritis in multiple sclerosisACTA OPHTHALMOLOGICA, Issue 1 2009Pavel Hradílek Abstract. Purpose:, Optic neuritis (ON) is a common manifestation of multiple sclerosis (MS). It is caused by the immune-mediated inflammation of the optic nerve. Some vascular factors that may influence blood flow in the ophthalmic artery (OA) have also been suggested as factors in the pathogenesis of ON. The purpose of our study was to evaluate blood flow velocities and resistance (RI) and pulsatile (PI) indices in the OA in both orbits in patients in the acute and chronic phases of unilateral ON and to compare these with equivalent findings in healthy control subjects. Methods:, Orbital colour Doppler imaging (CDI) was performed in 40 consecutive MS patients during acute unilateral ON prior to corticosteroid treatment. Optic neuritis was diagnosed on the basis of clinical presentation and facultative assessment of visual evoked potentials (VEPs). The peak systolic (PSV) and end-diastolic (EDV) velocities and RI and PI were measured in the OA in both eyes. We compared results from affected and unaffected orbits using the paired t -test. The same measurements were performed in 114 MS patients with a history of acute unilateral ON that occurred > 1 year prior to ultrasound examination. We also measured the same parameters in the middle cerebral arteries (MCAs) on both sides in all subjects in both groups. The same measurements were obtained in healthy controls. Results:, The PSV (p < 0.0001), RI (p < 0.0001) and PI (p < 0.0001) in the OA in the eye affected with acute ON were significantly higher than in the unaffected eye. There was no difference in EDV in the OA between affected and unaffected eyes (p > 0.05) in the group with acute ON. We did not observe any significant differences between eyes in either blood flow velocities or the RI or PI (p > 0.05) in the group in the chronic phase of ON or in the control group. All the parameters in the MCAs on both sides were normal in both the acute and chronic groups, as well as in the control group. Conclusions:, Pathophysiological changes during acute unilateral ON influence orbital haemodynamics, as is indicated by increased PSV, RI and PI in the OA in eyes affected with ON. However, these changes do not persist over longer periods. [source] Scrotal involvement in childhood Henoch-Schönlein purpuraACTA PAEDIATRICA, Issue 4 2007Tae-Sun Ha Abstract Aim: Henoch-Schönlein purpura (HSP) is a common childhood systemic vasculitis involving the skin, gastrointestinal tract, joint, kidneys and even scrotum. Methods: We retrospectively reviewed the clinical and laboratory data of 120 male patients with HSP and also evaluated the risk factors for scrotal involvement and the relation between scrotal involvement and other clinical features. Twenty-six out of 120 boys (21.7%) diagnosed with HSP had scrotal involvement. Results: Scrotal symptoms manifested as swelling in 88.5% and pain (or tenderness) in 69.2% of HSP patients with scrotal involvement. Neurologic symptoms, mainly headache and localized edema among various manifestations and high serum C3 level of laboratory profiles were more frequently observed in scrotal-involved group than in those of non-involved group. However, there was no difference in the outcomes of scrotal symptoms according to therapeutic modalities and the occurrence of scrotal involvement had no correlation with renal involvement from acute to chronic phase. Conclusions: We found that neurologic symptoms, localized edema and high serum C3 level show a significant relation with scrotal involvement in male HSP patients. Because scrotal involvement in male HSP patients is not rare, the accurate early diagnosis of HSP is mandatory by the early notification of purpura and imaging evaluations in order to avoid unnecessary procedures. [source] | ||||||||||