Resonance Imaging Evaluation Research Articles

Magnetic Resonance Imaging of a Coronary Fistula Manifesting as a Pericardial Effusion

A case of a congenital fistulous communication between the left circumflex coronary artery and coronary sinus that presented as a pericardial effusion and was diagnosed using a comprehensive cardiac magnetic resonance imaging (MRI) evaluation is presented. This is an unusual presentation of an uncommon condition, and the MRI features have not been described previously. Noninvasive cardiac assessment via MRI allows for identification of the anatomic basis and functional consequences of an unusual anomaly such as a coronary artery fistula.

Estudo da precisão diagnóstica do artrômetro KT1000TM na lesões do ligamento cruzado anterior

Este trabalho teve como objetivo principal averiguar a sensibilidade do Artrômetro Eletrônico KT-1000TM, na detecção das lesões do LCA. Foram avaliados 36 pacientes com histórico de entorse do joelho e exame clínico compatível com lesão do LCA. Os pacientes foram divididos em dois grupos. O Grupo 1 foi composto por 18 pacientes avaliados com menos de quatro semanas após o episódio do entorse. O Grupo 2 (dois) foi composto por 18 pacientes avaliados com mais de 4 (quatro) semanas após o episódio de entorse. Ambos os Grupos realizaram avaliação artrométrica (KT-1000TM) e avaliação pela ressonância magnética (RM). Após a análise dos dados obtidos pelas avaliações de imagem e Artrométrica, os pacientes foram submetidos a procedimentos artroscópicos para avaliação e tratamento da lesão, permitindo a comparação dos achados artroscópicos com os resultados da artrometria e da Ressonância Magnética. A precisão diagnóstica do artrômetro KT-1000TM foi de 100% em ambos os grupos, sendo que o teste mais sensível à presença de lesão do LCA foi o Teste de Tração Manual Máxima. A precisão diagnóstica da avaliação pela ressonância magnética foi de 94,4% no Grupo 1 e de 100% no grupo 2.

Magnetic resonance evaluation of remodeling process in patellar tendon graft.

Several studies have shown the accuracy of magnetic resonance imaging in evaluating the reconstructed anterior cruciate ligament. The purpose of the current study was to clarify the clinical usefulness of magnetic resonance imaging for evaluating the reconstructed anterior cruciate ligament in comparison with using arthroscopy. Sixty-nine patients who had an anterior cruciate ligament reconstruction using a bone-tendon-bone autograft were examined by magnetic resonance imaging and arthroscopy an average of 12 months after surgery. There were 41 males and 28 females with an average age of 25.9 years (range, 15-66 years). The interval from surgery to the magnetic resonance imaging or arthroscopic evaluation was a mean of 12 months (range, 4-32 months). The magnetic resonance imaging findings of the reconstructed anterior cruciate ligament were classified as either high, intermediate, or low intensity. The arthroscopic findings also were classified as either graft impingement at the intercondylar notch or no impingement. In the 47 anterior cruciate ligament grafts that were not impinged, the signal intensity remained low and did not increase during second-look arthroscopy. In contrast, 22 anterior cruciate ligament grafts that were impinged showed an increased signal intensity in the distal area of the graft at the time of the second-look arthroscopy. Furthermore, no significant correlation was observed between the presence of a high signal intensity and postoperative instability. The high signal intensity of the anterior cruciate ligament graft on magnetic resonance imaging was found to be caused by graft impingement. These findings therefore show a clear association between graft impingement and the subsequent appearance of the graft on magnetic resonance imaging.

Brain damage following cardiac valve replacement: A prospective study using diffusion-weighted magnetic resonance imaging and neuropsychological evaluation

Brain damage following cardiac valve replacement: A prospective study using diffusion-weighted magnetic resonance imaging and neuropsychological evaluation

Magnetic Resonance Imaging for Evaluation of Multicentric Infiltrating Ductal Carcinoma of the Breast

Magnetic Resonance Imaging for Evaluation of Multicentric Infiltrating Ductal Carcinoma of the Breast

3608 Comparison of cineventriculography, echo, and magnetic resonance imaging for evaluation of severity of mitral regurgitation: non-conformity of semiquantitative and quantitative grading

3608 Comparison of cineventriculography, echo, and magnetic resonance imaging for evaluation of severity of mitral regurgitation: non-conformity of semiquantitative and quantitative grading

Magnetic resonance imaging in evaluation of the common bile duct.

The ideal method for evaluation of the common bile duct (CBD) before or during cholecystectomy remains controversial. Magnetic resonance cholangiography (MRC) is a new, promising technique. A prospective evaluation is reported. Sixty-one patients (45 women) were studied by MRC. There were 29 patients with symptomatic gallstone disease and without clinical, biochemical or ultrasonographic evidence of CBD stones (group 1); 28 of them also underwent intraoperative cholangiography (IOC). In addition, there were 21 patients with symptomatic gallstone disease, with mild biochemical and ultrasonographic signs of CBD involvement (group 2), of whom 19 underwent IOC, and 11 patients with symptomatic CBD stones (group 3), nine of whom had preoperative endoscopic retrograde cholangiopancreatography (ERCP) following MRC. MRC showed that no patient in group 1 and three patients in group 2 had CBD stones. Three patients (one in group 1, two in group 2) did not undergo IOC because of technical or clinical problems. In group 3, ERCP confirmed the results of MRC in nine patients. Two patients underwent open surgery because of ultrasonographic, MRC and radiographic signs of pancreatic malignancy. MRC could replace IOC and ERCP for identification of asymptomatic CBD stones. In symptomatic patients MRC combined with other non-invasive imaging techniques can direct the surgeon to appropriate management.

Cerebral MRI and evoked potentials in Wilson disease. Comparison of findings in patients with neurological follow-up

Wilson's disease is caused by toxic copper accumulation, which leads predominantly to hepatic and basal ganglia damage. Characteristic findings in MRI and electrophysiologic examinations are described according to the occurrence of neurological symptoms. In the present study, 28 patients suffering from Wilson's disease (neurological type) were investigated. The results of MRI are compared with abnormalities of evoked potentials (BAEP, MSEP, T-VEP, MEP). All patients show hypodensities in the basal ganglial area (putamen and GI. pallidus) regularly combined with atrophy of the cerebrum and cerebellum in MRI. Signal abnormalities in the mesencephalic region (46% occurrence) and Nc. dentatus (36% occurrence) are combined with the other findings in variable patterns. Only slight changes are found in the pontine region. BAEP are disturbed in 71% of all cases and MSEP in 46%. Combined abnormalities of BAEP and MSEP were found in 39%. Pathological values occurred with a lower frequency in T-VEP (36%) and MEP (39%). The comparison of MRI findings with electrophysiological data done separately for each patient reveals no strong correlation between both methods. Individual MRI findings do not correspond with the patterns of disturbed evoked potentials and vice versa. Therefore we conclude that these methods, MRI and electrophysiological evaluation, supplement each other. Magnetic resonance imaging and electrophysiological evaluation should be performed simultaneously for therapy monitoring.

Counterfactual thinking and quality of life among women with silicone breast implants.

This study examined the relationship of counterfactual thinking (thoughts about how one's current situation might have turned out differently) with psychosocial adjustment and quality of life in a sample of women with silicone breast implants. Seventy-four women who were concerned about or who were experiencing problems with their implants were recruited following magnetic resonance imaging (MRI) evaluation. Participants completed measures of counterfactual thinking, psychosocial adjustment, and quality of life (QOL). Results indicated that counterfactual thinking was significantly associated with more psychosocial adjustment difficulties, more perceived implant-related health problems, and poorer QOL in the physical health domain. These findings provide additional insight into the factors that may influence adjustment in a complex and poorly understood population and also have implications for understanding the adjustment process to other types of illnesses.

Magnetic resonance imaging in the evaluation of congenital anomalies of the external genitalia

Objectives. To assess the value of magnetic resonance imaging (MRI) in the anatomic evaluation and management planning of complex congenital genitourinary anomalies. Methods: Multiplanar T 1 and T 2-weighted MR images were obtained in 6 pediatric patients with congenital genitourinary anomalies, including aphallia, diphallia, ectopic scrotum, and epispadias. The imaging studies were read by experienced radiologists and discussed with the urologic surgeons in a multidisciplinary conference. Results. Each congenital anomaly was demonstrated in detail by MRI. The MR images of penile agenesis showed hypoplastic corpora cavernosa and a vestigial bulb. In patients with penile duplication, MRI was able to delineate the course of each corporal body and the varying degree of thickness of the tunica albuginea. For the patient with scrotal ectopia, detailed MR images excluded both the possibility of urethral and corporal duplications and the presence of viable testes in the ectopic scrotum. In the case of epispadias, MRI illustrated the precise spatial relationship between the erectile bodies and urethra. Additionally, MRI identified related aberrant pelvic organs and provided images of the external genital structures. Conclusions. MRI, by rendering excellent anatomic interpretation of complex genital anomalies and associated abnormal pelvic tissues, assists surgeons in conceptualizing the anomalous structures and contributes to their formulation of management approaches.

Image analysis methods for assessing levels of image plane nonuniformity and stochastic noise in a magnetic resonance image of a homogeneous phantom.

Magnetic response image plane nonuniformity and stochastic noise are properties that greatly influence the outcome of quantitative magnetic resonance imaging (MRI) evaluations such as gel dosimetry measurements using MRI. To study these properties, robust and accurate image analysis methods are required. New nonuniformity level assessment methods were designed, since previous methods were found to be insufficiently robust and accurate. The new and previously reported nonuniformity level assessment methods were analyzed with respect to, for example, insensitivity to stochastic noise; and previously reported stochastic noise level assessment methods with respect to insensitivity to nonuniformity. Using the same image data, different methods were found to assess significantly different levels of nonuniformity. Nonuniformity levels obtained using methods that count pixels in an intensity interval, and obtained using methods that use only intensity values, were found not to be comparable. The latter were found preferable, since they assess the quantity intrinsically sought. A new method which calculates a deviation image, with every pixel representing the deviation from a reference intensity, was least sensitive to stochastic noise. Furthermore, unlike any other analyzed method, it includes all intensity variations across the phantom area and allows for studies of nonuniformity shapes. This new method was designed for accurate studies of nonuniformities in gel dosimetry measurements, but could also be used with benefit in quality assurance and acceptance testing of MRI, scintillation camera, and computer tomography systems. The stochastic noise level was found to be greatly method dependent. Two methods were found to be insensitive to nonuniformity and also simple to use in practice. One method assesses the stochastic noise level as the average of the levels at five different positions within the phantom area, and the other assesses the stochastic noise in a region outside the phantom area.

Magnetic resonance imaging for evaluation of otic labyrinth pathology.

The auditory (cochlear) labyrinth, the cochlea, holds the hearing sensory receptors. The vestibular labyrinth contains the sensory receptors for balance, which lie in the three semicircular canals and in the otolithic organs (the saccule and utricle). Pure tone audiometry and brain stem evoked audiometry can help to differentiate a peripheral cochlear disorder from central lesion. The type of nystagmus, severity of postural instability, and neurological evaluation can help to differentiate a peripheral vestibular disorder from a central vestibular lesion. The decision whether to perform an appropriate imaging such as brain imaging versus labyrinthine imaging depends on the clinical and paraclinical information provided to the radiologist by the neurotologist, neurologist, or other clinicians. The magnetic resonance imaging characteristics of peripheral cochlear and vestibular lesions are the main focus of this article.

Radial-sequence magnetic resonance imaging in evaluation of acetabular labrum

We investigated the usefulness of a radial-sequence magnetic resonance imaging (MRI) technique in the visualization of the acetabular labrum, which surrounds the acetabulum. In 22 hip joints of 12 volunteers, T2-weighted images were obtained on 24 radial planes of the acetabular rim, set at 15°-intervals, using the small tip angle gradient echo method. We examined 7 planes in the weight-bearing portion. The acetabular labrum in the weight-bearing portion was depicted in good contrast to the surrounding tissues. The shape of the labrum differed among individuals and also in the anterior and posterior portions of the labrum. The signal intensity of the labrum was low or partially moderate. There was a high signal intensity band on the base of the acetabular labrum in several portions, which should be carefully interpreted to avoid confusion with abnormality. We concluded that radial-sequence MRI could be a useful technique for evaluation of the condition of the acetabular labrum in the weight-bearing portion.

Application of magnetic resonance imaging for evaluation of the efficacy of SB 217242 in neointimal formation.

Although several factors have been implicated in the pathophysiology of vascular neointimal formation and restenosis after balloon angioplasty, current therapies have failed to alleviate these conditions. Because endothelin-1 (ET-1) has been implicated in the pathogenesis of the neointimal growth, this study examined the in vivo efficacy of SB 217242, a potent nonpeptide mixed ETA/ETB receptor antagonist with high oral bioavailability, in the rat carotid balloon angioplasty model. A novel magnetic resonance imaging (MRI) approach was used for evaluation. MRI is a high-resolution, noninvasive spatial imaging modality that can serially monitor arterial luminal caliber in vivo, along with histologic evaluation. In vivo luminal volumes for the left carotid artery (LCA) were measured by MRI at baseline (before surgery) and again at 14 days after angioplasty. SB 217242 (30 mg/kg/day p.o.) was administered daily for 14 days after angioplasty. On day 14, SB 217242 provided 20% protection (p < 0.05) on neointimal-mediated decrease in luminal volume as measured by MRI. The non-ballooned right carotid arteries of both groups had significantly increased luminal volume on day 14 with respect to baseline values, indicating compensation for the decreased luminal size of the LCA. Histologic analysis of the mean intimal-to-medial ratio demonstrated that SB 217242 provided 42% (p < 0.05) protection. These results demonstrate that ET receptor antagonism can inhibit neointimal formation after balloon angioplasty and that MRI technology can provide valuable insight for noninvasive assessment of vascular lesion development.

Magnetic resonance imaging in evaluation of congenital and acquired superior oblique palsy.

According to the recently popularized classification of superior oblique (SO) palsy based on congenital variations of the tendon, the primary pathology is the abnormality of the SO tendon rather than an innervational problem in congenital cases. If this hypothesis is true, denervation atrophy of SO muscle should not occur in patients with congenital SO palsy. Eight patients with traumatic and nine patients with definite congenital SO palsy underwent magnetic resonance imaging (MRI) of the orbit. SO muscle width and cross-sectional area measurements were taken from coronal images and compared with the clinically uninvolved superior oblique muscles. Atrophy of varying degrees was observed in the SO muscle both in congenital and acquired cases. No significant difference was found in the appearance of the SO muscle between acquired and congenital SO palsy groups. We have been unable to demonstrate abnormalities of the SO tendon in both groups. The MRI appearance of the SO muscle suggested that in congenital SO palsy, the pathology is not limited to the tendon; there also is an abnormality of the muscle itself.

PET Imaging of Recurrent Medullary Thyroid Cancer

Medullary carcinoma of the thyroid gland is a rare tumor. Its prognosis is mainly linked to surgery, because there is no valid alternative therapy to improve patients outcome. In this report, we discuss the recurrence of such a tumor in a 64-year-old female, focusing on magnetic resonance imaging and position emission tomography evaluation of this tumor.

Inadequacy of ultrasonography for monitoring response to treatment of liver metastases.

We prospectively evaluated the clinical efficacy of ultrasonography (US) in monitoring the effect of medical treatment in patients with liver metastases, by comparing serial US assessment with serial magnetic resonance imaging (MRI) evaluation and clinical outcome in a group of 41 patients with solid tumors. Both examinations were performed in patients with metastatic liver disease at the start of a new treatment modality and monthly thereafter for 3 months; close monitoring was prolonged beyond the third month in cases in which there was disagreement between the two techniques and the clinical course was not conclusive. Planned follow-up was completed in 37 cases. There was limited concordance between the two examinations: in 21 cases only (56.8%), US and MRI gave concordant information on the evolution of hepatic metastases; in eight cases, both agreed on progression of disease (PD), in 11 cases on stable disease (SD), and in one case each on partial response (PR) and complete response (CR). In the remaining 16 cases (43.2%), there was disagreement between the two examinations. On the basis of subsequent clinical course, this discrepancy was shown to be due to US inadequacy in 13 cases and to MRI inadequacy in one case; in two cases, the clinical course was not conclusive. The most striking limits of US appeared to be twofold: (1) a progressive appearance, with chemotherapy, of a diffusely inhomogeneous structure of the liver, resulting in obscuration of focal lesions (and a subsequent judgement of CR) in cases in which lesions were, on the contrary, detected at MRI and usually confirmed by subsequent clinical course; and (2) false US-determined PD in cases in which lesions proven at baseline MRI were noted at US only after one to two courses of therapy. We conclude that US, which is known to be inaccurate for screening of liver metastases, is unreliable for the follow-up of metastatic liver disease; despite its wide availability, low cost, and noninvasiveness, critical therapeutic decisions should not be made based on the outcome of this test.

Evaluation of alimentary tract foreign body: clinical and imaging review of 100 consecutive cases.

We investigated the cases of 100 consecutive patients with alimentary tract foreign bodies for clinical findings and use of imaging and compared our findings with those of other reported series. Most of our patients were children, and the alimentary tract foreign body was metal in most cases. There was no undue morbidity or mortality related to either conservative or interventional treatment. Imaging was useful in diagnosis and management of cases. Use of computed tomography and magnetic resonance imaging in evaluation of alimentary tract foreign bodies is discussed.

Neuropsychological and clinical correlates of temporal lobe anatomy in schizophrenia.

Twenty-five DSM-III schizophrenic patients were assessed neuromorphologically and neuropsychologically. Reduced temporal lobes were found through magnetic resonance imaging (MRI) evaluation. In addition, in order to look for the neuropsychological correlates of temporal anatomy in schizophrenia, patients were divided into cognitive normal and abnormal schizophrenics, according to their Luria Nebraska Neuropsychological Battery profile. The latter group had statistically significant temporal lobe abnormalities as assessed by MRI, irrespective of medication, clinical picture or any other relevant variables. The implication of such findings in the light of the diaschisis model is discussed.

Magnetic resonance imaging (MRI) evaluation of iron deposition in the liver, bone marrow and heart of sickle cell anemia (SCA) patients receiving hyper-transfusion therapy for stroke

Magnetic resonance imaging (MRI) evaluation of iron deposition in the liver, bone marrow and heart of sickle cell anemia (SCA) patients receiving hyper-transfusion therapy for stroke