Characteristic magnetic resonance imaging entheseal changes of knee synovitis in spondylarthropathy

Although studies generally support a positive association between alcohol consumption and lung-cancer risk, the relationship between specific alcoholic beverages and lung-cancer risk has been inconsistent. We examined recent and past alcoholic beverage intake among 261 incident cases and 615 population controls enrolled in a lung-cancer case-control study of African Americans and Caucasians in Los Angeles County between 1991 and 1994. An in-person interview elicited information about past alcohol intake from ages 30 to 40 y, smoking, other lung-cancer risk factors, as well as recent intake of alcohol, and recent dietary intake. An association was observed between recent hard-liquor consumption and lung-cancer risk. The odds ratio (OR) for 1 or more drinks (1.5 oz or 0.051 mL) per day of hard liquor compared with infrequent liquor drinking (0-3 drinks per month), adjusted for smoking, the matching factors, saturated fat and other alcoholic beverages was 1.87 [95% confidence interval (CI) = 1.02-3.42]. No appreciable association was observed for total alcohol, whereas small inverse associations were observed for beer and wine, although confidence intervals were wide. An elevated lung-cancer risk was also observed for past liquor consumption (between ages 30 and 40 y). The adjusted OR for 1 or more drinks per day of liquor compared with infrequent drinkers was 1.83 (95% CI = 1. 06-3.15). Confounding of the association between alcohol and lung cancer by smoking was apparent. Although we devoted considerable efforts to adjusting for smoking in our analyses, residual confounding is still possible because smoking and alcohol are closely associated. In addition, case-control studies including this study should be viewed with caution because of possible selection bias. An increased risk of lung cancer might occur with moderate drinking of hard liquor but confirmation is required in larger studies.     

Different approaches to synovial membrane volume determination by magnetic resonance imaging: manual versus automated segmentation

Automated fast (5-20 min) synovial membrane volume determination by MRI, based on pre-set post-gadolinium-DTPA enhancement thresholds, was evaluated as a substitute for a time-consuming (45-120 min), previously validated, manual segmentation method. Twenty-nine knees [rheumatoid arthritis (RA) 13, osteoarthritis (OA) 16] and 17 RA wrists were examined. At enhancement thresholds between 30 and 60%, the automated volumes (Syn(x%)) were highly significantly correlated to manual volumes (SynMan) (knees: rho = 0.78-0.91, P < 10(-5) to < 10(-9); wrists: rho = 0.87-0.95, P < 10(-4) to < 10(-6)). The absolute values of the automated estimates were extremely dependent on the threshold chosen. At the optimal threshold of 45%, the median numerical difference from SynMan was 7 ml (17%) in knees and 2 ml (25%) in wrists. At this threshold, the difference was not related to diagnosis, clinical inflammation or synovial membrane volume, e.g. no systematic errors were found. The inter-MRI variation, evaluated in three knees and three wrists, was higher than by manual segmentation, particularly due to sensitivity to malalignment artefacts. Examination of test objects proved the high accuracy of the general methodology for volume determinations (maximal error 6.3%). Preceded by the determination of reproducibility and the optimal threshold at the available MR unit, automated 'threshold' segmentation appears to be acceptable when changes rather than absolute values of synovial membrane volumes are most important, e.g. in clinical trials.     

Cost effectiveness of magnetic resonance imaging of the knee

When compared to diagnostic arthroscopy in patients with knee complaints consistent with internal derangement, MR imaging emerges as a cost effective diagnostic supplement to clinical examination. This article concludes that the results of MR imaging can be used as a guide for the management of knee pain.     

Measurement of localized cartilage volume and thickness of human knee joints by computer analysis of three-dimensional magnetic resonance images

RATIONALE AND OBJECTIVES: This work demonstrates a new method for computerized measurement of the dimensions (thickness and volume) of articular cartilage for any specified region of the human knee joint. Three-dimensional magnetic resonance (MR) images optimized for cartilage contrast have been analyzed using computerized edge-detection techniques, and the reproducibility of articular cartilage thickness and volume measurements is assessed. METHODS: A fat-suppressed, three-dimensional SPoiled GRass MR sequence (45/7.5/30 degrees) with total scan time of approximately 12 minutes was used to acquire volume images of human knee joints at spatial resolution of 0.6 x 1.2 x 1.2 mm. Measurements were made using six repeated scans for three healthy volunteers over a period of 2 months. The subsequent semi-automated image processing to establish total cartilage volume and cartilage thickness maps for the femur required approximately 60 minutes of operator time. RESULTS: The mean coefficient of variation for total cartilage volume for the six repeated scans for the three volunteers was 3.8%, and the average coefficient of variation for the user-selected cartilage plugs was 2.0%. The cartilage thickness maps from the repeated scans of the same knee were similar. CONCLUSIONS: Standard resolution MR images with fat-suppressed contrast lead to an objective and reproducible measurement of spatial dimensions of articular cartilage when analyzed semi-automatically using computerized edge-detection methods.     

Arthroscopy for chronic hemophilic synovitis of the knee

Between 1988 and 1995, 32 knee joints (29 patients) with hemophilic arthropathy underwent arthroscopy. The spectrum of procedures ranged from resection of fibrous plicae to synovectomy. Technical difficulties appeared in cases of scarred fixed patella, pronounced posterior tibia subluxation, and severe fibrous ankylosis. All operations done between 1988 and 1991 (23 operations; 21 patients) were reviewed retrospectively. The mean age of the patients in this series was 30 years and the mean followup was 5 years. On subjective evaluation, 13 operations achieved a definite improvement, five showed slight improvement, and two had no improvement (three operations were excluded). Arthroscopic surgery, as a relatively low risk technique, combined with early functional rehabilitation, can be used to achieve satisfactory results in patients with hemophilic arthropathy.     

Influence of magnetic resonance imaging on indications for arthroscopy of the knee

In a prospective study, magnetic resonance imaging was performed before arthroscopy for all patients (n = 121) with a meniscal tear (n = 125). Criteria of the study were stable cruciate and collateral ligaments, absence of pathologic radiographic findings, and absence of prior surgical interventions of the involved knee joint. In 43 knees (34%), the clinical diagnosis of a meniscal tear was discarded because of the results of the magnetic resonance imaging examination. Synovitis was diagnosed in 16 patients (13%), articular cartilage damage in 10 patients (8%), bone bruise injuries in 10 patients (8%), osteochondritis dissecans in 3 patients (2%), disruption of the inner layer of the medial collateral ligament in 3 patients (2%), and osteonecrosis in 1 patient. The use of magnetic resonance imaging in establishing diagnosis of disorders of the knee joint altered treatment in a significant proportion of patients. Magnetic resonance imaging should be done before arthroscopy of the knee in all cases in which the clinical diagnosis has been reduced to a suspected meniscus injury.     

Computed tomographic and magnetic resonance imaging of chronic odontoid fractures

STUDY DESIGN: The analysis of the imaging characteristics found in chronic odontoid fractures. OBJECTIVES: To determine the efficacy of computed tomography and magnetic resonance imaging in diagnosing a chronic odontoid fracture. SUMMARY OF BACKGROUND DATA: Radiographic examination of the cervical spine is intrinsic to the evaluation of all patients with blunt trauma. Injury to the craniocervical junction constitutes 19-25% of all cervical spine fractures. At the authors' trauma center computed tomography is routinely used instead of the open-mouth odontoid radiograph to facilitate cervical spine evaluation. This practice has increased the detection of fractures that are unrecognized in plain radiography, and has, at the same time, raised questions about the age and significance of these fractures. METHODS: Radiography, computed tomography, and magnetic resonance imaging studies were performed on three patients who came to the emergency department with odontoid fractures. Two patients had a history of severe trauma, and one had a history inconsistent with an acute odontoid fracture. One patient also had a technetium Tc 99m methylene dihydroxyphosphonate bone scan. The studies were obtained to determine the age of the fractures. RESULTS: All three patients were determined to have chronic odontoid fractures. This diagnosis was facilitated by the use of computed tomographic and magnetic resonance imaging. Computed tomography showed increased sclerosis in the proximal fracture fragment in all cases and well-corticated fracture edges in one patient. Magnetic resonance images showed normal bone marrow or bone sclerosis in the odontoid process. Soft tissue edema was absent. A bone scan was not useful in resolving this issue. CONCLUSION: Computed tomography and magnetic resonance imaging can be useful in determining the chronicity of an odontoid fracture.     

Comparison of muscle volume between congenital and acquired superior oblique palsies by magnetic resonance imaging

A panel of 13 highly informative dinucleotide repeats which are genetic markers for 17 cytokine genes and receptors is described. The marker panel is designed for use in fluorescence based semi-automated genotyping, with primers designed and labelled such that all 13 markers can be analysed in a single lane of a gel. Cytokine and cytokine receptors have a potential role in many diseases and pathological processes. Evidence suggests that cytokine production in vivo is influenced by polymorphisms within regulatory sequences of these genes. Genetic investigation of disease genes often requires genotyping of very large numbers of individuals. This panel of markers will, therefore, provide a useful tool to those wishing to undertake family-based linkage analysis studies of cytokine genes or large-scale association studies.     

Basic anatomy of the shoulder by magnetic resonance imaging

An understanding of the normal magnetic resonance (MR) infrastructural details of musculotendinous elements of the rotator cuff forms the basis for analysis of its pathology. The muscular bellies of the teres minor, infraspinatus, supraspinatus, and subscapularis are easily identified in MR images. In their lateral course both the supraspinatus and infraspinatus muscles transition to tendons gradually. Their lateral tendinous portions partially overlap and form a layered appearance on MR images. The subscapularis, with its fan-like tendinous insertional slips at the lesser tuberosity, can be identified easily in all imaging planes. The ligamentous structures of the shoulder, including the coracoacromial and coracohumeral ligaments, are visualized as low signal bands in all imaging planes. The capsuloligamentous structures including the superior, middle, and inferior glenohumeral ligament and glenoid labrum present considerable anatomic variations. This is especially true with respect to the anterior labrum, which varies from absent to a well-formed triangular appearance. Understanding the basic MRI anatomy of all soft tissue structures of the shoulder is essential for appropriate interpretation of lesions related to the shoulder.     

Post-transplant cerebral toxoplasmosis diagnosed by magnetic resonance imaging

We report on a case of an endogenous frontal sinolith and a literature review of classification and use of the terms rhinolith, and sinolith.     

Cardiac metastatic melanoma investigated by magnetic resonance imaging

A case of tricuspid valve regurgitation due to a non-penetrating chest trauma was presented. This case involves a 20-year-old man, who was admitted to a nearby hospital because of rib fracture, mandibular fracture, and hemorrhage of the left hemopneumothorax, caused by a traffic accident. Palpitation and chest discomfort were observed at admission time, but there was no follow-up. Tricuspid regurgitation was pointed out during surgery for the mandibular fracture, and he continued follow up treatment at an outpatient clinic. However his palpitation and chest discomfort worsened, and he was admitted to our department 8 month after injury. During surgery to repair the tricuspid valve, a papillary muscle rupture, valve cusp laceration, and anulus dilatation were found. We performed a papillary muscle repair (chorda tendineae reconstruction), valve cusp suture, and annuloplasty. Absence of the left pericardium was observed during the operation. We reported valve repair of traumatic tricuspid regurgitation which with papillary muscle rupture. Due to its rarity and the fact that there has been no reported cases of papillary muscle repair for traumatic tricuspid regurgitation in Japan, we used researched information on the subject.     

Three-dimensional echocardiographic measurement of right ventricular volume in children with congenital heart disease validated by magnetic resonance imaging

Measurement of right ventricular volume and function by two-dimensional echocardiography is unreliable because of the asymmetric shape of the right ventricle. The purpose of this study was to validate the accuracy of transthoracic three-dimensional echocardiography in assessing right ventricular volumes in children with congenital heart disease after surgical repair of the defects, by comparison with those measured by magnetic resonance imaging. We examined 13 children after repair of tetralogy of Fallot (10), hypoplastic left heart syndrome (2), or atrial septal defect (1). Each underwent magnetic resonance imaging followed by three-dimensional echocardiography done with a transthoracic 5 MHz, prototype internally rotating omniplane transducer. In both methods, endocardial borders were manually traced and volumetric slices were summated. Close correlation was observed between the two methods (R2 0.91 for end-systolic volumes, 0.90 for end-diastolic volumes, 0.64 for ejection fraction, and 0.92 for interobserver variability). A limits-of-agreement analysis showed no adverse trend between the two methods under values of 100 ml and low variation around the mean values. We conclude that three-dimensional echocardiography measurement of right ventricular volumes correlates closely with magnetic resonance imaging in children with operated congenital heart disease and may allow accurate serial evaluation in these patients.     

Functionality and connectivity analysis by magnetic resonance imaging

Magnetic resonance (MR is a remarkably versatile technology applicable to various aspects of medical science. Currently, there are three categories of MR techniques available for probing human brain function in detail. The first category comprises the most widely utilized techniques which make use of the metabolic effects of brain activation, represented by BOLD (blood oxygenation level dependent) functional magnetic resonance imaging (fMRI). The second category of techniques deals with apparent diffusion tensor probing the axonal connectivity and is represented by three dimensional anisotropy contrast (3DAC) axonography. The third category of techniques is a biological application of classical nuclear magnetic resonance (NMR) spectroscopy capable of providing biochemical information in vivo and is represented by spectroscopic imaging (SI). As techniques directly applicable to clinical medicine, BOLD fMRI and 3DAC axonography possess the highest potential.     

Asbestos-related pericardial thickening detected by magnetic resonance imaging

Magnetic resonance imaging was performed in four male asbestos workers in whom the chest radiograph revealed pleural but not pulmonary or pericardial disease. Patients underwent thoracic multislice spin echo imaging, with measurement of left and right ventricular volumes at end-diastole and end-systole, and a study of the flow in the superior vena cava as an indirect measure to the filling of the right ventricle. Patients also underwent respiratory function tests and high-resolution computed tomography (HRCT). Magnetic resonance, but not HRCT, showed pericardial thickening in two patients. Magnetic resonance demonstrated reduced diastolic flow in the superior vena cava in one patient, reflecting impaired right ventricular filling. All other magnetic resonance measurements of cardiac function were normal. HRCT demonstrated mild asbestosis in three patients in which neither the chest radiograph nor magnetic resonance showed signs of parenchymal disease, and pericardiac calcification without thickening in one patient. It is concluded that magnetic resonance is superior to HRCT in identifying pericardial thickening, but that HRCT is superior to magnetic resonance in identifying asbestos-related pleural and pulmonary disease.     

Magnetic resonance imaging of knee injuries in children

The appearances of knee injuries on MR imaging are less well documented in children than adults. Some patterns of injury are shared by both groups of patients, e. g. meniscal damage. The frequency of specific injuries may differ, e. g. anterior cruciate ligament (ACL) tear. Congenital abnormality, coexistent pathology and previous treatment of the knee appear to be associated with meniscal problems. Discoid menisci are seen most frequently in children and have unique features on MR scans. Cruciate ligament tears are difficult to diagnose in the smallest children. The ACL may not be identified due to its small size. Normal bone marrow signal may be confused with marrow infiltration or bone microfracture. Radiographically occult fractures around the knee appear to be strongly associated with ligamentous injury as in adult patients. Osteochondral fractures, osteochondral lesions and articular cartilage damage are revealed on MR scans, but their long-term effects are uncertain. It is possible to diagnose a range of knee injuries on MR scans in children. The biggest diagnostic challenge is in pre-school children.     

Magnetic resonance imaging study of hippocampal volume in chronic, combat-related posttraumatic stress disorder

This study used quantitative volumetric magnetic resonance imaging techniques to explore the neuroanatomic correlates of chronic, combat-related posttraumatic stress disorder (PTSD) in seven Vietnam veterans with PTSD compared with seven nonPTSD combat veterans and eight normal nonveterans. Both left and right hippocampi were significantly smaller in the PTSD subjects compared to the Combat Control and Normal subjects, even after adjusting for age, whole brain volume, and lifetime alcohol consumption. There were no statistically significant group differences in intracranial cavity, whole brain, ventricles, ventricle:brain ratio, or amygdala. Subarachnoidal cerebrospinal fluid was increased in both veteran groups. Our finding of decreased hippocampal volume in PTSD subjects is consistent with results of other investigations which utilized only trauma-unexposed control groups. Hippocampal volume was directly correlated with combat exposure, which suggests that traumatic stress may damage the hippocampus. Alternatively, smaller hippocampi volume may be a pre-existing risk factor for combat exposure and/or the development of PTSD upon combat exposure.