Direct MR arthrography of the shoulder: is exercise prior to imaging beneficial or detrimental?

PURPOSE: To define the beneficial and detrimental effects of adding exercise to direct magnetic resonance (MR) shoulder arthrography. MATERIALS AND METHODS: Direct, intraarticular, gadolinium arthrography of the shoulder was performed in 41 patients, who underwent 1.5-T MR imaging before and after 1 minute of arm swinging. Fourteen milliliters of dilute gadolinium solution was injected. Two readers blinded to exercise independently graded the randomly distributed images with a five-point scale for capsular contrast material resorption; extraarticular contrast material leakage; rotator cuff, glenoid labrum, and anterior capsule conspicuity; and partial-thickness or full-thickness rotator cuff tear and labral tear detectability. The sign test was performed to evaluate the significance of differences between preexercise and postexercise grading for each reader. A second review was performed, with direct side-by-side comparison of preexercise and postexercise images. RESULTS: There was evidence of increased capsular resorption after exercise but no alteration in the depiction of the rotator cuff tendons or glenoid labrum. There was no significant extraarticular contrast material leakage after exercise and no alteration in depiction of the anterior capsule. There was no difference in the detectability of rotator cuff or labral tears. CONCLUSION: Exercise with direct shoulder MR arthrography has no beneficial or detrimental effect on image quality or on the depiction of rotator cuff or labral tears.     

Warm-up prior to undertaking a dynamic psychomotor task: does it aid performance?

AIM: The purpose of this study was to examine the effect of differing types of warm-up on the performance of a psychomotor skill that required quick reaction and movement times (MTs), and whole-body co-ordination. METHODS: Subjects (n=12) carried out a psychomotor task which involved reacting to 1 of 3 lights, then running through a slalom course before kicking a mini-soccer ball at a target. The task was completed following rest, a physical warm-up, a skill-specific warm-up and a skill plus physical warm-up. In the physical, and skill plus physical warm-ups the subjects cycled on an ergometer at a workload calculated to induce exercise at their lactate threshold. The outcome dependent variables were time to initiate a movement (reaction time), time to complete the slalom run (MT) and two measures of passing accuracy(constant error and variable error. Biomechanical variables(knee, hip and ankle angles, and horizontal and vertical ankle velocities at contact(were also compared. RESULTS: A repeated measures analysis of variance showed no significant effect of warm-up type on any of the dependent variables. Stepwise multiple regression analyses showed that changes in heart rate from resting values to those before performance of the skill test (D HR pre-performance) and those after performance of the test (D HR post-performance) combined were significant predictors of MT (R(2)=0.31, P<0.001), while D HR post-performance significantly predicted reaction time (R(2)=0.12, P<0.02). CONCLUSIONS: It was concluded that warm-up provided no significant benefit in performance for a task that was dynamic in nature but that physical arousal probably aids reaction and MTs.     

Challenging a dogma of exercise physiology: does an incremental exercise test for valid VO 2 max determination really need to last between 8 and 12 minutes?

A widely cited recommendation is that to elicit valid maximal oxygen uptake (VO(2 max)) values, incremental exercise tests should last between 8 and 12 minutes. However, this recommendation originated from the findings of a single experimental study conducted by Buchfuhrer et al. in 1983. Although this study is an important contribution to scientific knowledge, it should not be viewed as sufficient evidence to support the recommendation for eliciting valid VO(2 max) values. At least eight studies have reported that durations as short as 5 minutes and as long as 26 minutes elicit VO(2 max) values similar to those derived from tests of 8-12 minutes' duration. Two studies reported that the shorter test protocols elicited significantly higher VO(2 max) values in untrained men and women. In three studies that reported significantly higher VO(2 max) values determined during tests of 8-12 minutes than during more prolonged tests, the prolonged tests were associated with maximal treadmill grades of 20-25%, compared with 6-10% in the shorter tests. Therefore, intolerable treadmill grades, rather than the prolonged test duration, may have limited the ability to elicit VO(2 max). In view of the available evidence, test administrators, reviewers and journal editors should not view 8-12 minutes' duration for incremental exercise tests as obligatory for valid VO(2 max) determination. Current evidence suggests that to elicit valid VO(2 max) values, cycle ergometer tests should last between 7 and 26 minutes and treadmill tests between 5 and 26 minutes. This is dependent on the qualification that short tests are preceded by an adequate warm-up and that treadmill grades do not exceed 15%. Current research is too limited to indicate appropriate test duration ranges for discontinuous test protocols, or protocols incorporating high treadmill grades.     

Rotator cuff tendinopathy/subacromial impingement syndrome: is it time for a new method of assessment?

Disorders of the shoulder are extremely common, with reports of prevalence ranging from 30% of people experiencing shoulder pain at some stage of their lives up to 50% of the population experiencing at least one episode of shoulder pain annually. In addition to the high incidence, shoulder dysfunction is often persistent and recurrent, with 54% of sufferers reporting ongoing symptoms after 3 years. To a large extent the substantial morbidity reflects (i) a current lack of understanding of the pathoaetiology, (ii) a lack of diagnostic accuracy in the assessment process, and (iii) inadequacies in current intervention techniques. Pathology of the rotator cuff and subacromial bursa is considered to be the principal cause of pain and symptoms arising from the shoulder. Generally these diagnostic labels relate more to a clinical hypothesis as to the underlying cause of the symptoms than to definitive evidence of the histological basis for the diagnosis or the correlation between structural failure and symptoms. Diagnosing rotator cuff tendinopathy or subacromial impingement syndrome currently involves performing a structured assessment that includes taking the patient's history in conjunction with performing clinical assessment procedures that generally involve tests used to implicate an isolated structure. Based on the response to the clinical tests, a diagnosis of rotator cuff tendinopathy or subacromial impingement syndrome is achieved. The clinical diagnosis is strengthened with the findings from supporting investigations such as blood tests, radiographs, ultrasound, magnetic resonance imaging (MRI), computed axial tomography (CT), radionucleotide isotope scan, single photon emission computed tomography, electromyography, nerve conduction and diagnostic analgesic injection. This process eventually results in the formation of a clinical hypothesis, and then, in conjunction with the patient, a management plan is decided upon and implemented. This paper focuses on the dilemmas associated with the current process, and an alternative method for the clinical examination of the shoulder for this group of patients is proposed.     

Discontinuation of metformin to prevent metformin-induced high colonic FDG uptake: is 48 h sufficient?

Annals of Nuclear Medicine - In this retrospective, single-center observational study, we investigated whether discontinuing metformin for at least 48&nbsp;h prevents metformin-induced...     

Ocular health among radiologists in the age of PACS: is it time for our profession to open its eyes to this issue in light of existing European legislation?

The regular use of visual display units (VDUs) at work has been shown to cause the development of a constellation of symptoms ranging from dry eyes to temporary myopia. European workers who use VDUs are now protected under detailed legislation enacted by the European Union (Directive 90/270/EEC). The use of picture archiving and communications systems, which are almost ubiquitous in European countries, means that, as a profession, radiologists fall under the remit of this legislation. This paper aims to assess the impact that full implementation of this law would have on a radiologist''s practice and to more broadly examine the issue of eye care as an occupational health issue in radiology. The authors conclude that eye care in the setting of regular VDU use among radiologists is an important quality control and occupational health issue. There is a clear legal basis requiring employers to provide regular eye examinations and reporting breaks. In the absence of leadership from employers on this issue individual radiologists have a responsibility to ensure that their work practices reflect the legal situation and minimise the effect of eye strain on their performance.The regular use of visual display units (VDUs) at work has been shown to cause the development of a constellation of symptoms ranging from dry eyes to temporary myopia. European workers who use VDUs are now protected under detailed legislation enacted by the European Union (Directive 90/270/EEC) [1]. The use of picture archiving and communications systems (PACS), which are almost ubiquitous in European countries, means that, as a profession, radiologists fall under the remit of this legislation. This paper aims to assess the impact that full implementation of this law would have on a radiologist''s practice and to more broadly examine the issue of eye care as an occupational health issue in radiology.     

The prepubertal years: a uniquely opportune stage of growth when the skeleton is most responsive to exercise?

The growing years may be the most opportune time in life for exercise to result in large increases in bone density, enough to reduce the risk of fracture late in life. However, it is not known if there is an 'optimal' time during growth when the skeleton is most responsive to exercise. Comparing the osteotrophic response to exercise between pre- and peripubertal children is complex because: (i) the development of the skeleton within each stage of puberty is characterised by differing temporal patterns of growth in bone size and mass; (ii) the hormonal regulation of the skeleton is unique to each stage of puberty; and (iii) it is difficult to equate the relative mechanical load placed on the prepubertal compared with the pubertal skeleton. There are sound biological bases for the hypotheses being proposed for both the pre- and peripubertal years being the time when the skeleton is most responsive to exercise; that is, exercise may enhance bone formation in a synergistic fashion in the presence of growth hormone (prepubertal years) or sex steroids (peripubertal years). The paucity of data and the complex methodology make it difficult to draw conclusions as to the most opportune time during growth when exercise may lead to the greatest osteotrophic response. The limited data available support the notion that the prepubertal years may be the most opportune time, due to increases in bone density and periosteal expansion of cortical bone.     

Clinically suspected pulmonary embolism: is it safe to withhold anticoagulation after a negative spiral CT?

The goal of this study was 3-month clinical outcome in non-anticoagulated patients with clinically suspected acute pulmonary embolism (PE) following a negative spiral CT. During a 6-month period 305 patients underwent spiral CT, of whom only 8 also had a lung scintigraphy. In patients with a final CT report read as not positive for acute PE, all hospital records and answers to a patient questionnaire were analyzed for episodes of venous thrombembolism (VTE). Acute PE was diagnosed at spiral CT in 61 patients (20 %). Twenty-six of the remaining 244 patients were excluded from further analysis because of (a) long-term anticoagulation due to symptomatic acute deep venous thrombosis (n = 5), clinically diagnosed acute PE (n = 2), chronic recurrent VTE (n = 4), and cardiac disorders (n = 5); and (b) a normal perfusion scintigram (n = 4) or a negative pulmonary arteriogram (n = 6). Three patients were lost to follow-up. Among the remaining 215 patients only 10 had undergone a negative lower extremity venous study. Sixteen patients (7 %) died during the follow-up period, 6 of whom underwent autopsy. Venous thrombembolism was diagnosed in three of the 215 patients (1.4 %, 95 % confidence limits: 0.5–4.0 %), one causing the patient's death. Two patients had advanced thoracic malignancies and the third severe chronic obstructive pulmonary disease (84 years old). A negative spiral CT may be able to exclude clinically significant acute PE with the same accuracy as a normal lung scintigraphy or a negative pulmonary arteriography. Received: 8 February 2000 Revised: 18 May 2000 Accepted: 22 May 2000     

Fluorine-18 fluorodeoxyglucose positron emission tomography in the staging and follow-up of lymphoma: is it time to shift gears?

Positron emission tomography (PET) imaging has become a very useful technique for staging and monitoring therapy response in lymphoma, providing unique information about the biological behavior of disease. Increased fluorine-18 fluorodeoxyglucose (FDG) uptake in lymphoma is based on elevated glycolysis and longer residence time of FDG in malignant cells compared with most normal tissues. The metabolic information provided by this technique suggests that FDG-PET may be more sensitive than the anatomical imaging modalities. Computed tomography (CT) is the principal imaging modality for the staging and restaging of lymphoma. Nonetheless, this technique has significant shortcomings, particularly in the post-therapy setting. Gallium-67 scintigraphy has played an important role in monitoring response to therapy and follow-up of patients; however, the sensitivity of 67Ga depends on the subtype of lymphoma and the size and location of disease. Published results strongly indicate that FDG-PET is superior to 67Ga imaging and may be equal or superior to CT for the detection of nodal as well as extranodal involvement in lymphoma.