Intracranial hemorrhage complicating acute stroke: how common is hemorrhagic stroke on initial head CT scan and how often is initial clinical diagnosis of acute stroke eventually confirmed?

BACKGROUND AND PURPOSE: Assessment of possible hemorrhage in acute stroke before appropriate therapy remains important. The aim of this study was to determine the frequency with which patients present with clinical stroke and have intracranial hemorrhage on initial noncontrast head CT scan (NCCT). In addition, we sought to determine the frequency with which initial clinical diagnosis acute stroke is confirmed in this group. METHODS: Medical records of 691 consecutive patients with admitting diagnosis of acute stroke were evaluated retrospectively. Results of initial NCCT performed within 24 hours after presentation were assessed. All patients were examined before anticoagulation or thrombolysis. Correlation with treatment and leading differential etiology was made. RESULTS: Twenty-five patients (25/691 [3.6%]) had hemorrhage. Twenty-three patients (23/25 [92%]) had intraparenchymal hemorrhage only. One patient (1/25 [4%]) had a combination of intraparenchymal and subarachnoid hemorrhage. One patient (1/25 [4%]) had subdural hemorrhage only. Twenty-two NCCT scans (22/25 [88%]) were performed within 6 hours of presentation. Seventeen NCCT scans (17/25 [68%]) were performed within 3 hours of presentation. CONCLUSION: Despite frequent concerns for intracranial hemorrhage complicating acute stroke and treatment, a low percentage of patients had this complication. Moreover, our frequency is much lower than the wide ranges reported elsewhere. The most common type of intracranial hemorrhage in this cohort was intraparenchymal, but subarachnoid and subdural hemorrhages were also diagnosed and must also be considered. Twenty-eight percent of patients with initial suspicion of acute ischemic stroke are eventually given other diagnoses. These results may have implications for use of CT imaging.     

Acquisition of MR perfusion images and contrast-enhanced MR angiography in acute ischaemic stroke patients: which procedure should be done first?

Multimodal MRI for acute ischaemic stroke usually includes perfusion imaging (PI) and contrast-enhanced neck MR angiography (CE-MRA), as well as diffusion-weighted imaging and T2* weighted imaging. Because both PI and CE-MRA require the infusion of contrast medium, the likelihood exists that one study may conflict with the other due to the accumulation of previously injected contrast medium. The purpose of this study is to determine the appropriate order of PI and CE-MRA in this multimodal MRI protocol for evaluation of acute ischaemic stroke. We studied 35 patients with acute ischaemic stroke in the unilateral middle cerebral artery territory. 17 patients underwent CE-MRA following PI (group A) and 18 patients underwent PI following CE-MRA (group B). For qualitative analysis of the CE-MRA and colour-coded maps of the PI, two independent observers graded the image quality. Interobserver agreement was assessed using kappa statistics, and we assessed the statistical differences of imaging quality between groups A and B using the Mann-Whitney U-test). For the quantitative analysis of PI, two parameters--the maximum change in the transverse relaxation rate (DeltaR2(max)) and the relative signal drop (DeltaS/S(0))--were calculated from the time-signal intensity curve of an unaffected middle cerebral artery territory, and we compared the differences in the parameters of group A and B (t-test). Interobserver agreements for CE-MRA and PI were good. In the qualitative analysis of CE-MRA and PI, no significant difference was observed between groups A and B. In the quantitative analysis of PI, there were no relevant differences in DeltaR2(max) and DeltaS/S(0) between the two groups. In simultaneous CE-MRA and PI, there was no deterioration of diagnostic imaging quality with regard to the order of the two post-contrast sequences. They can be performed according to the preference of each institution.     

Comparison of T2-weighted and contrast-enhanced T1-weighted MR imaging at 1.5?T for assessing the local extent of cervical carcinoma

Objective  

To compare two MR sequences at 1.5 T—T2-weighted and contrast-enhanced T1-weighted images—by using macroscopic sections to determine which image type enables the most accurate assessment of cervical carcinoma.     

Hyperintense globus pallidus on T1-weighted MR imaging in acute kernicterus: is it common or rare?

Globus pallidus involvement is a well-known magnetic resonance (MR) imaging finding of acute kernicterus. However, it is not clear how early the involvement of globus pallidus occurs and whether or not it is seen in every case. Therefore, we aimed to investigate the globus pallidus involvement in 13 neonates with acute kernicterus by MR imaging. Thirteen neonates who were admitted with jaundice, encephalopathy and indirect hyperbilirubinemia (mean, 37.0 mg/dl) were prospectively evaluated with cranial MR imaging. Pathological signal changes were noted concerning the globus pallidus. Eight of the 13 patients demonstrated bilateral, symmetric increased signal intensity in the globus pallidus on T1-weighted MR imaging. These lesions were not apparent on T2-weighted images. Multiple parenchymal punctuate T1 hyperintense lesions were detected in one patient without globus pallidus involvement. This appearance was consistent with hemorrhage. The MR imaging findings of the other four patients showed no evidence of abnormality. The symmetric involvement of globus pallidus seen as hyperintense on T1-weighted MR imaging is a common and characteristic finding of acute kernicterus.     

Breast cancer abutting the pectoralis major muscle on breast MRI: what are the clinical implications?

Objectives:Defining the posterior extent of breast cancer prior to surgery has clinical implications. However, there are limited data available to guide the interpretation of breast cancers seen on MRI that abut the pectoralis muscle but lack associated muscle enhancement.Methods:In this retrospective study of breast MRIs performed between May 2008 and July 2019, 43 female patients demonstrated breast cancers abutting the pectoralis muscle without enhancement of the muscle itself. Imaging features of the cancers as well as pathologic and clinical outcomes were recorded. Statistical analyses of associations between imaging findings and clinical outcomes were performed using Fisher’s exact test, logistic regression, a Mann–Whitney U test and/or Student’s t-test.Results:The pectoralis major muscle was pathologically invaded by carcinoma in 4/43 (9.3%). There was no significant association between pectoralis muscle invasion and any MR imaging feature of the breast cancer. Tumors causing deformation of the muscle contour by MRI, tumors larger in size, tumors with a larger extent abutting the muscle and tumors in which the imaging feature abutting the muscle was a mass or non-mass enhancement (rather than a spicule) were more commonly seen in patients with muscle invasion, although these did not reach statistical significance (p > 0.05).Conclusion:In this study, a lack of pectoralis muscle enhancement by MRI did not exclude pathologic muscle invasion by breast cancers abutting the muscle.Advances in knowledge:Knowledge of the likelihood of pectoralis muscle involvement for breast cancers abutting the pectoralis muscle on MRI may guide accurate interpretation and definition of the posterior extent of disease.     

Is the subthalamic nucleus hypointense on T2-weighted images? A correlation study using MR imaging and stereotactic atlas data

BACKGROUND AND PURPOSE: Although the subthalamic nucleus is the most frequently used target for surgical treatment of Parkinson's disease, the criteria on which it can be identified on T2-weighted images have never been clearly defined. This study was conducted to characterize the precise anatomic distribution of T2-weighted hyposignal in the subthalamic region and to correlate this hyposignal with iron content in the subthalamic nucleus. METHODS: The T2-weighted MR imaging acquisitions of 15 patients with Parkinson's disease were fused with a digitized version of the Schaltenbrand and Wahren anatomic atlas. The MR signal intensity within the anatomic limits of the subthalamic nucleus was evaluated. An anatomic specimen obtained at autopsy was used to evaluate iron content. RESULTS: In all patients, the subthalamic nucleus was hypointense on both sides in the anterior half of the nucleus. At more posterior levels of the nucleus, hypointensity was less frequently observed (20-80%). Hypointensity was never observed at the most posterior pole. Iron was present in the anteromedial part of the nucleus but absent at the most posterior levels. CONCLUSION: The hypointense signal intensity located lateral to the red nucleus and dorsolateral to the substantia nigra correlates with the presence of iron and corresponds anatomically to the subthalamic nucleus. It can therefore be used as a landmark for electrode implantation in patients with Parkinson's disease. It should, however, be emphasized that although hypointensity was always present in the anterior half of the subthalamic nucleus, the posterior part of the nucleus was not visible in most cases.     

Exercise in the management of type 2 diabetes mellitus: what are the benefits and how does it work?

In this article, we examine the results from meta-analyses of studies that have focused on the effects of supervised exercise in patients with established type 2 diabetes mellitus. Exercise has been clearly demonstrated to have benefits on blood glucose control (average reduction of glycated hemoglobin, 0.6%) and cardiovascular risk factors. These benefits are observed independently of any change in body mass index and fat mass, and are also seen in older populations. Multiple mechanisms are involved, and the improved insulin-sensitizing effect of exercise training is not restricted to muscle but extends to hepatic and adipose tissue. However, while the benefits of exercise in type 2 diabetes management are undisputable, it is not as easy to draw correlations between clinical benefit and the amount of physical activity included in daily life. Recent studies have shown encouraging results with moderate increases in physical activity, which are feasible for most patients and are sufficient to induce sustained positive changes for 2 years. Thus, the benefits of structured and supervised exercise in patients with type 2 diabetes have been consistently demonstrated. Currently, the primary challenge is to determine how long-term increased physical activity can be durably implemented in a patient's daily life.     

Ocular injuries in basketball and baseball: what are the risks and how can we prevent them?

Ocular trauma is a frequent result of sports-related injury during basketball and baseball. A screening sideline examination should be performed immediately to assess vision and evaluate the severity of damage. The team physician should be able to treat minor injuries and identify vision-threatening trauma for immediate referral. Injuries range from minor, including corneal abrasion and foreign bodies, to more severe, including hyphema, orbital fracture, and globe rupture. Resultant damage may be vision-threatening and permanent. Most of these injuries can be prevented with full-time use of sport-specific protective eyewear. Physicians should recommend appropriate eye protection and counsel patients accordingly.     

MR signal of the solid portion of pilocytic astrocytoma on T2-weighted images:is it useful for differentiation from medulloblastoma?

Background and purpose: Although imaging features of cerebellar pilocytic astrocytoma and medulloblastoma have been described in many texts, original comparisons of magnetic resonance intensity between these two tumours are limited. In the present study the results of magnetic resonance imaging (MRI) were reviewed, focusing especially on the signal intensity of the solid portion of these neoplasms. Methods: MR images of ten cerebellar pilocytic astrocytomas and ten medulloblastomas were reviewed. The signal intensities of the solid components were graded on a scale of 1 to 5, with higher scores indicating a signal intensity closer to that of water. The degree of enhancement, tumour cysts and peripheral oedema were evaluated on MR images. When the solid portion was heterogeneous (i.e. mixed signal intensity or degree of enhancement), the dominant area was selected for evaluation. Results: On T2-weighted images, the signal intensity of the solid portion was equal to that of cerebrospinal fluid (CSF) in 50% of pilocytic astrocytomas. No medulloblastomas showed such hyperintensity. Most medulloblastomas (80%) were isointense to grey matter. On T1-weighted images, the signal intensity varied widely in pilocytic astrocytomas; however, all medulloblastomas were iso- or hypointense to grey matter. The MR enhancement pattern, cystic component and peripheral oedema all varied in both tumour types and no specific features were identified. Conclusion: A signal intensity of the solid portion isointense to CSF on T2-weighted images was characteristic of cerebellar pilocytic astrocytomas; this was not observed in medulloblastomas. Attention to T2-weighted imaging of the solid portions of a tumour is easy and helpful in differentiating between cerebellar pilocytic astrocytoma and medulloblastoma.     

New iterative reconstruction techniques for cardiovascular computed tomography: how do they work, and what are the advantages and disadvantages?

The radiation doses associated with diagnostic CT scans has recently come under scrutiny. In the process of developing protocols with lower doses, it has become apparent that images reconstructed with a filtered back projection (FBP) technique are often inadequate. Although very fast and robust, FBP images are prone to high noise, streak artifacts and poor low contrast detectability in low dose situations. Manufacturers of CT equipment have responded to this limitation by developing new image reconstruction techniques that derive more information from the data set. These techniques are based on the use of maximum likelihood algorithms and are referred to at iterative reconstructions. This iterative process can be used on the slice data alone, a combination of raw and slice data or on the raw data alone. The latter approach, which is referred to as model based iterative reconstruction, is the most computationally demanding as it models the entire process, from the shape of the focal spot on the anode, the shape of the emerging x-ray beam, the three-dimensional interaction of the beam with the voxel in the patient and the two-dimensional interation of the beam with the detector. This article discusses the fundamentals of iterative reconstruction techniques, the pros and cons of the various manufacturer approaches and specific applications, especially to cardiovascular CT.     

Abdominal imaging findings on computed tomography in patients acutely infected with SARS-CoV-2: what are the findings?

Emergency Radiology - To investigate what findings are new on contrast-enhanced abdominopelvic CT in patients infected with SARS-CoV-2. Contrast-enhanced CT of the abdomen and pelvis of patients...     

Endometrial cancer: preoperative staging using three-dimensional T2-weighted turbo spin-echo and diffusion-weighted MR imaging at 3.0 T: a prospective comparative study

Objectives

To prospectively assess the efficacy of 3-T magnetic resonance (MR) imaging using the three-dimensional turbo spin-echo T2-weighted and diffusion-weighted technique (3D-TSE/DW) compared with that of conventional imaging using the two-dimensional turbo spin-echo T2-weighted and dynamic contrast-enhanced technique (2D-TSE/DCE) for the preoperative staging of endometrial cancer, with pathological analysis as the reference standard.

Methods

Seventy-one women with endometrial cancer underwent MR imaging using 3D-TSE/DW (b?=?1,000 s/mm²) and 2D-TSE/DCE. Two radiologists independently assessed the two imaging sets. Accuracy, sensitivity, and specificity for staging were analysed with the McNemar test; the areas under the receiver operating characteristic curve (Az) were compared with a univariate z-score test.

Results

The results for assessing deep myometrial invasion, accuracy, sensitivity, specificity and Az, respectively, were as follows: 3D-TSE/DW—observer 1, 87 %, 95 %, 85 % and 0.96; observer 2, 92 %, 84 %, 94 % and 0.95; 2D-TSE/DCE—observer 1, 80 %, 79 %, 81 % and 0.89; observer 2, 86 %, 84 %, 87 % and 0.86. Most of the values were higher with 3D-TSE/DW without significant differences (P?>?0.12). For assessing cervical stromal invasion, there were no significant differences in those values for both observers (P?>?0.6).

Conclusions

Accuracy of 3D-TSE/DW was at least equivalent to that of the conventional technique for the preoperative assessment of endometrial cancer.

Key Points

? New techniques in MR imaging help assess patients with endometrial cancer. ? A 3D T2-weighted TSE sequence seems equally as accurate as conventional techniques. ? Three-dimensional TSE/DW imaging does not require intravenous contrast material and is relatively quick. ? Tumour extent of endometrial cancer can be clearly shown on diffusion-weighted images. ? Junctional zone can be visualised well on 3D-TSE T2-weighted images.     

Eccentric exercises; why do they work, what are the problems and how can we improve them?

Eccentric exercises (EE) have proved successful in the management of chronic tendinopathy, particularly of the Achilles and patellar tendons, where they have been shown to be effective in controlled trials. However, numerous questions regarding EE remain. The standard protocols are time-consuming and require very motivated patients. EE are effective in some tendinopathies but not others. Furthermore, the location of the lesion can have a profound effect on efficacy; for example, standard EE in insertional lesions of the Achilles are ineffective. Until recently little was known of the effect of EE on tendinopathic tendons, although a greater understanding of this process is emerging. Additionally, recent in vivo evidence directly comparing eccentric and concentric exercises provides a possible explanation for the therapeutic benefit of EE. The challenge now is to make EE more effective. Suggestions on areas of future research are made.