RADIOLOGIA最新文献

Introduction

Various clinical and radiologic variables impact the neurologic prognosis of patients with ischemic cerebrovascular accidents. About 30% of ischemic cerebrovascular accidents are caused by proximal obstruction of the anterior circulation; in these cases, systemic thrombolysis is of limited usefulness. CT angiography is indicated in candidates for endovascular treatment. Various radiologic factors, including the grade of leptomeningeal collateral circulation, as well as the length, density, and extension of the thrombus, have been identified as predictors of neurologic prognosis after anterior ischemic cerebrovascular accidents due to proximal vascular obstruction. Final infarct volume correlations with mortality and long-term functional outcome in these patients. This study aimed to determine the best predictors of final infarct volume on CT angiography in patients with ischemic cerebral accidents due to proximal occlusion.

Materials and methods

This retrospective observational study included adults with ischemic cerebrovascular accidents due to obstruction of the anterior circulation diagnosed by CT angiography in the period comprising June 2009 through December 2019. We measured the length and density of the thrombus in unenhanced CT images, and we used the clot burden score to record the grade of leptomeningeal collateral circulation and the extension of the thrombus. Then we measured the final infarct volume on follow-up CT and analyzed the correlations among these radiologic factors in the infarct volume.

Results

We included 54 patients [mean age, 82 y; 41 (75%) women] with ischemic cerebrovascular accidents due to proximal occlusion. About 60% of the cerebrovascular accidents affected the right cerebral hemisphere, and the most commonly affected vessel was the M1 segment of the medial cerebral artery (40.7%). Final infarct volume correlated with the grade of leptomeningeal collateral circulation (p = 0.03) and with the clot burden score (p = 0.01). Neither the length nor the density of the thrombus correlated with final infarct volume.

Conclusion

The final infarct volume can be estimated on the initial CT angiogram. Nevertheless, we found no useful predictive factors in unenhanced CT images. The best independent radiologic predictors of the final infarct volume are the grade of collateral circulation and the clot burden score, especially in patients who did not undergo mechanical thrombectomy, because mechanical thrombectomy improves outcomes. These factors are important for decision making in the management of patients with ischemic cerebrovascular accidents due to proximal occlusion.

Generalized lymphatic anomaly (GLA) is an uncommon congenital disease secondary to the proliferation of lymphatic vessels in any organ except the central nervous system. GLA has a wide spectrum of clinical and radiological presentations, among which osteolytic lesions are the most widespread, being the ribs the most commonly affected bone. GLA is diagnosed mainly in children and young adults; nevertheless, on rare occasions it can remain asymptomatic and be detected incidentally in older patients. We present an unusual case of GLA in an asymptomatic 54-year-old man who had atypically distributed, purely cystic bone lesions on CT; measuring the Hounsfield (HU) of these lesions enabled us to suspect GLA. This suspicion was confirmed with MRI, PET/CT, CT-guided fine-needle aspiration biopsy, and fluoroscopy-guided percutaneous vertebral biopsy. After surgical resection of one of the lesions, histologic study provided the definitive diagnosis.

Background and objective

Acute aortic syndrome (AAS) is uncommon and difficult to diagnose, with great variability in clinical presentation. To develop a computerized algorithm, or clinical decision support system (CDSS), for managing and requesting imaging in the emergency department, specifically computerized tomography of the aorta (CTA), when there is suspicion of AAS, and to determine the effect of implementing this system. To determine the factors associated with a positive radiological diagnosis that improve the predictive capacity of CTA findings.

Materials and methods

After developing and implementing an evidence-based algorithm, we studied suspected cases of AAS. Chi-squared test was used to analyze the association between the variables included in the algorithm and radiological diagnosis, with 3 categories: no relevant findings, positive for AAS, and alternative diagnoses.

Results

130 requests were identified; 19 (14.6%) had AAS and 34 (26.2%) had a different acute pathology. Of the 19 with AAS, 15 had been stratified as high risk and 4 as intermediate risk. The probability of AAS was 3.4 times higher in patients with known aortic aneurysm (P = .021, 95% CI 1.2–9.6) and 5.1 times higher in patients with a new aortic regurgitation murmur (P = .019, 95% CI 1.3–20.1). The probability of having an alternative severe acute pathology was 3.2 times higher in patients with hypotension or shock (P = .02, 95% CI 1.2–8.5).

Conclusion

The use of a CDSS in the emergency department can help optimize AAS diagnosis. The presence of a known aortic aneurysm and new-onset aortic regurgitation were shown to significantly increase the probability of AAS. Further studies are needed to establish a clinical prediction rule.

In recent decades, the dreaded adverse effect of bisphosphonates, osteonecrosis of the jaw, has been widely reported and described in detail. Osteonecrosis of the jaw consists of the destruction of part of the maxilla as a consequence of these antiresorptive drugs. In recent years, new drugs that can also cause osteonecrosis of the jaw (e.g., some monoclonal antibodies or antiangiogenic drugs) have come on the market. For this reason, the term “bisphosphonate-related osteonecrosis of the jaw” has been replaced with “medication-related osteonecrosis of the jaw (MRONJ).

This review aims to describe the radiologic characteristics of MRONJ that, although nonspecific, radiologists need to recognize in the appropriate clinical context.

Prostate cancer is very common among men. Radiology, mainly through MRI, plays a key role in the different stages of prostate cancer: diagnosis, staging and treatment assessment. The correct management of MRI requires knowledge and proper use of the different guidelines developed for the acquisition, interpretation and reporting of MRI in diagnosis (PI-RADS guide), whole body staging (MET-RADS guide), active surveillance (PRECISE guide) and local recurrence (PI-RR guide) in prostate cancer. The objective of this article is to show an update and synthesis of the most relevant aspects of these MRI guidelines for an optimal use and thus providing a more effective management of prostate cancer.

Objective

To evaluate the behavior of adrenal adenomas and metastases with dual-energy CT, analyzing the attenuation coefficient in monochromatic images at three different levels of energy (45, 70, and 140 KeV) and the tissue concentrations of fat, water, and iodine in material density maps, with the aim of establishing optimal cutoffs for differentiating between these lesions and comparing our results against published evidence.

Materials and methods

This retrospective case-control study included oncologic patients diagnosed with adrenal metastases in the 6-12 months prior to the study who were followed up in our hospital between January and June 2020. For each case (patient with metastases) included in the study, we selected a control (patient with an adrenal adenoma) with a nodule of similar size. All patients were studied with a rapid-kilovoltage-switching dual-energy CT scanner, using a biphasic acquisition protocol. We analyzed the concentration of iodine in paired water-iodine images, the concentration of fat in the paired water-fat images, and the concentration of water in the paired iodine-water and fat-water images, in both the arterial and portal phases. We also analyzed the attenuation coefficient in monochromatic images (at 55, 70, and 140 KeV) in the arterial and portal phases.

Results

In the monochromatic images, in both the arterial and portal phases, the attenuation coefficient at all energy levels was significantly higher in the group of patients with metastases than in the group of patients with adenomas. This enabled us to calculate the optimal cutoffs for classifying lesions as adenomas or metastases, except for the arterial phase at 55 KeV, where the area under the receiver operating characteristic curve (AUC) for the estimated threshold (0.68) was not considered accurate enough to classify the lesions. For the arterial phase at 70 KeV, the AUC was 0.76 (95% CI: 0.663-0.899); the optimal cutoff (42.4 HU) yielded 92% sensitivity and 60% specificity. For the arterial phase at 140 KeV, the AUC was 0.94 (95% CI: 0.894-0.999); the optimal cutoff (18.9 HU) yielded 88% sensitivity and 94% specificity). For the portal phase at 55 KeV, the AUC was 0.76 (95% CI: 0.663-0.899); the optimal cutoff (95.4 HU) yielded 68% sensitivity and 84% specificity. For the portal phase at 70 KeV, the AUC was 0.82 (95% CI: 0.757-0.955); the optimal cutoff (58.4 HU) yielded 80% sensitivity and 84% specificity. For the portal phase at 140 KeV, the AUC was 0.9 (95% CI: 0.834v0.987); the optimal cutoff (16.35 HU) yielded 96% sensitivity and 84% specificity. In the material density maps, in the arterial phase, significant differences were found only for the iodine-water pair, where the concentration of water was higher in the group with metastases (1018.8 ± 7.6 mg/cm³ vs. 9