A meta-analysis of the effect of stent design on clinical and radiologic outcomes of carotid artery stenting.

OBJECTIVE: Procedural characteristics, including stent design, may influence the outcome of carotid artery stenting (CAS). A thorough comparison of the effect of stent design on outcome of CAS is thus warranted to allow for optimal evidence-based clinical decision making. This study sought to evaluate the effect of stent design on clinical and radiologic outcomes of CAS. METHODS: A systematic search was conducted in MEDLINE, Embase, and Cochrane databases in May 2018. Included were articles reporting on the occurrence of clinical short- and intermediate-term major adverse events (MAEs; any stroke or death) or radiologic adverse events (new ischemic lesions on postprocedural magnetic resonance diffusion-weighted imaging [MR-DWI], restenosis, or stent fracture) in different stent designs used to treat carotid artery stenosis. Random effects models were used to calculate combined overall effect sizes. Metaregression was performed to identify the effect of specific stents on MAE rates. RESULTS: From 2654 unique identified articles, two randomized, controlled trials and 66 cohort studies were eligible for analysis (including 46,728 procedures). Short-term clinical MAE rates were similar for patients treated with open cell vs closed cell or hybrid stents. Use of an Acculink stent was associated with a higher risk of short-term MAE compared with a Wallstent (risk ratio [RR], 1.51; P = .03), as was true for use of Precise stent vs Xact stent (RR, 1.55; P < .001). Intermediate-term clinical MAE rates were similar for open vs closed cell stents. Use of open cell stents predisposed to a 25% higher chance (RR, 1.25; P = .03) of developing postprocedural new ischemic lesions on MR-DWI. No differences were observed in the incidence of restenosis, stent fracture, or intraprocedural hemodynamic depression with respect to different stent design. CONCLUSIONS: Stent design is not associated with short- or intermediate-term clinical MAE rates in patients undergoing CAS. Furthermore, the division in open and closed cell stent design might conceal true differences in single stent efficacy. Nevertheless, open cell stenting resulted in a significantly higher number of subclinical postprocedural new ischemic lesions detected on MR-DWI compared with closed cell stenting. An individualized patient data meta-analysis, including future studies with prospective homogenous study design, is required to adequately correct for known risk factors and to provide definite conclusions with respect to carotid stent design for specific subgroups.

Role of MR-DWI and MR-PWI in the radiotherapy of implanted pulmonary VX-2 carcinoma in rabbits.

OBJECTIVE: To detect the activity of tumor cells and tumor blood flow before and after the radiotherapy of implanted pulmonary VX-2 carcinoma in rabbit models by using magnetic resonance diffusion-weighted imaging (MR-DWI) and magnetic resonance perfusion weighted imaging (MR-PWI), and to evaluate the effectiveness and safety of the radiotherapy based on the changes in the MR-DWI and MR-PWI parameters at different treatment stages. METHODS: A total of 56 rabbit models with implanted pulmonary VX-2 carcinoma were established, and then equally divided into treatment group and control group. MR-DWI and MR-PWI were separately performed using a Philips Acheiva 1.5T MRI machine (Philips, Netherland). MRI image processing was performed using special perfusion software and the WORKSPACE advanced workstation for MRI. MR-DWI was applied for the observation of tumor signals and the measurement of apparent diffusion coefficient (ADC) values; whereas MR-PWI was used for the measurement of wash in rate (WIR), wash out rate (WOR), and maximum enhancement rate (MER). The radiation treatment was performed using Siemens PRIMUS linear accelerator. In the treatment group, the radiotherapy was performed 21 days later on a once weekly dosage of 1,000 cGy to yield a total dosage of 5,000 cGy. RESULTS: THE ADC PARAMETERS IN THE REGION OF INTEREST ON DWI WERE AS FOLLOWS: on the treatment day for the implanted pulmonary VX-2 carcinoma, the t values at the center and the edge of the lesions were 1.352 and 1.461 in the treatment group and control group (P>0.05). During weeks 0-1 after treatment, the t values at the center and the edge of the lesions were 1.336 and 1.137 (P>0.05). During weeks 1-2, the t values were 1.731 and 1.736 (P<0.05). During weeks 2-3, the t values were 1.742 and 1.749 (P<0.05). During weeks 3-4, the t values were 2.050 and 2.127 (P<0.05). During weeks 4-5, the t values were 2.764 and 2.985 (P<0.05). The ADC values in the treatment group were significantly higher than in the control group. After the radiotherapy (5,000 cGy), the tumors remarkably shrank, along with low signal on DWI, decreased signal on ADC map, and remarkably increased ADC values. As shown on PWI, on the treatment day for the implanted pulmonary VX-2 carcinoma, the t values of the WIR, WOR, and MER at the center of the lesions were 1.05, 1.31, and 1.33 in the treatment group and control group (P>0.05); in addition, the t values of the WIR, WOR, and MER at the edge of the lesions were 1.35, 1.07, and 1.51 (P>0.05). During weeks 0-1 after treatment, the t values of the WIR, WOR, and MER at the center of the lesions were 1.821, 1.856, and 1.931 (P<0.05); in addition, the t values of the WIR, WOR, and MER at the edge of the lesions were 1.799, 2.016, and 2.137 (P<0.05). During weeks 1-1 after treatment, the t values of the WIR, WOR, and MER at the center of the lesions were 2.574, 2.156, and 2.059 (P<0.05) and the t values of the WIR, WOR, and MER at the edge of the lesions were 1.869, 2.058, and 2.057 (P<0.05). During weeks 2-3 after treatment, the t values of the WIR, WOR, and MER at the center of the lesions were 2.461, 2.098, and 2.739 (P<0.05) and the t values of the WIR, WOR, and MER at the edge of the lesions were 2.951, 2.625, and 2.154 (P<0.05). During weeks 3-4 after treatment, the t values of the WIR, WOR, and MER at the center of the lesions were 2.584, 2.107, and 2.869 (P<0.05) and the t values of the WIR, WOR, and MER at the edge of the lesions were 2.057, 2.637, and 2.951 (P<0.05). During weeks 4-5 after treatment, the t values of the WIR, WOR, and MER at the center of the lesions were 2.894, 2.827, and 3.285 (P<0.05) and the t values of the WIR, WOR, and MER at the edge of the lesions were 3.45, 3.246, and 3.614 (P<0.05). After the radiotherapy (500 cGy), the tumors shrank on the T1WI, WIR, WOR, and MER; meanwhile, the PWI parameter gradually decreased and reached its minimum value. CONCLUSIONS: MR-DWI and MR-PWI can accurately and directly reflect the inactivation of tumor cells and the tumor hemodynamics in rabbit models with implanted pulmonary VX-2 carcinoma, and thus provide theoretical evidences for judging the clinical effectiveness of radiotherapy for the squamous cell carcinoma of the lung.

Artificial Intelligence for Automated DWI/FLAIR Mismatch Assessment on Magnetic Resonance Imaging in Stroke: A Systematic Review.

We conducted this Systematic Review to create an overview of the currently existing Artificial Intelligence (AI) methods for Magnetic Resonance Diffusion-Weighted Imaging (DWI)/Fluid-Attenuated Inversion Recovery (FLAIR)-mismatch assessment and to determine how well DWI/FLAIR mismatch algorithms perform compared to domain experts. We searched PubMed Medline, Ovid Embase, Scopus, Web of Science, Cochrane, and IEEE Xplore literature databases for relevant studies published between 1 January 2017 and 20 November 2022, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We assessed the included studies using the Quality Assessment of Diagnostic Accuracy Studies 2 tool. Five studies fit the scope of this review. The area under the curve ranged from 0.74 to 0.90. The sensitivity and specificity ranged from 0.70 to 0.85 and 0.74 to 0.84, respectively. Negative predictive value, positive predictive value, and accuracy ranged from 0.55 to 0.82, 0.74 to 0.91, and 0.73 to 0.83, respectively. In a binary classification of ±4.5 h from stroke onset, the surveyed AI methods performed equivalent to or even better than domain experts. However, using the relation between time since stroke onset (TSS) and increasing visibility of FLAIR hyperintensity lesions is not recommended for the determination of TSS within the first 4.5 h. An AI algorithm on DWI/FLAIR mismatch assessment focused on treatment eligibility, outcome prediction, and consideration of patient-specific data could potentially increase the proportion of stroke patients with unknown onset who could be treated with thrombolysis.

Radiomic analysis on magnetic resonance diffusion weighted image in distinguishing triple-negative breast cancer from other subtypes: a feasibility study.

PURPOSE: This work aimed to explore whether radiomic features on magnetic resonance diffusion weighted image (MR DWI) can be used to identify triple-negative breast cancer (TNBC) and other subtypes (non-TNBC). MATERIALS AND METHODS: This retrospective study included 221 unilateral patients who underwent breast MR imaging prior to neoadjuvant chemotherapy. The subtypes of breast cancer include luminal A (n = 63), luminal B (n = 103), human epidermal growth factor receptor-2 (HER2) overexpressing (n = 30), and triple negative (n = 25). Radiomic features were extracted using Omini-Kinetic software on DWI. Student's t-test and Mann-Whitney U test were used to compare the features between TNBC and non-TNBC patients. Logistic regression analysis and receiver operating characteristic (ROC) curve were used to evaluate the diagnostic efficiency of radiomic features. The Fisher discriminant model was employed to distinguish TNBC and non-TNBC patients automatically. An additional validation dataset with 169 patients was utilized to validate the model. RESULTS: A total of 76 imaging features were extracted from each lesion on DWI images, and 12 radiomic features were statistically significant between TNBC and non-TNBC patients (P < 0.05). The area of receiver operating characteristic curve (AUC) was 0.817 to apply logistic regression analysis. The accuracy of Fisher discriminant model in distinguishing TNBC and non-TNBC patients was 95.4%, and leave-one-out cross validation was achieved with an accuracy of 83.7%. The same classification analysis of the validation dataset showed an accuracy of 83.4% and an AUC of 0.804. CONCLUSION: Breast lesions exhibit differences in radiomic features from DWI, enabling good discrimination between TNBC and non-TNBC tumors.

The comparison of the value of ct imaging and selected MRI sequences (including DWI) in the evaluation of axonal injuries.

BACKGROUND: Diffuse axonal injuries of the brain consist in the damage (overstretching or torsion) of white matter axons, as a result of the forces of energy waves, evoked in the moment of injury, together with its accelerating-retarding inertia effect. Patients with DAI are most frequently the casualties of high speed car accidents. Diffuse axonal injuries of the brain are one of the most common acute brain injuries, with lesions typically occurring in the periventricular white matter, corpus callosum, and on the borderline of the white and grey matter, subventricularly. The diagnosis of axonal injuries is difficult, as the majority of lesions found in DAI are of microscopic nature. MATERIAL/METHODS: The material included the evaluation of 8 patients with craniocerebral injuries, normal results of brain CT (or showing slight posttraumatic lesions), and in severe neurological clinical state (continuing coma), which was all suggestive of a diffuse axonal injury. The patients were subjected to brain MRI studies within an MRI trauma protocol including FLAIR and DWI sequences, as well as sagittal T2-weighed images, which shortened the diagnostic examination time and was sufficient for the visualisation of DAI-specific lesions. RESULTS: On MRI examination, seven patients were diagnosed with diffuse foci of high signal intensity, located in corpus callosum, basal ganglia, thalamus and brain stem, although the CT examination results were normal or revealing minor changes. The foci were most prominent in DWI images. DWI sequence showed a diffuse cytotoxic oedema of white matter in one case, in which the CT results were normal. CONCLUSIONS: The MRI examination with DWI should become a basic diagnostic tool in DAI. Due to patients' severe condition, the diagnostic process should be shortened. This could be done with the use of some selected sequences and projections of brain MRI, including transverse DWI and FLAIR, as well as T2-weighed images in sagittal plane, which reduces the time of the examination by approx. 12-15 minutes. Correct and quick diagnosis of a diffuse axonal injury is of major therapeutic and prognostic importance.

Primary breast angiosarcoma in a young woman.

INTRODUCTION: Angiosarcomas of the breast are a rare subtype of sarcomas that frequently are diagnosed after radiation therapy for primary breast cancer. Primary angiosarcomas are rare entities accounting 0.05% of all malignant breast neoplasm. PRESENTATION OF CASE: We report a case of primary angiosarcoma of the breast in a 25 years woman, with no previous radiotherapy, treated with a total mastectomy followed by radio-chemotherapy. DISCUSSION: Total mastectomy appears to be the only treatment known that has proven to benefit these patients. Adjuvant treatment has not proven value up until today. The 5-year disease free survival for grade 1 tumors can be as high as 76%, and up to 15% for grade 3. CONCLUSION: Due to the rarity of these tumors there is no standard therapies approach.