Acta radiologica最新文献

Background: Carotid artery stenting (CAS) is an interventional management in preventing ischemic stroke caused by carotid artery stenosis. After the treatment with CAS, in-stent restenosis caused by neointimal hyperplasia may develop.

Purpose: This study aims to obtain a better determination of neointimal hyperplasia using superb microvascular imaging (SMI), which provides a high-quality visualization of the endoluminal lesions, and to compare these results with B-mode and Doppler ultrasound (US).

Material and methods: A total of 106 patients who underwent CAS in our interventional radiology unit between 2018 and 2020 were retrospectively analyzed. In total, 44 patients whose procedure images and post-procedural follow-up Doppler US and SMI data could be accessed were included.

Results: There were nine patients who had in-stent restenosis. One patient had no velocity increase; however, on SMI the measurements showed in-stent restenosis both in area and diameter. The other eight patients had a stenosis degree in the range of 50%-79% on Doppler US. Five patients had in-stent restenosis, both in Doppler US and SMI, by area and diameter measurements. Two patients underwent digital subtraction angiography (DSA).

Conclusion: We suggest that using SMI with duplex sonography improves detecting neointimal hyperplasia and in-stent restenosis. With SMI, better visualization of the stent lumen may improve the patient selection for DSA.

Background: Bisphosphonate-associated stress fractures, atypical femur fractures (AFF), are a rare subgroup of femoral stress fractures. Their correct and early diagnosis is imperative for appropriate treatment.

Purpose: To investigate the sensitivity of written radiology reports to mention radiographic features of AFF, depending on the time period and academic level of the hospital.

Material and methods: We used 171 patients, aged 55 years or older, who sustained an AFF between 2008 and 2010 (early period) identified through the Swedish National Patient Register and radiographic review and 104 patients identified through the Swedish Fracture Register between 2015 and 2018 (late period). Plain radiographs were extracted from 72 radiology departments in Sweden and individually re-reviewed and classified based on the American Society for Bone and Mineral Research case definition for AFF. Radiology reports were viewed for mentioning AFF or stress/insufficiency features (true positives). The number of true positives was compared with the number of false positives for both periods using non-parametric statistics and using the gold standard as reference.

Results: We obtained 98 of the possible 171 reports with 7% of true positives for the early period and 77 of the possible 104 reports with 27% true positives for the late period (P < 0.001). The level of improvement over time was independent of the academic level of the hospital.

Conclusion: Despite improvements over time, written radiology reports seldom mention AFF features. Clinicians, specifically orthopedic surgeons, are encouraged to contribute to a correct and early diagnosis to tailor treatment, while awaiting improvements in radiology reports.

Background: Computed tomography (CT) is the gold standard imaging modality for the assessment of 3D bony morphology but incurs the cost of ionizing radiation exposure. High-resolution 3D magnetic resonance imaging (MRI) with CT-like bone contrast (CLBC) may provide an alternative to CT in allowing complete evaluation of both bony and soft tissue structures with a single MRI examination.

Purpose: To review the technical aspects of an optimized stack-of-stars 3D gradient recalled echo pulse sequence method (3D-Bone) in generating 3D MR images with CLBC, and to present a pictorial review of the utility of 3D-Bone in the clinical assessment of common musculoskeletal conditions.

Material and methods: 3D-Bone is a black-bone imaging technique for acquiring high-resolution 3D MR images with strong CLBC, achieved by first rendering as high a signal as possible from non-cortical bone tissues, and second by minimizing signal contrast between non-cortical bone tissues.

Results: 3D-Bone can be used in the clinical evaluation of bony morphology in common musculoskeletal conditions. Advantages include strong bone-soft tissue contrast, resistance to motion artefacts, simple hardware and software requirements, and straightforward image processing. Disadvantages include non-specificity for cortical bone, sensitivity to susceptibility artefacts, a lack of quantitative tissue measurements, as well as overall lower image resolution and bone-soft tissue contrast compared to CT.

Conclusion: The use of 3D MRI pulse sequences providing CLBC such as 3D-Bone could potentially offer complete clinical evaluation of bony morphology and soft tissues with a single MRI study for certain clinical indications, negating the need for ionizing radiation exposure from CT and reducing costs.

Background: The wide variability in thresholds on computed tomography (CT) perfusion parametric maps has led to controversy in the stroke imaging community about the most accurate measurement of core infarction.

Purpose: To investigate the feasibility of using U-Net to perform infarct core segmentation in CT perfusion imaging.

Material and methods: CT perfusion parametric maps were the input of U-Net, while the ground truth segmentation was determined based on diffusion-weighted imaging (DWI). The dataset used in this study was from the ISLES2018 challenge, which contains 63 acute stroke patients receiving CT perfusion imaging and DWI within 8 h of stroke onset. The segmentation accuracy of model outputs was assessed by calculating Dice similarity coefficient (DSC), sensitivity, and intersection over union (IoU).

Results: The highest DSC was observed in U-Net taking mean transit time (MTT) or time-to-maximum (Tmax) as input. Meanwhile, the highest sensitivity and IoU were observed in U-Net taking Tmax as input. A DSC in the range of 0.2-0.4 was found in U-Net taking Tmax as input when the infarct area contains < 1000 pixels. A DSC of 0.4-0.6 was found in U-Net taking Tmax as input when the infarct area contains 1000-1999 pixels. A DSC value of 0.6-0.8 was found in U-Net taking Tmax as input when the infarct area contains ≥ 2000 pixels.

Conclusion: Our model achieved good performance for infarct area containing ≥ 2000 pixels, so it may assist in identifying patients who are contraindicated for intravenous thrombolysis.

Background: Cesarean hysterectomy in the placenta accreta spectrum (PAS) remains challenging due to difficulty in controlling perioperative bleeding.

Purpose: To compare the effectiveness and safety of perioperative balloon occlusion with versus without pelvic artery embolization in PAS women who underwent a cesarean hysterectomy.

Material and methods: A total of 26 pathological confirmed cases of PAS were retrospectively reviewed and categorized into two groups: perioperative balloon occlusion at either the anterior division of the internal iliac artery or uterine artery followed by gelfoam embolization (n = 12, study group) and perioperative balloon occlusion alone (n = 14, control group). Intraoperative estimated blood loss (EBL), a unit of packed red blood cell (pRBC) transfusion, surgical time, transfer to the intensive care unit (ICU), postoperative hospitalization days, postoperative complications, and Apgar scores were compared between the two groups.

Results: The median and interquartile range (IQR) intraoperative EBL in the study group (1200 mL [700-2100 mLl]) was significantly lower compared to those in the control group (1900 mL [1300-3200 mL]) (P = 0.044). There was no significant difference between the study and control groups in units of pRBC blood transfusion, surgical time, transfer to the ICU, postoperative length of stay, postoperative complications, and mean Apgar score at 1 min and 5 min.

Conclusion: The perioperative combination of balloon occlusion followed by embolization of the pelvic artery before cesarean hysterectomy is more effective in reducing blood loss than perioperative balloon occlusion alone in PAS with no difference in postoperative complications or neonatal outcomes.

Background: The Bosniak classification is designed to standardize evaluation of cystic renal masses and to communicate the risk of malignancy.

Purpose: To determine whether radiologists vary in their communication of Bosniak class III and IV cystic renal masses.

Material and methods: This retrospective study included 186 patients with CT or MRI reporting a Bosniak class III or IV mass. Radiology reports were evaluated to determine the noun representing the mass, the modifier to convey the likelihood of cancer, and recommendations for urologic referral. Electronic medical records were reviewed to determine if the patient saw a urologist.

Results: Of the patients, 112 (60%) had a class III mass and 74 (40%) had a class IV mass. Class III masses were more likely to be represented by the noun "lesion" rather than a "mass" (61/112 [54%] vs. 31/112 [28%]). Class IV masses are more likely to be represented as a "mass" (36/74 [59%] vs. 28/74 [38%]; P < 0.015). Cancer was described in 100/186 (54%) cases: 38/112 (35%) class III masses and 62/74 (72%) class IV masses (P < 0.001). The cancer terminology used included "renal cell carcinoma" (n = 57), "neoplasm" (n = 12), and "malignancy/malignant" (n = 86). Most radiology reports (n = 133, 72%) did not recommend urologic referral but 183 (98%) patients were referred and 181 (97%) ultimately saw a urologist.

Conclusion: Radiologists vary in their communication of class III and IV masses, reflecting historical terminology usage, nuanced interpretations, and an evolving understanding of renal cell carcinoma biology. This variance had minimal impact on urologic referral rates.

Hyperperfusion is related to vessel recanalization, tissue reperfusion, and collateral circulation. To determine the prognostic impact of hyperperfusion after an acute ischemic stroke (AIS) identified by arterial spin labeling (ASL) cerebral blood flow. Studies published in PubMed, Embase, and Cochrane Library databases were searched. Studies assessing the diagnostic performance of ASL hyperperfusion after AIS were included. Functional prognosis, hemorrhagic transformation (HT), infarction volume, and penumbra salvage volume were evaluated. The standardized mean difference or risk ratio was pooled, implementing a random effect model. Multiple subgroup analyses were performed. Seven studies including 617 participants were included in this meta-analysis. ASL hyperperfusion in AIS was correlated well with symptom severity and outcome after 24 h National Institutes of Health Stroke Scale (NIHSS) and 90-day modified Rankin Scale (mRS). Earlier ASL hyperperfusion was associated with a smaller infarction volume and a larger penumbra salvage volume, while also indicating a higher risk of HT. In addition, in subgroup analysis, our results demonstrated that thrombolysis, mechanical thrombectomy treatment, early improvement of NIHSS, and involving infarction in cortical territory are associated with ASL hyperperfusion. ASL hyperperfusion was related to a favorable functional outcome but an increased risk of HT. Stroke patients with hyperperfusion showed smaller infarction volume and larger penumbra salvage volume than those with non-hyperperfusion.

Background: Segmentation of the cochlea in temporal bone computed tomography (CT) is the basis for image-guided otologic surgery. Manual segmentation is time-consuming and laborious.

Purpose: To assess the utility of deep learning analysis in automatic segmentation of the cochleae in temporal bone CT to differentiate abnormal images from normal images.

Material and methods: Three models (3D U-Net, UNETR, and SegResNet) were trained to segment the cochlea on two CT datasets (two CT types: GE 64 and GE 256). One dataset included 77 normal samples, and the other included 154 samples (77 normal and 77 abnormal). A total of 20 samples that contained normal and abnormal cochleae in three CT types (GE 64, GE 256, and SE-DS) were tested on the three models. The Dice similarity coefficient (DSC) and Hausdorff distance (HD) were used to assess the models.

Results: The segmentation performances of the three models improved after adding abnormal cochlear images for training. SegResNet achieved the best performance. The average DSC on the test set was 0.94, and the HD was 0.16 mm; the performance was higher than those obtained by the 3D U-Net and UNETR models. The DSCs obtained using the GE 256 CT, SE-DS CT, and GE 64 CT models were 0.95, 0.94, and 0.93, respectively, and the HDs were 0.15, 0.18, and 0.12 mm, respectively.

Conclusion: The SegResNet model is feasible and accurate for automated cochlear segmentation of temporal bone CT images.

Background: Different parotid tumors differ in terms of treatment strategies due to their distinct biological behaviors. Time-dependent diffusion magnetic resonance imaging (t_d-dMRI) can characterize and quantify the cytological indexes, and then aid the differential diagnosis of various tumors. However, the value of t_d-dMRI in the analysis of parotid gland tumors remains unclear.

Purpose: To investigate the value of quantitative parameters derived from t_d-dMRI in the analysis of parotid gland tumors.

Material and methods: In total, 39 patients with parotid gland tumors were prospectively enrolled, including 24 patients with polymorphic adenomas (PAs), eight with Warthin's tumors (WTs), and seven with malignant tumors (MTs). T_d-dMRI was performed for preoperative evaluation. Intracellular volume fraction (V_in), mean cell size (d), extracellular diffusion coefficient (D_ex), and cellularity were obtained based on the Imaging Microstructural Parameters Using Limited Spectrally Edited Diffusion model, and compared among the three groups. One-way ANOVA, Kruskal-Wallis test, and receiver operating characteristic (ROC) curve analysis were performed for further statistical analysis as appropriate.

Results: Significant differences were found in all t_d-dMRI-derived indexes among PAs, WTs, and MTs (all P < 0.05). V_in was the sole parameter with significant differences for all sub-group comparisons (PAs vs. WTs, P < 0.001; PAs vs. MTs, P = 0.031; WTs vs. MTs, P = 0.047). With V_in values of 0.267, 0.231, and 0.260 as threshold, respectively, optimal performance levels were obtained for differentiating PAs from WTs (area under the ROC curve [AUC]=0.932, sensitivity=0.917, and specificity=0.875), PAs from MTs (AUC=0.744, sensitivity=0.833, and specificity=0.714), and WTs from MTs (AUC=0.750, sensitivity=0.875, and specificity=0.714).

Conclusion: Microstructural parameters derived from t_d-dMRI, especially V_in, might be promising imaging biomarkers for characterizing parotid gland tumors.

Background: Acute ischemic stroke (AIS) refers to a sudden loss of blood flow in a region of the brain, which leads to a loss of neurological function.

Purpose: To unveil the efficacy of neuromuscular electrical stimulation (NMES) with modern rehabilitation techniques in AIS patients with post-motor dysfunction.

Material and methods: A total of 200 AIS patients with post-motor dysfunction were divided into groups A, B, C, and D (n = 50). Patients in the four groups were routinely treated with medicine, on this basis: group B received NMES treatment; group C received modern rehabilitation technology treatment; and group D was treated with NMES and modern rehabilitation technology. Rehabilitation effect, cerebral hemodynamic indices, neurological function recovery, Fugl-Meyer Assessment (FMA) and Motor Assessment Scale (MAS) scores, self-care, and quality of life were compared.

Results: After treatment, the total effective rate of group D was 96% higher than that of group A (64%), group B (82%), and group C (84%). Bilateral middle cerebral artery Vm and Vs and scores of FMA, MAS, functional independence measure, and modified Barthel index increased; RI and NHISS scores decreased; and all group D improved significantly versus groups A, B, and C, and both groups B and C improved significantly versus group A.

Conclusion: NMES with modern rehabilitation technologies synergistically treat motor dysfunction after AIS with ideal rehabilitation effect, improving cerebral hemodynamics, neurological and limb motor function recovery, and self-care ability and quality of life.