Differentiation of periapical granulomas and cysts by using dental MRI: a pilot study

The purpose of this pilot study was to evaluate whether periapical granulomas can be differentiated from periapical cysts in vivo by using dental magnetic resonance imaging(MRI). Prior to apicoectomy, 11 patients with radiographically confirmed periapical lesions underwent dental MRI, including fat-saturated T2-weighted(T2 wFS) images, non-contrast-enhanced T1-weighted images with and without fat saturation(T1 w/T1 wFS), and contrast-enhanced fat-saturated T1-weighted(T1 wFS+C) images. Two independent observers performed structured image analysis of MRI datasets twice. A total of 15 diagnostic MRI criteria were evaluated, and histopathological results(6 granulomas and 5 cysts) were compared with MRI characteristics. Statistical analysis was performed using intraclass correlation coefficient(ICC), Cohen’s kappa(κ), Mann–Whitney U-test and Fisher’s exact test. Lesion identification and consecutive structured image analysis was possible on T2 wFS and T1 wFS+C MRI images. A high reproducibility was shown for MRI measurements of the maximum lesion diameter(intraobserver ICC = 0.996/0.998; interobserver ICC = 0.997), for the "peripheral rim" thickness(intraobserver ICC = 0.988/0.984; interobserver ICC = 0.970), and for all non-quantitative MRI criteria(intraobserver-κ = 0.990/0.995; interobserver-κ = 0.988). In accordance with histopathological results, six MRI criteria allowed for a clear differentiation between cysts and granulomas:(1) outer margin of lesion,(2) texture of "peripheral rim" in T1 wFS+C,(3)texture of "lesion center" in T2 wFS,(4) surrounding tissue involvement in T2 wFS,(5) surrounding tissue involvement in T1 wFS+C and(6) maximum "peripheral rim" thickness(all: P < 0.05). In conclusion, this pilot study indicates that radiation-free dental MRI enables a reliable differentiation between periapical cysts and granulomas in vivo. Thus, MRI may substantially improve treatment strategies and help to avoid unnecessary surgery in apical periodontitis.

Treatment practice of vasospasm during endovascular thrombectomy: an international survey

Background and aim The clinical importance and management of vasospasm as a complication during endovascular stroke treatment(EVT)has not been well studied.We sought to investigate current expert opinions in neurointervention and therapeutic strategies of iatrogenic vasospasm during EVT.Methods We conducted an anonymous international online survey(4 April 2023 to 15 May 2023)addressing treatment standards of neurointerventionalists(NIs)practising EVT.Several illustrative cases of patients with vasospasm during EVT were shown.Two study groups were compared according to the NI’s opinion regarding the potential influence of vasospasm on patient outcome after EVT using descriptive analysis.Results In total,534 NI from 56 countries responded,of whom 51.5%had performed>200 EVT.Vasospasm was considered a complication potentially influencing the patient’s outcome by 52.6%(group 1)whereas 47.4%did not(group 2).Physicians in group 1 more often added vasodilators to their catheter flushes during EVT routinely(43.7%vs 33.9%,p=0.033)and more often treated severe large-vessel vasospasm with vasodilators(75.3%vs 55.9%;p<0.001),as well as extracranial vasospasm(61.4%vs 36.5%,p<0.001)and intracranial medium-vessel vasospasm(27.1%vs 11.2%,p<0.001),compared with group 2.In case of a large-vessel vasospasm and residual and amenable medium-vessel occlusion during EVT,the study groups showed different treatment strategies.Group 2 continued the EVT immediately more often,without initiating therapy to treat the vasospasm first(9.6%vs 21.1%,p<0.001).Conclusion There is disagreement among NIs about the clinical relevance of vasospasm during EVT and its management.There was a higher likelihood of use of preventive and active vasodilator treatment in the group that perceived vasospasm as a relevant complication as well as differing interventional strategies for continuing an EVT in the presence of a large-vessel vasospasm.