Background: Thyroid nodules are highly prevalent, affecting up to 75% of the population, yet most are benign. The limited specificity of ultrasound-based workup leads to substantial overdiagnosis and overtreatment, underscoring the need for improved imaging-based classification. Diffusion-weighted MRI (DWI), quantified via the apparent diffusion coefficient (ADC), has emerged as a promising imaging biomarker. This meta-analysis updates pooled diagnostic performance metrics and systematically evaluates which DWI acquisition techniques, imaging parameters, and combinations with other MRI modalities are most promising for clinical translation. Methods: PubMed, Web of Science, Scopus, and ProQuest were systematically searched. Pooled sensitivity, specificity, and area under the curve (AUC) were calculated using bivariate random-effects models. The effects of b-value, magnetic field strength, echo time, and diffusion model on diagnostic accuracy and ADC values were examined through subgroup and meta-regression analyses. Results: Forty-six studies (3003 nodules) were included. Pooled sensitivity and specificity were 0.84 (95% CI: 0.81–0.86) and 0.88 (95% CI: 0.85–0.90), with an AUC of 0.912. Intravoxel incoherent motion and diffusion kurtosis imaging showed no added value over the mono-exponential model. For the mono-exponential model, a negative association between b-values and reported ADCs was observed, whereas no association was found between b-values and diagnostic accuracy. Magnetic field strength and echo time did not affect ADCs. Combining DWI with morphological imaging showed the potential to further enhance diagnostic performance. Conclusions: DWI holds strong potential to improve the diagnostic workup of thyroid nodules. Technical standardization, particularly of key acquisition parameters, should be pursued to enable clinical implementation.

Objective: The insertion of venous catheters into supra-aortic vessels is a standard procedure in the treatment of a large number of diseases. Incorrect placement of venous catheters into and accidental perforation of arterial vessels is a rare but serious complication that can lead to severe bleeding, dissections, and strokes. Materials and Methods: We present a case of iatrogenic malposition of a Broviac catheter into the right vertebral artery and its successful treatment through stenting of the perforation site using a Walrus balloon catheter to achieve a secure treatment position and eventually cover the perforation site. Additionally, we conducted a systematic literature review on endovascular rescue procedures in inadvertent injuries of the supra-aortic arteries related to venous catheter placement. Results: A balloon guide catheter was used to achieve a secure treatment position for the deployment of a stent graft covering the perforation site, ensuring no significant arterial hemorrhage occurred during the removal of the incorrectly placed Broviac catheter. The review of the literature on endovascular rescue procedures for supra-aortic arterial vessel damage caused by venous catheter placement revealed that endovascular treatment has been successful in all reported cases of catheter-related supra-aortic arterial injury. Primary stent graft placement without additional actions was the most common treatment approach. Conclusions: In the treatment of iatrogenic injuries to the supra-aortic vessels, endovascular treatment strategies represent a safe, reliable, and generally recognized option and thus are used much more frequently than surgical procedures. Key point: In rare cases of accidental malposition of venous catheters into supra-aortic arterial vessels, endovascular insertion of a stent graft covering the perforation site using a balloon guide catheter can be a safe treatment option.

The number of stem cell transplants for hematologic malignancies has doubled since 2000 and continues to rise. Acute complications within the first 100 days post-transplant are linked to high morbidity and mortality of up to 30%. Since all organ systems can be affected and symptoms may be subtle, imaging plays a central role in early detection and monitoring of these complications. In response to increasing transplant numbers, expanding indications, and rapid therapeutic advances, the European Society for Blood and Marrow Transplantation (EBMT) revised its handbook in 2024. Most existing reviews on imaging acute complications post-transplant are five to ten years old. This article aims to provide an updated overview for radiologists increasingly confronted with acute complications after stem cell transplantation. The structure of this systematic review follows the updated EBMT Handbook. A systematic search was conducted in the PUBMED database to identify original studies on imaging of acute post-transplant complications from the past five years. A supplementary selective search helped to integrate the findings into the EBMT-handbook-aligned framework. A total of 29 original studies published in the last five years were included, providing new insights into imaging of acute complications post-HSCT. This review offers a concise overview of typical acute organ-specific complications following stem cell transplantation and highlights recent advances in imaging.