Now showing items 21-40 of 1419

    • Distribution and bulk flow analyses of the intraflagellar transport (IFT) motor kinesin-2 support an "on-demand" model for Chlamydomonas ciliary length control

      Patel, Mansi B; Griffin, Paul J; Olson, Spencer F; Dai, Jin; Hou, Yuqing; Malik, Tara; Das, Poulomi; Zhang, Gui; Zhao, Winston; Witman, George B.; et al. (2024-03-08)
      Most cells tightly control the length of their cilia. The regulation likely involves intraflagellar transport (IFT), a bidirectional motility of multi-subunit particles organized into trains that deliver building blocks into the organelle. In Chlamydomonas, the anterograde IFT motor kinesin-2 consists of the motor subunits FLA8 and FLA10 and the nonmotor subunit KAP. KAP dissociates from IFT at the ciliary tip and diffuses back to the cell body. This observation led to the diffusion-as-a-ruler model of ciliary length control, which postulates that KAP is progressively sequestered into elongating cilia because its return to the cell body will require increasingly more time, limiting motor availability at the ciliary base, train assembly, building block supply, and ciliary growth. Here, we show that Chlamydomonas FLA8 also returns to the cell body by diffusion. However, more than 95% of KAP and FLA8 are present in the cell body and, at a given time, just ~1% of the motor participates in IFT. After repeated photobleaching of both cilia, IFT of fluorescent kinesin subunits continued indicating that kinesin-2 cycles from the large cell-body pool through the cilia and back. Furthermore, growing and full-length cilia contained similar amounts of kinesin-2 subunits and the size of the motor pool at the base changed only slightly with ciliary length. These observations are incompatible with the diffusion-as-a-ruler model, but rather support an "on-demand model," in which the cargo load of the trains is regulated to assemble cilia of the desired length.
    • Fleischner Society: Glossary of Terms for Thoracic Imaging

      Bankier, Alexander A; MacMahon, Heber; Colby, Thomas; Gevenois, Pierre Alain; Goo, Jin Mo; Leung, Ann N C; Lynch, David A; Schaefer-Prokop, Cornelia M; Tomiyama, Noriyuki; Travis, William D; et al. (2024-02-27)
      Members of the Fleischner Society have compiled a glossary of terms for thoracic imaging that replaces previous glossaries published in 1984, 1996, and 2008, respectively. The impetus to update the previous version arose from multiple considerations. These include an awareness that new terms and concepts have emerged, others have become obsolete, and the usage of some terms has either changed or become inconsistent to a degree that warranted a new definition. This latest glossary is focused on terms of clinical importance and on those whose meaning may be perceived as vague or ambiguous. As with previous versions, the aim of the present glossary is to establish standardization of terminology for thoracic radiology and, thereby, to facilitate communications between radiologists and clinicians. Moreover, the present glossary aims to contribute to a more stringent use of terminology, increasingly required for structured reporting and accurate searches in large databases. Compared with the previous version, the number of images (chest radiography and CT) in the current version has substantially increased. The authors hope that this will enhance its educational and practical value. All definitions and images are hyperlinked throughout the text. Click on each figure callout to view corresponding image. © RSNA, 2024 Supplemental material is available for this article. See also the editorials by Bhalla and Powell in this issue.
    • Hippocampal subfields and thalamic nuclei associations with clinical outcomes in multiple sclerosis: An ultrahigh field MRI study

      Santini, Tales; Chen, Chenyi; Zhu, Wen; Liou, Jr-Jiun; Walker, Elizabeth; Venkatesh, Shruthi; Farhat, Nadim; Sajewski, Andrea; Alkhateeb, Salem; Saranathan, Manojkumar; et al. (2024-02-27)
      Background: Previous studies have shown that thalamic and hippocampal neurodegeneration is associated with clinical decline in Multiple Sclerosis (MS). However, contributions of the specific thalamic nuclei and hippocampal subfields require further examination. Objective: Using 7 Tesla (7T) magnetic resonance imaging (MRI), we investigated the cross-sectional associations between functionally grouped thalamic nuclei and hippocampal subfields volumes and T1 relaxation times (T1-RT) and subsequent clinical outcomes in MS. Methods: High-resolution T1-weighted and T2-weighted images were acquired at 7T (n=31), preprocessed, and segmented using the Thalamus Optimized Multi Atlas Segmentation (THOMAS, for thalamic nuclei) and the Automatic Segmentation of Hippocampal Subfields (ASHS, for hippocampal subfields) packages. We calculated Pearson correlations between hippocampal subfields and thalamic nuclei volumes and T1-RT and subsequent multi-modal rater-determined and patient-reported clinical outcomes (∼2.5 years after imaging acquisition), correcting for confounders and multiple tests. Results: Smaller volume bilaterally in the anterior thalamus region correlated with worse performance in gait function, as measured by the Patient Determined Disease Steps (PDDS). Additionally, larger volume in most functional groups of thalamic nuclei correlated with better visual information processing and cognitive function, as measured by the Symbol Digit Modalities Test (SDMT). In bilateral medial and left posterior thalamic regions, there was an inverse association between volumes and T1-RT, potentially indicating higher tissue degeneration in these regions. We also observed marginal associations between the right hippocampal subfields (both volumes and T1-RT) and subsequent clinical outcomes, though they did not survive correction for multiple testing. Conclusion: Ultrahigh field MRI identified markers of structural damage in the thalamic nuclei associated with subsequently worse clinical outcomes in individuals with MS. Longitudinal studies will enable better understanding of the role of microstructural integrity in these brain regions in influencing MS outcomes.
    • Incidence and clinical outcomes of perforations during mechanical thrombectomy for medium vessel occlusion in acute ischemic stroke: A retrospective, multicenter, and multinational study

      Dmytriw, Adam A; Musmar, Basel; Salim, Hamza; Ghozy, Sherief; Siegler, James E; Kobeissi, Hassan; Shaikh, Hamza; Khalife, Jane; Abdalkader, Mohamad; Klein, Piers; et al. (2024-02-26)
      Background: Mechanical thrombectomy (MT) has revolutionized the treatment of acute ischemic stroke (AIS) due to large vessel occlusion (LVO), but its efficacy and safety in medium vessel occlusion (MeVO) remain less explored. This multicenter, retrospective study aims to investigate the incidence and clinical outcomes of vessel perforations (confirmed by extravasation during an angiographic series) during MT for AIS caused by MeVO. Methods: Data were collected from 37 academic centers across North America, Asia, and Europe between September 2017 and July 2021. A total of 1373 AIS patients with MeVO underwent MT. Baseline characteristics, procedural details, and clinical outcomes were analyzed. Results: The incidence of vessel perforation was 4.8% (66/1373). Notably, our analysis indicates variations in perforation rates across different arterial segments: 8.9% in M3 segments, 4.3% in M2 segments, and 8.3% in A2 segments (p = 0.612). Patients with perforation had significantly worse outcomes, with lower rates of favorable angiographic outcomes (TICI 2c-3: 23% vs 58.9%, p < 0.001; TICI 2b-3: 56.5% vs 88.3%, p < 0.001). Functional outcomes were also worse in the perforation group (mRS 0-1 at 3 months: 22.7% vs 36.6%, p = 0.031; mRS 0-2 at 3 months: 28.8% vs 53.9%, p < 0.001). Mortality was higher in the perforation group (30.3% vs 16.8%, p = 0.008). Conclusion: This study reveals that while the occurrence of vessel perforation in MT for AIS due to MeVO is relatively rare, it is associated with poor functional outcomes and higher mortality. The findings highlight the need for increased caution and specialized training in performing MT for MeVO. Further prospective research is required for risk mitigation strategies.
    • A novel swine model of selective middle meningeal artery catheterization and embolization

      Mokin, Maxim; Pionessa, Donald; Koenigsknecht, Carmon; Gutierrez, Liza; Setlur Nagesh, Swetadri Vasan; Meess Tuttle, Karen M; Spengler, Mike; Akkad, Yousef; Vakharia, Kunal; Shapiro, Maksim; et al. (2024-02-22)
      Background: Middle meningeal artery (MMA) embolization is a promising intervention as a stand-alone or adjunct treatment to surgery in patients with chronic subdural hematomas. There are currently no large animal models for selective access and embolization of the MMA for preclinical evaluation of this endovascular modality. Our objective was to introduce a novel in vivo model of selective MMA embolization in swine. Methods: Diagnostic cerebral angiography with selective microcatheter catheterization into the MMA was performed under general anesthesia in five swine. Anatomical variants in arterial meningeal supply were examined. In two animals, subsequent embolization of the MMA with a liquid embolic agent (Onyx-18) was performed, followed by brain tissue harvest and histological analysis. Results: The MMA was consistently localized as a branch of the internal maxillary artery just distal to the origin of the ascending pharyngeal artery. Additional meningeal supply was observed from the external ophthalmic artery, although not present consistently. MMA embolization with Onyx was technically successful and feasible. Histological analysis showed Onyx material within the MMA lumen. Conclusions: Microcatheter access into the MMA in swine with liquid embolic agent delivery represents a reproducible model of MMA embolization. Anatomical variations in the distribution of arterial supply to the meninges exist. This model has a potential application for comparing therapeutic effects of various embolic agents in a preclinical setting that closely resembles the MMA embolization procedure in humans.
    • Use of the pRESET LITE thrombectomy device in combined approach for medium vessel occlusions: A multicenter evaluation

      Wang, Maud; Henkes, Hans; Ghozy, Sherief; Siegler, James E; Shaikh, Hamza; Khalife, Jane; Abdalkader, Mohamad; Klein, Piers; Nguyen, Thanh N; Heit, Jeremy J; et al. (2024-02-21)
      Purpose: Our purpose was to assess the efficacy and safety of the pRESET LITE stent retriever (Phenox, Bochum, Germany), designed for medium vessel occlusion (MeVO) in acute ischemic stroke (AIS) patients with a primary MeVO. Methods: We performed a retrospective analysis of the MAD MT Consortium, an integration of prospectively maintained databases at 37 academic institutions in Europe, North America, and Asia, of AIS patients who underwent mechanical thrombectomy with the pRESET LITE stent retriever for a primary MeVO. We subcategorized occlusions into proximal MeVOs (segments A1, M2, and P1) vs. distal MeVOs/DMVO (segments A2, M3-M4, and P2). We reviewed patient and procedural characteristics, as well as angiographic and clinical outcomes. Results: Between September 2016 and December 2021, 227 patients were included (50% female, median age 78 [65-84] years), of whom 161 (71%) suffered proximal MeVO and 66 (29%) distal MeVO. Using a combined approach in 96% of cases, successful reperfusion of the target vessel (mTICI 2b/2c/3) was attained in 85% of proximal MeVO and 97% of DMVO, with a median of 2 passes (IQR: 1-3) overall. Periprocedural complications rate was 7%. Control CT at day 1 post-MT revealed a hemorrhagic transformation in 63 (39%) patients with proximal MeVO and 24 (36%) patients with DMVO, with ECASS-PH type hemorrhagic transformations occurring in 3 (1%) patients. After 3 months, 58% of all MeVO and 63% of DMVO patients demonstrated a favorable outcome (mRS 0-2). Conclusion: Mechanical thrombectomy using the pRESET LITE in a combined approach with an aspiration catheter appears effective for primary medium vessel occlusions across several centers and physicians.
    • Auto-segmentation of Adult-Type Diffuse Gliomas: Comparison of Transfer Learning-Based Convolutional Neural Network Model vs. Radiologists

      Wan, Qi; Kim, Jisoo; Lindsay, Clifford; Chen, Xin; Li, Jing; Iorgulescu, J Bryan; Huang, Raymond Y; Zhang, Chenxi; Reardon, David; Young, Geoffrey S; et al. (2024-02-21)
      Segmentation of glioma is crucial for quantitative brain tumor assessment, to guide therapeutic research and clinical management, but very time-consuming. Fully automated tools for the segmentation of multi-sequence MRI are needed. We developed and pretrained a deep learning (DL) model using publicly available datasets A (n = 210) and B (n = 369) containing FLAIR, T2WI, and contrast-enhanced (CE)-T1WI. This was then fine-tuned with our institutional dataset (n = 197) containing ADC, T2WI, and CE-T1WI, manually annotated by radiologists, and split into training (n = 100) and testing (n = 97) sets. The Dice similarity coefficient (DSC) was used to compare model outputs and manual labels. A third independent radiologist assessed segmentation quality on a semi-quantitative 5-scale score. Differences in DSC between new and recurrent gliomas, and between uni or multifocal gliomas were analyzed using the Mann-Whitney test. Semi-quantitative analyses were compared using the chi-square test. We found that there was good agreement between segmentations from the fine-tuned DL model and ground truth manual segmentations (median DSC: 0.729, std-dev: 0.134). DSC was higher for newly diagnosed (0.807) than recurrent (0.698) (p < 0.001), and higher for unifocal (0.747) than multi-focal (0.613) cases (p = 0.001). Semi-quantitative scores of DL and manual segmentation were not significantly different (mean: 3.567 vs. 3.639; 93.8% vs. 97.9% scoring ≥ 3, p = 0.107). In conclusion, the proposed transfer learning DL performed similarly to human radiologists in glioma segmentation on both structural and ADC sequences. Further improvement in segmenting challenging postoperative and multifocal glioma cases is needed.
    • Hydroxyapatite deposition disease, an overlooked differential diagnosis in the emergency department: a case series and review of literature

      Patel, Jay; Tai, Ryan; Sereni, Christopher; Joshi, Ganesh (2024-02-15)
      Hydroxyapatite crystal deposition disease (HADD) poses diagnostic challenges in the emergency department (ED) as it may clinically present similarly to infection and other musculoskeletal conditions. Misdiagnosis often leads to unnecessary treatments and resource over-utilization. This review article provides an overview of HADD in seven patients who presented to the ED secondary to an acute presentation of this disease process. HADD is a prevalent pathology, which commonly involves the shoulder, followed by the hip, elbow, wrist, and knee. Predisposing risk factors, such as diabetes and certain genetic factors, have also been identified. Clinical history and imaging, particularly radiographs, play a vital role in diagnosing HADD, with characteristic calcification patterns observed in different stages of the disease. Conservative nonsurgical therapy is the mainstay of treatment, providing effective symptom relief in over 90% of cases. By recognizing HADD as a crucial differential diagnosis for patients with acute or chronic pain, healthcare resource utilization can be optimized, leading to improved patient care in the ED.
    • Robust thalamic nuclei segmentation from T1-weighted MRI using polynomial intensity transformation [preprint]

      Vidal, Julie P; Danet, Lola; Péran, Patrice; Pariente, Jérémie; Cuadra, Meritxell Bach; Zahr, Natalie M; Barbeau, Emmanuel J; Saranathan, Manojkumar (2024-02-01)
      Accurate segmentation of thalamic nuclei, crucial for understanding their role in healthy cognition and in pathologies, is challenging to achieve on standard T1-weighted (T1w) magnetic resonance imaging (MRI) due to poor image contrast. White-matter-nulled (WMn) MRI sequences improve intrathalamic contrast but are not part of clinical protocols or extant databases. In this study, we introduce histogram-based polynomial synthesis (HIPS), a fast preprocessing transform step that synthesizes WMn-like image contrast from standard T1w MRI using a polynomial approximation for intensity transformation. HIPS was incorporated into THalamus Optimized Multi-Atlas Segmentation (THOMAS) pipeline, a method developed and optimized for WMn MRI. HIPS-THOMAS was compared to a convolutional neural network (CNN)-based segmentation method and THOMAS modified for T1w images (T1w-THOMAS). The robustness and accuracy of the three methods were tested across different image contrasts (MPRAGE, SPGR, and MP2RAGE), scanner manufacturers (PHILIPS, GE, and Siemens), and field strengths (3T and 7T). HIPS-transformed images improved intra-thalamic contrast and thalamic boundaries, and HIPS-THOMAS yielded significantly higher mean Dice coefficients and reduced volume errors compared to both the CNN method and T1w-THOMAS. Finally, all three methods were compared using the frequently travelling human phantom MRI dataset for inter- and intra-scanner variability, with HIPS displaying the least inter-scanner variability and performing comparably with T1w-THOMAS for intra-scanner variability. In conclusion, our findings highlight the efficacy and robustness of HIPS in enhancing thalamic nuclei segmentation from standard T1w MRI.
    • Multifocal emphysematous osteomyelitis, a do not miss diagnosis for the emergency radiologist: a case report with literature review

      Saha, Debajyoti; Tai, Ryan; Kapare, Vaishali; Joshi, Ganesh (2024-01-25)
      Emphysematous osteomyelitis (EO) is an uncommon fatal condition with high morbidity and mortality. Simultaneous involvement of the axial and appendicular skeleton with multifocal disease is even rarer, with only a few cases being reported in the literature. We present a case of multifocal emphysematous osteomyelitis in a 56-year-old woman with concurrent emphysematous pyelonephritis complicated by psoas and epidural abscesses. The causative organism in our patient was Escherichia coli. Emergency radiologists should be aware of this condition and differentiate it from other benign entities that can present with intraosseous gas. Prompt diagnosis is important given the high morbidity and mortality with this condition. This case report emphasizes the specific pattern of intraosseous gas seen with EO, which can help diagnose EO with confidence.
    • Appropriate Use of Medical Interpreters in the Breast Imaging Clinic

      Feliciano-Rivera, Yara Z; Yepes, Monica M; Sanchez, Priscila; Kalambo, Megan; Elahi, Fatima; Wahab, Rifat A; Jackson, Tatianie; Mehta, Tejas S; Net, Jose (2024-01-24)
      More than 25 million Americans have limited English-language proficiency (LEP) according to the U.S. Census Bureau. This population experiences challenges accessing health care and is least likely to receive preventive health care, including screening mammogram. In a setting where the breast radiologist does not speak the language of their patient, using certified medical interpreter services is fundamental. Medical interpreter use is associated with improved clinical care and patient satisfaction and can potentially increase adherence to screening mammograms and follow-up in patients with LEP. Title VI of the Civil Rights Act requires interpreter services for patients with LEP who are receiving federal financial assistance. Failure to provide interpretative services when necessary is considered discriminatory and illegal. The use of untrained medical interpreters, including ad hoc interpreters (eg, family, friends, or untrained staff), is associated with more medical errors, violation of confidentiality, and poor health outcomes. Types of medical interpretation services available to address language barriers include in-person interpretation, telephone and video remote interpretation, and qualified bilingual staff. Proper training and certification of medical interpreters is essential to prevent misinterpretations and ensure patient safety. When using an interpreter service, speak to and maintain eye contact with the patient, address the patient directly and seat the interpreter next to or slightly behind the patient, use visual aids whenever possible, and have the patient repeat the information to verify comprehension. Breast radiologists can address disparities in breast cancer screening and treatment by promoting effective communication.
    • Community Radiology Beyond the Relative Value Unit

      Mehta, Tejas S; Rosen, Max P (2024-01-23)
      Academic institutions receive direct and indirect financial benefits based on the communities they serve, including research funding, which is essential for advancing medicine. To strive for social equity and to minimize disparities in outcomes between populations, diversity in research participation that is representative of the global population is necessary. Diversity in members of the clinical research team is also important because it fosters scientific innovation, increases the likelihood of participation in under-resourced populations, and enhances public trust.
    • Sex Differences in Outcomes of Late-Window Endovascular Stroke Therapy

      Abdalkader, Mohamad; Ning, Shen; Qureshi, Muhammad M; Haussen, Diogo C; Strbian, Daniel; Nagel, Simon; Demeestere, Jelle; Puetz, Volker; Mohammaden, Mahmoud H; Olive Gadea, Marta; et al. (2024-01-22)
      Background: The association between sex and outcome after endovascular thrombectomy of acute ischemic stroke is unclear. The aim of this study was to compare the clinical and safety outcomes between men and women treated with endovascular thrombectomy in the late 6-to-24-hour window period. Methods: This multicenter, retrospective observational cohort study included consecutive patients who underwent endovascular thrombectomy of anterior circulation stroke in the late window from 66 clinical sites in 10 countries from January 2014 to May 2022. The primary outcome was the 90-day ordinal modified Rankin Scale score. Secondary outcomes included 90-day functional independence (FI), return of Rankin (RoR) to prestroke baseline, FI or RoR, symptomatic intracranial hemorrhage, and mortality. Multivariable and inverse probability of treatment weighting methods were used. We explored the interaction of sex with baseline characteristics on the outcomes ordinal modified Rankin Scale and FI or RoR. Results: Of 1932 patients, 1055 were women and 877 were men. Women were older (77 versus 69 years), had higher rates of atrial fibrillation, hypertension, and greater prestroke disability, but there was no difference in baseline National Institutes of Health Stroke Scale score. Inverse probability of treatment weighting analysis showed no difference between women and men in ordinal modified Rankin Scale (odds ratio, 0.98 [95% CI, 0.79-1.21]), FI or RoR (odds ratio, 0.98 [95% CI, 0.78-1.22]), severe disability or mortality (odds ratio, 0.99 [95% CI, 0.80-1.23]). The multivariable analysis of the above end points was concordant. There were no interactions between baseline characteristics and sex on the outcomes of ordinal modified Rankin Scale and FI or RoR. Conclusions: In late presenting patients with anterior circulation stroke treated with endovascular thrombectomy in the 6 to 24-hour window, there was no difference in clinical or safety outcomes between men and women.
    • The impact of postoperative aspirin in patients undergoing Woven EndoBridge: a multicenter, institutional, propensity score-matched analysis

      Dmytriw, Adam A; Musmar, Basel; Salim, Hamza; Aslan, Assala; Cancelliere, Nicole M; McLellan, Rachel M; Algin, Oktay; Ghozy, Sherief; Dibas, Mahmoud; Lay, Sovann V; et al. (2024-01-18)
      Background: The Woven EndoBridge (WEB) device is frequently used for the treatment of intracranial aneurysms. Postoperative management, including the use of aspirin, varies among clinicians and institutions, but its impact on the outcomes of the WEB has not been thoroughly investigated. Methods: This was a retrospective, multicenter study involving 30 academic institutions in North America, South America, and Europe. Data from 1492 patients treated with the WEB device were included. Patients were categorized into two groups based on their postoperative use of aspirin (aspirin group: n=1124, non-aspirin group: n=368). Data points included patient demographics, aneurysm characteristics, procedural details, complications, and angiographic and functional outcomes. Propensity score matching (PSM) was applied to balance variables between the two groups. Results: Prior to PSM, the aspirin group exhibited significantly higher rates of modified Rankin scale (mRS) mRS 0-1 and mRS 0-2 (89.8% vs 73.4% and 94.1% vs 79.8%, p<0.001), lower rates of mortality (1.6% vs 8.6%, p<0.001), and higher major compaction rates (13.4% vs 7%, p<0.001). Post-PSM, the aspirin group showed significantly higher rates of retreatment (p=0.026) and major compaction (p=0.037) while maintaining its higher rates of good functional outcomes and lower mortality rates. In the multivariable regression, aspirin was associated with higher rates of mRS 0-1 (OR 2.166; 95% CI 1.16 to 4, p=0.016) and mRS 0-2 (OR 2.817; 95% CI 1.36 to 5.88, p=0.005) and lower rates of mortality (OR 0.228; 95% CI 0.06 to 0.83, p=0.025). However, it was associated with higher rates of retreatment (OR 2.471; 95% CI 1.11 to 5.51, p=0.027). Conclusions: Aspirin use post-WEB treatment may lead to better functional outcomes and lower mortality but with higher retreatment rates. These insights are crucial for postoperative management after WEB procedures, but further studies are necessary for validation.
    • Raising Cultural Awareness and Addressing Barriers to Breast Imaging Care for Black Women

      Jackson, Tatianie; Wahab, Rifat A; Bankston, Karen; Mehta, Tejas S (2023-12-23)
      Health care disparities, which are differences in the attainment of full health potential among population groups, have been documented across medical conditions, clinical settings, and diagnostic and treatment modalities. Deeply rooted health care disparities due to many factors have affected how Black women (BW) view medical care including screening mammography. This article explores health care disparities around breast cancer in BW and how patient distrust, provider biases, race, and social determinants of health continue to have negative effects on breast cancer outcomes in BW, despite medical advances in breast cancer detection and management. In addition, this article addresses the importance of culturally competent care for BW around breast cancer awareness, screening, and treatment, and offers strategies to address disparities and rebuild trust.
    • Evaluation of ChatGPT and Google Bard Using Prompt Engineering in Cancer Screening Algorithms

      Nguyen, Daniel; Swanson, Daniel; Newbury, Alex; Kim, Young H (2023-12-15)
      Large language models (LLMs) such as ChatGPT and Bard have emerged as powerful tools in medicine, showcasing strong results in tasks such as radiology report translations and research paper drafting. While their implementation in clinical practice holds promise, their response accuracy remains variable. This study aimed to evaluate the accuracy of ChatGPT and Bard in clinical decision-making based on the American College of Radiology Appropriateness Criteria for various cancers. Both LLMs were evaluated in terms of their responses to open-ended (OE) and select-all-that-apply (SATA) prompts. Furthermore, the study incorporated prompt engineering (PE) techniques to enhance the accuracy of LLM outputs. The results revealed similar performances between ChatGPT and Bard on OE prompts, with ChatGPT exhibiting marginally higher accuracy in SATA scenarios. The introduction of PE also marginally improved LLM outputs in OE prompts but did not enhance SATA responses. The results highlight the potential of LLMs in aiding clinical decision-making processes, especially when guided by optimally engineered prompts. Future studies in diverse clinical situations are imperative to better understand the impact of LLMs in radiology.
    • A role for mutations in AK9 and other genes affecting ependymal cells in idiopathic normal pressure hydrocephalus

      Yang, Hong Wei; Lee, Semin; Berry, Bethany C; Yang, Dejun; Zheng, Shaokuan; Carroll, Rona S; Park, Peter J; Johnson, Mark D (2023-12-15)
      Idiopathic normal pressure hydrocephalus (iNPH) is an enigmatic neurological disorder that develops after age 60 and is characterized by gait difficulty, dementia, and incontinence. Recently, we reported that heterozygous CWH43 deletions may cause iNPH. Here, we identify mutations affecting nine additional genes (AK9, RXFP2, PRKD1, HAVCR1, OTOG, MYO7A, NOTCH1, SPG11, and MYH13) that are statistically enriched among iNPH patients. The encoded proteins are all highly expressed in choroid plexus and ependymal cells, and most have been associated with cilia. Damaging mutations in AK9, which encodes an adenylate kinase, were detected in 9.6% of iNPH patients. Mice homozygous for an iNPH-associated AK9 mutation displayed normal cilia structure and number, but decreased cilia motility and beat frequency, communicating hydrocephalus, and balance impairment. AK9+/- mice displayed normal brain development and behavior until early adulthood, but subsequently developed communicating hydrocephalus. Together, our findings suggest that heterozygous mutations that impair ventricular epithelial function may contribute to iNPH.
    • Braid stability after flow diverter treatment of intracranial aneurysms: a systematic review and meta-analysis

      Ortega-Gutierrez, Santiago; Rodriguez-Calienes, Aaron; Vivanco-Suarez, Juan; Cekirge, H Saruhan; Hanel, Ricardo A; Dibas, Mahmoud; Lamin, Saleh; Rice, Hal; Saatci, Isil; Fiorella, David; et al. (2023-12-14)
      Background: The aim of this study was to evaluate the overall rates of braid changes associated with flow diverter (FD) treatment for intracranial aneurysms (IAs). Additionally, we sought to provide an overview of the currently reported definitions related to these complications. Methods: A systematic search was conducted from the inception of relevant literature up to April 2023, encompassing six databases. The included studies focused on patients with IAs treated with FDs. We considered four main outcome measures as FD braid changes: (1) fish-mouthing, (2) device braid narrowing, (3) device braid collapsing, and (4) device braid deformation. The data from these studies were pooled using a random-effects model. Results: A total of 48 studies involving 3572 patients were included in the analysis. Among them, 14 studies (39%) provided definitions for fish-mouthing. However, none of the included studies offered specific definitions for device braid narrowing, collapsing, or deformation, despite reporting rates for these complications in six, five, and three studies, respectively. The pooled rates for braid changes were as follows: 3% (95% CI 2% to 4%, I2=27%) for fish-mouthing, 7% (95% CI 2% to 20%, I2=85%) for narrowing, 1% (95% CI 0% to 3%, I2=0%) for collapsing, and 1% (95% CI 1% to 4%, I2=0%) for deformation. Conclusion: The findings of this study suggest that FD treatment for IAs generally exhibits low rates of fish-mouthing, device braid narrowing, collapsing, and deformation. However, the lack of standardized definitions hinders the ability to compare device outcomes objectively, emphasizing the need for uniform definitions for FD braid changes in future prospective studies on FD.
    • Trastuzumab Deruxtecan‒Related Interstitial Lung Disease/Pneumonitis: Computed Tomography Imaging Patterns to Guide Diagnosis and Management

      Nishino, Mizuki; Kusumoto, Masahiko; Bankier, Alexander A; Kurihara, Yasuyuki; Zhang, Lin; Rasheed, Zeshaan; Meinhardt, Gerold; Arunachalam, Meena; Taitt, Corina; Wang, Qiang; et al. (2023-12-07)
      Purpose: Trastuzumab deruxtecan (T-DXd) is an antibody-drug conjugate approved for the treatment of several advanced cancers; however, severe or fatal interstitial lung disease/pneumonitis can occur. We characterized the computed tomography (CT) patterns of T-DXd‒related pneumonitis as a marker for its clinical severity. Materials and methods: Ninety patients with advanced cancers who developed T-DXd‒related pneumonitis in two completed single-arm clinical trials were included. Three radiologists independently characterized the CT patterns of pneumonitis at diagnosis, for analyses of those patterns' relationships with clinical severity and pneumonitis outcome. Results: T-DXd‒related pneumonitis most commonly presented with cryptogenic organizing pneumonia (COP) pattern, observed in 65 patients (72%), followed by a newly identified COP/hypersensitivity pneumonitis (HP) pattern (13%), acute interstitial pneumonia (AIP)/acute respiratory distress syndrome (ARDS) pattern (11%), and HP pattern (3%). A subset of cases with COP pattern demonstrated an atypical distribution with upper and peripheral lung involvement (6/65; 9%). CT patterns were associated with Common Terminology Criteria for Adverse Events severity grades of pneumonitis, with the AIP/ARDS pattern having higher grades compared with others (P < .0001). Fatal pneumonitis was more common in the AIP/ARDS pattern than in others (P = .005). The onset of pneumonitis was earlier in the AIP/ARDS pattern compared with others (median time to onset: at 17.9 v 32.7 weeks of therapy; P = .019). Pneumonitis was treated by withholding T-DXd with or without corticosteroids in most patients (78/90; 87%). Conclusion: T-DXd‒related pneumonitis most commonly demonstrated a COP pattern, with a subset having an atypical distribution. The AIP/ARDS pattern was indicative of severe, potentially fatal pneumonitis, and requires immediate clinical attention to mitigate serious adverse events.
    • Breast Imaging Fellowship Training in the United States: A National Survey of Fellowship Program Directors

      Weinstein, Joshua D; Mehta, Rashmi J; Mehta, Tejas S; Kavandi, Hadiseh; Brook, Alexander; Phillips, Jordana (2023-11-30)
      Objective: To provide an updated characterization of breast imaging fellowship programs in the United States to identify opportunities for improvement and standardization. Methods: An anonymous survey was e-mailed to program directors of breast imaging fellowship programs listed on the Society of Breast Imaging website. The survey was open from April 23, 2021, through May 27, 2021. The survey was deemed exempt by the IRB. Results: Forty-seven of 80 (59%) program directors responded, of which 36/47 (77%) represented programs dedicated 100% to breast imaging, and 11/47 (23%) represented programs dedicated 50%-75% to breast imaging. Common elements to most programs include tumor boards (47/47, 100%), journal clubs (39/47, 83%), case-based teaching sessions (35/47, 74%), didactic lectures (40/47, 85%), and participation in radiology-pathology conferences (29/47, 62%). Mammography Quality and Standards Act audit training (22/47, 47%), mammography quality control training (22/47, 47%), and formal communication training (19/47, 40%) were less common. Most programs provide exposure to wire (42/47, 89%) and wire-free localization procedures (45/47, 96%), but exposure to contrast-enhanced mammography (13/47, 28%) and molecular breast imaging (4/47, 9%) was limited. A small majority of programs (25/47, 53%) do not require weekday call; however, more (31/47, 66%) have weekend call responsibilities. Many programs (29/47, 62%) offer at least 3 weeks of elective time, which may be clinical or nonclinical. Conclusion: Breast imaging fellowship programs vary in curricula, modality exposure, and academic policies. The results of this survey can help guide further efforts to standardize and optimize fellowship training.