Perianal Fistulizing Crohn's Disease-Associated Anorectal and Fistula Cancers: Systematic Review and Expert Consensus.

BACKGROUND & AIMS: Perianal fistulizing Crohn's disease (PFCD)-associated anorectal and fistula cancers are rare but often devastating diagnoses. However, given the low incidence and consequent lack of data and clinical trials in the field, there is little to no guidance on screening and management of these cancers. To inform clinical practice, we developed consensus guidelines on PFCD-associated anorectal and fistula cancers by multidisciplinary experts from the international TOpClass consortium. METHODS: We conducted a systematic review by standard methodology, using the Newcastle-Ottawa Scale quality assessment tool. We subsequently developed consensus statements using a Delphi consensus approach. RESULTS: Of 561 articles identified, 110 were eligible, and 76 articles were included. The overall quality of evidence was low. The TOpClass consortium reached consensus on 6 structured statements addressing screening, risk assessment, and management of PFCD-associated anorectal and fistula cancers. Patients with long-standing (>10 years) PFCD should be considered at small but increased risk of developing perianal cancer, including squamous cell carcinoma of the anus and anorectal carcinoma. Risk factors for squamous cell carcinoma of the anus, notably human papilloma virus, should be considered. New, refractory, or progressive perianal symptoms should prompt evaluation for fistula cancer. There was no consensus on timing or frequency of screening in patients with asymptomatic perianal fistula. Multiple modalities may be required for diagnosis, including an examination under anesthesia with biopsy. Multidisciplinary team efforts were deemed central to the management of fistula cancers. CONCLUSIONS: Inflammatory bowel disease clinicians should be aware of the risk of PFCD-associated anorectal and fistula cancers in all patients with PFCD. The TOpClass consortium consensus statements outlined herein offer guidance in managing this challenging scenario.

MRI and PSMA PET/CT of Biochemical Recurrence of Prostate Cancer.

Prostate cancer may recur several years after definitive treatment, such as prostatectomy or radiation therapy. A rise in serum prostate-specific antigen (PSA) level is the first sign of disease recurrence, and this is termed biochemical recurrence. Patients with biochemical recurrence have worse survival outcomes. Radiologic localization of recurrent disease helps in directing patient management, which may vary from active surveillance to salvage radiation therapy, androgen-deprivation therapy, or other forms of systemic and local therapy. The likelihood of detecting the site of recurrence increases with higher serum PSA level. MRI provides optimal diagnostic performance for evaluation of the prostatectomy bed. Prostate-specific membrane antigen (PSMA) PET radiotracers currently approved by the U.S. Food and Drug Administration demonstrate physiologic urinary excretion, which can obscure recurrence at the vesicourethral junction. However, MRI and PSMA PET/CT have comparable diagnostic performance for evaluation of local recurrence after external-beam radiation therapy or brachytherapy. PSMA PET/CT outperforms MRI in identifying recurrence involving the lymph nodes and bones. Caveats for use of both PSMA PET/CT and MRI do exist and may cause false-positive or false-negative results. Hence, these techniques have complementary roles and should be interpreted in conjunction with each other, taking the patient history and results of any additional prior imaging studies into account. Novel PSMA agents at various stages of investigation are being developed, and preliminary data show promising results; these agents may revolutionize the landscape of prostate cancer recurrence imaging in the future. ©RSNA, 2023 Quiz questions for this article are available through the Online Learning Center. See the invited commentary by Turkbey in this issue. The slide presentation from the RSNA Annual Meeting is available for this article.

Knowing the ABCs: teaching the principles of radiology to medical students in Turkey.

BACKGROUND: Radiology education in Turkey is mainly taught during clinical years of medical school and often lacks main principles. Exposure to the fundamentals of radiology at an early stage of medical education may drastically help students generate a better understanding of radiology and expand their interest in the specialty. With the Principles of Radiology Course that we provided, pre- and post-session tests, and assessment survey at the end of the course, we aimed to evaluate the effectiveness of such an online course among Turkish medical students. METHODS: A total of nine online sessions on imaging modalities principles was developed by radiology professors. Each session was given through Zoom by radiologists from different U.S.-institutions to Turkish medical students from state (n = 33) and private (n = 8) universities. Pretests and post-tests were given to participants via Qualtrics before and after each session, respectively. Paired two-sample t-tests were conducted to detect the variance and p=-.05 was used as the significance level. An evaluation survey was distributed at the end of the course to collect their feedback through SurveyMonkey. RESULTS: A total of 1,438 predominantly Turkish (99.32%) medical students engaged with this course. An average of 506 students completed both pre-test and post-test. There was a statistically significant (p < .001) increase in the scores in post-test (mean[range]:7.58[5.21-8.53]) relative to pre-test (mean[range]:5.10[3.52-8.53]). Four hundred and thirty-nine participants (F/M:63.33%/35.54%) completed the end-of-course survey. A total of 71% and 69.70% of the participants strongly agreed that the course would be useful in their clinical practice and had increased their understanding of radiology. They also reported that their level of confidence in the subjects had increased 68% and reached a weighted average of 3.09/4. The survey revealed that 396 (90.21%) of the participants strongly or somewhat agree that introductory principles and concepts should be presented in earlier years of medical education. Compared to in-person education, 358 (81.55%) found the course extremely or very convenient. CONCLUSION: Online lecture series consisting of the principles of the radiological imaging modalities can be offered to Turkish medical students to enhance their grasp of the various imaging modalities and their correct clinical application.

The RSNA International COVID-19 Open Radiology Database (RICORD).

The coronavirus disease 2019 (COVID-19) pandemic is a global health care emergency. Although reverse-transcription polymerase chain reaction testing is the reference standard method to identify patients with COVID-19 infection, chest radiography and CT play a vital role in the detection and management of these patients. Prediction models for COVID-19 imaging are rapidly being developed to support medical decision making. However, inadequate availability of a diverse annotated data set has limited the performance and generalizability of existing models. To address this unmet need, the RSNA and Society of Thoracic Radiology collaborated to develop the RSNA International COVID-19 Open Radiology Database (RICORD). This database is the first multi-institutional, multinational, expert-annotated COVID-19 imaging data set. It is made freely available to the machine learning community as a research and educational resource for COVID-19 chest imaging. Pixel-level volumetric segmentation with clinical annotations was performed by thoracic radiology subspecialists for all COVID-19-positive thoracic CT scans. The labeling schema was coordinated with other international consensus panels and COVID-19 data annotation efforts, the European Society of Medical Imaging Informatics, the American College of Radiology, and the American Association of Physicists in Medicine. Study-level COVID-19 classification labels for chest radiographs were annotated by three radiologists, with majority vote adjudication by board-certified radiologists. RICORD consists of 240 thoracic CT scans and 1000 chest radiographs contributed from four international sites. It is anticipated that RICORD will ideally lead to prediction models that can demonstrate sustained performance across populations and health care systems.

Clinical Importance of Incidental Homogeneous Renal Masses That Measure 10-40 mm and 21-39 HU at Portal Venous Phase CT: A 12-Institution Retrospective Cohort Study.

BACKGROUND. Incidental homogeneous renal masses are frequently encountered at portal venous phase CT. The American College of Radiology Incidental Findings Committee's white paper on renal masses recommends additional imaging for incidental homogeneous renal masses greater than 20 HU, but single-center data and the Bosniak classification version 2019 suggest the optimal attenuation threshold for detecting solid masses should be higher. OBJECTIVE. The purpose of this article is to determine the clinical importance of small (10-40 mm) incidentally detected homogeneous renal masses measuring 21-39 HU at portal venous phase CT. METHODS. We performed a 12-institution retrospective cohort study of adult patients who underwent portal venous phase CT for a nonrenal indication. The date of the first CT at each institution ranged from January 1, 2008, to January 1, 2014. Consecutive reports from 12,167 portal venous phase CT examinations were evaluated. Images were reviewed for 4529 CT examinations whose report described a focal renal mass. Eligible masses were 10-40 mm, well-defined, subjectively homogeneous, and 21-39 HU. Of these, masses that were shown to be solid without macroscopic fat; classified as Bosniak IIF, III, or IV; or confirmed to be malignant were considered clinically important. The reference standard was renal mass protocol CT or MRI, ultrasound of definitively benign cysts or solid masses, single-phase contrast-enhanced CT or unenhanced MRI showing no growth or morphologic change for 5 years or more, or clinical follow-up 5 years or greater. A reference standard was available for 346 masses in 300 patients. The 95% CIs were calculated using the binomial exact method. RESULTS. Eligible masses were identified in 4.2% of patients (514/12,167; 95% CI, 3.9-4.6%). Of 346 masses with a reference standard, none were clinically important (0%; 95% CI, 0-0.9%). Mean mass size was 17 mm; 72% (248/346) measured 21-30 HU, and 28% (98/346) measured 31-39 HU. CONCLUSION. Incidental small homogeneous renal masses measuring 21-39 HU at portal venous phase CT are common and highly likely benign. CLINICAL IMPACT. The change in attenuation threshold signifying the need for additional imaging from greater than 20 HU to greater than 30 HU proposed by the Bosniak classification version 2019 is supported.

Diagnostic performance of adrenal CT in the differentiation of adenoma and pheochromocytoma.

BACKGROUND: Differentiation of adenoma and pheochromocytoma on computed tomography (CT) may be problematic. PURPOSE: To investigate if adenoma and pheochromocytoma can be differentiated with adrenal CT. MATERIAL AND METHODS: A total of 147 pathologically proven adrenal masses (119 adenomas, 28 pheochromocytomas) that had undergone adrenal CT were retrospectively evaluated. Lesion attenuation on unenhanced phase (UEP), portal phase (PP), 15-min delayed phase (DP), absolute/relative percentage enhancement wash-out (APEW/RPEW), and qualitative features were recorded. Student's t-test for parametric data, Mann-Whitney U test for non-parametric data, and Fisher's exact test for categorical data were used. Diagnostic performance of CT attenuation was assessed by area under the curve (AUC) of the receiver operating characteristics. RESULTS: APEW of adenomas was not significantly different from pheochromocytomas; 68.4% and 59% (P = 0.284). Adenomas had significantly higher RPEW; 57.3% vs. 37.4% (P = 0.004). Of pheochromocytomas, 50% met APEW >60% or RPEW >40% criteria, and therefore were misclassified as adenoma on wash-out CT. Of those, 80% (4/5) were < 3 cm. UEP, PP, and DP attenuations of pheochromocytomas were significantly higher than adenomas; however, they were overlapping. AUC for UEP, PP, and DP was 0.906, 0.784, and 0.926, respectively. Larger pheochromocytomas were more likely to contain necrosis compared to smaller pheochromocytomas and adenomas; 41.6% vs. 12.5% vs. 3%. Homogeneous enhancement was seen in 25% of pheochromocytomas and 49% of adenomas (P = 0.018). No significant difference was found in terms of lesion borders and presence of fat/calcification (P > 0.05). CONCLUSIONS: A considerable percentage of pheochromocytomas, especially smaller ones, demonstrate adenoma-like wash-out on CT. Heterogeneous enhancement, higher attenuation, and necrosis are more suggestive of pheochromocytoma.

Differentiation of Malignant and Benign Adrenal Lesions With Delayed CT: Multivariate Analysis and Predictive Models.

OBJECTIVE: The purpose of this study is to identify imaging and patient parameters that affect the diagnostic performance of delayed contrast-enhanced CT for distinguishing malignant from benign adrenal lesions larger than 1 cm in adult patients and to derive predictive models. MATERIALS AND METHODS: This retrospective study assessed 97 pathologically proven adrenal lesions that had undergone unenhanced, portal venous, and 15-minute delayed CT. Quantitatively, single-parameter evaluations of lesion attenuation (in Hounsfield units) and absolute percentage enhancement washout (APEW) and relative percentage enhancement washout (RPEW) were performed. In addition, descriptive CT features (lesion size, margin definition, heterogeneity vs homogeneity, fat, and calcification) and patients' demographic characteristics and medical history of malignancy were evaluated for association with lesion status using multiple logistic regression with stepwise model selection. Areas under the ROC curve (Az) were determined for univariate and multivariate analyses. Leave-one-lesion-out cross-validation was applied to ascertain the predictive performance of single-parameter and multivariate evaluations. RESULTS: The Az values for unenhanced attenuation, portal venous attenuation, delayed attenuation, APEW, and RPEW were 0.835, 0.534, 0.847, 0.792, and 0.871, respectively. Multivariate analyses revealed that portal venous attenuation, delayed attenuation, and APEW were significant features, with an Az of 0.923 when combined. The addition of the descriptive CT features increased the Az to 0.938; patient age and a history of malignancy were additional significant factors, increasing the Az to 0.956 and 0.972, respectively. The combined predictive classifier yielded 89% accuracy under cross-validation, compared with the best commonly applied single-parameter evaluation (77% for RPEW < 40%). CONCLUSION: Multivariate imaging evaluation applied to delayed contrast-enhanced CT alone, with or without patient characteristics, improves diagnostic performance for characterizing adrenal lesions beyond those of single-parameter evaluations. Predictive formulas assessing the probabilities of lesion benignity or malignancy are provided.

Utility of Intermediate-Delay Washout CT Images for Differentiation of Malignant and Benign Adrenal Lesions: A Multivariate Analysis.

OBJECTIVE: The objective of this study was to identify features that impact the diagnostic performance of intermediate-delay washout CT for distinguishing malignant from benign adrenal lesions. MATERIALS AND METHODS: This retrospective study evaluated 127 pathologically proven adrenal lesions (82 malignant, 45 benign) in 126 patients who had undergone portal venous phase and intermediate-delay washout CT (1-3 minutes after portal venous phase) with or without unenhanced images. Unenhanced images were available for 103 lesions. Quantitatively, lesion CT attenuation on unenhanced (UA) and delayed (DL) images, absolute and relative percentage of enhancement washout (APEW and RPEW, respectively), descriptive CT features (lesion size, margin characteristics, heterogeneity or homogeneity, fat, calcification), patient demographics, and medical history were evaluated for association with lesion status using multiple logistic regression with stepwise model selection. Area under the ROC curve (Az) was calculated from both univariate and multivariate analyses. The predictive diagnostic performance of multivariate evaluations was ascertained through cross-validation. RESULTS: Az for DL, APEW, RPEW, and UA was 0.751, 0.795, 0.829, and 0.839, respectively. Multivariate analyses yielded the following significant CT quantitative features and associated Az when combined: RPEW and DL (Az = 0.861) when unenhanced images were not available and APEW and UA (Az = 0.889) when unenhanced images were available. Patient demographics and presence of a prior malignancy were additional significant factors, increasing Az to 0.903 and 0.927, respectively. The combined predictive classifier, without and with UA available, yielded 85.7% and 87.3% accuracies with cross-validation, respectively. CONCLUSION: When appropriately combined with other CT features, washout derived from intermediate-delay CT with or without additional clinical data has potential utility in differentiating malignant from benign adrenal lesions.

Correction of Motion Artifacts From Shuttle Mode Computed Tomography Acquisitions for Body Perfusion Imaging Applications.

OBJECTIVE: The aim of this study was to investigate the feasibility of shuttle-mode computed tomography (CT) technology for body perfusion applications by quantitatively assessing and correcting motion artifacts. METHODS: Noncontrast shuttle-mode CT scans (10 phases, 2 nonoverlapping bed locations) were acquired from 4 patients on a GE 750HD CT scanner. Shuttling effects were quantified using Euclidean distances (between-phase and between-bed locations) of corresponding fiducial points on the shuttle and reference phase scans (prior to shuttle mode). Motion correction with nonrigid registration was evaluated using sum-of-squares differences and distances between centers of segmented volumes of interest on shuttle and references images. RESULTS: Fiducial point analysis showed an average shuttling motion of 0.85 ± 1.05 mm (between-bed) and 1.18 ± 1.46 mm (between-phase), respectively. The volume-of-interest analysis of the nonrigid registration results showed improved sum-of-squares differences from 2950 to 597, between-bed distance from 1.64 to 1.20 mm, and between-phase distance from 2.64 to 1.33 mm, respectively, averaged over all cases. CONCLUSIONS: Shuttling effects introduced during shuttle-mode CT acquisitions can be computationally corrected for body perfusion applications.

Multidisciplinary approach to diagnostic radiology education: a novel educational intervention for Turkish medical students.

Teleconferencing can facilitate a multidisciplinary approach to teaching radiology to medical students. This study aimed to determine whether an online learning approach enables students to appreciate the interrelated roles of radiology and other specialties during the management of different medical cases. Turkish medical students attended five 60-90-minute online lectures delivered by radiologists and other specialists from the United States and Canada through Zoom meetings between November 2020 and January 2021. Student ambassadors from their respective Turkish medical schools recruited their classmates with guidance from the course director. Students took a pretest and posttest to assess the knowledge imparted from each session and a final course survey to assess their confidence in radiology and the value of the course. A paired t-test was used to assess pretest and posttest score differences. A 4-point Likert-type scale was used to assess confidence rating differences before and after attending the course sessions. A total of 1,458 Turkish medical students registered for the course. An average of 437 completed both pre- and posttests when accounting for all five sessions. Posttest scores were significantly higher than pretest scores for each session (P < 0.001). A total of 546 medical students completed the final course survey evaluation. Students' rating of their confidence in their radiology knowledge increased after taking the course (P < 0.001). Students who took our course gained an appreciation for the interrelated roles of different specialties in approaching medical diagnoses and interpreting radiological findings. These students also reported an increased confidence in radiology topics and rated the course highly relevant and insightful. Overall, our findings indicated that multidisciplinary online education can be feasibly implemented for medical students by video teleconferencing.

Lemann Index for assessing bowel damage in Crohn's disease: a real world study.

BACKGROUND & AIMS: The Lemann Index (LI), an endpoint to measure cumulative structural bowel damage in Crohn's disease (CD), has been recently updated and validated. We applied this to investigate predictors of bowel damage in a real-world cohort. METHODS: We performed a retrospective study (2008-2022) involving two tertiary referral IBD centers in the US. MR or CT enterographies were reviewed by study radiologists and endoscopy reports by study gastroenterologists, to calculate LI. Baseline and follow-up LI were calculated. We defined high bowel damage as LI ≥2. Factors associated with high LI were identified in patients with ≥2 LI scores using multivariate logistic regression and then assessed for a change in LI (increase vs. no change/decrease) using a multivariate linear mixed-effects model. RESULTS: 447 patients with CD had a median first LI of 7 [IQR, 1.25-14.55]. Median LI scores were significantly different when categorized by disease duration; 2.0 [IQR, 0.6-5.9] for <2 years, 2.6 [IQR, 0.6-9.6] for ≥2 and <10 years, and 12.5 [IQR, 6.4-21.5] for ≥10 years with a p <0.01. Disease duration, presence of perianal disease, elevated C-reactive protein, and Harvey-Bradshaw index, were associated with a high LI at inclusion and increase in LI during follow-up (all p <0.01). CONCLUSIONS: The updated LI quantified cross-sectional and longitudinal cumulative bowel damage in a real-world cohort of patients with CD with predictors identified for a longitudinal increase in LI. Further studies for prospective validation of LI and identification of multi-omic predictors of bowel damage are needed.

Seeing Radiology Curricula Through Turkish Medical Students' Eyes: A Survey of Turkish Medical Schools' Radiology Education.

INTRODUCTION: Radiology education is essential for nonradiologist specialists and practitioners as well as for radiologists. We conducted a survey to gather the opinions of Turkish medical students from first to sixth grade regarding their radiology curricula, radiology education content, and perceptions of various imaging modalities and to assess the amount, adequacy, and homogeneity of radiology education in various schools. METHODS: Turkish medical students were reached by student ambassadors from 10 different schools of medicine via social media and email. They were provided with a 20-question survey-via the SurveyMonkey platform-related to their radiology curriculum and their perceptions of the radiology education at their schools and of different imaging modalities. Subjective parameters were scaled by a 4-point Likert scale and the results are reported by percentages of students. RESULTS: A total of 988 medical students (F/M: 61%/39%) from 41 different medical schools participated in this survey. Of those, 57% were preclinical students (≤ third year of medical school), while 43% were clinical students (> third year). More than half of the students (51%) stated that the amount of radiology education included in their curriculum was too little, while 44% of them stated it was just right and only 5% stated it was too much. Only 31% of the participants stated that they were able to review radiology images on their own. When asked about their level of confidence in identifying the position of lines and tubes, pneumonia, pneumothorax, and pleural effusion on chest radiographs, 41%, 39%, 41%, and 41% of the participants, respectively, stated that they were not confident. Thirty-five percent of the participants had not received any training in comparing normal to abnormal imaging of bone fractures, pneumonia, pleural effusion, subdural hemorrhage, or pneumothorax. The majority of the Turkish medical students in this survey had never heard (57%) nor used (64%) the American College of Radiology Appropriateness Criteria. CONCLUSIONS: The radiology curriculum in Turkey differs among various schools and most students stated that preclinical radiology course content was inadequate. Further studies and improvements must be conducted to provide high-quality, equitable radiology education that begins during preclinical training with respect to the students' opinions.

The RSNA Cervical Spine Fracture CT Dataset.

This dataset is composed of cervical spine CT images with annotations related to fractures; it is available at https://www.kaggle.com/competitions/rsna-2022-cervical-spine-fracture-detection/.

Abbreviated Liver Magnetic Resonance Imaging Protocols and Applications.

Abbreviated magnetic resonance imaging (AMRI) approach became a hot topic in liver imaging recently. Different AMRI protocols including noncontrast AMRI (NC-AMRI), hepatobiliary-AMRI (HBP-AMRI) using gadoxetic acid, and dynamic-AMRI (Dyn-AMRI) using extracellular contrast agent, have been described in the literature. In this review, the use of these AMRI approaches in various indications including hepatocellular carcinoma (HCC) screening and surveillance in chronic liver disease; fat, iron, and fibrosis screening and assessment in nonalcoholic fatty liver disease (NAFLD); and finally liver metastasis screening and surveillance in patients with colorectal cancer are summarized.

Extramural venous invasion (EMVI) revisited: a detailed analysis of various characteristics of EMVI and their role as a predictive imaging biomarker in the neoadjuvant treatment response in rectal cancer.

PURPOSE: To assess whether size, diameter, and large vein involvement of MR-detected extramural venous invasion (MR-EMVI) have an impact on neoadjuvant therapy response in rectal adenocarcinoma. METHODS: 57 patients with locally advanced rectal adenocarcinoma scanned with MRI before and after neoadjuvant therapy were included. Two abdominal radiologists evaluated the images with special emphasis on EMVI, on initial staging and after neoadjuvant treatment. The sensitivity and specificity of MRI for detection of rest EMVI were determined. The association of various MR-EMVI characteristics including number, size, and main vein involvement with treatment response was investigated. In subjects with discordance of radiology and pathology, elastin stain was performed, and images and slides were re-evaluated on site with a multidisciplinary approach. RESULTS: At initial evaluation, 17 patients were MR-EMVI negative (29.8%) and 40 were MR-EMVI positive (70.2%). Complete/near-complete responders had less number (mean 1.45) and smaller diameter of MR-EMVI (mean 1.8 mm), when compared with partial responders (2.54 and 3.3 mm; p < 0.005). The sensitivity of MRI for rest EMVI detection was high, specificity was moderate, and in one patient elastin stain changed the final decision. In five patients with rest MR-EMVI positivity, carcinoma histopathologically had a distinctive serpiginous perivascular spread, growing along the track of vascular bundle, although it did not appear in intravascular spaces. CONCLUSION: This study demonstrates that not only the presence, but also size and number of EMVI that may be significant clinically and thus these parameters also ought to be incorporated to the MRI evaluation and prognostication of treatment response. From pathology perspective, tumors growing alongside major vessels may also reflect EMVI even if they are not demonstrably "intravascular."

An intrathyroidal nodule consisting of papillary thyroid cancer and ectopic hyperechoic parathyroid adenoma: a case report.

A 53-year-old woman with fatigue lasting for 6 weeks and increased parathormone level underwent a neck ultrasound. It revealed a large, lobulated, solid intrathyroidal nodule consisting of hypoechoic component with microcalcifications and hy-perechoic component with vascularity on Doppler mode. There were also subcentimetric intrathyroidal hypo- and hyperechoic nodules. Upon the diagnosis of papillary thyroid cancer on fine-needle aspiration biopsy, a total thyroidectomy procedure was performed. In the histopathologic evaluation, the hypoechoic component was diagnosed as papillary thyroid cancer, while the hyperechoic component was diagnosed as ectopic parathyroid adenoma. Subcentimetric nodules were demonstrated as multi-foci of papillary thyroid cancer.

Performance of native and gadoxetate-enhanced liver and spleen T1 mapping for noninvasive diagnosis of clinically significant portal hypertension: preliminary results.

PURPOSE: In this preliminary study, our aim was to assess the utility of quantitative native-T1 (T1-pre), iron-corrected T1 (cT1) of the liver/spleen and T1 mapping of the liver obtained during hepatobiliary phase (T1-HBP) post-gadoxetate disodium, compared to spleen size/volume and APRI (aspartate aminotransferase-to-platelet ratio index) for noninvasive diagnosis of clinically significant portal hypertension [CSPH, defined as hepatic venous pressure gradient (HVPG) ≥ 10 mm Hg]. METHODS: Forty-nine patients (M/F: 27/22, mean age 53y) with chronic liver disease, HVPG measurement and MRI were included. Breath-held T1 and cT1 measurements were obtained using an inversion recovery Look-Locker sequence and a T2* corrected modified Look-Locker sequence, respectively. Liver T1-pre (n = 49), spleen T1 (obtained pre-contrast, n = 47), liver and spleen cT1 (both obtained pre-contrast, n = 30), liver T1-HBP (obtained 20 min post gadoxetate disodium injection, n = 36) and liver T1 uptake (ΔT1, n = 36) were measured. Spleen size/volume and APRI were also obtained. Spearman correlation coefficients were used to assess the correlation between each of liver/spleen T1/cT1 parameters, spleen size/volume and APRI with HVPG. ROC analysis was performed to determine the performance of measured parameters for diagnosis of CSPH. RESULTS: There were 12/49 (24%) patients with CSPH. Liver T1-pre (r = 0.287, p = 0.045), liver T1-HBP (r = 0.543, p = 0.001), liver ΔT1 (r = - 0.437, p = 0.008), spleen T1 (r = 0.311, p = 0.033) and APRI (r = 0.394, p = 0.005) were all significantly correlated with HVPG, while liver cT1, spleen cT1 and spleen size/volume were not. The highest AUCs for the diagnosis of CSPH were achieved with liver T1-HBP, liver ΔT1 and spleen T1: 0.881 (95%CI 0.76-1.0, p = 0.001), 0.852 (0.72-0.98, p = 0.002) and 0.781 (0.60-0.95, p = 0.004), respectively. CONCLUSION: Our preliminary results demonstrate the potential of liver T1 mapping obtained during HBP post gadoxetate disodium for the diagnosis of CSPH. These results require further validation.

Radiomic signatures of posterior fossa ependymoma: Molecular subgroups and risk profiles.

BACKGROUND: The risk profile for posterior fossa ependymoma (EP) depends on surgical and molecular status [Group A (PFA) versus Group B (PFB)]. While subtotal tumor resection is known to confer worse prognosis, MRI-based EP risk-profiling is unexplored. We aimed to apply machine learning strategies to link MRI-based biomarkers of high-risk EP and also to distinguish PFA from PFB. METHODS: We extracted 1800 quantitative features from presurgical T2-weighted (T2-MRI) and gadolinium-enhanced T1-weighted (T1-MRI) imaging of 157 EP patients. We implemented nested cross-validation to identify features for risk score calculations and apply a Cox model for survival analysis. We conducted additional feature selection for PFA versus PFB and examined performance across three candidate classifiers. RESULTS: For all EP patients with GTR, we identified four T2-MRI-based features and stratified patients into high- and low-risk groups, with 5-year overall survival rates of 62% and 100%, respectively (P < .0001). Among presumed PFA patients with GTR, four T1-MRI and five T2-MRI features predicted divergence of high- and low-risk groups, with 5-year overall survival rates of 62.7% and 96.7%, respectively (P = .002). T1-MRI-based features showed the best performance distinguishing PFA from PFB with an AUC of 0.86. CONCLUSIONS: We present machine learning strategies to identify MRI phenotypes that distinguish PFA from PFB, as well as high- and low-risk PFA. We also describe quantitative image predictors of aggressive EP tumors that might assist risk-profiling after surgery. Future studies could examine translating radiomics as an adjunct to EP risk assessment when considering therapy strategies or trial candidacy.

Spin-echo and diffusion-weighted MRI in differentiation between progressive massive fibrosis and lung cancer.

PURPOSE: We aimed to investigate the value of magnetic resonance imaging (MRI)-based parameters in differentiating between progressive massive fibrosis (PMF) and lung cancer. METHODS: This retrospective study included 60 male patients (mean age, 67.0±9.0 years) with a history of more than 10 years working in underground coal mines who underwent 1.5 T MRI of thorax due to a lung nodule/mass suspicious for lung cancer on computed tomography. Thirty patients had PMF, and the remaining ones had lung cancer diagnosed histopathologically. The sequences were as follows: coronal single-shot turbo spin echo (SSH-TSE), axial T1- and T2-weighted spin-echo (SE), balanced turbo field echo, T1-weighted high-resolution isotropic volume excitation, free-breathing and respiratory triggered diffusion-weighted imaging (DWI). The patients' demographics, lesion sizes, and MRI-derived parameters were compared between the patients with PMF and lung cancer. RESULTS: Apparent diffusion coefficient (ADC) values of DWI and respiratory triggered DWI, signal intensities on T1-weighted SE, T2-weighted SE, and SSH-TSE imaging were found to be significantly different between the groups (p < 0.001, for all comparisons). Median ADC values of free-breathing DWI in patients with PMF and cancer were 1.25 (0.93-2.60) and 0.76 (0.53-1.00) (× 10-3 mm2/s), respectively. Most PMF lesions were predominantly iso- or hypointense on T1-weighted SE, T2-weighted SE, and SSH-TSE, while most malignant ones predominantly showed high signal intensity on these sequences. CONCLUSION: MRI study including SE imaging, specially T1-weighted SE imaging and ADC values of DWI can help to distinguish PMF from lung cancer.