Rapid Classification of Sarcomas Using Methylation Fingerprint: A Pilot Study.

Sarcoma classification is challenging and can lead to treatment delays. Previous studies used DNA aberrations and machine-learning classifiers based on methylation profiles for diagnosis. We aimed to classify sarcomas by analyzing methylation signatures obtained from low-coverage whole-genome sequencing, which also identifies copy-number alterations. DNA was extracted from 23 suspected sarcoma samples and sequenced on an Oxford Nanopore sequencer. The methylation-based classifier, applied in the nanoDx pipeline, was customized using a reference set based on processed Illumina-based methylation data. Classification analysis utilized the Random Forest algorithm and t-distributed stochastic neighbor embedding, while copy-number alterations were detected using a designated R package. Out of the 23 samples encompassing a restricted range of sarcoma types, 20 were successfully sequenced, but two did not contain tumor tissue, according to the pathologist. Among the 18 tumor samples, 14 were classified as reported in the pathology results. Four classifications were discordant with the pathological report, with one compatible and three showing discrepancies. Improving tissue handling, DNA extraction methods, and detecting point mutations and translocations could enhance accuracy. We envision that rapid, accurate, point-of-care sarcoma classification using nanopore sequencing could be achieved through additional validation in a diverse tumor cohort and the integration of methylation-based classification and other DNA aberrations.

Follow-up of liver metastases: a comparison of deep learning and RECIST 1.1.

OBJECTIVES: To compare liver metastases changes in CT assessed by radiologists using RECIST 1.1 and with aided simultaneous deep learning-based volumetric lesion changes analysis. METHODS: A total of 86 abdominal CT studies from 43 patients (prior and current scans) of abdominal CT scans of patients with 1041 liver metastases (mean = 12.1, std = 11.9, range 1-49) were analyzed. Two radiologists performed readings of all pairs; conventional with RECIST 1.1 and with computer-aided assessment. For computer-aided reading, we used a novel simultaneous multi-channel 3D R2U-Net classifier trained and validated on other scans. The reference was established by having an expert radiologist validate the computed lesion detection and segmentation. The results were then verified and modified as needed by another independent radiologist. The primary outcome measure was the disease status assessment with the conventional and the computer-aided readings with respect to the reference. RESULTS: For conventional and computer-aided reading, there was a difference in disease status classification in 40 out of 86 (46.51%) and 10 out of 86 (27.9%) CT studies with respect to the reference, respectively. Computer-aided reading improved conventional reading in 30 CT studies by 34.5% for two readers (23.2% and 46.51%) with respect to the reference standard. The main reason for the difference between the two readings was lesion volume differences (p = 0.01). CONCLUSIONS: AI-based computer-aided analysis of liver metastases may improve the accuracy of the evaluation of neoplastic liver disease status. CLINICAL RELEVANCE STATEMENT: AI may aid radiologists to improve the accuracy of evaluating changes over time in metastasis of the liver. KEY POINTS: • Classification of liver metastasis changes improved significantly in one-third of the cases with an automatically generated comprehensive lesion and lesion changes report. • Simultaneous deep learning changes detection and volumetric assessment may improve the evaluation of liver metastases temporal changes potentially improving disease management.

Modified Transhumeral Amputation: A Case Report.

CASE: A 7-year-old boy presented with osteosarcoma of the ulna that required a transhumeral amputation. The patient completed neoadjuvant chemotherapy before surgery. To prevent bone overgrowth and improved prosthetic fitting, a modified amputation was performed with acute shortening and distal epiphysis preservation. CONCLUSION: In this modified amputation, bone overgrowth was not seen and repeated surgeries for stump shaping were prevented. The modified technique enabled length for the prosthetic elbow and a wide stump for better fitting. In cases of transhumeral amputation in children, the modified technique should be considered.

Knee intra-articular extraskeletal aneurysmal bone cyst: a case report and review of literature.

Aneurysmal bone cyst (ABC) is a benign locally destructive lesion that usually developed in the bone cavity of bones, less commonly on the surface of cortical bones and very rarely develop outside the bone. There are only 35 reports of extraskeletal aneurysmal bone cyst (ESABC) in the English literature. We report a case of a 12-year-old female with no history of trauma who presented with knee pain. Imaging studies revealed an infrapatellar mass that was fast to calcify during a period of 3 months. MRI showed high T2 center, low T1 signal, and heterogenic enhancement with a rim of low intensity consistent with calcified boarders surrounded by severe soft tissue edema. The lesion was surgically excised, and a histological examination revealed an aneurysmal bone cyst possibly arising within myositis ossificans or heterotopic ossification. In her last follow-up 1.5 years after the surgical excision, the patient was symptom free and without signs of recurrence. To the best of our knowledge, this is the first reported case of an intra-articular ESABC located in the knee.

Intravenous Line Phase-Wrap Artifact at Bilateral Axial 3-T Breast MRI: Identification, Analysis, and Solution.

Purpose: To understand and remove the source of a phase-wrap artifact produced by residual contrast agent in the intravenous line during acquisition of bilateral axial 3-T dynamic contrast material-enhanced (DCE) breast MRI. Materials and Methods: A two-part study involved a phantom experiment, followed by an institutional review board approved clinical intervention, to evaluate the phase-wrap artifact at MRI. A phantom model evaluated artifact production by using an intravenous line filled with fluids with varying concentrations of gadolinium-based contrast agent (0, 0.4, 0.8, 1.2, 1.6, and 2 mmol/mL) and by positioning the simulated intravenous line within several fields of view (FOV) at 3-T MRI in breast coils. Next, a clinical assessment was performed with a total of 400 patients (control group:interventional group, 200:200) to determine the effect of taping the intravenous line to the patients' backs. Breast MR images were assessed blindly for the presence of the artifact. Software was used for statistical analysis with a P value of less than .05 considered a significant difference. Results: In the phantom model, the artifact was produced only with a 0.4 mmol/mL gadolinium concentration and when the tubing was either close to the edge or within a FOV of 350-450 mm. In the clinical experiment, the artifact was more prevalent in the retrospective control group than in the prospective intervention group (52.5% [105 of 200] vs 22% [44 of 200]; P < .005). Conclusion: The presence of phase-wrap artifacts can be reduced by moving the contrast agent intravenous line out of the FOV during acquisition by taping it to a patient's back during bilateral axial 3-T DCE breast MRI.Keywords: Breast, MR-Imaging, Phantom Studies© RSNA, 2020.

Radiography, abdominal CT and MRI compared with sacroiliac joint CT in diagnosis of structural sacroiliitis.

OBJECTIVE: To assess the performance of pelvic plain radiograph (radiography), abdominal CT and sacroiliac joint MRI (MRI) compared with sacroiliac joints CT (SI joint CT) for the diagnosis of structural sacroiliitis in a population suffering from spondyloarthritis (SpA) meeting the New York or ASAS criteria. METHODS: All SpA patients eligible for biologic treatment who received a pre-therapeutic check-up including the four imaging techniques in the same year were selected from 2005 to 2012. An assessment of sacroiliitis was based independently by a rheumatologist and a radiologist on radiography according to the modified New York criteria and on abdominal CT, MRI and SI Joint CT depending on the presence of erosion on at least two consecutive slices. A final diagnosis was established for conflicting exams. RESULTS: Of the 58 selected patients, sacroiliitis was diagnosed on radiography, abdominal CT, MRI and SI Joint CT in 32, 26, 34 and 35 patients, respectively. Inter-reader agreements for the grade of sacroiliitis were substantial with a weighted Kappa that varied between 0.60 and 0.76 and they were moderate for the diagnosis of sacroiliitis with a Kappa that varied between 0.45 and 0.55 for the four imaging modalities. The sensitivities of radiography, abdominal CT and MRI were 82.8%, 71.4% and 85.7% respectively and the specificities were 86.9%, 100% and 82.6% respectively with excellent accuracy and positive predictive value and good negative predictive value. CONCLUSION: This study demonstrates the relevance of MRI and abdominal CT for the diagnosis of structural sacroiliitis with good sensitivities and excellent specificities. These imaging modalities may also contribute for the diagnosis of structural sacroiliitis.

Radiography and abdominal CT compared with sacroiliac joint CT in the diagnosis of sacroiliitis.

Background The presence of structural sacroiliitis is strong evidence for the diagnosis of spondyloarthritis (SpA). Purpose To assess the performance of abdominal computed tomography (CT) and pelvic plain radiography for the diagnosis of structural sacroiliitis compared with sacroiliac CT (SI joint CT) considered the reference technique in patients with SpA. Material and Methods All SpA patients eligible for biologic treatment were selected from 2005 to 2012. An assessment of sacroiliitis was based on radiography according to the modified New York criteria and on abdominal CT and SI joint CT scans depending on the presence of erosion on at least two consecutive slices. A senior rheumatologist and radiologist independently scored the grade and diagnosis of structural sacroiliitis for the three imaging modalities. After a consensus reading of conflicting examinations (radiography and CT), a final diagnosis of structural sacroiliitis was attained. Results Of the 72 patients selected, sacroiliitis was diagnosed on radiography, abdominal CT, and SI joint CT in 40, 31, and 44 patients, respectively. Inter-reader agreements for the grade of sacroiliitis were substantial for the three imaging modalities, with a weighted kappa range of 0.63-0.75 (95% confidence interval [CI], 0.52-0.83), and they were moderate for the diagnosis of sacroiliitis, with a kappa range of 0.50-0.55 (95% CI, 0.32-0.74). The sensitivity and specificity were 79.1% and 70.5%, respectively, for radiography and 82.1% and 100%, respectively, for abdominal CT. Conclusion This study demonstrates the relevance of abdominal CT for the diagnosis of structural sacroiliitis, with good sensitivity and excellent specificity. These imaging techniques avoid unnecessary examinations.

Dual-energy based spectral electronic cleansing in non-cathartic computed tomography colonography: an emerging novel technique.

Computed tomography colonography (CTC) with reduced or without bowel catharsis and with fecal tagging has emerged to improve CTC tolerability in patients and their subsequent compliance with colorectal cancer screening. With fecal tagging, electronic cleansing is performed by postprocessing software that removes remnants of contrast material. However, because the technique is threshold based, artifacts that lower the image quality and accuracy of the examination may be noted. Spectral electronic cleansing, based on dual-energy CT and on material-specific cleansing, decreases the number of artifacts and improves image quality. In this review we describe spectral cleansing with reduced catharsis CTC and illustrate its potential benefits.