Publications

The coronavirus disease 2019 (COVID-19) pandemic caused by the novel severe acute respiratory syndrome coronavirus (SARS-CoV-2) has affected almost every country in the world resulting in severe morbidity, mortality and economic hardship, altering the landscape of healthcare forever. Its devastating and most frequent thoracic and cardiac manifestations have been well reported since the start of the pandemic. Its extra-thoracic manifestations are myriad and understanding them is critical in diagnosis and disease management. The role of radiology is growing in the second wave and second year of the pandemic as the multiorgan manifestations of COVID-19 continue to unfold. Musculoskeletal, neurologic and vascular disease processes account for a significant number of COVID-19 complications and understanding their frequency, clinical sequelae and imaging manifestations is vital in guiding management and improving overall survival. The authors aim to provide a comprehensive overview of the pathophysiology of the virus along with a detailed and systematic imaging review of the extra-thoracic manifestation of COVID-19. In Part I, abdominal manifestations of COVID-19 in adults and multisystem inflammatory syndrome in children will be reviewed. In Part II, manifestations of COVID-19 in the musculoskeletal, central nervous and vascular systems will be reviewed.

INTRODUCTION: Prognostic models for malignant pleural mesothelioma have been limited to demographics, symptoms, and laboratory values. We hypothesize higher accuracy using both tumor and patient characteristics. The mesothelioma prognostic test (MPT) and molecular subtype based on claudin-15-to-vimentin expression ratio are molecular signatures associated with survival. Tumor volume (TV) has improved performance compared with clinical staging, whereas neutrophil-to-lymphocyte ratio (NLR) is prognostic for malignant pleural mesothelioma.

METHODS: Tumor specimens and clinical data were collected prospectively from patients who underwent extrapleural pneumonectomy (EPP) or pleurectomy and decortication (PD) during 2007 to 2014. MPT and claudin-15-to-vimentin ratio were determined by real-time quantitative polymerase chain reaction, whereas TV was assessed from preoperative scans. Risk groups were derived from combinations of adverse factors on the basis of the Cox model. Predictive accuracy was assessed using Harrell's c-index.

RESULTS: MPT, molecular subtype, TV, and NLR were independently prognostic in patients with EPP (N = 191), suggesting equal weighting in a final three-group model (c = 0.644). In the PD cohort (N = 193), MPT poor risk combined with TV greater than 200 cm3 was associated with triple the risk compared with other subgroups (hazard ratio = 2.94, 95% confidence interval: 1.70-5.09, p < 0.001) persisting when adjusted for molecular subtype, NLR, performance status, and serum albumin to yield a final three-group model (c = 0.641). The EPP and PD models achieved higher accuracy than published models (c ≤ 0.584, c ≤ 0.575) and pathologic staging (c = 0.554, c = 0.571).

CONCLUSIONS: The novel models use pretreatment parameters obtained from minimally invasive biopsy, imaging, and blood tests to evaluate the expected outcome of each type of surgery in newly diagnosed patients and improve stratification on clinical trials.

OBJECTIVE: To assess accuracy of dual-energy computed tomography (DECT) to differentiate uric acid from calcium urinary stones in dual-energy split filter vs sequential-spiral vs dual-source acquisition.

METHODS: Thirty-four urinary stones (volume 89.0 ± 77.4 mm³; 17 calcium stones, 17 uric acid stones) were scanned in a water-filled phantom using a split-filter equipped CT scanner (SOMATOM Definition Edge, Siemens Healthineers, Forchheim, Germany) in split-filter mode at 120 kVp and sequential-spiral mode at 80 and 140 kVp. Additional DE scans were acquired at 80 and 140 kVp (tin filter) with a dual-source CT scanner (SOMATOM Definition FLASH, Siemens Healthineers). Scans were performed with a CTDIvol of 7.3 mGy in all protocols. Urinary stone categorization was based on dual energy ratio (DER) using an automated 3D segmentation. As reference standard, infrared spectroscopy was used to determine urinary stone composition.

RESULTS: All three DECT techniques significantly differentiated between uric acid and calcium stones by attenuation values and DERs (p < 0.001 for all). Split-filter DECT provided higher DERs for uric acid stones, when compared with dual-source and sequential-spiral DECT, and lower DERs for calcified stones when compared with dual-source DECT (p < 0.001 for both), leading to a decreased accuracy for material differentiation.

CONCLUSION: Split-filter DECT, sequential-spiral DECT and dual-source DECT all allow for the acquisition of DER to classify urinary stones.

ADVANCES IN KNOWLEDGE: Split-filter DECT enables the differentiation between uric acid and calcium stones despite decreased spectral separation when compared with dual-source and dual-spiral DECT.

PURPOSE: To evaluate diagnostic accuracy and clinical outcomes of patients with porcelain gallbladder (GB) diagnosed on CT.

MATERIALS AND METHODS: In this IRB-approved, HIPAA-compliant study, consecutive patients with porcelain gallbladder reported on CT between December 1, 2000 and August 31, 2017 in a tertiary academic center were included. Two radiologists independently reviewed CT images and confirmed presence of porcelain gallbladder. Discrepant cases were reviewed by a third reader with 15 years of experience in abdominal imaging. Porcelain gallbladder diagnosis was confirmed by surgery/pathology or follow-up imaging.

RESULTS: Porcelain gallbladder was reported in 133 CT studies. Radiologist review and pathology results confirmed porcelain gallbladder in 90/133 (68%) patients (age 71.6 ± 13.8 years, 57% female). One third (42/133; 32%) of CT reports were false positive; 1/133 (1%) remained indeterminate. Frequent pitfalls included: stones filling the whole gallbladder lumen in 39/43 (91%), sludge in 3/43 (7%) and mucosal enhancement in 2/43 (5%). In 5/90 (6%) patients, concurrent gallbladder cancer was noted on the initial CT scan. No patient developed subsequent gallbladder cancer during 6.6 ± 4.6 years of follow-up. One third (30/90, 33%) of patients with porcelain gallbladder have deceased during the follow-up period, all from unrelated causes.

CONCLUSION: At the time of presentation with porcelain gallbladder, 6% of patients had concurrent gallbladder cancer. No patient with porcelain gallbladder alone diagnosed on CT developed gallbladder cancer during a follow-up of 6.6 ± 4.6 years. Porcelain gallbladder is overcalled on CT, with frequent pitfalls including gallstones filling the whole gallbladder lumen, sludge, and wall enhancement.

Acute aortic syndrome (AAS) includes the entities of acute aortic dissection, intramural hematoma, and penetrating atherosclerotic ulcer. AAS typically presents with sudden onset of severe, tearing, anterior, or interscapular back pain. Symptoms may be dominated by malperfusion syndrome, due to obstruction of the lumen of the aorta and/or a side branch when the intimal and medial layers are separated. Timely diagnosis of AAS is crucial to permit prompt management; for example, early mortality rates are reported to be 1% to 2% per hour after the onset of symptoms for untreated ascending aortic dissection. The appropriateness assigned to each imaging procedure was based on the ability to obtain key information that is used to plan open surgical, endovascular, or medical therapy. This includes, but is not limited to, confirming the presence of AAS; classification; characterization of entry and reentry sites; false lumen patency; and branch vessel compromise. Using this approach, CT, CTA, and MRA are all considered usually appropriate in the initial evaluation of AAS if those procedures include intravenous contrast administration. Ultrasound is also considered usually appropriate if the acquisition is via a transesophageal approach. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Preoperative ultrasound-guided lateral abdominal wall botulinum toxin injection is a promising method for improving patient outcomes and reducing recurrence rates after ventral hernia repair. A review of the literature demonstrates variability in the procedural technique, without current standardization of protocols. As radiologists may be increasingly asked to perform ultrasound-guided botulinum toxin injections of the lateral abdominal wall, familiarity with the procedure and current literature is necessary.

BACKGROUND: This study sought to examine the impact of nodule density on recurrence and survival in female patients with lung adenocarcinoma treated by lobectomy or sublobar resection.

METHODS: In this retrospective study of female patients who underwent surgical resection for pathologic stage IA adenocarcinoma, patients with preoperative imaging were included for analysis if the consolidation-to-tumor ratio was 0.5 (solid-predominant ground-glass opacity [GGO]) to 1.0 (solid). Kaplan-Meier curves were generated to estimate overall survival (OS) and disease-free survival (DFS). Risk estimates were calculated using multivariable Cox proportional hazards models.

RESULTS: For all 357 patients sublobar resection demonstrated worse 5-year DFS compared with lobectomy (76.4% vs 67.9%, P = .05). Multivariable modeling showed worse DFS with sublobar resection (hazard ratio, 1.55; P = .06) and tumors ≥ 2 cm (hazard ratio, 2.32; P = .05). On radiologic evaluation the solid-predominant GGO group (n = 81) demonstrated a smaller solid component compared with the solid nodule group (n = 163; 1.49 cm vs. 1.84 cm, respectively; P < .001) yet comparable total size. The solid-predominant GGO group showed improved 5-year OS (90.8 vs 76.8, P = .01) and DFS (79.3 vs 67.2, P = .05) compared with the solid nodule group. Additionally the solid-predominant GGO group demonstrated equivalent OS (90.8% vs 90.8%, P = .93) and DFS (76.0% vs 81.7%, P = .60) with sublobar resection compared with lobectomy.

CONCLUSIONS: In this report of female patients with stage IA adenocarcinoma, sublobar resection was associated with worse DFS compared with lobectomy in whole-group analysis. However patients with solid-predominant GGOs demonstrated improved 5-year OS and DFS compared with patients with solid nodules with equivalent outcomes regardless of resection type.

There is currently no consensus regarding preferred clinical outcome measures following image-guided tumor ablation or clear definitions of oncologic end points. This consensus document proposes standardized definitions for a broad range of oncologic outcome measures with recommendations on how to uniformly document, analyze, and report outcomes. The initiative was coordinated by the Society of Interventional Oncology in collaboration with the Definition for the Assessment of Time-to-Event End Points in Cancer Trials, or DATECAN, group. According to predefined criteria, based on experience with clinical trials, an international panel of 62 experts convened. Recommendations were developed using the validated three-step modified Delphi consensus method. Consensus was reached on when to assess outcomes per patient, per session, or per tumor; on starting and ending time and survival time definitions; and on time-to-event end points. Although no consensus was reached on the preferred classification system to report complications, quality of life, and health economics issues, the panel did agree on using the most recent version of a validated patient-reported outcome questionnaire. This article provides a framework of key opinion leader recommendations with the intent to facilitate a clear interpretation of results and standardize worldwide communication. Widespread adoption will improve reproducibility, allow for accurate comparisons, and avoid misinterpretations in the field of interventional oncology research. Published under a CC BY 4.0 license. Online supplemental material is available for this article. See also the editorial by Liddell in this issue.

Gastrointestinal (GI) bleeding is a common potentially life-threatening medical condition frequently requiring multidisciplinary collaboration to reach the proper diagnosis and guide management. GI bleeding can be overt (eg, visible hemorrhage such as hematemesis, hematochezia, or melena) or occult (eg, positive fecal occult blood test or iron deficiency anemia). Upper GI bleeding, which originates proximal to the ligament of Treitz, is more common than lower GI bleeding, which arises distal to the ligament of Treitz. Small bowel bleeding accounts for 5-10% of GI bleeding cases commonly manifesting as obscure GI bleeding, where the source remains unknown after complete GI tract endoscopic and imaging evaluation. CT can aid in identifying the location and cause of bleeding and is an important complementary tool to endoscopy, nuclear medicine, and angiography in evaluating patients with GI bleeding. For radiologists, interpreting CT scans in patients with GI bleeding can be challenging owing to the large number of images and the diverse potential causes of bleeding. The purpose of this pictorial review by the Society of Abdominal Radiology GI Bleeding Disease-Focused Panel is to provide a practical resource for radiologists interpreting GI bleeding CT studies that reviews the proper GI bleeding terminology, the most common causes of GI bleeding, key patient history and risk factors, the optimal CT imaging technique, and guidelines for case interpretation and illustrates many common causes of GI bleeding. A CT reporting template is included to help generate radiology reports that can add value to patient care. An invited commentary by Al Hawary is available online. Online supplemental material is available for this article. ©RSNA, 2021.