ACR Appropriateness Criteria® Routine Chest Imaging.

Routine chest imaging has been used to identify unknown or subclinical cardiothoracic abnormalities in the absence of symptoms. Various imaging modalities have been suggested for routine chest imaging. We review the evidence for or against the use of routine chest imaging in different clinical scenarios. This document aims to determine guidelines for the use of routine chest imaging as initial imaging for hospital admission, initial imaging prior to noncardiothoracic surgery, and surveillance imaging for chronic cardiopulmonary disease. 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 process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

The Pre-Radiology Internship: Room for Improvement?

BACKGROUND: A clinical internship is currently required by the American Board of Radiology prior to Radiology residency. The purpose of this investigation is to evaluate practicing radiologists' perspectives on the value of the internship and their recommendations for optimization. METHODS: A five-minute online survey was distributed via email to practicing radiologist members of the American College of Radiology. RESULTS: A total of 566 completed responses (11.3% response rate) were received. Most respondents agreed that their internship was essential for improving non-radiology clinical knowledge (84%) and affirming their decision to become a radiologist (74%). Most respondents (59%) disagree that the one-year internship before residency should be eliminated. Most (53%) of the radiologists in an academic practice agreed that internship should be integrated into Radiology residency. If radiologists were to redesign the internship ("PreRad Internship"), a majority of the respondents would include training in other medical specialties (71%), working along technologists (55%) and informatics/AI/computer science (54%). While the greatest proportion (50%) of interventional radiologists reported a Surgery internship would be the most beneficial for their primary subspecialty (50%), diagnostic radiologists most commonly (27%) reported the PreRad Internship would be the most beneficial. The greatest proportions of Abdominal-, Breast-, and Neuroradiology-trained respondents reported a PreRad Internship would be the most beneficial internship for their primary field of subspecialty Radiology practice (32%, 36%, and 33%, respectively). CONCLUSION: The internship before Radiology residency offers some benefits but could be further optimized. There is support from practicing radiologists for a redesigned, more Radiology-specific PreRad Internship.

Added Value of Magnetic Resonance Over Computed Tomography in Distinguishing Nonneoplastic Complex Thymic Cysts From Malignant Cystic Thymic Neoplasms.

PURPOSE: The aim of the study was to evaluate cystic thymic masses by using computed tomography (CT) and magnetic resonance (MR) scoring systems to differentiate nonneoplastic thymic cysts from cystic thymic neoplasms. METHODS: This retrospective multisite study included adult patients who underwent CT and MR imaging of the chest between 2007 and 2020 with any of the following impressions on cross-sectional imaging studies: "thymic mass with cystic component," "unilocular or multilocular cystic thymic lesion," "complex thymic cyst," "thymic cyst with hemorrhage." Two blinded radiologists reviewed and recorded specific imaging features as well as overall impressions on both CT and MR using a Likert scale scoring system. Data were analyzed, and diagnostic accuracy of CT and MR was compared using areas under the receiver operating characteristic curves (AUC). RESULTS: Fifty-six patients were included, of which 45 (80%) had benign masses. Total of 21 patients (38%) had indeterminate scores on CT of which 3 (14%) were malignant, while only 6 (11%) had indeterminate scores on MR and 1 was malignant. Magnetic resonance scoring system (AUC, 0.95) performed better than CT scoring system (AUC, 0.86) in distinguishing benign versus malignant lesions (P = 0.06). Lack of enhancement within the mass was completely predictive of benign etiology (P < 0.001). Wall thickness of an enhancing cyst was predictive of malignancy, with AUC 0.93. CONCLUSIONS: Magnetic resonance yielded higher specificity allowing a larger number of lesions to be confidently assigned a benign diagnosis. This could help in averting unnecessary follow-up, biopsies, or surgery. The authors recommend follow-up imaging with MR for prevascular masses, even those appearing "solid" on CT.

ACR Appropriateness Criteria® Diffuse Lung Disease.

Diffuse lung disease, frequently referred to as interstitial lung disease, encompasses numerous disorders affecting the lung parenchyma. The potential etiologies of diffuse lung disease are broad with several hundred established clinical syndromes and pathologies currently identified. Imaging plays a critical role in diagnosis and follow-up of many of these diseases, although multidisciplinary discussion is the current standard for diagnosis of several DLDs. This document aims to establish guidelines for evaluation of diffuse lung diseases for 1) initial imaging of suspected diffuse lung disease, 2) initial imaging of suspected acute exacerbation or acute deterioration in cases of confirmed diffuse lung disease, and 3) clinically indicated routine follow-up of confirmed diffuse lung disease without acute deterioration. 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.

ACR Appropriateness Criteria® Nontraumatic Chest Wall Pain.

Chest pain is a common reason that patients may present for evaluation in both ambulatory and emergency department settings, and is often of musculoskeletal origin in the former. Chest wall syndrome collectively describes the various entities that can contribute to chest wall pain of musculoskeletal origin and may affect any chest wall structure. Various imaging modalities may be employed for the diagnosis of nontraumatic chest wall conditions, each with variable utility depending on the clinical scenario. We review the evidence for or against use of various imaging modalities for the diagnosis of nontraumatic chest wall pain. 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.

ACR Appropriateness Criteria® Imaging of Mediastinal Masses.

Mediastinal masses can present with symptoms, signs, and syndromes or incidentally. Selecting the appropriate diagnostic imaging study for mediastinal mass evaluation requires awareness of the strengths and weaknesses of the various imaging modalities with regard to tissue characterization, soft tissue contrast, and surveillance. This publication expounds on the differences between chest radiography, CT, PET/CT, ultrasound, and MRI in terms of their ability to decipher and surveil mediastinal masses. Making the optimal imaging choice can yield diagnostic specificity, avert unnecessary biopsy and surgery, guide the interventionist when necessary, and serve as a means of surveillance for probably benign, but indeterminate mediastinal masses. 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.

ACR appropriateness criteria imaging of mediastinal masses

Mediastinal masses can present with symptoms, signs, and syndromes or incidentally. Selecting the appropriate diagnostic imaging study for mediastinal mass evaluation requires awareness of the strengths and weaknesses of the various imaging modalities with regard to tissue characterization, soft tissue contrast, and surveillance. This publication expounds on the differences between chest radiography, CT, PET/CT, ultrasound, and MRI in terms of their ability to decipher and surveil mediastinal masses. Making the optimal imaging choice can yield diagnostic specificity, avert unnecessary biopsy and surgery, guide the interventionist when necessary, and serve as a means of surveillance for probably benign, but indeterminate mediastinal masses. 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.

Imaging of the Middle and Visceral Mediastinum.

The visceral mediastinum contains important vascular and non-vascular structures including the heart, great vessels, lymph nodes, and portions of the esophagus and trachea. Multiple imaging modalities, including chest radiography, computed tomography, MR imaging, and nuclear medicine studies, can be used to detect, diagnose, and characterize masses in this compartment. Lymphadenopathy is the most common process involving the visceral mediastinum and can be seen with a wide variety of diseases. Less commonly seen entities include foregut duplication cysts, neoplasms and other lesions arising from the trachea and esophagus, paragangliomas as well as other mesenchymal tumors.

A pictorial review of lung torsion using 3D CT cinematic rendering.

Lung torsion is the abnormal rotation of a lobe or lung around its bronchovascular pedicle. It most commonly occurs in the setting of pulmonary resection, though it has also been described after large-volume thoracentesis and video-assisted thoracic surgery, as well as spontaneously. Resulting ischemia can lead to infarction, making this an emergent diagnosis. As findings are often nonspecific, a high index of suspicion is required, especially in the postsurgical setting. 2D CT angiography findings are subtle and include direct signs of pedicle rotation on CT as well as indirect findings including loss of normal parenchymal enhancement, atelectasis of torsed lobe/lung, and abnormal fissure position. These direct and indirect findings are often appreciated on different window presets and upon review of images in multiple planes, with need to collate the information subsequently. 3D cinematic rendering (CR) using multi-planar light sources can readily highlight spatial relationships of vasculature in the chest and may be able to assist in the confident diagnosis of this sometimes subtle but life-threatening pathology. We have provided the first characterization of common lung torsion findings on 3D CR.

Contribution of FDG-PET/CT to the management of esophageal cancer patients at multidisciplinary tumor board conferences.

BACKGROUND: A multidisciplinary team approach to the management of esophageal cancer patients leads to better clinical decisions. PURPOSE: The contribution of CT, endoscopic and laparoscopic ultrasound to clinical staging and treatment selection by multidisciplinary tumor boards (MTB) in patients with esophageal cancer is well documented. However, there is a paucity of data addressing the role that FDG-PET/CT (PET/CT) plays to inform the clinical decision-making process at MTB conferences. The aim of this study was to assess the impact and contribution of PET/CT to clinical management decisions and to the plan of care for esophageal cancer patients at the MTB conferences held at our institution. MATERIALS AND METHODS: This IRB approved study included all the cases discussed in the esophageal MTB meetings over a year period. The information contributed by PET/CT to MTB decision making was grouped into four categories. Category I, no additional information provided for clinical management; category II, equivocal and misguiding information; category III, complementary information to other imaging modalities, and category IV, information that directly changed clinical management. The overall impact on management was assessed retrospectively from prospectively discussed clinical histories, imaging, histopathology, and the official minutes of the MTB conferences. RESULTS: 79 patients (61 males and 18 females; median age, 61 years, range, 33-86) with esophageal cancer (53 adenocarcinomas and 26 squamous cell carcinomas) were included. The contribution of PET/CT-derived information was as follows: category I in 50 patients (63%); category II in 3 patients (4%); category III in 8 patients (10%), and category IV information in 18 patients (23%). Forty-five patients (57%) had systemic disease, and in 5 (11%) of these, metastatic disease was only detected by PET/CT. In addition, PET/CT detected previously unknown recurrence in 4 (9%) of 43 patients. In summary, PET/CT provided clinically useful information to guide management in 26 of 79 esophageal cancer patients (33%) discussed at the MTB. CONCLUSION: The study showed that PET/CT provided additional information and changed clinical management in 1 out of 3 (33%) esophageal cancer cases discussed at MTB conferences. These results support the inclusion whenever available, of FDG-PET/CT imaging information to augment and improve the patient management decision process in MTB conferences.

Is Asking Questions on Rounds a Teachable Skill? A Randomized Controlled Trial to Increase Attendings' Asking Questions.

BACKGROUND: Morning bedside rounds remain an essential part of Internal Medicine residency education, but rounds vary widely in terms of educational value and learner engagement. OBJECTIVE: To evaluate the efficacy of an intervention to increase the number and variety of questions asked by attendings at the bedside and assess its impact. DESIGN: We conducted a randomized, controlled trial to evaluate the efficacy of our intervention. PARTICIPANTS: Hospitalist attendings on the general medicine service were invited to participate. Twelve hospitalists were randomized to the experimental group and ten hospitalists to the control group. INTERVENTION: A one-hour interactive session which teaches and models the method of asking questions using a non-medical case, followed by practice using role plays with medical cases. MAIN MEASURES: Our primary outcome was the number of questions asked by attendings during rounds. We used audio-video recordings of rounds evaluated by blinded reviewers to quantify the number of questions asked, and we also recorded the type of question and the person asked. We assessed whether learners found rounds worthwhile using anonymous surveys of residents, patients, and nurses. KEY RESULTS: Blinded analysis of the audio-video recordings demonstrated significantly more questions asked by attendings in the experimental group compared to the control group (mean number of questions 23.5 versus 10.8, p< 0.001) with significantly more questions asked of the residents (p<0.003). Residents rated morning bedside rounds with the experimental attendings as significantly more worthwhile compared to rounds with the control group attendings (p=0.009). CONCLUSION: Our study findings highlight the benefits of a one-hour intervention to teach faculty a method of asking questions during bedside rounds. This educational strategy had the positive outcome of including significantly more resident voices at the bedside. Residents who rounded with attendings in the experimental group were more likely to "strongly agree" that bedside rounds were "worthwhile".

Cystic Fibrosis from Childhood to Adulthood: What Is New in Imaging Assessment?

Advanced pulmonary disease continues to remain the leading cause of morbidity and mortality in patients with cystic fibrosis (CF), with pulmonary imaging playing a crucial role in early detection, longitudinal monitoring, as well as prelung and postlung transplant evaluation. This article reviews the specific imaging features of CF using conventional imaging modalities (chest radiographs and high-resolution computed tomography [HRCT]) as well as emerging imaging technologies (digital chest tomosynthesis and MR imaging). In addition, the authors review the CF-specific HRCT imaging findings that are essential in the evaluation of these patients in the pre-lung transplant and post-lung transplant settings.

Image Quality and Lesion Detection on Deep Learning Reconstruction and Iterative Reconstruction of Submillisievert Chest and Abdominal CT.

OBJECTIVE. The objective of this study was to compare image quality and clinically significant lesion detection on deep learning reconstruction (DLR) and iterative reconstruction (IR) images of submillisievert chest and abdominopelvic CT. MATERIALS AND METHODS. Our prospective multiinstitutional study included 59 adult patients (33 women, 26 men; mean age ± SD, 65 ± 12 years old; mean body mass index [weight in kilograms divided by the square of height in meters] = 27 ± 5) who underwent routine chest (n = 22; 16 women, six men) and abdominopelvic (n = 37; 17 women, 20 men) CT on a 640-MDCT scanner (Aquilion ONE, Canon Medical Systems). All patients gave written informed consent for the acquisition of low-dose (LD) CT (LDCT) after a clinically indicated standard-dose (SD) CT (SDCT). The SDCT series (120 kVp, 164-644 mA) were reconstructed with interactive reconstruction (IR) (adaptive iterative dose reduction [AIDR] 3D, Canon Medical Systems), and the LDCT (100 kVp, 120 kVp; 30-50 mA) were reconstructed with filtered back-projection (FBP), IR (AIDR 3D and forward-projected model-based iterative reconstruction solution [FIRST], Canon Medical Systems), and deep learning reconstruction (DLR) (Advanced Intelligent Clear-IQ Engine [AiCE], Canon Medical Systems). Four subspecialty-trained radiologists first read all LD image sets and then compared them side-by-side with SD AIDR 3D images in an independent, randomized, and blinded fashion. Subspecialty radiologists assessed image quality of LDCT images on a 3-point scale (1 = unacceptable, 2 = suboptimal, 3 = optimal). Descriptive statistics were obtained, and the Wilcoxon sign rank test was performed. RESULTS. Mean volume CT dose index and dose-length product for LDCT (2.1 ± 0.8 mGy, 49 ± 13mGy·cm) were lower than those for SDCT (13 ± 4.4 mGy, 567 ± 249 mGy·cm) (p < 0.0001). All 31 clinically significant abdominal lesions were seen on SD AIDR 3D and LD DLR images. Twenty-five, 18, and seven lesions were detected on LD AIDR 3D, LD FIRST, and LD FBP images, respectively. All 39 pulmonary nodules detected on SD AIDR 3D images were also noted on LD DLR images. LD DLR images were deemed acceptable for interpretation in 97% (35/37) of abdominal and 95-100% (21-22/22) of chest LDCT studies (p = 0.2-0.99). The LD FIRST, LD AIDR 3D, and LD FBP images had inferior image quality compared with SD AIDR 3D images (p < 0.0001). CONCLUSION. At submillisievert chest and abdominopelvic CT doses, DLR enables image quality and lesion detection superior to commercial IR and FBP images.

Thoracic Manifestations of Rheumatoid Arthritis.

Rheumatoid arthritis (RA) is commonly associated with pulmonary disease that can affect any anatomic compartment of the thorax. The most common intrathoracic manifestations of RA include interstitial lung disease, airway disease, pleural disease, rheumatoid nodules, and drug-induced toxicity. Patients with RA with thoracic involvement often present with nonspecific respiratory symptoms, although many are asymptomatic. Therefore, clinicians should routinely consider pulmonary disease when evaluating any patient with RA, particularly one with known risk factors. The optimal screening, diagnostic, and treatment strategies for RA-associated pulmonary disease remain uncertain and are the focus of ongoing investigation.

Can fully iterative reconstruction technique enable routine abdominal CT at less than 1 mSv?

OBJECTIVE: We assessed the effect of the forward projected model-based reconstruction technique (FIRST) on lesion detection of routine abdomen CT at <1 mSv. MATERIALS AND METHODS: Thirty-seven adult patients gave written informed consent for acquisition of low-dose CT (LDCT) immediately after their clinically-indicated, standard of care dose (SDCT), routine abdomen CT on a 640-slice MDCT (Aquillion One, Canon Medical System). The LDCT series were reconstructed with FIRST (at STD (Standard) and STR (Strong) levels), and SDCT series with filtered back projection (FBP). Two radiologists assessed lesions in LD-FBP and FIRST images followed by SDCT images. Then, SDCT and LDCT were compared for presence of artifacts in a randomized and blinded fashion. Patient demographics, size and radiation dose descriptors (CTDIvol, DLP) were recorded. Descriptive statistics and inter-observer variability were calculated for data analysis. RESULTS: Mean CTDIvol for SDCT and LDCT were 13 ± 4.7 mGy and 2.2 ± 0.8 mGy, respectively. There were 46 true positive lesions detected on SDCT. Radiologists detected 38/46 lesions on LD-FIRST-STD compared to 26/46 lesions on LD-FIRST-STR. The eight lesions (liver and kidney cysts, pancreatic lesions, sub-cm peritoneal lymph node) missed on LD-FIRST-STD were seen in patients with BMI > 25.8 kg/m2. Diagnostic confidence for lesion assessment was optimal in LD-FIRST-STD setting in most patients regardless of their size. The inter-observer agreement (kappa-value) for overall image quality were 0.98 and 0.84 for LD-FIRST-STD and STR levels, respectively. CONCLUSION: FIRST enabled optimal lesion detection in routine abdomen CT at less than 1 mSv radiation dose in patients with body mass less than ≤25.8 kg/m2.

Significance of the Reverse Halo Sign in Immunocompromised Patients.

OBJECTIVE. The purpose of this study is to assess the most common causes of the reverse halo sign (RHS) in immunocompromised patients and to identify clinicoradiologic features that help in achieving a specific diagnosis. MATERIALS AND METHODS. This retrospective study included 70 patients with hematologic malignancy, neutropenia, or history of solid organ transplant or stem cell transplant who had the RHS at chest CT. Absolute neutrophil count, imaging features of the RHS, and presence of pleural effusions were noted and correlated with the specific diagnosis. A decision tree was constructed from predictive imaging features and compared with radiologist assessment for infectious versus noninfectious cause. RESULTS. Infection, including fungal and bacterial pneumonia, was the most common cause of the RHS (66%), followed by organizing pneumonia (26%). Noninfectious causes such as organizing pneumonia were more likely in the solid organ transplant group, whereas infections were more likely in patients with hematologic malignancy and stem cell transplant. Among fungal pneumonias, aspergillosis (20%) was as common as mucormycosis (19%). In univariate analysis, neutropenia, rim thickness, central ground-glass attenuation, and lesion diameter correlated with infectious cause. A decision tree using neutropenia, rim thickness, central ground-glass attenuation, and pleural effusion could differentiate infectious from noninfectious cause with accuracy of 78%, compared with radiologist accuracy of 81%. CONCLUSION. Infections are more likely to cause RHS than noninfectious processes in immunocompromised patients, and aspergillosis may be as likely overall as mucormycosis because of its higher frequency in these patients. A decision tree using clinical and imaging features can help differentiate infectious from noninfectious causes of RHS.

Predictive Features for Anterior Mediastinal Mass Diagnoses.

OBJECTIVE: We set out to evaluate a set of demographic and computed tomography imaging features for diagnosing anterior mediastinal masses. METHODS: We identified 223 patients with anterior mediastinal masses, which we divided into training and validation sets. One radiologist evaluated computed tomography imaging features on the training set. Then, predictive features were identified, and 3 radiologists evaluated these on the validation set. A naive Bayesian classifier based on the features was compared with the radiologists' first-choice diagnosis. RESULTS: Internal mammary lymphadenopathy and mediastinal encasement were strongly associated with lymphomas. Low attenuation and midline location were strongly associated with benign lesions, and older age was associated with thymic epithelial neoplasms. The average accuracy of the 3 radiologists' diagnoses was 78%, compared with 71% for the classifier. CONCLUSIONS: Nine demographic and imaging features were found to be helpful in diagnosing anterior mediastinal masses. By using these features, radiologists can suggest the diagnosis with fair accuracy.