Fluoroscopic Evaluation of Duodenal Diseases.

The duodenum can be affected by a variety of abnormalities because of its development during embryogenesis and its dual intra- and retroperitoneal location. If small bowel embryogenesis is disturbed, congenital errors occur. Although some congenital variants may be asymptomatic and inconsequential to the patient, other anomalies can result in life-threatening emergencies such as malrotation, leading to midgut volvulus. Many infectious processes affect the duodenum, including duodenal ulcers and opportunistic infection in patients with HIV/AIDS or Crohn disease. Small bowel malignancies are uncommon but important to recognize, because the duodenum can be involved in polyposis syndromes or the development of primary adenocarcinoma, neuroendocrine tumors, lymphoma, and metastasis. Although endoscopy is currently the most used diagnostic method to assess the lumen of the upper gastrointestinal tract, fluoroscopy is a valuable adjunct technique and the study of choice for many diseases, specifically those for which anatomic and functional information is required. Fluoroscopy is also commonly used postoperatively to assess for complications such as obstruction and extraluminal leaks. Compared with endoscopy, fluoroscopy is an inexpensive and noninvasive technique that provides salient anatomic information and allows delineation of the duodenal mucosa and assessment of real-time duodenal motility. The authors examine the broad spectrum of conditions that can involve the duodenum, including congenital, infectious, inflammatory, and neoplastic abnormalities, and review their typical appearances at fluoroscopy. Online supplemental material is available for this article. ©RSNA, 2022.

CT Detectability of Small Low-Contrast Hypoattenuating Focal Lesions: Iterative Reconstructions versus Filtered Back Projection.

Purpose To investigate performance in detectability of small (≤1 cm) low-contrast hypoattenuating focal lesions by using filtered back projection (FBP) and iterative reconstruction (IR) algorithms from two major CT vendors across a range of 11 radiation exposures. Materials and Methods A low-contrast detectability phantom consisting of 21 low-contrast hypoattenuating focal objects (seven sizes between 2.4 and 10.0 mm, three contrast levels) embedded into a liver-equivalent background was scanned at 11 radiation exposures (volume CT dose index range, 0.5-18.0 mGy; size-specific dose estimate [SSDE] range, 0.8-30.6 mGy) with four high-end CT platforms. Data sets were reconstructed by using FBP and varied strengths of image-based, model-based, and hybrid IRs. Sixteen observers evaluated all data sets for lesion detectability by using a two-alternative-forced-choice (2AFC) paradigm. Diagnostic performances were evaluated by calculating area under the receiver operating characteristic curve (AUC) and by performing noninferiority analyses. Results At benchmark exposure, FBP yielded a mean AUC of 0.79 ± 0.09 (standard deviation) across all platforms which, on average, was approximately 2% lower than that observed with the different IR algorithms, which showed an average AUC of 0.81 ± 0.09 (P = .12). Radiation decreases of 30%, 50%, and 80% resulted in similar declines of observer detectability with FBP (mean AUC decrease, -0.02 ± 0.05, -0.03 ± 0.05, and -0.05 ± 0.05, respectively) and all IR methods investigated (mean AUC decrease, -0.00 ± 0.05, -0.04 ± 0.05, and -0.04 ± 0.05, respectively). For each radiation level and CT platform, variance in performance across observers was greater than that across reconstruction algorithms (P = .03). Conclusion Iterative reconstruction algorithms have limited radiation optimization potential in detectability of small low-contrast hypoattenuating focal lesions. This task may be further complicated by a high degree of variation in radiologists' performances, seemingly exceeding real performance differences among reconstruction algorithms. © RSNA, 2018 Online supplemental material is available for this article.

A Checklist Manifesto: Effectiveness of Checklist Use in Hands-On Simulation Examining Competency in Contrast Reaction Management in a Randomized Controlled Study.

OBJECTIVE: The purpose of this article is to assess the performance of a contrast reaction management checklist for optimal management of a contrast reaction scenario created using a high-fidelity hands-on simulation. MATERIALS AND METHODS: A safety checklist was designed that presented the five adverse events that most commonly occur after administration of IV contrast medium as well as their step-by-step management. Forty-three radiology residents were randomized into two groups, a checklist group (n = 22) and a control group (n = 21), as stratified by postgraduate year. Participants took written tests involving multiple-choice questions 2 months before and immediately after participating in the high-fidelity simulation scenario, which was videotaped and independently evaluated by three graders. RESULTS: Both groups had similar scores on the multiple-choice question tests taken before and after participation in the simulation (p = 0.35 and p = 0.62, respectively). In the simulation, the checklist group scored significantly higher than the control group with regard to their overall management of a severe contrast reaction (85.1% vs 64.8%; p = 0.001), including individual scores for first-line treatment of bronchospasm (97.0% vs 91.3%; p = 0.035) and use of the correct route of administration and dose of epinephrine (77.3% vs 45.2%; p = 0.021). CONCLUSION: A standardized contrast reaction management checklist can reduce the number of treatment errors that occur during a simulated severe contrast reaction, particularly with regard to proper administration of epinephrine and treatment of bronchospasm. Such a checklist could be used by radiologists, technologists, and nurses to improve patient safety as a result of improved contrast reaction management and teamwork skills.

Idiopathic Calcinosis Cutis Universalis Treated Successfully with Oral Diltiazem-A Case Report.

Idiopathic calcinosis cutis is very rare and difficult to treat. Various medical modalities of treatment described with inconsistent results include chelating agents, colchicine, and probenecid. Calcium channel blockers are known to work by inhibiting intracellular entry of calcium. We successfully treated a case of idiopathic calcinosis cutis using oral diltiazem.

Ethical Issues in Radiology Journalism, Peer Review, and Research.

OBJECTIVE: Although some research and publication practices are clearly unethical, including fraud and plagiarism, other areas of research and publication, such as informed consent and conflicts of interest, fall into grayer areas. CONCLUSION: The purposes of this article are, therefore, to review a variety of relevant ethical issues in radiology-related journalism, peer review, and research; to review the radiology literature to date that has addressed these issues; and to present position statements and potential solutions to these problems.

CT of Atypical and Uncommon Presentations of Hepatocellular Carcinoma.

OBJECTIVE: The purpose of this article is to familiarize radiologists with uncommon presentations of hepatocellular carcinoma (HCC) with an emphasis on the CT spectrum of atypical appearances. CONCLUSION: HCC is the fifth most common neoplasm worldwide and the second most common cause of cancer-related death. In many cases, HCC can be confidently diagnosed with noninvasive imaging. However, there are numerous unusual appearances of HCC with which the radiologist must be familiar.

A novel reporting system to improve accuracy in appendicitis imaging.

OBJECTIVE: The purpose of this study was to ascertain if standardized radiologic reporting for appendicitis imaging increases diagnostic accuracy. MATERIALS AND METHODS: We developed a standardized appendicitis reporting system that includes objective imaging findings common in appendicitis and a certainty score ranging from 1 (definitely not appendicitis) through 5 (definitely appendicitis). Four radiologists retrospectively reviewed the preoperative CT scans of 96 appendectomy patients using our reporting system. The presence of appendicitis-specific imaging findings and certainty scores were compared with final pathology. These comparisons were summarized using odds ratios (ORs) and the AUC. RESULTS: The appendix was visualized on CT in 89 patients, of whom 71 (80%) had pathologically proven appendicitis. Imaging findings associated with appendicitis included appendiceal diameter (odds ratio [OR] = 14 [> 10 vs < 6 mm]; p = 0.002), periappendiceal fat stranding (OR = 8.9; p < 0.001), and appendiceal mucosal hyperenhancement (OR = 8.7; p < 0.001). Of 35 patients whose initial clinical findings were reported as indeterminate, 28 (80%) had appendicitis. In this initially indeterminate group, using the standardized reporting system, radiologists assigned higher certainty scores (4 or 5) in 21 of the 28 patients with appendicitis (75%) and lower scores (1 or 2) in five of the seven patients without appendicitis (71%) (AUC = 0.90; p = 0.001). CONCLUSION: Standardized reporting and grading of objective imaging findings correlated well with postoperative pathology and may decrease the number of CT findings reported as indeterminate for appendicitis. Prospective evaluation of this reporting system on a cohort of patients with clinically suspected appendicitis is currently under way.

Three-dimensional conformal radiation therapy in the liver: MRI findings along a time continuum.

Recent development of 3-dimensional conformal radiation therapies provides a concentrated radiation dose to the tumor. To achieve this goal, a complex design of multiple narrow beamlets is used to shape the radiation exposure to conform to the shape of the tumor. Imaging findings after novel radiation therapy techniques differ from those of conventional radiation therapy. This article discusses changes in the liver parenchyma and tumor after conformal radiation therapy focusing on magnetic resonance imaging.

Academic portfolio in the digital era: organizing and maintaining a portfolio using reference managers.

The academic portfolio has become an integral part of the promotions process. Creating and maintaining an academic portfolio in paper-based or web-based formats can be a cumbersome and time-consuming task. In this article, we describe an alternative way to efficiently organize an academic portfolio using a reference manager software, and discuss some of the afforded advantages. The reference manager software Papers (Mekentosj, Amsterdam, The Netherlands) was used to create an academic portfolio. The article outlines the key steps in creating and maintaining a digital academic portfolio. Using reference manager software (Papers), we created an academic portfolio that allows the user to digitally organize clinical, teaching, and research accomplishments in an indexed library enabling efficient updating, rapid retrieval, and easy sharing. To our knowledge, this is the first digital portfolio of its kind.

Enteral contrast in the computed tomography diagnosis of appendicitis: comparative effectiveness in a prospective surgical cohort.

OBJECTIVE: Our goal was to perform a comparative effectiveness study of intravenous (IV)-only versus IV + enteral contrast in computed tomographic (CT) scans performed for patients undergoing appendectomy across a diverse group of hospitals. BACKGROUND: Small randomized trials from tertiary centers suggest that enteral contrast does not improve diagnostic performance of CT for suspected appendicitis, but generalizability has not been demonstrated. Eliminating enteral contrast may improve efficiency, patient comfort, and safety. METHODS: We analyzed data for adult patients who underwent nonelective appendectomy at 56 hospitals over a 2-year period. Data were obtained directly from patient charts by trained abstractors. Multivariate logistic regression was utilized to adjust for potential confounding. The main outcome measure was concordance between final radiology interpretation and final pathology report. RESULTS: A total of 9047 adults underwent appendectomy and 8089 (89.4%) underwent CT, 54.1% of these with IV contrast only and 28.5% with IV + enteral contrast. Pathology findings correlated with radiographic findings in 90.0% of patients who received IV + enteral contrast and 90.4% of patients scanned with IV contrast alone. Hospitals were categorized as rural or urban and by their teaching status. Regardless of hospital type, there was no difference in concordance between IV-only and IV + enteral contrast. After adjusting for age, sex, comorbid conditions, weight, hospital type, and perforation, odds ratio of concordance for IV + enteral contrast versus IV contrast alone was 0.95 (95% CI: 0.72-1.25). CONCLUSIONS: Enteral contrast does not improve CT evaluation of appendicitis in patients undergoing appendectomy. These broadly generalizable results from a diverse group of hospitals suggest that enteral contrast can be eliminated in CT scans for suspected appendicitis.

Human whole-blood (1)H2O longitudinal relaxation with normal and high-relaxivity contrast reagents: influence of trans-cell-membrane water exchange.

PURPOSE: Accurate characterization of contrast reagent (CR) longitudinal relaxivity in whole blood is required to predict arterial signal intensity in contrast-enhanced MR angiography (CE-MRA). This study measured the longitudinal relaxation rate constants (R1 ) over a concentration range for non-protein-binding and protein-binding CRs in ex vivo whole blood and plasma at 1.5 and 3.0 Tesla (T) under physiologic arterial conditions. METHODS: Relaxivities of gadoteridol, gadobutrol, gadobenate, and gadofosveset were measured for [CR] from 0 to 18 mM [mmol(CR)/L(blood)]: the latter being the upper limit of what may be expected in CE-MRA. RESULTS: In plasma, the (1) H2 O R1 [CR]-dependence was nonlinear for gadobenate and gadofosveset secondary to CR interactions with the serum macromolecule albumin, and was well described by an analytical expression for effective 1:1 binding stoichiometry. In whole blood, the (1) H2 O R1 [CR]-dependence was markedly non-linear for all CRs, and was well-predicted by an expression for equilibrium exchange of water molecules between plasma and intracellular spaces using a priori parameter values only. CONCLUSION: In whole blood, (1) H2 O R1 exhibits a nonlinear relationship with [CR] over 0 to 18 mM CR. The nonlinearity is well described by exchange of water between erythrocyte and plasma compartments, and is particularly evident for high relaxivity CRs.

Biostatistics primer for the radiologist.

OBJECTIVE: The purpose of this article is to review the most common data analysis methods encountered in radiology-based studies. Initially, description of variable types and their corresponding summary measures are provided; subsequent discussion focuses on comparison of these summary measures between groups, with a particular emphasis on regression analysis. CONCLUSION: Knowledge of statistical applications is critical for radiologists to accurately evaluate the current literature and to conduct scientifically rigorous studies. Misapplication of statistical methods can lead to inappropriate conclusions and clinical recommendations.

Surgical resection of a malignant liver lesion: what the surgeon wants the radiologist to know.

OBJECTIVE: Hepatic malignancy is a common and lethal disease, whether due to a primary tumor or metastasis. There are numerous treatment options available depending on the stage of the disease and medical condition of the patient, including systemic chemotherapy, transcatheter embolization, thermal ablation, and surgical resection. In a subset of patients with liver malignancy, surgical resection can offer the best chance of long-term survival and potentially even cure. This article reviews the major indications and contraindications for resection, basic surgical techniques and terminology, key clinical and imaging preoperative workup, and pertinent interventional oncology procedures in the management of hepatic malignancy. CONCLUSION: Diagnostic and interventional radiology plays an important role in the assessment and treatment of malignant hepatic lesions. Radiologists should be familiar with how surgeons select, work up, and treat candidates for liver resection to provide the most clinically valuable service.

Hepatocellular carcinoma in the noncirrhotic liver.

OBJECTIVE: Hepatocellular carcinomas (HCCs) that arise in noncirrhotic livers have several histologic and biochemical features that distinguish them from HCCs occurring in the setting of cirrhosis. Because the presentation, management, and prognosis of these entities are distinct, the accurate preoperative characterization of these lesions is of great clinical significance. We review the pathogenesis, imaging appearance, and clinical implications of noncirrhotic HCCs as they pertain to the clinical radiologist. CONCLUSION: HCCs that develop in noncirrhotic patients have distinct etiologic, cytogenetic, histopathologic, and clinical features. Despite a larger tumor burden at the time of HCC diagnosis, noncirrhotic patients with HCC have better overall survival and disease-free survival than cirrhotic patients with HCC. Knowledge of the precise clinical and imaging features of this entity and of other diagnostic considerations for the noncirrhotic liver is essential for improved patient care.

Newer PET application with an old tracer: role of 18F-NaF skeletal PET/CT in oncologic practice.

The skeleton is one of the most common sites for metastatic disease, particularly from breast and prostate cancer. Bone metastases are associated with considerable morbidity, and accurate imaging of the skeleton is important in determining the appropriate therapeutic plan. Sodium fluoride labeled with fluorine 18 (sodium fluoride F 18 [(18)F-NaF]) is a positron-emitting radiopharmaceutical first introduced several decades ago for skeletal imaging. (18)F-NaF was approved for clinical use as a positron emission tomographic (PET) agent by the U.S. Food and Drug Administration in 1972. The early use of this agent was limited, given the difficulties of imaging its high-energy photons on the available gamma cameras. For skeletal imaging, it was eventually replaced by technetium 99m ((99m)Tc)-labeled agents because of the technical limitations of (18)F-NaF. During the past several years, the widespread availability and implementation of hybrid PET and computed tomographic (CT) dual-modality systems (PET/CT) have encouraged a renewed interest in (18)F-NaF PET/CT for routine clinical use in bone imaging. Because current PET/CT systems offer high sensitivity and spatial resolution, the use of (18)F-NaF has been reevaluated for the detection of malignant and nonmalignant osseous disease. Growing evidence suggests that (18)F-NaF PET/CT provides increased sensitivity and specificity in the detection of bone metastases. Furthermore, the favorable pharmacokinetics of (18)F-NaF, combined with the superior imaging characteristics of PET/CT, supports the routine clinical use of (18)F-NaF PET/CT for oncologic imaging for skeletal metastases. In this article, a review of the indications, imaging appearances, and utility of (18)F-NaF PET/CT in the evaluation of skeletal disease is provided, with an emphasis on oncologic imaging.

Comprehensive imaging review of abnormalities of the umbilical cord.

A complete fetal ultrasonographic (US) study includes assessment of the umbilical cord for possible abnormalities. Knowledge of the normal appearance of the umbilical cord is necessary for the radiologist to correctly diagnose pathologic conditions. Umbilical cord abnormalities can be related to cord coiling, length, and thickness; the placental insertion site; in utero distortion; vascular abnormalities; and primary tumors or masses. These conditions may be associated with other fetal anomalies and aneuploidies, and their discovery should prompt a thorough fetal US examination. Further workup and planning for a safe fetal delivery may include fetal echocardiography and karyotype analysis. Doppler US is a critical tool for assessment and diagnosis of vascular cord abnormalities. US also can be used for follow-up serial imaging evaluation of conditions that could result in fetal demise. Recent studies suggest that three- or four-dimensional Doppler US of the fetal umbilical cord and abdominal vasculature allows more accurate diagnosis of vascular abnormalities. Doppler US also is invaluable in assessment of fetal growth restriction since hemodynamic changes in the placenta or fetus would appear as a spectral pattern of increased resistance to forward flow in the fetal umbilical artery. Early detection of umbilical cord abnormalities and close follow-up can reduce the risk of morbidity and mortality and assist in decision making.

Errors of epinephrine administration during severe allergic-like contrast reactions: lessons learned from a bi-institutional study using high-fidelity simulation testing.

PURPOSE: To determine the most common errors of epinephrine administration during severe allergic-like contrast reaction management using high-fidelity simulation surrogates. MATERIALS AND METHODS: IRB approval and informed consent were obtained for this HIPAA-compliant bi-institutional prospective study of 40 radiology residents, fellows, and faculty who were asked to manage a structured high-fidelity severe allergic-like contrast reaction scenario (i.e., mild hives progressing to mild bronchospasm, then bronchospasm unresponsive to bronchodilators, and finally anaphylactic shock) on an interactive manikin. Intravenous (IV) and intramuscular epinephrine ampules were available to all participants, and the manikin had a functioning intravenous catheter for all scenarios. Video recordings of their performance were reviewed by experts in contrast reaction management, and errors in epinephrine administration were recorded and characterized. RESULTS: No participant (0/40) failed to give indicated epinephrine, but more than half (58% [23/40]) committed an error while doing so. The most common mistake was to administer epinephrine as the first-line treatment for mild bronchospasm (33% [13/40]). Other common errors were to administer IV epinephrine without a subsequent IV saline flush or concomitant IV fluids (25% [10/40]), administer an overdose of epinephrine (8% [3/40]), and administer epinephrine 1:1000 intravenously (8% [3/40]). CONCLUSION: Epinephrine administration errors are common. Many radiologists fail to administer albuterol as the first-line treatment for mild bronchospasm and fail to flush the IV catheter when administering IV epinephrine. High-fidelity contrast reaction scenarios can be used to identify areas for training improvement.

MDCT of acute cecal conditions.

The cecum comprises a relatively short segment of the gastrointestinal tract, but it can be affected by numerous acute conditions. Acute conditions may arise from processes primary to the cecum, such as volvulus, bascule, neoplasm, and trauma. Alternatively, acute conditions can be due to secondary to systemic or nearby pathology, such as infection, inflammatory processes, ischemia, and infarction. While it is common to suspect appendicitis as the etiology of acute right lower quadrant abdominal pain, the cecum should also be considered as a potential cause of pain, especially in the setting of an abnormal or absent appendix. Multi-detector computed tomography (MDCT) has evolved to become the best imaging modality to evaluate patients presenting with right lower quadrant abdominal pain or suspected acute cecal pathology. Strengths of MDCT include rapid acquisition of images, high spatial resolution, and ability to create multi-planar reconstructed images. In this pictorial review, we illustrate and describe key MDCT findings for various acute cecal conditions with which the emergency radiologist should be familiar.