CT Interpretation Research Articles

The Golden Rule: Decreasing Delays in Imaging and Diagnosis in Trauma Activations in a Rural Emergency Department

Background: Trauma is a leading cause of morbidity and mortality in the United States and outcomes are worsening in a time-dependent manner. We developed a series of protocol changes to speed time to care. We hypothesized this bundle of care would improve several imaging metrics. Methods: We compared various imaging time metrics from 3 months before the changes to 6 months afterwards. The primary outcome was time to CT interpretation. Secondary outcomes included time to X-ray interpretation and emergency department length of stay. Results: Primary and secondary outcome analysis demonstrated significant improvement. Improvements were also noted in severe subgroups. Conclusion: The data suggest decreased time from the traumatic mechanism to identification of pathology. Future work should evaluate the effect of this intervention on clinical outcomes.

Pictorial guide for variants of Covid-19: CT imaging and interpretation.

Typical radiologic images of Covid-19 pneumonia consists in a wide spectrum of chest manifestations, which range from peripheral predominant ground-glass opacities to an organizing pneumonia pattern, with additional features including crazy-paving, consolidations, fibrotic streaks and linear opacities. With variants imaging profile of Covid-19 evolves, producing relatively atypical/indeterminate CT pattern of pulmonary involvement, which overlap with imaging features of a variety of other respiratory diseases, including infections, drug reaction and hypersensitivity pneumonia. Our knowledge of these radiological findings is incomplete and there is a need to strengthen the recognition of the many faces of Covid-19 pneumonia.

Crohn's disease active inflammation assessment with iodine density from dual-energy CT enterography: comparison with endoscopy and conventional interpretation.

To compare terminal ileum (TI) mucosal iodine density obtained at dual-energy CT enterography (DECTE) with conventional CT interpretation and endoscopy in patients with Crohn's disease (CD). Twenty-three CD patients (14 men; mean[SD] age:48.1[16.7] years) with endoscopy within 30days of DECTE were retrospectively identified. An inflammatory bowel disease gastroenterologist reviewed endoscopic images. Two radiologists qualitatively assessed the presence of active TI inflammation. Mean iodine density normalized to the aorta (I%), mean absolute iodine density (I), and iodine density standard deviation (ISD) from the distal 2cm ileum (TI) mucosa obtained using semiautomatic prototype software were compared with endoscopic assessment using Mann Whitney tests. The optimal threshold I% and I were determined from receiver operating curves (ROC). Sensitivity and specificity of conventional interpretation and determined iodine thresholds were compared using McNemar's test. Inter-reader agreement was assessed using kappa. A p < 0.05 indicated statistical significance. Twelve (52.1%) patients had endoscopic active inflammation. I% was 37.9[13.3]% for patients with and 21.7[7.5]% for patients without endoscopic active inflammation (p = 0.001). The optimal ROC threshold 24.6% had 100% sensitivity and 81.8% specificity (AUC = 0.909, 95% CI 0.777-1). I was 2.44[0.73]mg/mL for patients with and 1.77[1.00]mg/mL for patients without active endoscopic inflammation (p =0.0455). The optimal ROC threshold 1.78mg/mL I had 91.7% sensitivity and 63.6% specificity (AUC = 0.75, 95% CI 0.532-0.968). ISD was similar for patients with and without endoscopic active inflammation (0.82[0.33]mg/mL and 0.77[0.28]mg/mL, respectively, p = 0.37). Conventional interpretation sensitivity and specificity (R1/R2) were 83.3%/91.7% and 72.7%/54.5%, respectively (all p > 0.05) with moderate inter-reader agreement (Κ = 0.542[95% CI 0.0202-0.088]). Mean normalized iodine density is highly sensitive and specific for endoscopic active inflammation. DECTE could be considered as a surrogate to endoscopy in CD patients. Despite trends towards improved sensitivity and specificity compared with conventional interpretation, future larger studies are needed.

Evaluation of neuroradiology emergency MRI interpretations: low discrepancy rates between on-call radiology residents' preliminary interpretations and neuroradiologists' final reports.

To evaluate the performance of on-call radiology residents in interpreting alone brain and spine MRI studies performed after hours, to describe their mistakes, and to identify influencing factors that increased the occurrence of errors. A total of 328 MRI examinations performed during a 13-month period (from December 1, 2019, to January 1, 2021) were prospectively included. Discrepancies between the preliminary interpretation of on-call radiology residents and the final reports of attending neuroradiologists were noted and classified according to a three-level score: level 1 (perfect interpretation or minor correction), level 2 (important correction without immediate change in patient management), or level 3 (major correction with immediate change in patient management). Categorical data were compared using Fisher's exact test. The overall discrepancy rate (level-2 and level-3 errors) was 16%; the rate of major discrepancies (only level-3 errors) was 5.5%. The major-discrepancy rate of second-year residents, when compared with that of senior residents, was significantly higher (p = 0.02). Almost all of the level-3 errors concerned cerebrovascular pathology. The most common level-2 errors involved undescribed aneurysms. We found no significant difference in the major-discrepancy rate regarding time since the beginning of the shift. The great majority of examinations were correctly interpreted. The rate of major discrepancies in our study was comparable to the data in the literature, and there was no adverse clinical outcome. The level of residency has an effect on the rate of serious errors in residents' reports. • The rate of major discrepancies between preliminary MRI interpretations by on-call radiology residents and final reports by attending neuroradiologists is low, and comparable to discrepancy rates reported for head CT interpretations. • The youngest residents made significantly more serious errors when compared to senior residents. • There was no adverse clinical outcome in patient morbidity as a result of an initial misdiagnosis.

The diagnostic performance of platelet function analyzer-100 (PFA-100) in Thai children with mucocutaneous bleeding disorder

BackgroundClosure time (CT), a parameter measured by platelet function analyzer (PFA-100), is used to assess primary hemostasis. However, some factors (e.g., ethnicity and age) may affect its cut-off value or reference range. Moreover, the diagnostic performance of CT in the Thai and Southeast Asian populations has not been reported in any study. Therefore, this study aims to evaluate the diagnostic performance of CT in patients with mucocutaneous bleeding disorder using the established cut-off value from Thai children. MethodsCT from both collagen/epinephrine (COL/EPI) and collagen/adenosine 5- diphosphate (COL/ADP) cartridges and complete blood count were performed in both healthy volunteers and known cases of primary hemostatic disorders. The cut-off value and diagnostic performance of CT was determined using receiver operating characteristic curve analysis. ResultsThe cut-off value of both COL/EPI and COL/ADP in this study was somewhat prolonged than the other studies because of the higher prevalence of non-responsiveness of platelets to epinephrine stimulation in the Asian than the Western. Nonetheless, the diagnostic performance was comparable to the previous studies. In addition, the diagnostic performance could be enhanced when the CT from both cartridges was interpreted together. ConclusionThe cut-off value in this study was more prolonged than in other studies due to the variation of ethnicity. Consequently, each laboratory should establish and/or verify its own CT reference range prior to use in clinical practice. Furthermore, CT interpretation of both cartridges together resulted in a better diagnostic performance than interpreting each cartridge separately.

The impact of three-dimensional reconstruction and standardised CT interpretation (AMIGO) on the anatomical understanding of mesenteric vascular anatomy for planning complete mesocolic excision surgery: A randomised crossover study.

Preoperative planning is a crucial aspect of safe complete mesocolic excision (CME) surgery. 3D models derived from imaging may help improve anatomical understanding of the complex vascular anatomy. Here, we assessed the effect of 3D models on surgeons' anatomical understanding in comparison to a systematic approach for CT scan interpretation (AMIGO). Fifteen cases were included in the study. Two GI radiology consultants reviewed each scan to ascertain the vascular anatomy. Virtual 3D models were produced and displayed on a web-based platform (https://skfb.ly/6OZUZ). A total of 13 surgical trainees were recruited. Candidates were assessed after baseline anatomical training and subsequently using the AMIGO method and 3D models. Five cases were randomly allocated in each round of testing for each participant. The primary outcome measure was an objective vascular anatomy knowledge score. The secondary outcome measure was subjective feedback from participants. Both 3D and AMIGO significantly improved anatomical understanding in comparison to baseline testing. However, 3D was superior to AMIGO (3D [n=65; median score 8/14] vs. AMIGO [n=65; median score 6/14; p<0.0001]. For 13/15 patient cases examined, 3D was superior to the AMIGO method. Eleven participants demonstrated better anatomical understanding using 3D models versus AMIGO. Ten participants preferred 3D models in comparison to standard CT imaging. 3D models improve anatomical understanding of mesenteric vascular anatomy in a group of colorectal surgical trainees in comparison to a formal CT interpretation method. 3D models may be a useful planning adjunct to 2D imaging for CME surgery.

Transfer patient imaging: discordances between community and subspecialist emergency radiologists.

To determine the rate and nature of significant discordances between community and subspecialist emergency radiologists' interpretations of cross-sectional exams performed on patients transferred to our trauma center. Outside hospital CT and MRI exams performed on transfer trauma patients are routinely overread by subspecialist emergency radiologists, specifying either concordance or discordance with the interpretation by the community radiologist. We evaluated the discordant reports for clinical significance, defined as an additional finding or difference in interpretation which was likely to affect patient management. The total rate of significant discordances, rate by modality, rate by body region, and rate per patient transferred were calculated. The most common errors were identified, and the distribution of errors among individual community radiologists was examined. 9175 exams were reviewed. Significant discordances were encountered in 4.1% of exams: 3.9% for CT and 6.7% for MRI; 5.1% for head and neck exams, 3.3% for spine, 3.8% for torso, and 2.9% for extremities. The discordance rate per patient transferred was 7.7%. The most common discordances involved missing injuries to the cranio-cervical junction, missing or misinterpreting vascular injuries in the neck, and incompletely characterizing facial fractures. Discordances were evenly spread among 220 community radiologists. There is frequent discordance between community and emergency radiologists' interpretations of CT and MRI exams, leading to a change in transferred patient management. Thus, trauma center radiologists provide added value overreading these patients' exams. It is difficult to predict which patients or exams will contain discordances, justifying routine overreading of all such exams.

Long-Term Effects of Hypoglossal Nerve Division on Tongue: A Technical Note on CT Interpretation and Clinical Correlation

Long-Term Effects of Hypoglossal Nerve Division on Tongue: A Technical Note on CT Interpretation and Clinical Correlation

CT of the Difficult Acute Aortic Syndrome.

Acute aortic syndrome (AAS) is classically attributed to three underlying pathologic conditions-aortic dissection (AD), intramural hematoma (IMH), and penetrating atherosclerotic ulcer (PAU). In the majority of cases, the basics of image interpretation are not difficult and have been extensively reviewed in the literature. In this article, the authors extend existing imaging overviews of AAS by highlighting additional factors related to the diagnosis, classification, and characterization of difficult AAS cases. It has been well documented that AAS is caused not only by an AD but by a spectrum of lesions that often have overlap in imaging features and are not clearly distinguishable. Specifically, phase of contrast enhancement, flow artifacts, and flapless AD equivalents can complicate diagnosis and are discussed. While the A/B dichotomy of the Stanford system is still used, the authors subsequently emphasize the Society for Vascular Surgery's new guidelines for the description of acute aortic pathologic conditions given the expanded use of endovascular techniques used in aortic repair. In the final section, atypical aortic rupture and pitfalls are described. As examples of pericardial and shared sheath rupture become more prevalent in the literature, it is important to recognize contrast material third-spacing and mediastinal blood as potential mimics. By understanding these factors related to difficult cases of AAS, the diagnostic radiologist will be able to accurately refine CT interpretation and thus provide information that is best suited to directing management. Online supplemental material is available for this article. ©RSNA, 2021.

Accuracy and Clinical Utility of Reports from Outside Hospitals for CT of the Cervical Spine in Blunt Trauma.

Multidetector CT is the workhorse for detecting blunt cervical spine injury. There is no standard of care for re-interpretation of radiology images for patients with blunt trauma transferred to a higher level of care. The clinical impact of discrepancies of cervical spine CT reads remains unclear. We evaluated the discordance between primary (from referring hospitals) and secondary radiology interpretations (from a receiving level I tertiary trauma center) of cervical spine CT scans in patients with blunt trauma and assessed the clinical implications of missed cervical spine fractures. Medical records of patients with blunt trauma transferred to our institution between 2008 and 2015 were reviewed. Primary and secondary interpretations were compared and categorized as concordant and discordant. Two senior neuroradiologists adjudicated discordant reports. The benefit of re-interpretation was determined. For discordant cases, outcomes at discharge, injury severity pattern, treatment, and arrival in a cervical collar were assessed. Six hundred fifty patients were included; 608 (94%) presented with concordant reports: 401 (61.7%) with fractures and 207 (31.8%) with no fractures. There were 42 (6.5%) discordant reports; 18 (2.8%) were cervical spine injuries undetected on the primary interpretation. Following adjudication, the secondary interpretation improved the sensitivity (99.3% versus 95.7%) and specificity (99.1% versus 91.7%) in detecting cervical spine fractures compared with the primary interpretation alone (P < .001). There was an overall 6.5% discordance rate between primary and secondary interpretations of cervical spine CT scans. The secondary interpretation of the cervical spine CT increased the sensitivity and specificity of detecting cervical spine fractures in patients with blunt trauma transferred to higher-level care.

Rates and clinical impact of discordant X-ray and CT imaging in transfers to a pediatric emergency department.

Children are often transferred to a Pediatric Emergency Department (PED) for definitive care after completion of diagnostic imaging. There is a paucity of data on the concordance rates of interpretation of imaging studies between referral and PED. Our objective is to describe the rates and clinical impact of discordant interpretation of X-rays and CT in children transferred to a PED. This was a retrospective cohort study of patients over a 12-month period from 12/1/2017-11/30/2018 with X-ray (XR) and CT performed prior to transfer to our PED. We compared referral radiology interpretations to those of pediatric radiologists to determine concordance. Encounters with discordant imaging interpretations were further evaluated for clinical impact (none, minor or major) based on need for additional laboratory workup, consultation, and changes in management and disposition. We analyzed 899 patient encounters. There were high rates of concordance in both XR and CT interpretation (668/743; 89.9%, 95% CI 0.87-0.91 and 205/235; 87.2%, 95% CI 0.82-0.91, respectively). XR discordance resulted in minor clinical impact in 34 patients (45%, 95% CI 0.35-0.57) and a major clinical impact in 28 patients (37%, 95% CI 0.27-0.49). CT discordance resulted in minor clinical impact in 10 patients (33%, 95% CI 0.19-0.51) of patients and major clinical impact in 15 patients (50%, 95% CI 0.33-0.67). The most common discordances with major clinical impact were related to pneumonia on XR chest and appendicitis or inflammatory bowel disease on CT abdomen. In patients transferred to the PED, concordance of XR and CT interpretations was high. A majority of discordant interpretations led to clinical impact meaningful to the patient and emergency medicine (EM) physician. Referring EM physicians might consider the benefit of pediatric radiology consultation upon transfer, especially for imaging diagnoses related to pneumonia, appendicitis, or inflammatory bowel disease.

1073 Synchronous Cholecystitis and Appendicitis: A Case Report Highlighting Learning Points on Medical Imaging and Consent

Abstract Laparoscopic appendicectomy and laparoscopic cholecystectomy are separately two of the most common emergency surgical procedures carried out in the UK. Only a small number of synchronous presentations of acute appendicitis and acute cholecystitis have been reported in surgical literature and this rare co-existent pathology gives rise to several valuable learning points with regards to laparoscopy, medical imaging interpretation and the consent process. Our case report involves a 58-year-old female patient presenting with both RUQ and RIF pain and positive Murphy’s sign on clinical examination. US scan demonstrated several gallstones within a thin-walled gallbladder. Subsequent CT scan reported acute appendicitis which was treated definitively with laparoscopic surgery. Intraoperatively a perforated gangrenous gallbladder containing multiple calculi was discovered, and the decision was made to perform a double procedure of laparoscopic appendicectomy and cholecystectomy. Histopathology confirmed synchronous pathology of appendicitis with faecolith and calculus cholecystitis. This case demonstrates the importance of considering multiple pathologies when assessing a patient with ambiguous and migratory abdominal pain. It reinforces the importance of diagnostic laparoscopy to rule out multiple pathologies. This acts as a cautionary case against over-reliance on medical imaging and reminds surgeons of their obligation to maintain competence in CT interpretation plus correlation of imaging with clinical assessment of the patient. Readers should also be reminded that the consent process for surgical interventions should be undertaken meticulously in patients with ambiguous abdominal pain.

137 Multi-Center Analysis of Point-of-Care Ultrasound in the Diagnosis of Small Bowel Obstruction and Prediction of Surgical Intervention

The management and diagnosis of small bowel obstruction (SBO) relies on diagnostic imaging. While multiple studies have evaluated the performance of POCUS in diagnosis of SBO, further studies are needed to help establish if and how the test can be used in clinical practice. We sought to analyze the prognostic ability of POCUS to diagnosis SBO and identify patients requiring surgical intervention. 401 patients with suspected SBO who were prospectively enrolled at five separate emergency departments (ED) of tertiary care hospitals were included in this study. Clinician pretest probability, patient symptoms, physical examination and POCUS findings including bowel dilation, peristalsis, wall edema, abdominal free fluid, and transition points were used to determine the most reliable findings in diagnosis and severity grading of SBO. All POCUS images were reviewed and interpreted by an independent reviewer, who made a prediction of whether or not a SBO was present. Radiologist CT interpretations and applicable surgeon intra-operative findings were used as a reference standard. All findings were placed into a nomogram, to calculate an appropriate predictive model for POCUS as an imaging modality for SBO. The discriminative ability of the nomogram was tested using C statistics, calibration plots, and Kaplan-Meier curves. The derivation cohort included 401 patients who underwent POCUS for suspected SBO (mean age 55 years, 41% female). All patients underwent abdominal CT and 31% of the patients had a SBO by CT. Of the 124 patients diagnosed with SBO, 35% required surgical intervention and 91% of these patients were positive for SBO by POCUS. There was an 84% agreement between POCUS reviewer and radiologist/surgeon findings. A stepwise selection of clinically important variables showed identified small bowel diameter, positive free fluid in the abdomen, clinician pretest probability, and patient age as relevant factors in the identification of SBO. The nomogram revealed good predictive ability as indicated by a high C-statistic for SBO diagnosis. When combined with clinical factors including physician gestalt and patient demographics, POCUS is a reliable method of accurately diagnosing SBO and identifying patients who may need a surgical intervention. This holds true across multiple emergency departments and ultrasound users.

Emergency CT misdiagnosis in acute aortic syndrome.

This cross-sectional study assessed the accuracy of emergency CT reports at presentation in acute aortic syndrome (AAS). Retrospective identification of cases of AAS presenting within a large health board with three acute hospitals receiving adult patients between January 2013 and December 2016. CT studies and reports at presentation were reviewed for discrepancies related to diagnosis, complications and classification by two cardiovascular radiologists. The specialist interest of the original reporters, clinically suspected diagnosis at referral for CT and technical adequacy of the scans were also assessed. False-positive diagnoses were identified and evaluated separately. Among 88 consecutive confirmed cases of AAS at least one discrepancy was identified in 31% (n = 27), including failure to identify or misinterpretation of the AAS itself in 15% (n = 13), haemorrhage in 13% (n = 11), branch involvement in 9% (n = 8), and misclassification in 3% (n = 3). All discrepancies occurred among the 80% (n = 70) of cases reported by radiologists without specialist cardiovascular interest. 26% (n = 23/88) of AAS cases were not clinically suspected at referral for CT and although this was associated with suboptimal protocols, only 51% of CT scans among suspected cases were technically adequate. Seven false-positive diagnoses were identified, three of which related to motion artefact. Significant discrepancies are common in the emergency CT assessment of positive cases AAS and this study highlights important pitfalls in CT technique and interpretation. The absence of discrepancies among radiologists with specialist cardiovascular interest suggests both suspected and confirmed cases warrant urgent specialist review. CT angiography is central to the diagnosis of AAS; however, significant radiology discrepancies are common among non-specialists. This study highlights important pitfalls in both CT technique as well as interpretation and supports routine specialist cardiovascular imaging input in the emergency assessment of AAS.

Artificial Intelligence DENTOMO: Opportunities and Prospects for analysis of CBCT in Dentistry

Analysis of artificial intelligence DENTOMO application efficiency, its opportunities and prospects for Interpretation of Cone Beam CT in Dentistry and developing model for automatic analysis cone beam computed tomography in Dentistry. The presented model is based on two convolutional neural networks, includes a database and knowledge base, harmonized with SNOMED Clinical Terms is a systematically organized computer processable collection of medical terms providing codes, terms, synonyms and definitions used in clinical documentation and reporting. The accuracy of AI model was assessed by calculating the ratio of false identifications to the true ones in each case. The model of artificial intelligence DENTOMO, which allows automated deciphering the CT in maxillofacial area, was developed and implemented in practical dentistry. The developed model automatically decodes cone beam CT images, identifies, and classifies the anatomical structures of the human dental system, and reveals the pathological processes and their dynamics in dentistry system. The developed model rather accurately identified the natural teeth in the frontal group as well in the group of premolars and molars. The recognition accuracy surpassed 90%. It should be noted that the developed model includes the possibility of “training”, which can improve the quality of evaluation of diagnostic features and related parameters. Moreover, it can add the current diagnostic potencies with novel features. Testing of DENTOMO model demonstrated a reasonable effectiveness in deciphering the CT of dental system. The developed technology allows computerizing and objectifying interpretation of CT of the dental system.

Interpretation of 4D CT for Parathyroid Localization—Retrospective Case Series

Abstract Introduction: Patients referred with primary hyperparathyroidism undergo in-office surgeon-performed ultrasonography. Approximately two thirds of patients undergo additional localization w...

Comparative Study between CT and MRI in Assessment of Laryngeal Cartilage Invasion in Laryngeal Carcinoma

Abstract Background: Laryngeal cancer comprises 2 to 5% of all malignant diseases diagnosed annually worldwide. Cartilage invasion by the laryngeal cancer is of great importance through the staging of laryngeal carcinoma according to TNM classi-fication and has a great impact on management plan. There is a scarcity in the published literature regarding the comparison between MRI and CT for assessment of cartilage involvement. Aim of Study: To assess the validity of MRI and to compare this with CT findings in predicting inner and outer thyroid cartilage laminae invasion in patients with laryngeal carcinoma. Patients and Methods: The present study was an obser-vational analytical study that was carried out from January 2018 to June 2019 at the Radiology Department of Faculty of Medicine, Cairo University. A total of 30 patients with laryngeal carcinoma were included. CT and MRI was done for all patients. Results: There was a good agreement between readers in CT interpretation in term of inner lamina involvement (K=0.78) and very good agreement in term of outer lamina involvement (K=0.87). While in MRI interpretation, there was a very good agreement between readers in term of inner lamina involvement (K=0.83) and outer lamina involvement (K=0.92). However higher accuracy & confidence levels were found on interpre-tation of both CT and MRI together. We found a higher interobserver agreement between interpretation of CT and MRI together (K=1.00). Conclusion: MRI showed high validity and precision in detecting inner and outer thyroid lamina invasion by laryngeal caner than CT scan. We found that the combination of CT and MRI together was associated with more accuracy and confidence level for the readers.

CT of Penetrating Abdominopelvic Trauma.

Penetrating abdominopelvic trauma usually results from abdominal cavity violation from a firearm injury or a stab wound and is a leading cause of morbidity and mortality from traumatic injuries. Penetrating trauma can have subtle or complex imaging findings, posing a diagnostic challenge for radiologists. Contrast-enhanced CT is the modality of choice for evaluating penetrating injuries, with good sensitivity and specificity for solid-organ and hollow viscus injuries. Familiarity with the projectile kinetics of penetrating injuries is an important skill set for radiologists and aids in the diagnosis of both overt and subtle injuries. CT trajectography is a useful tool in CT interpretation that allows the identification of subtle injuries from the transfer of kinetic injury from the projectile to surrounding tissue. In CT trajectography, after the entry and exit wounds are delineated, the two points can be connected by placing cross-cursors and swiveling the cut planes obliquely in orthogonal planes to obtain a double-oblique orientation to visualize the wound track in profile. The path of the projectile and its ensuing damage is not always straight, and the imaging characteristics of free fluid of different attenuation in the abdomen (including hemoperitoneum) can support the diagnosis of visceral and vascular injuries. In addition, CT is increasingly used for evaluation of patients after damage control surgery and helps guide the management of injuries that were overlooked at surgery. An invited commentary by Paes and Munera is available online. Online supplemental material is available for this article. ©RSNA, 2021.

Imaging of treatment response during systemic therapy for hepatocellular carcinoma.

Systemic therapy for the treatment of hepatocellular carcinoma (HCC) has rapidly evolved over the last 4 years; eight new drug regimens have gained Food and Drug Administration approval for treatment of advanced HCC since 2017. As several lines of therapy are now available for the treatment of HCC, accurate CT and MRI treatment response assessment is important for informing optimal management of affected patients. This article will review the systemic therapies currently approved for the treatment of HCC, focusing on items most pertinent to radiologists. Treatment response assessment of patients with HCC undergoing systemic therapy differs from treatment response assessment of patients receiving locoregional therapies, and principle differences will be highlighted. Finally, this review will provide a framework for the interpretation of CT and MRI examinations of patients with HCC being treated with systemic therapy and will explore the relevant scientific data currently available.

CT for Evaluation of Hemoptysis.

Hemoptysis, which is defined as expectoration of blood from the alveoli or airways of the lower respiratory tract, is an alarming clinical symptom with an extensive differential diagnosis. CT has emerged as an important noninvasive tool in the evaluation of patients with hemoptysis, and the authors present a systematic but flexible approach to CT interpretation. The first step in this approach involves identifying findings of parenchymal and airway hemorrhage. The second step is aimed at determining the mechanism of hemoptysis and whether a specific vascular supply can be implicated. Hemoptysis can have primary vascular and secondary vascular causes. Primary vascular mechanisms include chronic systemic vascular hypertrophy, focally damaged vessels, a dysplastic lung parenchyma with systemic arterial supply, arteriovenous malformations and fistulas, and bleeding at the capillary level. Evaluating vascular mechanisms of hemoptysis at CT also entails determining if a specific vascular source can be implicated. Although the bronchial arteries are responsible for most cases of hemoptysis, nonbronchial systemic arteries and the pulmonary arteries are important potential sources of hemoptysis that must be recognized. Secondary vascular mechanisms of hemoptysis include processes that directly destroy the lung parenchyma and processes that directly invade the airway. Understanding and employing this approach allow the diagnostic radiologist to interpret CT examinations accurately in patients with hemoptysis and provide information that is best suited to directing subsequent treatment. ©RSNA, 2021.