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Hepatocellular carcinoma (HCC) is the most common primary malignant tumor of the liver worldwide. Noninvasive diagnosis of HCC is possible based on imaging features, without the need for tissue diagnosis. Liver Imaging Reporting and Data System (LI-RADS) CT/MRI diagnostic algorithm allows for standardized radiological interpretation and reporting of imaging studies for patients at high risk for HCC. Diagnostic categories of LR-1 to LR-5 designate each liver observation to reflect the probability of overall malignancy, HCC, or benignity based on imaging features, where LR-5 category has 95% probability of HCC. Optimal imaging protocol and scanning technique as described by the technical recommendations for LI-RADS are essential for the depiction of features to accurately characterize liver observations. The LI-RADS MRI technical guidelines recommend the minimum required sequences of T1-weighted out-of-phase and in-phase Imaging, T2-weighted Imaging, and multiphase T1-weighted Imaging. Additional sequences, including diffusion-weighted imaging, subtraction imaging, and the hepatobiliary phase when using gadobenate dimeglumine as contrast, improve diagnostic confidence, but are not required by the guidelines. These optional sequences can help differentiate true lesions from pseudolesions, detect additional observations, identify parenchymal observations when other sequences are suboptimal, and improve observations conspicuity. This manuscript reviews the optional sequences, the advantages they offer, and discusses technical optimization of these sequences to obtain the highest image quality and to avoid common artifacts.

Artificial Intelligence (AI) continues to shape the practice of radiology, with imaging of hepatocellular carcinoma (HCC) being of no exception. This article prepared by members of the LI-RADS Treatment Response (TR LI-RADS) work group and associates, presents recent trends in the utility of AI applications for the volumetric evaluation and assessment of HCC treatment response. Various topics including radiomics, prognostic imaging findings, and locoregional therapy (LRT) specific issues will be discussed in the framework of HCC treatment response classification systems with focus on the Liver Reporting and Data System treatment response algorithm (LI-RADS TRA).

There have been many publications detailing imaging features of malignant transformation of intraductal papillary mucinous neoplasms (IPMN), management and recommendations for imaging follow-up of diagnosed or presumed IPMN. However, there is no consensus on several practical aspects of imaging IPMN that could serve as a clinical guide for radiologists and enable future data mining for research. These aspects include how to measure IPMN, define reporting terminology, standardize reporting and unify guidelines for surveillance. The Society of Abdominal Radiology (SAR) created multiple Disease-Focused Panels (DFP) comprised multidisciplinary panel members who focus on a particular disease, with the goal to develop ways for radiologists to improve patient care, education, and research. DFP members met to identify the current controversies and limitations of imaging pancreatic IPMN. This paper aims to provide a practical review of the key imaging characteristics of IPMN for trainees and practicing radiologists, to guide uniformity of performance and interpretation of surveillance imaging studies, and to improve communication with clinicians by providing a lexicon and reporting template based on the experience of the SAR-DFP panel members.

Preoperative prediction of perineural invasion (PNI) and Kirsten RAS (KRAS) mutation in colon cancer is critical for treatment planning and patient management. We developed machine learning models for diagnosis of PNI and KRAS mutation in colon cancer patients by interpreting preoperative CT. This retrospective study included 207 patients who received surgical resection in our institution. The underlying tumor characteristics were described by analyzing CT image texture quantitatively. The key radiomics features were determined with similarity analysis followed by RELIEFF method among 306 CT imaging features. Eight kernel-based support vector machines classifiers were constructed using individual (II, III, or IV) or multi-stage (II + III + IV) patient cohorts for predicting PNI and KRAS mutation. The model performances were evaluated using accuracy, receiver operating curve, and decision curve analyses. Multi-stage classifiers obtained AUC of 0.793 and 0.862 for detecting PNI and KRAS mutation for test cohort. Moreover, individual-stage classifiers demonstrated significantly improved diagnostic performance at all stages (IIAUC: [0.86; 0.99], IIIAUC: [0.99; 0.99], and IVAUC: [1.00; 1.00], respectively, for PNI and KRAS mutation in test cohort). Besides, stage II tumor is better described with coarse texture features while more detailed features are required for better characterization of advanced-stage tumors (III and IV) for diagnoses of PNI or KRAS mutation. Machine learning models developed using preoperative CT data can predict PNI and KRAS mutation in colon cancer patients with satisfactory performance. Individual-stage models better-characterized the relationship between CT features and PNI or KRAS mutation than multi-stage models and demonstrated good prediction scores.

Gastrointestinal bleeding is a common cause for hospital admissions and is an important cause of morbidity and mortality. Although endoscopy is accepted as the standard initial diagnostic modality for the evaluation of gastrointestinal bleeding, multiphasic computed tomography (CT) imaging has become an alternative diagnostic tool. Dual-energy CT with post-processing techniques may have additional advantages over single-energy computed tomography in evaluation of gastrointestinal bleeding. In this article, we discuss the role of dual-energy CT in the evaluation of gastrointestinal bleeding with potential advantages over conventional CT and limitations.

Background Preoperative detection of lymph node (LN) metastasis is critical for planning treatments in colon cancer (CC). The clinical diagnostic criteria based on the size of the LNs are not sensitive to determine metastasis using CT images. In this retrospective study, we investigated the potential value of CT texture features to diagnose LN metastasis using preoperative CT data and patient characteristics by developing quantitative prediction models. Methods A total of 390 CC patients, undergone surgical resection, were enrolled in this monocentric study. 390 histologically validated LNs were collected from patients and randomly separated into training (312 patients, 155 metastatic and 157 normal LNs) and test cohorts (78 patients, 39 metastatic and 39 normal LNs). Six patient characteristics and 146 quantitative CT imaging features were analyzed and key variables were determined using either exhaustive search or least absolute shrinkage algorithm. Two kernel-based support vector machine classifiers (patient-characteristic model and radiomic-derived model), generated with 10-fold cross-validation, were compared with the clinical model that utilizes long-axis diameter for diagnosis of metastatic LN. The performance of the models was evaluated on the test cohort by computing accuracy, sensitivity, specificity, and area under the receiver operating curve (AUC). Results The clinical model had an overall diagnostic accuracy of 64.87%; specifically, accuracy of 65.38% and 62.82%, sensitivity of 83.87% and 84.62%, and specificity of 47.13% and 41.03% for training and test cohorts, respectively. The patient-demographic model obtained accuracy of 67.31% and 73.08%, the sensitivity of 62.58% and 69.23%, and specificity of 71.97% and 76.23% for training and test cohorts, respectively. Besides, the radiomic-derived model resulted in an accuracy of 81.09% and 79.49%, sensitivity of 83.87% and 74.36%, and specificity of 78.34% and 84.62% for training and test cohorts, respectively. Furthermore, the diagnostic performance of the radiomic-derived model was significantly higher than clinical and patient-demographic models (p Conclusions The texture of the LNs provided characteristic information about the histological status of the LNs. The radiomic-derived model leveraging LN texture provides better preoperative diagnostic accuracy for the detection of metastatic LNs compared to the clinically accepted diagnostic criteria and patient-demographic model.

Background There is a lack of well-established clinical tools for predicting dendritic cell (DC) vaccination response of pancreatic ductal adenocarcinoma (PDAC). DC vaccine treatment efficiency was demonstrated using histological analysis in pre-clinical studies; however, its usage was limited due to invasiveness. In this study, we aimed to investigate the potential of MRI texture features for detection of early immunotherapeutic response as well as overall survival (OS) of PDAC subjects following dendritic cell (DC) vaccine treatment in LSL-KrasG12D;LSL-Trp53R172H;Pdx-1-Cre (KPC) transgenic mouse model of pancreatic ductal adenocarcinoma (PDAC). Materials and methods KPC mice were treated with DC vaccines, and tumor growth was dynamically monitored. A total of a hundred and fifty-two image features of T2-weighted MRI images were analyzed using a kernel-based support vector machine model to detect treatment effects following the first and third weeks of the treatment. Moreover, univariate analysis was performed to describe the association between MRI texture and survival of KPC mice as well as histological tumor biomarkers. Results OS for mice in the treatment group was 54.8 ± 22.54 days while the control group had 35.39 ± 17.17 days. A subset of three MRI features distinguished treatment effects starting from the first week with increasing accuracy throughout the treatment (75% to 94%). Besides, we observed that short-run emphasis of approximate wavelet coefficients had a positive correlation with the survival of the KPC mice (r = 0.78, p r = 0.84, p r = − 0.97, p r = 0.81, p Conclusion Our results demonstrate that MRI texture features can be used as imaging biomarkers for early detection of therapeutic response following DC vaccination in the KPC mouse model of PDAC. Besides, MRI texture can be utilized to characterize tumor microenvironment reflected with histology analysis.

Transarterial radioembolization is a novel therapy that has gained rapid clinical acceptance for the treatment of hepatocellular carcinoma (HCC). Segmental radioembolization [also termed radiation segmentectomy (RS)] is a technique that can deliver high doses (> 190 Gy) of radiation selectively to the hepatic segment(s) containing the tumor. The aim of this comprehensive review is to provide an illustrative summary of the most relevant imaging findings encountered after radiation segmentectomy. A 62-patient cohort of Child-Pugh A patients with solitary HCC

Radiologists play a central role in the assessment of patient response to locoregional therapies for hepatocellular carcinoma (HCC). The identification of viable tumor following treatment guides further management and potentially affects transplantation eligibility. Liver Imaging Reporting and Data Systems (LI-RADS) first introduced the concept of LR-Treated in 2014, and a new Treatment Response Algorithm is included in the 2017 update to assist radiologists in image interpretation of HCC after locoregional therapy. In addition to offering imaging criteria for viable and nonviable HCC, new concepts of nonevaluable tumors as well as tumors with equivocal viability are introduced. Existing guidelines provided by Response Evaluation Criteria In Solid Tumors (RECIST) and modified RECIST address patient-level assessments and are routinely used in clinical trials but do not address the variable appearances following different locoregional therapies. The new LI-RADS Treatment Response Algorithm addresses this gap and offers a comprehensive approach to assess treatment response for individual lesions after a variety of locoregional therapies, using either contrast-enhanced CT or MRI.

Pregnant patients can receive allergy premedication prior to a contrast-enhanced computed tomography exam if the exam is indicated. The risks and benefits of allergy premedication for pregnant patients will be discussed, as well as imaging strategies for the pregnant patient with a contrast allergy. Alternative imaging including ultrasound, noncontrast magnetic resonance imaging, or noncontrast computed tomography can be diagnostic depending on the clinical scenario and is usually preferred, allowing physicians to avoid giving allergy premedication in pregnancy, a 13 h delay, and risking a breakthrough reaction.

Hemorrhage of the kidneys and adrenal glands has many etiologies. In the adrenal glands, trauma, anticoagulation, stress, sepsis, surgery, and neoplasms are common causes of hemorrhage. In the kidneys, reasons for hemorrhage include trauma, bleeding diathesis, vascular diseases, infection, infarction, hemorrhagic cyst rupture, the Antopol-Goldman lesion, and neoplasms. Angiomyolipoma and renal cell carcinoma are the neoplasms most commonly associated with hemorrhage in the kidneys and adrenal cortical carcinoma, metastases, and pheochromocytoma are associated with hemorrhage in the adrenal glands. Understanding the computed tomography and magnetic resonance imaging features, and causes of hemorrhage in the kidneys and adrenal glands is critical. It is also important to keep in mind that mimickers of hemorrhage exist, including lymphoma in both the kidneys and adrenal glands, and melanoma metastases in the adrenal glands. Appropriate imaging follow-up of renal and adrenal hemorrhage should occur to exclude an underlying malignancy as the cause. If there is suspicion for malignancy that cannot be definitively diagnosed on imaging, surgery or biopsy may be warranted. Angiography may be indicated when there is a suspected underlying vascular disease. Unnecessary intervention, such as nephrectomy, may be avoided in patients with benign causes or no underlying disease. Appropriate management is dependent on accurate diagnosis of the cause of renal or adrenal hemorrhage and it is incumbent upon the radiologist to determine the etiology.

Gallbladder perforation is a potentially life-threatening condition commonly seen as a complication of acute cholecystitis. Urgent surgical intervention is often needed to reduce serious morbidity and mortality. It presents a diagnostic challenge due to nonspecific symptoms, leading to a delay in diagnosis. Imaging plays a vital role in early identification of this potentially fatal condition and evaluation by more than one imaging modality may be required to make the diagnosis. Knowledge of specific and ancillary imaging findings is crucial to avoid misdiagnosis. In this article, we will review the risk factors, pathophysiology, and surgical classification of gallbladder perforation and discuss the role of multimodality imaging in its diagnosis. Differential diagnoses on imaging will also be discussed.

The original version of this article was published with a error in the initials of the first, fifth and sixth author name: Jonathon Weber, Frank Miller and Jeanne Horowitz. The correct author's initials should be Jonathon D. Weber, Frank H Miller, and Jeanne M Horowitz. It is now corrected with this correction.

Liver-directed intra-arterial therapies are palliative treatment options for patients with unresectable liver cancer; their use has also resulted in patients being downstaged leading to curative resection and transplantation. These intra-arterial therapies include transarterial embolization, conventional transarterial chemoembolization (TACE), drug-eluting bead TACE and radioembolization. Assessment of imaging response following these liver-directed intra-arterial therapies is challenging but pivotal for patient management. Size measurements based on computed tomography or magnetic resonance imaging (MRI) have been traditionally used to assess tumor response to therapy. However, these anatomic changes lag behind functional changes and may require months to occur. Further, these intra-arterial therapies cause acute tumor necrosis, which may result in a paradoxical increase in tumor size on early follow-up imaging despite complete cell death or necrosis. This concept is unique comparing to changes seen following systemic chemotherapy. The recent development of functional imaging techniques including diffusion-weighted MRI (DW MRI) and positron emission tomography (PET) allow for early assessment of treatment response and even prediction of overall tumor response to intra-arterial therapies. Although the results of DW MRI and PET studies are promising, the impact of these imaging modalities to assess treatment response has been limited without standardized protocols. The aim of this review article is to delineate the best practice for assessing tumor response in patients with primary or secondary hepatic malignancies undergoing intra-arterial therapies.

The purpose of this study was to investigate the effects of a prospective ECG-gated, low kilovoltage and low mAs protocol on image quality and radiation dose when acquiring CT angiography of the thoracic aorta (CTTA). Sixty patients with a body mass index (BMI) of less than 30 and a heart rate of less than 100 beats per minute (bpm) were included in the study. Thirty consecutive patients were examined with retrospective ECG-gating and standard parameters (group A) (120 kVp, 340 reference effective mAs).The next thirty (group B) were examined with prospective ECG-gating, 100 kVp and 170 mAs. Quantitative analysis included measurements of image resolution of the thoracic aorta at three levels, mean attenuation in the aorta and signal to noise ratio (SNR). Qualitative analysis assessed image artifact and graded image quality on five point scales. Effective radiation doses were estimated. The radiation dose of group A was 26.2 ± 6.0 mSv (mean ± standard deviation). For group B it was 2.9 ± 0.5 mSv (P

We compared the effect of low-density barium sulfate neutral oral contrast agent on the diameter of normal appendix and its luminal content versus that of water on multidetector-row CT. CT scans of 24 patients who had been imaged on two separate occasions for the evaluation of pancreatic pathology, once with water and subsequently with low-density barium sulfate as the neutral oral contrast agent were evaluated (total of 48 scans). Studies were randomized and reviewed in consensus on a workstation in the stack mode by two radiologists blinded to the type of oral contrast. The appendix was measured at baseline and 10 days later to obtain an average diameter. Results of the water and low-density barium sulfate groups were compared using paired t test. Contents of the appendiceal lumen were also noted (gas, fluid, mixed, and collapsed appendix). The average diameter of the appendix for scans obtained with water and low-density barium sulfate was 4.09 ± 0.87 mm (median, 4.22 mm; range, 2.50-5.65 mm) and 4.13 ± 0.93 mm (median, 4 mm, range, 2.2-5.65 mm), respectively. This difference was not statistically significant (P = 0.69). There was no statistically significant difference in the appendiceal content when water or low-density barium sulfate were used as oral contrast (χ (2) = 4.25, P = 0.89). Low-density barium sulfate does not affect appendiceal content or diameter and, therefore, should not adversely affect evaluation of the appendix on multidetector row CT.

The purpose of this study was to assess the feasibility of diagnosing appendicitis based on coronal reformations without the aid of transverse images. Abdominal and pelvic computed tomography (CT) scans of 53 patients (27 with appendicitis and 26 without appendicitis) were reviewed. All scans were obtained using a four-slice multi-detector row CT. The radiologists were not aware of the final diagnosis. Cases were reviewed for the visualization of the appendix and presence of appendicitis. All images were reviewed on picture archiving and communication systems. There were no false positives for diagnosing appendicitis when using either the transverse or coronal reformations. Appendicitis was not seen on the coronal images in one case, and there were no false negatives when transverse reformations alone were used. This difference was not statistically significant (p < 0.0001 for both modes of display). The sensitivity for diagnosing appendicitis based on the coronal images alone was 96%, the specificity was 100%, and the accuracy was 98%. Coronal reformations decreased the number of images reviewed by 19%. CT diagnosis of appendicitis based on the coronal images is accurate.

Feasibility of diagnosing small bowel obstruction on multidetector-row computed tomography (MDCT) using coronal reformations alone is evaluated. Three radiologists with subspecialty training in abdominal imaging reviewed abdominopelvic CT of 67 patients in consensus. Thirty-four patients had surgically proven small bowel obstruction. The remaining 33 patients had CT for other reasons and had no intestinal obstruction. The images were displayed in either axial or coronal planes and were reviewed on separate days . Each CT was evaluated for the presence of small bowel obstruction and its etiology when applicable. Thirty-three (100%) of 33 patients were correctly diagnosed not to have intestinal obstruction on coronal images. Thirty-four (100%) of 34 patients were correctly diagnosed to have small bowel obstruction on both forms of image display. There were five patients where the final surgical diagnosis for the etiology of small bowel obstruction did not agree with the interpretation of either the coronal or axial images; however, in all five patients, the interpretations of axial and coronal images were similar. In only one patient, the etiology of small bowel obstruction based on the coronal images did not agree with that of axial images and the surgical result; however, the site of small bowel obstruction was correctly diagnosed. There were approximately 20% fewer images in the coronal reformation data set, and the radiologists found review of these images to be easier for localizing the zone of transition in small bowel obstruction. Very high diagnostic accuracy can be achieved based on coronal reformations alone, and this form of image display may potentially be substituted for the conventional axial images. Since there are fewer images to review when the studies are displayed in coronal plane, this may positively impact radiologist workflow.

The purpose of this paper is to assess the incidence of visualization of the normal appendix on magnetic resonance imaging (MRI) examinations of the pelvis in a large adult population and to compare the yield of commonly used sequences. Pelvic MRI scans of 111 randomly selected patients were retrospectively reviewed by two fellowship-trained body imagers. Thirty-six cases, where the entire cecum and terminal ileum were not included in the field of view, were excluded. A normal appendix was definitively visualized in 55 of 71 patients on T1 spin echo (SE) sequences (78%). The appendix was seen on 25 of 42 (60%) half-Fourier single-shot turbo spin echo T2. Visualization rates were 42% on pre-gadolinium T1 FS GRE, 54% on post-gadolinium T1 fat-suppressed gradient echo, and 17% of short tau inversion recovery sequences. MRI is an effective modality for visualization of the normal appendix. This may have important implications in patients with abdominal or pelvic pain, as visualization of a normal appendix should exclude the possibility of acute appendicitis from the differential diagnosis.

The terms wandering liver, hepatic torsion, and hepatic vagrancy have been applied to cases in which hepatic hypermobility results in displacement of the liver from its normal position within the right upper quadrant of the abdomen. This is thought to result from multiple factors, including the lack of normal hepatic suspensory ligaments, persistence of the ventral mesentery, and lack of inferior vena cava tethering Siddins and Cade (Aust N Z J Surg 60:400-403, 1990). A wandering liver has been described in both adults Siddins and Cade (Aust N Z J Surg 60:400-403, 1990), Tate (Am Surg 59:455-458, 1993), Chiavarini and Chang (Radiology 115:47-48, 1974), Cope and Levy (South Afr Med J 40:366-369, 1966), Sharov (Vestn Roentgenol Radiol 35:63-64, 1960), Puthenpurayil et al. (AJR 177:1113-1115, 2001), Fuentes et al. (AJR 188:331-333, 2007) and children Feins and Borger (AJR 188:331-333, 2007), Al-Ali et al. (Pediatr Radiol 27:287, 1997), and it is usually associated with bowel obstruction Siddins and Cade (Aust N Z J Surg 60:400-403, 1990), Tate (Am Surg 59:455-458, 1993), Chiavarini and Chang (Radiology 115:47-48, 1974), Cope and Levy (South Afr Med J 40:366-369, 1966), Sharov (Vestn Roentgenol Radiol 35:63-64, 1960), Fuentes et al. (AJR 188:331-333, 2007), Feins and Borger (AJR 188:331-333, 2007). We report a case of an incidental wandering liver in an adult without associated obstruction, diagnosed by multidetector computed tomography with multiplanar reformations.

We describe an extremely rare case of an ileocolic intussusception with an appendiceal mucocele as the lead-point and cause of acute right lower quadrant pain in an adult patient. There are only few reported cases of this entity in the radiologic literature. We describe the multislice (computed tomography) CT features and emphasize the value of multiplanar reformations. We also discuss how specific findings on CT should allow for a correct preoperative diagnosis.

The objective of the study was to assess the feasibility of using a personal digital assistant (PDA) as a medium for the interpretation of cranial CT scans of trauma patients. Twenty-one noncontrast cranial CT scans were transferred in their entirety to a PDA from the picture archiving and communications system (PACS) utilizing General Electric (GE) PathSpeed PACS Web Server interface and synchronization. All CT scans had been interpreted by board-certified radiologists prior to the study. Seven of the scans demonstrated subarachnoid hemorrhage, seven demonstrated subdural hematomas, and the remaining scans were normal. After transfer to the PDA, all images were separately reviewed in a blinded manner by a radiologist and a neurosurgeon. Images were graded for their quality and diagnostic utility in the evaluation of intracranial hemorrhage. Image quality was categorized as excellent, very good, acceptable for diagnosis, or not acceptable for diagnosis. Based on the radiologic diagnosis, recommendation for surgical management was made by the reviewing neurosurgeon. The accuracy rate for both the radiologist and the neurosurgeon in the detection of intracranial hemorrhage was 95%. There was one false negative which was attributed to error in judgment rather than poor image quality. This diagnostic error did not affect patient management. The sensitivity and specificity for detection of intracranial hemorrhage were 93% and 100%, respectively. Image quality was judged to be excellent in 90% of the cases and very good in the remaining 10%. Our results suggest that the PDA is a robust medium for interpretation of CT scans in patients with suspected hemorrhage following intracranial injury. In this setting, the PDA should be considered for teleradiology purposes.

esophageal myotomy Carla B Harmath, Jeanne M Horowitz, Senta M Berggruen, Nancy A Hammond, Paul Nikolaidis, Frank H Miller, Lori A Goodhartz, Ezra N Teitelbaum, Eric S Hungness, Vahid Yaghmai Department of Radiology, Northwestern University Feinberg School of Medicine, 676 North Saint Clair Street, Suite 800, Chicago, IL 60614, USA Department of Surgery, Northwestern University Feinberg School of Medicine, Chicago, IL, USA