Disease involving the pancreas can be a significant diagnostic challenge to the interpreting radiologist. Moreover, the majority of disease processes involving the pancreas carry high significant morbidity and mortality either due to their natural process or related to their treatment options. As such, it is critical for radiologists to not only provide accurate information from imaging to guide patient management, but also deliver that information in a clear manner so as to aid the referring physician. Read More
Both restrictive and malabsorptive types of bariatric surgery may be associated with short- and long-term complications. The lack of small bowel obstruction is not necessarily indicative of a normal study, as a variety of non-obstructed complications exist. These include stenosis at the gastrojejunostomy, leaks, abscesses, hemorrhage, internal hernias, and gastric band erosions. Read More
Purpose: To determine when 18F-choline PET/CT can truly identify local recurrence of prostate cancer.
Methods: 1031 patients from 3 European centers underwent (18)F-choline PET/CT (FCH PET/CT) for recurrent disease; 131 subjects (12.7%) showed a positive FCH uptake in the prostatic gland or prostatic fossa. Read More
Objective: To establish highly specific criteria for predicting non-enhancement in T1-hyperintense non-fat-containing (T1-high) renal lesions using unenhanced fat-suppressed T1-weighted (T1-FS) images.
Materials And Methods: This IRB-approved, HIPAA-compliant, retrospective study included T1-high renal lesions found between 7/1/2012 and 7/1/2014. The largest lesion diameter and heterogeneity, mean signal intensity of lesion, and adjacent renal cortex were recorded from T1-FS images. Read More
The differential diagnosis of splenic masses is broad and often hinges on the enhancement characteristics of the lesions. Most radiologists are familiar with the differential diagnosis of hypovascular lesions such as fungal infections, sarcoidosis/granulomatous disease, infarctions, and cysts. However, to our knowledge, there is no review article that presents the specific multimodality imaging features of vascular splenic lesions as a group. Read More
Purpose: To correlate RECIST, volumetric criteria, and tumor growth kinetics at multidetector-computed tomography with tumor metabolic activity at FDG PET in colorectal liver metastases (CRCLM) treated with bevacizumab-based chemotherapy.
Methods: Thirty-two CRCLM in 20 patients treated with bevacizumab-based chemotherapy were evaluated. Pre- and post-treatment CT scans were used to calculate reciprocal of doubling time (RDT), percentage change in the lesion's longest transaxial diameter (RECIST 1. Read More
Purpose: The purpose of this study is to evaluate the utility of color Doppler ultrasound (CDU) in the assessment of ovarian torsion following a negative contrast-enhanced computed tomography (CT) examination.
Methods: This is a retrospective study of women who presented to the ED with abdominal pain and received both a contrast-enhanced CT and CDU within a 24-h period. The abdominal/pelvic CT examinations were evaluated for findings specific to torsion, including ovarian size greater than 5 cm, the presence of free fluid, uterine deviation, fallopian tube thickening, ovarian fat stranding, smooth wall thickening, the presence of the "twisted pedicle" sign, and abnormal ovarian enhancement. Read More
Objective: To determine the diagnostic performance of imaging criteria for distinguishing Ig-G4-associated autoimmune cholangiopathy (IAC) from primary sclerosing cholangitis (PSC) and bile duct malignancy.
Methods: A medical records search between January 2008 and October 2013 identified 10 patients (8 M, 2 F, mean age 61 years, range 34-82) with a clinical diagnosis of IAC. Fifteen cases of PSC (6 M, 9 F, mean age 50, range 22-65) and 15 cases of biliary malignancy (7 M, 8 F, mean age 65, range 48-84) were randomly selected for comparative analysis. Read More
Purpose: To compare the Medicare population cost of colorectal cancer (CRC) screening of average risk individuals by CT colonography (CTC) vs. optical colonoscopy (OC).
Methods: The authors used Medicare claims data, fee schedules, established protocols, and other sources to estimate CTC and OC per-screen costs, including the costs of OC referrals for a subset of CTC patients. Read More
Background: The aim of the present study was to investigate the use and value of maximum standardized uptake value (SUV max) on positron emission tomography/computed tomography (PET/CT) images as a prognostic marker for patients with locally advanced pancreatic cancer (LAPC).
Materials And Methods: The medical records of all consecutive patients who underwent PET/CT examination in our institution were retrospectively reviewed. Inclusion criteria were histologically or cytologically proven LAPC. Read More
Purpose: Diffusion-weighted whole-body imaging with background body signal suppression/T2 image fusion (DWIBS/T2) strongly contrasts cancerous tissue against background healthy tissues. Positron emission tomography/computed tomography (PET/CT) applies the uptake of 18-fluorodeoxyglucose in the diagnosis of cancer. Our aim was to compare DWIBS/T2 and PET/CT in patients with upper gastrointestinal cancers. Read More
Purpose: Determine intra- and inter-examination repeatability of magnitude-based magnetic resonance imaging (MRI-M), complex-based magnetic resonance imaging (MRI-C), and magnetic resonance spectroscopy (MRS) at 3T for estimating hepatic proton density fat fraction (PDFF), and using MRS as a reference, confirm MRI-M and MRI-C accuracy.
Methods: Twenty-nine overweight and obese pediatric (n = 20) and adult (n = 9) subjects (23 male, 6 female) underwent three same-day 3T MR examinations. In each examination MRI-M, MRI-C, and single-voxel MRS were acquired three times. Read More
Purpose: The purpose of our study was to evaluate the sensitivity, specificity, and accuracy of ultrasound (US) as compared to magnetic resonance imaging (MRI) in pregnant patients with suspected appendicitis for visualization of the appendix, accuracy at diagnosing acute appendicitis, the ability of each modality to identify alternate diagnoses of pain and whether gestational age (GA) has an association with appendix identification rates.
Methods: We retrospectively reviewed the records of 140 pregnant patients with suspected appendicitis to determine the efficacy of US and MRI to identify the appendix, diagnose or exclude acute appendicitis, identify alternative etiologies for clinical presentation, and the affect of GA on identification of the appendix. Imaging results were correlated with surgical pathology in patients who underwent surgery. Read More
Objective: The purpose of this study is to describe our experience with the role of CT-guided percutaneous drainage of loculated intra-abdominal collections consisting entirely of gas.
Materials And Methods: An IRB-approved retrospective study analyzing patients with air-only intra-abdominal collections over an 8-year period was undertaken. Seven patients referred for percutaneous drainage were included. Read More
Purpose: The objective of this study is to compare MR imaging features of small hepatocellular carcinoma (HCC) (≤ 2 cm) in normal, fibrotic, and cirrhotic liver.
Methods: A total of 215 patients with 235 pathologically proven sHCC were retrospectively analyzed. Patients were classified into three groups according to the patients' liver condition: patients with normal liver (F0, group 1), fibrosis without cirrhosis (F1-3, group 2), and cirrhosis (F4, group 3). Read More
Sarcoidosis is mainly a disease of the respiratory system; however, several other organ systems may be affected in the course of the disease. Liver is one of the most frequently affected organs in the setting of sarcoidosis after lungs and lymph nodes. Microscopic hepatic involvement is common in these patients but is mostly clinically silent. Read More
Purpose: Dual-energy computed tomography (DECT) has shown the capability of differentiating uric acid (UA) from non-UA stones with 90-100% accuracy. With the invention of dual-source (DS) scanners, both low- and high-energy images are acquired simultaneously. However, DECT can also be performed by sequential acquisition of both images on single-source (SS) scanners. Read More
The purpose of this two-part article is to review the cross-sectional imaging features of benign and malignant ampullary conditions with endoscopic and histopathologic correlation and to present the most common pitfalls in the evaluation of the ampulla. In this part, we will review the mesenchymal and secondary neoplasms of the ampulla, a vast array of benign ampullary conditions, causes of bulging papilla, and pitfalls. Familiarity with ampullary pathologic conditions and pitfalls, as well as the use of optimized MDCT and MRI techniques, may improve the diagnostic accuracy of radiologists facing ampullary abnormalities. Read More
The purpose of this two-part article is to review the cross-sectional anatomy of the ampulla and periampullary region, to propose novel and optimized MDCT and MRI techniques that allow accurate evaluation of the ampulla of Vater, and to summarize the cross-sectional imaging features of benign and malignant ampullary conditions. In this first part, we will review the normal anatomy of the ampullary region, provide suggestions on how to optimize evaluation of the ampullary region by MDCT and MRI, and review the imaging features of select epithelial neoplasms of the ampulla. Familiarity with the normal ampullary anatomy and the pathologic conditions involving the ampulla, as well as the use of optimized MDCT and MRI techniques, may improve the diagnostic accuracy of radiologists facing ampullary abnormalities. Read More
Endoscopic retrograde cholangiopancreatography (ERCP) in patients with surgically altered upper gastrointestinal anatomy, such as Roux-en-Y gastric bypass (RYGB), can be more challenging compared to those with a normal anatomy. Detailed assessment of cross-sectional imaging features by the radiologist, especially the pancreaticobiliary anatomy, strictures, and stones, is very helpful to the endoscopist in planning the procedure. In addition, any information on enteral anastomoses (for e. Read More
Purpose: There are distinct quantifiable features characterizing renal cell carcinomas on contrast-enhanced CT examinations, such as peak tumor enhancement, tumor heterogeneity, and percent contrast washout. While qualitative visual impressions often suffice for diagnosis, quantitative metrics if developed and validated can add to the information available from standard of care diagnostic imaging. The purpose of this study is to assess the use of quantitative enhancement metrics in predicting the Fuhrman grade of clear cell RCC. Read More
Purpose: The objective of this study is to assess the performance of qualitative and quantitative imaging features for the differentiation of deep venous thrombosis (DVT) from mixing artifact on routine portal venous phase abdominopelvic CT.
Methods: This retrospective study included 40 adult patients with a femoral vein filling defect on portal venous phase CT and a Duplex ultrasound (n = 36) or catheter venogram (n = 4) to confirm presence or absence of DVT. Two radiologists (R1, R2) assessed the femoral veins for various qualitative and quantitative features. Read More
Purpose: To develop predictive models for lymph node (LN) metastasis in testicular germ cell tumors.
Materials And Methods: 291 patients with testicular germ cell tumors were included, which were divided into seminomatous and nonseminomatous groups. For screening the risk factors for LN metastasis, the tumor-related characteristics (including histopathological information and tumor markers) alpha fetoprotein and the lymph node-related features on CT were compared between metastatic cases and nonmetastatic cases. Read More
Department of Radiology, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Shuai Fu Yuan #1, Dongcheng Dist., Beijing, 100730, People's Republic of China.
Purpose: To discuss the diverse imaging features of pancreatic and extra-pancreatic lesions of IgG4-related disease (IgG4-RD) on multi-detector CT (MDCT).
Methods: This retrospective study was approved by our institutional research ethics board, and informed consent was waived. From 2008 to 2013, 159 patients including 120 men (mean age 57 years; range 27-79 years) and 39 women (mean age 51 years; range 25-83 years) who met the comprehensive diagnostic criteria for IgG4-RD (2011) were enrolled. Read More
Laparoscopic radial nephrectomy (LRN) and microwave ablation (MWA) are optional treatment for renal cell carcinoma (RCC). However, the comparative study with two techniques remains lacking. The aim of this study was to evaluate midterm results of MWA vs. Read More
Purpose: To explore the role of histogram analysis of apparent diffusion coefficient (ADC) MRI maps based on entire tumor volume data in determining pancreatic neuroendocrine tumor (PNT) grade.
Methods And Materials: Retrospective evaluation of 22 patients with PNTs included low-grade (G1; n = 15), intermediate-grade (G2; n = 4), and high-grade (G3; n = 3) tumors. Regions of interest containing the lesion were drawn on every section of the ADC map containing the tumor and summated to obtain histograms for entire tumor volume. Read More
Gastro-duodenal obstruction encompasses a spectrum of benign and malignant disease. Historically, chronic peptic ulcer disease was the main cause of gastro-duodenal obstruction, whereas now malignant cause with gastric carcinomas for gastric obstruction and pancreatic tumors for duodenal obstruction predominate. This paper reviews the role of CT in diagnosing gastro-duodenal obstruction, its level, its cause by identifying intraluminal, parietal, or extrinsic process, and the presence of complication. Read More
Purpose: To retrospectively evaluate CT sensitivity for characterizing adrenal adenoma according to lesion size.
Materials And Methods: Between January 2004 and November 2012, 140 patients with 140 histologically proven adenomas underwent preoperative adrenal CT protocols consisting of unenhanced CT, early enhanced CT, and delayed enhanced CT. Adenomas were divided into three size groups: small adenoma (n = 60), ≥ 1 to <2 cm; medium adenoma (n = 47), ≥ 2 to <3 cm; and large adenoma (n = 33), ≥ 3 cm. Read More
Amyloidosis is extremely rare, with an estimated 2225 new US cases reported annually. Signs and symptoms of the disease are subtle and imaging findings are not pathognomonic. Currently, diagnosis requires biopsy to demonstrate the deposition of amyloid. Read More
Purpose: (18)F-FDG PET/CT is used to characterize many malignancies, but is not recommended for localized prostate cancer. This study explores the value of multi-parametric MRI (mpMRI) in characterizing incidental prostate (18)F-FDG uptake.
Methods: Thirty-one patients who underwent (18)F-FDG PET/CT for reasons unrelated to prostate cancer and prostate mpMRI were eligible for this retrospective study. Read More
Objective: Rectal cancers are the second most common GI carcinoma. Prognosis and therapeutic decisions hinge on the extent of disease. We present a comprehensive structured approach for staging rectal cancer using MRI to ensure the clear, concise, and standardized communication of disease extent to guide optimal treatment planning. Read More
Hemangiomas are common lesions, best known for their appearance in the liver. Their appearance in less common locations, such as the gastrointestinal and genitourinary tracts, is less well known. We will review the typical and atypical appearance of hemangiomas in these locations on sonography, CT, and MRI. Read More
In CT colonography, orally administered positive-contrast fecal-tagging agents are used for differentiating residual fluid and feces from true lesions. However, the presence of high-density tagging agent in the colon can introduce erroneous artifacts, such as local pseudo-enhancement and beam-hardening, on the reconstructed CT images, thereby complicating reliable detection of soft-tissue lesions. In dual-energy CT colonography, such image artifacts can be reduced by the calculation of virtual monochromatic CT images, which provide more accurate quantitative attenuation measurements than conventional single-energy CT colonography. Read More
In CT colonography (CTC), orally administered positive-contrast fecal-tagging agents can cause artificial elevation of the observed radiodensity of adjacent soft tissue. Such pseudo-enhancement makes it challenging to differentiate polyps and folds reliably from tagged materials, and it is also present in dual-energy CTC (DE-CTC). We developed a method that corrects for pseudo-enhancement on DE-CTC images without distorting the dual-energy information contained in the data. Read More
The modeling of tracer kinetics with use of low-temporal-resolution data is of central importance for patient dose reduction in dynamic contrast-enhanced CT (DCE-CT) study. Tracer kinetic models of the liver vary according to the physiologic assumptions imposed on the model, and they can substantially differ in the ways how the input for blood supply and tissue compartments are modeled. In this study, single-input flow-limited (FL), Tofts-Kety (TK), extended TK (ETK), Hayton-Brady (HB), two compartment exchange (2CX), and adiabatic approximation to the tissue homogeneity (AATH) models were applied to the analysis of liver 4-phase DCE-CT data with fully continuous-time parameter formulation, including the bolus arrival time. Read More
Purpose: To investigate the incidence of high T2 signal rims surrounding leiomyomas, evaluate if a particular T2-weighted sequence is more effective in depicting this rim, and determine if this sign is useful in differentiating pedunculated leiomyomas from other solid adnexal masses.
Materials And Methods: In this retrospective study, two radiologists evaluated 233 T2 dark pelvic masses (223 uterine leiomyomas and 10 ovarian fibromas) in 60 women (mean age 47) on Magnetic resonance imaging for the presence of a high signal rim. Three different T2-weighted sequences were reviewed independently for uterine leiomyomas: half-Fourier acquisition single-shot turbo spin echo (HASTE), SPACE, and T2 with fat saturation (T2 FS). Read More
Purpose: To assess feasibility of and agreement between magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) for estimating hepatic proton density fat fraction (PDFF) in children with known or suspected nonalcoholic fatty liver disease (NAFLD).
Materials And Methods: Children were included in this study from two previous research studies in each of which three MRI and three MRS acquisitions were obtained. Sequence acceptability, and MRI- and MRS-estimated PDFF were evaluated. Read More
Purpose: To evaluate the efficacy of a knowledge-based iterative model reconstruction (IMR) algorithm for reducing image noise in ultralow-dose (ULD) CT for urolithiasis.
Materials And Methods: A total of 103 patients diagnosed with urinary stones (n = 276) were enrolled. Regular dose (RD) scans (120 kV and 150 mAs, maximal tube current in dose modulation) were reconstructed using filtered back-projection (FBP, RD-FBP), and ULD scans (100 kV and 20 mAs, fixed tube current) were reconstructed with FBP (ULD-FBP), statistical iterative reconstruction (IR; ULD-iDose), and a knowledge-based IMR algorithm (ULD-IMR). Read More
Pregnant women with an acute abdomen present a critical issue due to the necessity for an immediate diagnosis and treatment; in fact, a diagnostic delay could worsen the outcome for both the mother and the fetus. There is evidence that emergencies during pregnancy are subject to mismanagement; however, the percentage of errors in the diagnosis of emergencies in pregnancy has not been studied in depth. The purpose of this article is to review the most common imaging error emergencies. Read More
Surgical resection of colorectal metastatic disease has increased as surgeons have adopted a more aggressive ideology. Current exclusion criteria are patients for whom a negative resection margin is not feasible or a future liver remnant (FLR) of greater than 20% is not achievable. The goal of preoperative imaging is to identify the number and distribution of liver metastases, in addition to establishing their relation to relevant intrahepatic structures. Read More
Colorectal cancer (CRC) is the second most common cause of cancer death in the US. Earlier detection can allow treatment with curative intent and improve prognosis. Optical and virtual colonoscopy are widely used in screening for colonic polyps and in the investigation of suspected CRC. Read More