Infiltrative hepatocellular carcinoma: what radiologists need to know.

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related death worldwide. The macroscopic growth pattern of HCC is subdivided into three categories: nodular, massive, and infiltrative. Infiltrative HCC accounts for 7%-20% of HCC cases and is confirmed at pathologic analysis on the basis of the spread of minute tumor nodules throughout large regions of the liver. Infiltrative HCC may represent a diagnostic challenge because it is often difficult to distinguish from background changes in cirrhosis at imaging. Infiltrative HCC usually spreads over multiple hepatic segments, occupying an entire hepatic lobe or the entire liver, and it is frequently associated with portal vein tumor thrombosis. The tumor is usually ill defined at ultrasonography and shows minimal and inconsistent arterial enhancement and heterogeneous washout at contrast material-enhanced computed tomography and magnetic resonance (MR) imaging. The tumor may be more visible among the surrounding liver parenchyma at diffusion-, T1-, and T2-weighted MR imaging. Several liver diseases can mimic the infiltrative appearance of this malignancy, including focal confluent fibrosis, hepatic fat deposition, hepatic microabscesses, intrahepatic cholangiocarcinoma, and diffuse metastatic disease (pseudocirrhosis). The prognosis for patients with infiltrative HCC is poor because the tumor is often markedly advanced and associated with vascular invasion at presentation. Survival after surgical resection is decreased; thus, infiltrative HCC is a contraindication for resection and transplantation. Knowledge of the key tumor characteristics and imaging findings will help radiologists formulate a correct and timely diagnosis to improve patient management.

Biliary strictures and masses: an expanded differential diagnosis.

Biliary strictures and masses are commonly a result of cholangiocarcinoma. However, there are several congenital, infectious, inflammatory, autoimmune, iatrogenic, and neoplastic etiologies that should also be considered in the differential diagnosis. Knowledge of the key imaging and clinical findings will aid in facilitating the diagnosis and treatment.

Radiogenomics of clear cell renal cell carcinoma: preliminary findings of The Cancer Genome Atlas-Renal Cell Carcinoma (TCGA-RCC) Imaging Research Group.

PURPOSE: To investigate associations between imaging features and mutational status of clear cell renal cell carcinoma (ccRCC). MATERIALS AND METHODS: This multi-institutional, multi-reader study included 103 patients (77 men; median age 59 years, range 34-79) with ccRCC examined with CT in 81 patients, MRI in 19, and both CT and MRI in three; images were downloaded from The Cancer Imaging Archive, an NCI-funded project for genome-mapping and analyses. Imaging features [size (mm), margin (well-defined or ill-defined), composition (solid or cystic), necrosis (for solid tumors: 0%, 1%-33%, 34%-66% or >66%), growth pattern (endophytic, <50% exophytic, or ≥50% exophytic), and calcification (present, absent, or indeterminate)] were reviewed independently by three readers blinded to mutational data. The association of imaging features with mutational status (VHL, BAP1, PBRM1, SETD2, KDM5C, and MUC4) was assessed. RESULTS: Median tumor size was 49 mm (range 14-162 mm), 73 (71%) tumors had well-defined margins, 98 (95%) tumors were solid, 95 (92%) showed presence of necrosis, 46 (45%) had ≥50% exophytic component, and 18 (19.8%) had calcification. VHL (n = 52) and PBRM1 (n = 24) were the most common mutations. BAP1 mutation was associated with ill-defined margin and presence of calcification (p = 0.02 and 0.002, respectively, Pearson's χ (2) test); MUC4 mutation was associated with an exophytic growth pattern (p = 0.002, Mann-Whitney U test). CONCLUSIONS: BAP1 mutation was associated with ill-defined tumor margins and presence of calcification; MUC4 mutation was associated with exophytic growth. Given the known prognostic implications of BAP1 and MUC4 mutations, these results support using radiogenomics to aid in prognostication and management.

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.

In search of a consensus: evaluation of the patient with hematuria in an era of cost containment.

OBJECTIVE: The purpose of this article is to describe the current consensus guidelines for nonimaging triage and ultimate preferred imaging approach for the patient with unexplained hematuria. CONCLUSION: Numerous consensus guidelines from varying societies have outlined preferred imaging pathways for the patient with unexplained urologic causes of hematuria. Future guidelines will need to take into account disease prevalence, radiation considerations, and cost.

Cystic hepatic lesions: a review and an algorithmic approach.

OBJECTIVE: The purpose of this article is to review the different cystic hepatic lesions, with an emphasis on the imaging features that help to differentiate them, and to propose a practical algorithm for approaching the diagnosis of these lesions. CONCLUSION: The number and morphology of the lesions and determination of whether there is a solid component are key imaging features that are helpful for approaching the diagnosis of cystic hepatic lesions. Familiarity with these features and knowledge of the clinical associations will help the radiologist to establish a definitive diagnosis or provide a reasonable differential diagnosis.

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.

Utility of additional CT examinations driven by completion of a standard trauma imaging protocol in patients transferred for minor trauma.

Many clinicians order focused computed tomography (CT) examinations for trauma patients based on history and physical examinations. Trauma patients transferred to our level I trauma center undergo an extensive, nonfocused standard trauma CT protocol. We hypothesize that the use of the standard trauma CT protocol does not contribute significant clinical information for patient care when compared with CT examinations based on history and physical examination. We aim to quantify the utility of the additional CT examinations required by our institution's trauma protocol compared with emergent CT examinations dictated by the patient's history and physical examination findings. In this IRB-approved study, we retrospectively evaluated 132 trauma patients transferred to our center who underwent additional CT examinations as determined by fulfillment of our institution's standard trauma CT protocol. The emergency radiologist evaluated the CT examinations acquired after the patient's transfer to determine if there were any additional acute findings that were identified on these additional examinations compared with the initial assessment undertaken at the outside institution. A total of 101 patients transferred to our trauma center met inclusion criteria. The majority of these patients sustained minor trauma. The standard trauma protocol generated 474 negative CT examinations in 101 patients. In seven patients, there were unexpected acute findings. However, these unexpected acute findings did not change clinical management in any of the patients. After initial evaluation, the acquisition of additional nonfocused CT examinations based on the standard trauma CT protocol provides little useful clinical information in patients who are transferred for minor trauma. Rather, CT utilization should be based on clinical findings. Replacement of standard trauma CT protocol with focused CT examinations in trauma patients is a way to curtail overutilization, thereby decreasing health care cost and the amount of patient radiation exposure.

Correlation of ultrasound findings with the Bethesda cytopathology classification for thyroid nodule fine-needle aspiration: a primer for radiologists.

OBJECTIVE: Ultrasound and ultrasound-guided fine-needle aspiration play a critical role in the evaluation of thyroid nodules. The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) was developed to facilitate communication among cytopathologists, radiologists, and referring physicians. The reporting scheme has rapidly become one of the most important contributions to thyroid nodule management. In this article, we review the significance of the TBSRTC categories and their implications in stratifying risk in the management of thyroid nodules. CONCLUSION: Knowledge of TBSRTC will allow the radiologist to better understand the criteria for thyroid nodule specimen adequacy, the components of risk stratification, and the standard terminology used for effective communication between patients and clinicians.

Hepatic transplantation: postoperative complications.

Advances in surgical techniques and immunosuppression have made orthotopic liver transplantation a first-line treatment for many patients with end-stage liver disease. The early detection and treatment of postoperative complications has contributed significantly to improved graft and patient survival with imaging playing a critical role in detection. Complications that can lead to graft failure or patient mortality include vascular abnormalities, biliary abnormalities, allograft rejection, and recurrent or post-transplant malignancy. Vascular abnormalities include stenosis and thrombosis of the hepatic artery, portal vein, and inferior vena cava, as well as hepatic artery pseudoaneurysm, arteriovenous fistula, and celiac stenosis. Biliary abnormalities include strictures, bile leak, obstruction, recurrent disease, and infection. While imaging is not used to diagnose allograft rejection, it plays an important role in identifying complications that can mimic rejection. Ultrasound is routinely performed as the initial imaging modality for the detection and follow-up of both early and delayed complications. Cholangiography and magnetic resonance cholangiopancreatography are used to characterize biliary complications and computed tomography is used to confirm abnormal findings on ultrasound or for the evaluation of postoperative collections. The purpose of this article is to describe and illustrate the imaging appearances and management of complications associated with liver transplantation.

Pneumopericardium due to gastropericardial fistula: a delayed, rare complication of gastric bypass surgery.

Pneumopericardium is a rare clinical finding with various etiologies. Pneumopericardium ranges from an asymptomatic to life-threatening condition, e.g., in cases of cardiac tamponade. The underlying etiology should be sought so that treatment can be expedited. Pneumopericardium may result from traumatic and nontraumatic etiologies. Although the mortality associated with pneumopericardium is high, its rarity precludes determination of its true incidence. We present an unusual case of pneumopericardium due to gastropericardial fistula which developed as a delayed complication of a Roux-en-Y gastric bypass performed 11 years prior.

Imaging of the female perineum in adults.

The female perineum is a diamond-shaped structure inferior to the pelvic diaphragm and between the symphysis pubis and coccyx. The perineum is divided into the anterior urogenital triangle and the posterior anal triangle; the vulva represents the external genitalia. A wide array of diseases affect the female perineum in adults. Vulvar trauma, infection (including Fournier gangrene), developmental lesions, and thrombophlebitis can be investigated with various imaging modalities; vulvar malignancies are best imaged with magnetic resonance (MR) imaging to identify local-regional extent of disease. MR imaging is also the modality of choice for imaging of the distal urethra, although imaging of a urethral diverticulum also includes voiding cystourethrography and ultrasonography. The distal vagina at the level of the introitus is best imaged with MR imaging for assessment of Bartholin gland cysts and malignancies. Diseases encountered in the anus include anal carcinoma, fistula-in-ano, and anovaginal fistula, which can all be imaged with various modalities offering different sensitivities and fields of view. Lastly, musculoskeletal neoplasms affecting the perineum and vulva include mesenchymal, lipomatous, nerve sheath, and osseous neoplasms. These neoplasms can be imaged with both computed tomography and MR imaging, although the latter provides higher soft-tissue contrast and greater anatomic detail for diagnosis and determination of the extent of necessary surgery. Familiarity with the anatomy of the female perineum and appropriate selection of imaging modalities facilitate prompt and accurate diagnosis and treatment.

Seminal vesicle cysts causing pelvic pain: importance of computed tomography.

A seminal vesicle cyst is a rare etiology of pelvic pain. However, its rarity may result in oversight or misinterpretation if the radiologist or emergency physician is unfamiliar with this entity. Seminal vesicle cysts may cause pelvic pain because of mass effect, infection, internal hemorrhage, or urinary and bladder obstruction. Because seminal vesicle cysts rarely result in physical examination findings or laboratory abnormalities, pelvic computed tomography plays a pivotal role in their diagnosis and in evaluating patients with pelvic pain. Recognition of the imaging findings of seminal vesicle cysts is necessary to allow prompt, accurate diagnosis. Therefore, emergency physicians and radiologists interpreting examinations from the emergency department should be familiar with these imaging findings because seminal vesicle cysts may be the etiology of pelvic pain and the patient may benefit from urologic consultation and cyst aspiration or resection. The purposes of this article are to provide examples of pelvic pain caused by seminal vesicle cysts, illustrate the key imaging findings on computed tomography, and briefly review the literature.

Imaging of acute conditions affecting the hepatic vasculature.

Liver imaging primarily consists of evaluating the parenchyma and biliary system. However, the liver has a rich, complex vascularity which can also be affected by numerous disease processes. By considering disease processes that primarily affect the hepatic veins, portal veins, and hepatic arteries, an anatomy-based approach of hepatic vascular diseases can be applied to image interpretation to allow rapid diagnosis and prompt initiation of treatment. Computed tomography, magnetic resonance imaging, and ultrasound are all effectively used to evaluate the liver and can play complimentary roles. In this article, the key imaging findings of acute conditions affecting the hepatic veins (passive congestion, acute thrombosis/Budd-Chiari, stenosis), portal veins (thrombosis, phlebitis, stenosis), hepatic arteries (laceration, pseudoaneurysm, thrombosis), and arteriovenous structures (hereditary hemorrhagic telangiectasis, arteriovenous fistula) will be reviewed.

Imaging of acute right lower quadrant abdominal pain: differential diagnoses beyond appendicitis.

Evaluation of acute right lower quadrant pain remains a common and challenging clinical scenario for emergency medicine physicians due to frequent nonspecific signs, symptoms, and physical examination findings. Therefore, imaging has evolved to play a pivotal role in the emergency setting. While appendicitis is a common cause for acute pain, there are numerous other important differential considerations with which the radiologist must be aware. The purpose of this review is to list an anatomy-based, encompassing differential diagnosis in addition to acute appendicitis for right lower quadrant pain; demonstrate the key imaging findings of numerous differential considerations; and describe helpful imaging and clinical features useful in narrowing the differential diagnosis.

Kidney-pancreas transplantation: assessment of key imaging findings in the acute setting.

For patients with diabetes, insulin therapy can be an effective treatment for years. However, many diabetics eventually develop complications from the disease, including neuropathy, amputations, atherosclerosis, and kidney failure. While kidney failure can be managed with dialysis, difficulties with monitoring fluid intake and diet, bone loss, anemia, and venous access can be problematic for the patient. Due to the decreased life expectancy and difficulties of medical management of patients with diabetes and renal failure, combined renal-pancreas transplantation is an increasingly used option available to type 1 diabetics with concurrent renal failure due to refinements of surgical technique and immunosuppressive therapy. Due to the increasing number of kidney-pancreas transplant patients, longer post-transplant survival, and increasing number of hospitals performing the procedure, more transplant patients are having their care increasingly shifted away from the major transplant centers to general community hospitals. In many kidney-pancreas transplants patients who present to the emergency department for suspected transplant dysfunction, imaging plays a critical initial role in their diagnosis and management. Therefore, it has become increasingly important that community and emergency department radiologists be able to recognize the normal imaging appearance of renal-pancreas transplants and to identify acute findings.

Acute conditions affecting the perinephric space: imaging anatomy, pathways of disease spread, and differential diagnosis.

The perinephric space is an important, central compartment of the retroperitoneum which may host various acute conditions. Imaging evaluation of the perinephric space requires an understanding of its anatomy and the pathways of disease spread to and from other retroperitoneal compartments. Numerous acute conditions can affect the perinephric space and may occur in isolation, extend from nearby retroperitoneal structures, or be part of a systemic condition. Familiarity with the key imaging findings of acute conditions affecting the perinephric space is imperative to facilitate diagnosis and guide treatment. The purpose of this article is to review and illustrate the relevant anatomy, pathways of disease spread, and acute pathology encountered during cross-sectional imaging evaluation of the perinephric space.

Impact of measurement method on interobserver variability of apparent diffusion coefficient of lesions in prostate MRI.

PURPOSE: To compare the inter-observer variability of apparent diffusion coefficient (ADC) values of prostate lesions measured by 2D-region of interest (ROI) with and without specific measurement instruction. METHODS: Forty lesions in 40 patients who underwent prostate MR followed by targeted prostate biopsy were evaluated. A multi-reader study (10 readers) was performed to assess the agreement of ADC values between 2D-ROI without specific instruction and 2D-ROI with specific instruction to place a 9-pixel size 2D-ROI covering the lowest ADC area. The computer script generated multiple overlapping 9-pixel 2D-ROIs within a 3D-ROI encompassing the entire lesion placed by a single reader. The lowest mean ADC values from each 2D-small-ROI were used as reference values. Inter-observer agreement was assessed using the Bland-Altman plot. Intraclass correlation coefficient (ICC) was assessed between ADC values measured by 10 readers and the computer-calculated reference values. RESULTS: Ten lesions were benign, 6 were Gleason score 6 prostate carcinoma (PCa), and 24 were clinically significant PCa. The mean±SD ADC reference value by 9-pixel-ROI was 733 ± 186 (10-6 mm2/s). The 95% limits of agreement of ADC values among readers were better with specific instruction (±112) than those without (±205). ICC between reader-measured ADC values and computer-calculated reference values ranged from 0.736-0.949 with specific instruction and 0.349-0.919 without specific instruction. CONCLUSION: Interobserver agreement of ADC values can be improved by indicating a measurement method (use of a specific ROI size covering the lowest ADC area).

Imaging of hepatobiliary disorders complicating pregnancy.

OBJECTIVE: A variety of uncommon, but potentially devastating, hepatobiliary disorders may complicate pregnancy. Because of their rarity, such disorders may elude diagnosis and treatment may be delayed. Although some of these disorders can be diagnosed clinically, imaging plays an important role in the diagnosis of several pregnancy-related hepatobiliary disorders. CONCLUSION: The radiologist should be familiar with the imaging findings of hepatobiliary diseases that complicate pregnancy and can result in significant maternofetal morbidity and mortality.

Cross-sectional imaging of acute abdominal conditions in the oncologic patient.

Cross-sectional imaging of acute abdominal conditions encompasses a broad differential diagnosis, including traumatic, inflammatory, and infectious etiologies. In addition, an underappreciated contributor to the acute abdomen is oncologic disease and its treatment. Oncologic patients are at increased risk in the development of numerous acute abdominal conditions due to a combination of tumor invasion, sequelae of treatment, and altered immune response. Cross-sectional imaging of the oncologic patient poses several unique challenges due to the need to be able to evaluate surgically altered anatomy, evaluation of treatment response, and potential untoward effects of neoplasia and its treatment. The radiologist plays a pivotal role in the multidisciplinary approach to cancer diagnosis and management. In addition to diagnosis and follow-up assessment of disease response, the radiologist should be familiar with the imaging findings of acute conditions affecting the oncologic patient to optimize patient care. Recognition of key imaging findings can allow prompt diagnosis and facilitate treatment for potentially lethal abdominal conditions in the complex oncologic patient, thereby reducing morbidity and mortality.