Preoperative localization of breast malignancies using traditional ultrasound and digital techniques can be challenging, particularly after neoadjuvant chemotherapy when the target is not conspicuous. The purpose of this paper is to pictorially present nontraditional techniques that have been helpful in preoperative localization before surgery. We will discuss techniques for breast lesion localization using computed tomography (CT) and magnetic resonance imaging (MRI) as well as axillary lymph node localization using tomosynthesis, CT, and MRI.

Digital breast tomosynthesis (DBT) has become an important tool in breast imaging. It decreases the call-back rate while increasing the cancer detection rate on screening mammography and is useful for diagnostic examination of noncalcified lesions and for the evaluation of patients presenting with clinical symptoms. Management challenges and dilemmas that are encountered with abnormalities detected on DBT and lacking a sonographic correlate can now be addressed with tomosynthesis-guided core biopsy.

Mediastinal and paracardiac lesions are usually first diagnosed on a chest radiograph or echocardiogram. Often, a computed tomography is obtained to further delineate these lesions. CT may be suboptimal for evaluation of enhancement characteristics and direct extension into the adjacent mediastinal structures. With its intrinsic superior soft-tissue characterization, magnetic resonance imaging (MRI) can better delineate these lesions, their internal tissue characteristics, and identify adhesion/invasion into adjacent structures. This pictorial essay provides a brief synopsis of the key MRI sequences and their utility in further characterizing mediastinal and paracardiac lesions.

Computed tomography-guided pulmonary nodule microcoil localization is done preoperatively to fluoroscopic-guided video-assisted thoracoscopic surgical resection. This pictorial essay explains and illustrates the microcoil localization technique, various microcoil placement errors, intraoperative fluoroscopy-guided resection, and postmicrocoil localization complications.

Schwannomas are benign soft-tissue tumors that arise from peripheral nerve sheaths throughout the body and are commonly encountered in patients with neurofibromatosis Type 2. The vast majority of schwannomas are benign, with rare cases of malignant transformation reported. In this pictorial review, we discuss the magnetic resonance imaging (MRI) appearance of schwannomas by demonstrating a collection of tumors from different parts of the body that exhibit similar MRI characteristics. We review strategies to distinguish schwannomas from malignant soft-tissue tumors while exploring the anatomic and histologic origins of these tumors to discuss how this correlates with their imaging findings. Familiarity with the MRI appearance of schwannomas can help aid in the differential diagnosis of soft-tissue masses, especially in unexpected locations.

Given the widespread use of transjugular intrahepatic portosystemic shunt (TIPS) creation for the treatment of portal hypertensive complications, a working knowledge of portal venous anatomy is critical for interventional radiologists. The right portal vein – which is most commonly accessed during TIPS – is subject to various anatomic variants that may potentially impact procedure success. This pictorial essay characterizes the anatomic patterns of the right portal vein branching in terms of type and frequency based on case series review. The work also explains the potential procedural implications of the right portal vein anatomic variations as they pertain to TIPS technical success.

Vaginal bleeding in the first trimester has wide differential diagnoses, the most common being a normal early intrauterine pregnancy, with other potential causes including spontaneous abortion and ectopic pregnancy. The incidence of ectopic pregnancy is approximately 2% of all reported pregnancies and is one of the leading causes of maternal mortality worldwide. Clinical signs and symptoms of ectopic pregnancy are often nonspecific. History of pelvic pain with bleeding and positive β-human chorionic gonadotropin should raise the possibility of ectopic pregnancy. Knowledge of the different locations of ectopic pregnancy is of utmost importance, in which ultrasound imaging plays a crucial role. This pictorial essay depicts sonographic findings and essential pitfalls in diagnosing ectopic pregnancy.

Despite progress in noninvasive imaging with computed tomography and magnetic resonance imaging, conventional angiography still contributes to the diagnostic workup of oncologic and other diseases. Arteriography can reveal tumors not evident on cross-sectional imaging, in addition to defining aberrant or unexpected arterial supply to targeted lesions. This additional and potentially unanticipated information can alter management decisions during interventional procedures.

The term "small round blue cell" is frequently used as a cursory radiologic pathological correlation of aggressive tumors throughout the body. We present a pictorial essay of common and uncommon subtypes of small round blue cell tumors in the chest illustrating the characteristic radiologic findings of each lesion. In addition, we review the pathologic findings of each tumor subtype with characteristic hematoxylin- and eosin-stained photomicrographs and immunohistochemical and molecular studies. Represented tumors include small cell carcinoma, Ewing sarcoma, extranodal marginal zone B-cell lymphoma, embryonal rhabdomyosarcoma, desmoplastic small round cell tumor, and posttransplant lymphoproliferative disorder. Understanding and ability to recognize these lesions are essential to broaden the radiologist's differential diagnosis and help guide patient care.

Fungal infections of the nose and paranasal sinuses can be categorized into invasive and non-invasive forms. The clinical presentation and course of the disease is primarily determined by the immune status of the host and can range from harmless or subtle presentations to life threatening complications. Invasive fungal infections are categorized into acute, chronic or chronic granulomatous entities. Immunocompromised patients with poorly controlled diabetes mellitus, HIV and patients receiving chemotherapy or chronic oral corticosteroids are mostly affected. Mycetoma and Allergic Fungal Rhinosinusitis are considered non-invasive forms. Computer tomography is the gold-standard in sinonasal imaging and is complimented by Magnetic resonance imaging (MRI) as it is superior in the evaluation of intraorbital and intracranial extensions. The knowledge and identification of the characteristic imaging patterns in invasive - and non- invasive fungal rhinosinusitis is crucial and the radiologist plays an important role in refining the diagnosis to prevent a possible fatal outcome.

The main objective of this pictorial essay is to illustrate the sonographic appearance of the postoperative carpal tunnel and median nerve. Carpal tunnel surgical treatment failures have been shown to occur in up to 19% of a large series requiring re-exploration. Surgical management options for recurrent carpal tunnel syndrome (CTS) include revision release, neurolysis, vein wrapping, and fat grafting procedures. While several descriptions of median nerve entrapment in CTS exist in the ultrasound literature, little is written regarding its postoperative appearance. We report the sonographic changes in the appearance of the median nerve and postoperative carpal tunnel.

Medical imaging has changed to a great extent over the past few decades. It has been revolutionized by three-dimensional (3D) imaging techniques. Despite much of modern medicine relying on 3D imaging, which can be obtained accurately, we keep on being limited by visualization of the 3D content on two-dimensional flat screens. 3D-printing of graspable models could become a feasible technique to overcome this gap. Therefore, we printed pre- and postoperative 3D-models of a complex congenital heart defect. With this example, we intend to illustrate that these models hold value in preoperative planning, postoperative evaluation of a complex procedure, communication with the patient, and education of trainees. At this moment, 3D printing only leaves a small footprint, but makes already a big impression in the domain of cardiology and cardiovascular surgery. Further studies including more patients and more validated applications are needed to streamline 3D printing in the clinical setting of daily practice.

Acute abdomen is one of the most common clinical conditions requiring a radiological investigation. Ultrasound is the primary modality of choice which can diagnose some of the common causes of acute abdomen. However, sometimes the underlying cause for the pain is far more complicated than expected mandating a high degree of suspicion to suggest further investigation with contrast enhanced computed tomography or magnetic resonance imaging. Here, we have compiled a comprehensive series of selected cases to highlight the conditions which can be easily overlooked unless carefully sought for. This article also emphasizes the importance of multimodality approach to arrive at the final diagnosis with an increased overall diagnostic accuracy which in turn improves patient management and prognosis.

Varices commonly occur in liver cirrhosis patients and are classified as esophageal (EV), gastroesophageal (GEV), or isolated gastric (IGV) varices. These vessels may be supplied and drained by several different afferent and efferent pathways. A working knowledge of variceal anatomy is imperative for Interventional Radiologists performing transjugular intrahepatic portosystemic shunt and embolization/obliteration procedures. This pictorial essay characterizes the angiographic anatomy of varices in terms of type and frequency of venous filling and drainage, showing that different varices have distinct vascular anatomy. EVs typically show left gastric vein filling and “uphill” drainage, and GEVs and IGVs exhibit additional posterior/short gastric vein contribution and “downhill” outflow. An understanding of these variceal filling and drainage pathways can facilitate successful portal decompression and embolization/obliteration procedures.

While the more common forms of breast cancer are well understood and recognized, there are many important rare malignancies that are less appreciated. Many of these cancers have imaging findings that, when understood, help to formulate a more educated differential diagnosis. In this article, the clinical features, imaging, and pathologic findings of rare breast malignancies will be discussed.

There are a few signs in radiology which are based on many common objects or patterns that we come across in our routine lives. The objective behind the association between such common objects and the corresponding pathologies is to make the reader understand and remember the disease process. These signs do not necessarily indicate a particular disease, but are usually suggestive of a group of similar pathologies which will facilitate in the narrowing down of the differential diagnosis. These signs can be seen in different imaging modalities like plain radiograph and computed tomography. In this essay, we describe 24 classical radiological signs used in chest imaging, which would be extremely helpful in routine clinical practice not only for radiologists but also for chest physicians and cardiothoracic surgeons.

Non-ischemic cardiomyopathies are defined as either primary or secondary diseases of the myocardium resulting in cardiac dysfunction. While primary cardiomyopathies are confined to the heart and can be genetic or acquired, secondary cardiomyopathies show involvement of the heart as a manifestation of an underlying systemic disease including metabolic, inflammatory, granulomatous, infectious, or autoimmune entities. Non-ischemic cardiomyopathies are currently classified as hypertrophic, dilated, restrictive, or unclassifiable, including left ventricular non-compaction. Cardiovascular Magnetic Resonance Imaging (CMRI) not only has the capability to assess cardiac morphology and function, but also the ability to detect edema, hemorrhage, fibrosis, and intramyocardial deposits, providing a valuable imaging tool in the characterization of non-ischemic cardiomyopathies. This pictorial essay shows some of the most important non-ischemic cardiomyopathies with an emphasis on magnetic resonance imaging features.

Ischemic heart disease is the leading cause of death worldwide. In the last two decades, cardiovascular magnetic resonance imaging (CMRI) has emerged as the primary imaging tool in the detection and prognostic assessment of ischemic heart disease. In a single study, CMRI allows evaluation of not only myocardial wall perfusion, but also the presence, acuity, and extent of myocardial ischemia and infarction complications. Also, rest and stress perfusion imaging can accurately depict inducible ischemia secondary to significant coronary artery stenosis. We present a pictorial review of the assessment of ischemic cardiomyopathy with an emphasis on CMRI features.

The purpose of this article is to describe the imaging characteristics of a variety of benign breast tumors that may be encountered in daily practice, in order to formulate an appropriate differential diagnosis and to establish concordance between the imaging and the pathologic findings, and to assist the clinician with appropriate management.

Basically malignant tumors in the retroperitoneal region arise from a heterogeneous group of tissues: mesodermal, neurogenic, germ cell, and lymphoid. Although rare, benign tumors and cystic masses can be also encountered in retroperitoneal space. Developments in computed tomography (CT) and magnetic resonance imaging (MRI) have contributed to both diagnosis and staging of the retroperitoneal tumors. High spatial resolution and superiority in calcification make CT indispensable; on the other hand, MRI has a better soft-tissue contrast resolution which is essential for the assessment of vascular invasion and tissue characterization. The aim of this article is to review the CT and MRI features of retroperitoneal tumors and their subsequent management.

Positron emission tomography with computed tomography (PET-CT) is an integral part of oncology practice in the current-day scenario. The hybrid anatomical and metabolic imaging information in this imaging modality provides access to a wealth of incidental findings which can have implications in the management of the patient, especially when surgical options are being considered. In this pictorial essay, we present incidentally detected mediastinal vascular anomalies on PET-CT, along with a review of associated literature.

Though congenital pericardial absence is often asymptomatic, complications can be life threatening. To date, few short case reports, primarily from the pre-CT and MR era, describe congenital absence of the right pericardium. We present a more comprehensive discussion of the embryologic derangements causing such defects and offer an up-to-date review of characteristic radiologic findings. Recognition of characteristic imaging findings of congenital pericardial absence is crucial in guiding diagnosis and management.

Cardiac conduction devices (CCDs) depend on correct anatomic positioning to function properly. Chest radiography is the preferred imaging modality to evaluate CCD's anatomic location, lead wire integrity, and help in identifying several complications. In this pictorial review, our goal is to familiarize radiologists with CCD implantation techniques, appropriate positioning of the device, common causes of malfunction, methods to improve report accuracy, and assure maximal therapeutic benefit.

This pictorial essay briefly discusses methods for optimizing bowel imaging with magnetic resonance imaging (MRI) and illustrates the MRI appearance of a variety of unusual lesions involving or related specifically to the large bowel.

Magnetic resonance angiography (MRA) provides noninvasive visualization of the vascular supply of soft tissue masses and vascular pathology, without harmful radiation. This is important for planning an endovascular intervention, and helps to evaluate the efficiency and effectiveness of the treatment. MRA with conventional extracellular contrast agents relies on accurate contrast bolus timing, limiting the imaging window to first-pass arterial phase. The recently introduced blood pool contrast agent (BPCA), gadofosveset trisodium, reversibly binds to human serum albumin, resulting in increased T1 relaxivity and prolonged intravascular retention time, permitting both first-pass and steady-state phase high-resolution imaging. In our practice, high-quality MRA serves as a detailed "roadmap" for the needed endovascular intervention. Cases of aortoiliac occlusive disease, inferior vena cava thrombus, pelvic congestion syndrome, and lower extremity arteriovenous malformation are discussed in this article. MRA was acquired at 1.5 T with an 8-channel phased array coil after intravenous administration of gadofosveset (0.03 mmol/kg body weight), at the first-pass phase. In the steady-state, serial T1-weighted 3D spoiled gradient echo images were obtained with high resolution. All patients underwent digital subtraction angiography (DSA) and endovascular treatment. MRA and DSA findings of vascular anatomy and pathology are discussed and correlated. BPCA-enhanced MRA provides high-quality first-pass and steady-state vascular imaging. This could increase the diagnostic accuracy and create a detailed map for pre-intervention planning. Understanding the pharmacokinetics of BPCA and being familiar with the indications and technique of MRA are important for diagnosis and endovascular intervention.

Ectopic pregnancies occur in approximately 1.4% of all pregnancies and account for 15% of pregnancy-related deaths. Considering the high degree of mortality, recognizing an ectopic pregnancy is important. Signs and symptoms of an ectopic pregnancy are nonspecific and include pain, vaginal bleeding, and an adnexal mass. Therefore, imaging can play a critical role in diagnosis. There are different types of ectopic pregnancies, which are tubal, cornual, cesarean scar, cervical, heterotopic, abdominal, and ovarian. Initial imaging evaluation of pregnant patients with pelvic symptoms is by ultrasonography, transabdominal, transvaginal or both. We review the sonographic appearance of different types of ectopic pregnancies that will aid in accurate and prompt diagnosis.

The purpose of this pictorial essay is to demonstrate the imaging features (ultrasound, mammogram, and magnetic resonance imaging (MRI)) of AlloDerm^® (LifeCell Corp.; Branchburg, NJ), an acellular dermal matrix sometimes used in both primary and reconstructive breast surgeries. AlloDerm^® is derived from cadaveric dermis and provides an immunologically inert scaffold in tissue reconstruction. Since there is little literature on the imaging of this substance, radiologists may be unfamiliar with its appearance in breast imaging. For this manuscript, ex vivo and in vivo images of AlloDerm^® in postmastectomy patients were evaluated using different imaging modalities. The appearance of AlloDerm^® can vary based on length of time postsurgery and incorporation into the host. AlloDerm^® appears as an isodense to glandular tissue on a mammogram and isoechoic to glandular tissue on ultrasound imaging. On MRI, in comparison with normal breast parenchyma, AlloDerm^® is hyperintense on T2-weighted imaging and isointense on T1-weighted imaging and demonstrates mild enhancement. To the best of the authors' knowledge, this is the first multimodality imaging description of AlloDerm^® used in postmastectomy patients. The conformation of AlloDerm^® at surgical placement and the degree of host cell migration and neoangiogenesis are factors to take into consideration when performing diagnostic evaluations; and, familiarity with the various imaging appearances of AlloDerm^® can be helpful to exclude residual or recurrent disease.

The adrenal gland is a common site of a large spectrum of abnormalities like primary tumors, hemorrhage, metastases, and enlargement of the gland from external hormonal stimulation. Most of these lesions represent nonfunctioning adrenal adenomas and thus warrant a conservative management. Multi-detector computed tomography (CT) and magnetic resonance (MR) imaging are still considered highly specific and complementary techniques for the detection and characterization of adrenal abnormalities. Radiologist can establish a definitive diagnosis for most adrenal masses (i.e., carcinoma, hemorrhage) based on imaging alone. Imaging therefore can differentiate malignant lesions from those benign and avoid unnecessary aggressive management of benign lesions. The article gives an overview of the adrenal lesions and their imaging characteristics seen on CT and MR imaging.

The differential diagnosis for a cardiac mass includes primary and metastatic neoplasms. While primary cardiac tumors are rare, metastatic disease to the heart is a common finding in cancer patients. Several "tumor-like" processes can mimic a true cardiac neoplasm with accurate diagnosis critical at guiding appropriate management. We present a pictorial essay of the most common benign cardiac masses and "mass-like" lesions with an emphasis on magnetic resonance imaging features.

Transjugular intrahepatic portosystemic shunt (TIPS) is an established and effective treatment for the complications of portal hypertension. The non-trivial rates of shunt dysfunction inherent to TIPS mandate familiarity with the imaging diagnosis and endovascular management of this phenomenon. Herein, we present a pictorial review of the various angiographic patterns of TIPS dysfunction and illustrate traditional and innovative technical approaches to shunt revision.

Congenital cystic diseases of the lung are a rare but significant cause of morbidity in children and young adults presenting with respiratory distress and repeated chest infections. They consist of cystic adenomatoid malformation, bronchogenic cyst, pulmonary sequestration, and congenital lobar emphysema. Surgical treatment is a safe and an effective method of treatment. Chest X-ray and computed tomography are the key imaging modalities used for diagnosis.

The imaging features of 42 histopathologically confirmed cases of Gastrointestinal Stromal Tumors (GIST) were analyzed, to observe the pattern of metastasis. At presentation 22 of 42 patients (52.3%) showed metastasis. During follow-up, three more cases developed metastasis, within one year of resection. Mesentery, omentum, and liver were the most frequent sites for metastasis. Other sites that were rarely reported to be involved were increasingly recognized to show metastasis due to longer survival. The metastasis often showed attenuation and enhancement characteristics, similar to primary GIST, and frequently showed necrosis, hemorrhage, and calcification.

Ultrasound (US) of the shoulder is the most commonly requested examination in musculoskeletal US diagnosis. Sports injuries and degenerative and inflammatory processes are the main sources of shoulder pain and functional limitations. Because of its availability, low cost, dynamic examination process, absence of radiation exposure, and ease of patient compliance, US is the preferred mode for shoulder imaging over other, more sophisticated, and expensive methods. Operator dependence is the main disadvantage of US examinations. Use of high range equipment with high resolution transducers, adhering to a strict examination protocol, good knowledge of normal anatomy and pathological processes and an awareness of common pitfalls are essential for the optimal performance and interpretation of shoulder US. This article addresses examination techniques, the normal sonographic appearance of tendons, bursae and joints, and the main pathological conditions found in shoulder ultrasonography.

Schizencephaly is a brain-destructive lesion relating to clefts in the fetal brain that usually communicate with the ventricular system, subarachnoid space, or both. It presents as two types: Type I (closed) and Type II (open). During pregnancy, it may be suspected in the course of ultrasonography, which highlights ventricular dilatation and brain abnormalities. Usually, the diagnosis is confirmed postnatally using trans-fontanel ultrasonography. The etiology of schizencephaly is still unknown, but it may be derived from a primary disorder of brain development or from bilateral middle cerebral artery occlusion. Many causative agents including vascular insult, infections, toxins, and medications have been associated with this malformation. We present a pictorial essay of six cases of schizencephaly that were suspected on prenatal ultrasound scans and confirmed postnatally by trans-fontanel, two-dimensional and three-dimensional ultrasonography.

Fascioliasis refers to a zoonosis caused by Fasciola hepatica, a trematode infecting herbivores, but also occurs in humans who ingest the metacercaria found in fresh water plants. Infection in humans is common in developing countries and is also not uncommon in Europe. Diagnosis of this infection is difficult, as the history and symptoms are nonspecific and stool analysis for eggs is negative until the disease is in an advanced state by when the parasite has reached the biliary system. The clinical course consists of two phases; first a hepatic parenchymal phase in which immature larvae invade the liver parenchyma, followed by a ductal phase characterized by the excretion of larvae into the bile ducts. Parenchymal Phase: Ultrasonography (US) findings are nonspecific in this early phase. Computerized tomography (CT) may demonstrate subcapsular low attenuation regions in the liver. Magnetic Resonance imaging (MRI) can also be utilized to establish liver parenchymal involvement, and is better than CT in characterizing hemorrhagic lesions, as well as identifying more lesions relative to CT. Ductal Phase: US examination is most useful at this stage, with its ability to demonstrate the live movement of the worms within the dilated ducts. A CT demonstrates dilated central biliary ducts with periportal tracking, whereas, mild ductal dilatation is poorly appreciated under MRI. Therefore, familiarity with the multimodality imaging features of fascioliasis, in combination with an available confirmatory enzyme-linked immunoassay, would be most helpful for early diagnosis.

Non-coronary incidental findings are not rare. Kirsch et al found 67% non-coronary abnormalities with coronary computed tomography angiography (CCTA). Radiologists are expected to identify the extracoronary, intra- and para-cardiac anatomical structures and distinguish them from pathologic processes in CCTA. We have reviewed 2000 CCTA studies done at our institution with 64-MDCT. This pictorial essay presents case studies of non-atherosclerotic cardiovascular findings to recognize cardiac anatomic structures and how to distinguish them from pathologic processes. Correct interpretation of benign, clinically insignificant findings is crucial to avoid unnecessary additional imaging tests.

Orthotopic liver transplantation is an important treatment option for patients with end-stage liver disease. Advances in surgical technique, along with improvements in organ preservation and immunosuppression have improved patient outcomes. Post-operative complications, however, can limit this success. Ultrasound is the primary imaging modality for evaluation of hepatic transplants, providing real-time information about vascular flow in the graft. Graft vascular complications are not uncommon, and their prompt recognition is crucial to allow for timely graft salvage. A multimodality approach including CT angiography, MRI, or conventional angiography may be necessary in cases of complex transplant vascular anatomy or when sonography and Doppler are inconclusive to diagnose the etiologies of these complications. The purpose of this article is to familiarize radiologists with the normal post-transplant vascular anatomy and the imaging appearances of the major vascular complications that may occur within the hepatic artery, portal vein, and venous outflow tract, with an emphasis on ultrasound.

Traditionally, fluoroscopic examinations such as enteroclysis, upper GI studies, and small bowel follow through exams have been the procedures of choice in evaluating inflammatory bowel disease (IBD) in pediatric populations. With the advent of multidetector computed tomography (MDCT), it has subsequently become a complementary examination in imaging inflammatory bowel disease. A major advantage of MDCT over fluoroscopic examination is its ability to directly visualize bowel mucosa, as well as demonstrate extra-enteric complications of IBD such as abscesses, fistulae, and sinus tracts. The major disadvantage of CT however is exposure to ionizing radiation, especially in IBD patients of the pediatric age group who maybe repeatedly imaged due to exacerbations. As a result, magnetic resonance enterography (MRE) is becoming increasingly important in the evaluation and follow-up of pediatric patients with IBD. This pictorial essay will summarize the multi-modality imaging findings of IBD with emphasis on MRE including the imaging protocol and procedure. For the purposes of this article, patients less than 17 years of age have been considered to represent the pediatric population.

Angiogenesis plays a key role in physiological and pathophysiological processes and is recognized as being essential for tumor growth and metastases. The recent oncological development of anti-angiogenic drugs brings with it a need for angiogenesis quantification and monitoring of response. The nature of these agents means that traditional anatomical methods of assessing morphologic change are outmoded and functional imaging techniques and/or agents are necessary. Herein, we describe the various imaging techniques that can be employed to assess angiogenesis, along with their inherent advantages and disadvantages and discuss the current and future developments in the field.

Surgical management is considered for specific indications in Crohn's disease and a wide variety of surgeries is performed. The purpose of this pictorial essay is to depict manifestations of Crohn's disease that indicates surgery, various surgical procedures that are performed, and the complications arising from these surgical procedures. Surgical indications including obstruction due to strictures or adhesions, fistulae and abscesses, and surgeries for these conditions, such as, ileocecectomy, stricturoplasty, small bowel resection, fecal diversion, segmental colectomy, and lysis of adhesions and their complications will be discussed and their imaging will also be illustrated.

Rheumatoid arthritis (RA) is a common disorder that affects the joints. RA is a systemic disease associated with relatively frequent and variable pleuropulmonary manifestations. This article reviews the common and potentially serious thoracic sequelae in terms of pleural disease, pulmonary nodules, airways disorders, and interstitial disease, as well as pulmonary side effects of antirheumatic medication. An imaging-guided approach to classification of RA-associated lung disease is outlined and the comparative values of different imaging modalities are discussed. An appreciation of current knowledge of epidemiology, pathological correlation, and prognostic implications of different RA-associated lung disease is provided. We highlight importance of considering pertinent differential diagnoses to avoid misdiagnosis, and outline common pitfalls in dealing with pleuropulmonary rheumatoid disease.

Image-guided percutaneous drainage is an excellent minimally invasive method for dealing with infectious complications in the pediatric population. A thorough understanding of drainage procedures in children can often lead to improved patient outcomes. Indications for percutaneous drainage will be reviewed, including abscesses related to appendicitis, post-surgical abscess formation, and abscesses related to Crohn's disease. This pictorial essay will help the radiologist better understand the common etiologies of abscesses in children that may require percutaneous drainage, the special considerations for catheter placement, patient preparation, and anesthesia or sedation issues unique to the pediatric population.

Fetal magnetic resonance imaging (MRI) continues to prove a useful problem solving tool for diagnostic and management decision making issues encountered in the antenatal period. In this paper, we attempt to review basic fetal MRI protocol considerations and demonstrate key imaging findings through multiple modalities, with pathologic correlation in several cases. A study of five fetal MRI cases, from our institution, were selected in order to highlight both the indications for, and benefits obtained from this advanced imaging technique. Fetal MRI proved useful in each case in better defining fetal anomalies, especially where ultrasound (due to drawbacks such as shadowing by pelvic bones) was unable to be completely diagnostic. The more in-depth study made possible by MRI also helped with formulation of disease prognosis and estimation of survival chances of the fetus. Further, MRI as a diagnostic and prognostic tool has become more ubiquitous across the medical community. This imparts tangible benefit to patients, who are now able to find this service within arm's reach. Whereas previously these patients were obligatorily referred up to 90 miles away from our centre for further medical work-up, now a large percentage can obtain their prenatal imaging and perinatal care locally. In addition, medical education benefits as new types of cases, those with pathology of the antenatal period, are retained for work-up and management in these large community settings. Cases from our institution exemplify these types of pathologies, from fetal chest masses to a syndromic presentation of bilateral renal agenesis.

Diffusion-Weighted Magnetic Resonance Imaging (DWI) obtains information useful in diagnosing several diseases through the measurement of random, Brownian diffusion of water molecules in tissues. This pictorial essay illustrates the main factors, i.e., ratio between the volume occupied by cells and the extracellular space, composition of the extracellular space, and temperature, that determine the rate of the water diffusion. The mechanism through which these influencing factors affect water diffusion is explained. Clinical and experimental examples, derived both from physiology and from non-human models, are described.

When assessing joints with various imaging modalities, it is important to focus on the extraarticular soft tissues that may clinically mimic joint pathology. One such extraarticular structure is the bursa. Bursitis can clinically be misdiagnosed as joint-, tendon- or muscle-related pain. Pathological processes are often a result of inflammation that is secondary to excessive local friction, infection, arthritides or direct trauma. It is therefore important to understand the anatomy and pathology of the common bursae in the appendicular skeleton. The purpose of this pictorial essay is to characterize the clinically relevant bursae in the appendicular skeleton using diagrams and corresponding multimodality images, focusing on normal anatomy and common pathological processes that affect them. The aim is to familiarize radiologists with the radiological features of bursitis.

Diagnostic imaging plays an important role in the assessment of patients with mechanical cardiac assist devices. Therefore, it is important for radiologists to be familiar with the basic components, function, and radiographic appearances of these devices in order to appropriately diagnose complications. The purpose of this pictorial essay is to review indications, components, normal imaging appearances, and complications of surgically and percutaneously implanted ventricular assist devices, intra-aortic balloon pumps, and cardiac meshes.

Sonography (ultrasound) is used routinely to assess an infant with nonbilious projectile emesis. Fluoroscopic upper gastrointestinal (UGI) series has been the standard method to evaluate infants with bilious emesis. We use sonographic UGI routinely to assess infants with nonbilious emesis as well as infants with bilious emesis. This essay illustrates our technique, the results obtained using this technique for normal anatomy, and the commonly encountered pathology.

The purpose of this paper is to identify indications for volumetric X-ray digital linear tomosynthesis (DLT) with single- and dual-energy subtraction techniques for artificial pulmonary nodule detection and compare X-ray DLT, X-ray digital radiography, and computed tomography.

Neurosarcoidosis is an uncommon condition with protean manifestations. Magnetic resonance imaging (MRI) is often used in the diagnostic evaluation and follow-up of patients with neurosarcoidosis. Therefore, familiarity with the variety of MRI appearances is important. In this pictorial essay, the range of possible patterns of involvement in neurosarcoidosis are depicted and discussed. These include intracranial and spine leptomeningeal involvement, cortical and cerebral white matter lesions, corpus callosum involvement, sellar and suprasellar involvement, periventricular involvement, cranial nerve involvement, cavernous sinus involvement, hydrocephalus, dural involvement, ischemic lesions, perivascular involvement, orbit lesions, osseous involvement, nerve root involvement, and spinal cord intramedullary involvement. Differential diagnoses for each pattern of involvement of neurosarcoidosis are also provided.

Tunica albuginea (TA) cyst is the most common extratesticular benign mass, which is usually palpable. Ultrasound examination is the imaging modality of choice to characterize palpable testicular lesions. This pictorial essay presents the spectrum of sonographic features of TA cysts in order to assist radiologists in making the correct diagnosis and avoid unnecessary surgeries.