Value of diffusion-weighted magnetic resonance imaging in the diagnosis of pyomyoma

Pyomyomas are rare lesions that develop from the suppurative degeneration of ischemic leiomyomas. Pyomyomas can lead to sepsis, so early diagnosis is crucial. Due to their rarity and often nonspecific findings on ultrasonography and computed tomography diagnosis is often delayed. We present a case of a woman who presented with abdominal pain and fever. The computed tomography showed a large hypodense uterine lesion with slight peripheral enhancement without gas in the lesion. The diffusion-weighted magnetic resonance imaging showed restricted diffusion, demonstrating the presence of pus and confirming the diagnosis of pyomyoma. Diffusion-weighted imaging should be done in cases of suspected pyomyomas when computed tomography findings are nonspecific.     

Imaging of cystic or cyst-like neck masses

Cystic or cyst-like neck masses form a unique category within head and neck radiology with unique differential diagnoses. The precise anatomical location and imaging appearances are important for accurate diagnosis and formulating the differential diagnoses of cystic lesions in the neck. In vast majority of cases ultrasound, sometimes supplemented by fine-needle aspiration cytology (FNAC), is adequate for pre-treatment assessment. For large, deep-seated lesions assessment using magnetic resonance imaging (MRI) or computed tomography (CT) often provides useful supplementary information. Radiologists should be aware of imaging findings of common cystic neck masses to help in their appropriate management.     

Cystic masses of the spleen: radiologic-pathologic correlation.

Many focal splenic lesions may appear to be cystic at cross-sectional imaging. In this article, the following types of cystic splenic masses are discussed: congenital (true cyst), inflammatory (abscesses, hydatid cyst), vascular (infarction, peliosis), posttraumatic (hematoma, false cyst), and neoplastic (hemangioma, lymphangioma, lymphoma, metastasis). The key findings at ultrasound, computed tomography, and magnetic resonance imaging can be correlated with underlying gross and microscopic pathologic findings. Although tissue sampling is still required in many cases to yield a definitive diagnosis, recognition and understanding of the spectrum of imaging and pathologic features of these lesions often help narrow the differential diagnosis.     

Sclerosing Angiomatoid Nodular Transformation of the Spleen: A Diagnostic Conundrum

A splenic lesion often represents a diagnostic challenge due to relative scarcity and the broad differential diagnosis. Sclerosing Angiomatoid Nodular Transformation (SANT) of the spleen is usually encountered only incidentally. Although benign, patients with SANT often receive splenectomy, due to its rarity, diagnostic uncertainty and sometimes intimidating imaging morphology and size. Imaging features on computed tomography, magnetic resonance and positron emission tomography have a high diagnostic value for SANT and help differentiate this entity from other splenic lesions. When the imaging parameters are matched with core needle biopsy tissue analysis, further watchful waiting can be recommended in order to avoid splenectomy.     

Computed tomography and magnetic resonance imaging of lesions at masticator space

We aim to review the normal anatomy and imaging appearance of masticator space lesions. Because the masticator space is not amenable to direct examination, cross-sectional imaging with computed tomography and magnetic resonance imaging play an important role in diagnosis and characterization of lesions occurring there. Masticator space lesions can be classified on the basis of their origin into the following categories: inflammatory lesions, benign tumors, malignant tumors, vascular lesions, and developmental lesions. A diverse spectrum of malignant tumors and benign lesions are seen extending from the adjacent spaces. In addition, one should also be familiar with pseudolesions as well as post-treatment changes in the masticator space that can be mistaken for pathologic conditions.     

Late enhancement on cardiac computed tomography in a patient with cardiac sarcoidosis

Cardiac computed tomography (CT) angiography permits detection of myocardial scars through “late enhancement.” We report the case of a patient with suspected cardiac sarcoidosis. Because of implanted defibrillator leads, magnetic resonance imaging was not possible. Dual-source CT with intravenous contrast injection was used as an alternative technique to detect late myocardial enhancement. A typical pattern of myocardial scarring allowed us to establish the diagnosis of cardiac sarcoidosis. CT imaging may be an alternative diagnostic tool to visualize late enhancement in patients with contraindications to magnetic resonance imaging.     

Blunt diaphragmatic lesions: Imaging findings and pitfalls

Blunt diaphragmatic lesions (BDL) are uncommon in trauma patients, but they should be promptly recognized as a delayed diagnosis increases morbidity and mortality. It is well known that BDL are often overlooked at initial imaging, mainly because of distracting injuries to other organs. Sonography may directly depict BDL only in a minor number of cases. Chest X-ray has low sensitivity in detecting BDL and lesions can be reliably suspected only in case of intra-thoracic herniation of abdominal viscera. Thanks to its wide availability, time-effectiveness and spatial resolution, multi-detector computed tomography (CT) is the imaging modality of choice for diagnosing BDL; several direct and indirect CT signs are associated with BDL. Given its high tissue contrast resolution, magnetic resonance imaging can accurately depict BDL, but its use in an emergency setting is limited because of longer acquisition times and need for patient’s collaboration.     

Descripción radiológica de las neoplasias quísticas pancreáticas

Although most cystic pancreatic lesions are pseudocysts, it is important to do a thorough differential diagnosis with true cystic tumors because cystic tumors are potentially malignant. Sometimes computed tomography and magnetic resonance imaging cannot establish the definitive diagnosis, making it necessary to perform other imaging tests such as endoscopic ultrasound, which in addition to morphological information, can also enable cytologic and biochemical analysis of the lesion through puncture and aspiration of its contents. Combining all these findings nearly always provides enough diagnostic information to allow the appropriate approach in each case.This article describes the specific morphological characteristics for each cystic pancreatic tumor on computed tomography, magnetic resonance imaging, and endoscopic ultrasound and reviews the guidelines for managing these types of lesions.     

Cerebellopontine angle-petromastoid mass lesions: comparative study of diagnosis with MR imaging and CT

Capabilities of computed tomography (CT) and magnetic resonance (MR) imaging in the diagnosis of cerebellopontine angle-petromastoid (CPA-PM) lesions were compared in 75 patients. CT and MR demonstrated 95.8% and 98.7% of the lesions, respectively. MR was often more helpful for characterization of neuromas, epidermoid cysts, exophytic gliomas, and vascular lesions, while CT was usually more informative for meningiomas, metastases, and tympanomastoid cholesteatomas. A specific diagnosis could be made with MR for most types of lesions through use of relaxation parameters and characteristic morphologic changes. Size, shape, location, and contour of the lesions, however, were generally more helpful for differential diagnosis than relaxation times. With the exception of metastatic lesions, cholesteatomas, and some meningiomas, MR was usually more helpful than CT in defining the full extent of the lesions and their relationships to contiguous structures. MR, because of its high accuracy in lesion detection, characterization, and localization, is a suitable primary diagnostic modality for evaluating patients with suspected CPA-PM lesions.     

Divertículos caliciales en niños: hallazgos radiológicos y formas de presentación

A calyceal diverticulum consists of a cystic eventration in the renal parenchyma that is lined with transitional cell epithelium with a narrow infundibular connection with the calyces or pelvis of the renal collector system; thus, the term pyelocalyceal diverticulum would be more accurate. Very rare in pediatric patients, calyceal diverticula can be symptomatic and require treatment. Calyceal diverticula are underdiagnosed because they can be mistaken for simple renal cysts on ultrasonography. To determine the approach to their follow-up and management, the diagnosis must be confirmed by excretory-phase computed tomography (CT) or magnetic resonance imaging (MRI).This article aims to show the different ways that calyceal diverticula can present in pediatric patients; it emphasizes the ultrasonographic findings that enable the lesion to be suspected and the definitive findings that confirm the diagnosis on CT and MRI. It also discusses the differential diagnosis with other cystic kidney lesions and their treatment.     

Intracanalicular arachnoid cyst mimicking acoustic neuroma: CT and MRI.

A patient with a surgically proven intracanalicular arachnoid cyst was studied using computed tomography, magnetic resonance imaging, and air CT cisternography. The lesion had a similar radiographic appearance to acoustic neuroma and therefore, although rare, must be considered in the differential diagnosis of intracanalicular mass lesions. We report a case in which examination was performed, in evaluating the lesion, utilizing high-resolution air CT cisternography and magnetic resonance imaging (MRI).     

Posterior dislocation of the long head of biceps tendon: case report and review of the literature

Posterior or lateral dislocation of the long head of biceps is a rare complication of shoulder dislocation that can result in inability to relocate the humerus. The diagnosis should be suspected when certain radiographic features are present at the initial presentation. Other imaging modalities can aid diagnosis when clinical management is unsuccessful or protracted. We present a case of surgically proven posterior dislocation of the biceps tendon with conventional radiographic, computed tomography and magnetic resonance imaging assessment. The literature on this subject is reviewed, and imaging features associated with the diagnosis are described.     

Computed tomography and magnetic resonance imaging of an infiltrative lesion of the anterior visual pathways

Infiltrative lesions of the optic chiasm and optic nerves are uncommon. The authors report such a case and discuss the differential diagnosis, paying particular attention to imaging. In the reported case high-resolution computed tomography and magnetic resonance imaging revealed thickening of the optic chiasm and intracranial optic nerves, a pattern characteristic of an inflammatory or neoplastic process.     

Musculoskeletal lesions with fluid-fluid level: a pictorial essay

A fluid-fluid level was identified in 11.2% of focal lesions of bone. Fluid-fluid levels are observed on cross-sectional imaging with either computed tomography (CT) or magnetic resonance (MR) imaging. They become apparent when a fluid collection containing substances of different density is allowed to settle, and when the plane of imaging is perpendicular to the fluid level. For instance, within a collection of blood, the cellular components will settle dependently, with the lower density plasma forming a layer superiorly. The difference in the density of these layers can be observed on CT imaging. With MR imaging, these layers will have different signal characteristics, allowing for visualization of the fluid-fluid level.The presence of fluid-fluid levels within a musculoskeletal lesion is an important finding, which can significantly aid in the differential diagnosis. This finding can be observed in a wide variety of lesions: osseous and soft tissue masses, neoplastic or nonneoplastic lesions, malignant or benign neoplasms, and primary or metastatic malignancies. When a fluid-fluid level is detected, in conjunction with clinical history, the differential diagnosis for a lesion can often be limited to a few choices. For this reason, it is important to be aware of the multiple lesions that can produce fluid-fluid levels, as well as their differentiating characteristics and typical presentations. We will review both osseous and soft tissue lesions, focusing on their imaging characteristics and other important findings.     

The clinical evaluation of bone tumors

Bone tumors are uncommon clinical entities that are often a source of diagnostic and therapeutic uncertainty. Evaluating these lesions starts with a patient history and physical examination Imaging then begins with radiographs, followed by advanced imaging modalities, such as magnetic resonance imaging, computed tomography, or bone scan. Biopsy can be performed to establish histologic diagnosis by either closed or open means. Treatment options range from observation to wide resection with reconstruction or amputation. Surveillance schedules vary depending on the type of tumor that is being treated. An algorithm for the evaluation, work-up, and diagnosis of bone tumors is presented.     

Primary fourth ventricular meningioma: a case report of an adult male

Primary fourth ventricular meningiomas are extremely rare and often misdiagnosed as other tumors. They have no characteristic imaging appearance on computed tomography and magnetic resonance imaging. Therefore, differentiating the lesion from common lesions in the fourth ventricle can be diagnostically challenging. In this report, we present a 25-year-old man with fourth ventricular meningioma and refer to the usefulness of diffusion-weighted imaging and apparent diffusion coefficient measurements for the differential diagnosis of fourth ventricular tumors.     

The imaging features of protruding esophageal lesions

Except for squamous cell carcinoma and adenocarcinoma, lesions that protrude into the esophagus are rare, and include benign and malignant tumors. The imaging findings of these lesions on esophagography, computed tomography (CT), and magnetic resonance imaging (MRI) are often non-specific. However, some of them reveal characteristic imaging findings. In addition, esophagography, CT, and MRI are useful to evaluate location, extent, invasion, vascularity, lymphadenopathy, and metastasis. Knowledge of the imaging features of protruding esophageal lesions helps to narrow the differential diagnosis. We describe the main features of esophageal protruding lesions.     

Splenic abnormalities: an overview on sectional images

Spleen, an organ that produces and controls blood cells, is a major regulatory site of the immune system. However, it is not necessary for the preservation of the vital functions, a feature that made this structure underlooked by most of radiologists and clinicians. In this paper, a working knowledge about the differential diagnosis of the sectional imaging techniques were presented. Computed tomography provides the basic information about this organ and its neighboring structures. The addition of the iodinated contrast media helps to further demarcate its parenchymal lesions. Magnetic resonance imaging, by virtue of its superb soft tissue contrast and lesion characterization, is used for the splenic lesions in which differential diagnosis were not reached by computed tomography. Organ-specific contrast media will be an important adjunct to magnetic resonance imaging in the near future.     

Fat-containing soft-tissue masses of the extremities

The authors review the radiologic spectrum of fat-containing soft-tissue masses of the extremities, with emphasis on computed tomography, magnetic resonance imaging, and pathologic correlation. These masses include both common and uncommon, benign and malignant lesions, such as lipoma, intramuscular and intermuscular lipoma, neural fibrolipoma, lipoblastoma, lipomatosis, hibernoma, hemangioma, elastofibroma, and liposarcoma, as well as lesions that may mimic fat-containing soft-tissue masses. Imaging studies of fat-containing lesions will often allow a specific presumptive diagnosis. When a specific diagnosis is not possible, however, knowledge of the spectrum of fat-containing lesions will allow a suitably ordered differential diagnosis.     

Imaging of stress fractures of the spine

Back pain caused by stress fractures, fatigue, or insufficiency, affects varied patient populations based on the level of physical activity and bone mineral density. Stress fractures may involve the vertebral body, pars interarticularis, and the pedicle; often overlooked are stress fractures of the sacrum or bony pelvis, which can mimic pain of spinal origin and delay diagnosis. The choice of optimal imaging (radiographs, nuclear medicine, magnetic resonance imaging, and computed tomography) also depends on the patient population under study and the clinically suspected diagnosis. The diagnosis typically determines which imaging modality is best to follow healing or progression.