Interval Change in Diffusion and Perfusion MRI Parameters for the Assessment of Pseudoprogression in Cerebral Metastases Treated With Stereotactic Radiation.

Objective: Apparent increases in the size of cerebral metastases after stereotactic radiosurgery (SRS) can be caused by pseudoprogression or true disease progression, which poses a diagnostic challenge at conventional MRI. The purpose of this study was to assess whether interval change in DWI and perfusion MRI parameters can differentiate pseudoprogression from progressive disease after treatment with SRS.

Materials And Methods: Patients with apparent growth of cerebral metastases after SRS treatment who underwent pre- and post-SRS DWI, dynamic susceptibility contrast (DSC)-MRI, and perfusion dynamic contrast-enhanced (DCE)-MRI were retrospectively evaluated.

Fractures of the posterolateral maxillary sinus: a masticator space blowout injury?

Background And Purpose: Segmental, depressed fractures of the posterolateral maxillary sinus may occur as a result of trauma to the masticator space, previously described in association with mandibular fractures. The authors hypothesize that the fracture is due to a transient increase in pressure in the masticator space (blow out) and therefore should be seen in association with other regional fractures.

Materials And Methods: Injuries of the masticator space were retrospectively identified by searching the imaging database from January 2014 to November 2014 for keywords that would identify regional trauma.

Differentiation of solitary brain metastasis from glioblastoma multiforme: a predictive multiparametric approach using combined MR diffusion and perfusion.

Introduction: Solitary brain metastasis (MET) and glioblastoma multiforme (GBM) can appear similar on conventional MRI. The purpose of this study was to identify magnetic resonance (MR) perfusion and diffusion-weighted biomarkers that can differentiate MET from GBM.

Methods: In this retrospective study, patients were included if they met the following criteria: underwent resection of a solitary enhancing brain tumor and had preoperative 3.

Migrating bullet: A case of a bullet embolism to the pulmonary artery with secondary pulmonary infarction after gunshot wound to the left globe.

Bullet embolism is a rare phenomenon following gunshot injuries. We present a case of a 25-year-old male who sustained a gunshot wound to his left globe with the bullet initially lodged in his right transverse sinus. The bullet ultimately embolized to a left lower lobe pulmonary artery resulting in a pulmonary infarct.

Acute stroke imaging: what clinicians need to know.

Advances in technology and software applications have contributed to new imaging modalities and strategies in the evaluation of patients with suspected acute cerebral infarction. Routine computed tomography (CT) and magnetic resonance imaging (MRI) have been the standard studies in stroke imaging, which have been complemented by CT and MR angiography, diffusion-weighted MR imaging, and cerebral perfusion studies, while conventional angiography is typically reserved for intra-arterial therapy. The purpose of this article is to review the variety of imaging studies available in the acute stroke setting, and to discuss the utility of each and the pertinent associated main findings.

Impact of hindsight bias on interpretation of nonenhanced computed tomographic head scans for acute stroke.

Objective: To determine whether knowledge of the presence or the absence of acute stroke from review of follow-up studies, including diffusion-weighted magnetic resonance imaging (DW-MRI) head scans, biases the retrospective review of a radiologist's detection of acute stroke on nonenhanced computed tomographic (CT) scans of the head.

Methods: Forty-four consecutive patients with acute cerebral infarction as defined by positive DW-MRI and a CT scan within 48 hours before the MRI were identified. In addition, 30 control patients with negative DW-MRI results and a head CT scan within 48 hours before the MRI were chosen.

Paratracheal air cysts: a common finding on routine CT examinations of the cervical spine and neck that may mimic pneumomediastinum in patients with traumatic injuries.

Background And Purpose: Collections of extraluminal paratracheal gas may be present on CT images of the neck and cervical spine and the radiologist may question whether this is related to a pathologic process. This study is designed to demonstrate the appearance, clinical presentation, and prevalence of paratracheal air cysts, which, on CT examinations of the neck, can mimic abnormal extraluminal air.

Materials And Methods: From January 1, 2005, through May 22, 2005, a total of 702 CT examinations of the cervical spine or soft tissue of the neck were reviewed.

On-call radiology: community standards and current trends.

The issues regarding on-call radiology are complex and contentious. Both academic and private practice radiology centers have encountered increasing workloads in recent years. Some academic centers are utilizing night float systems or other models of call to address the increasing complexity and volume of after-hours cases.

Can MRI signal characteristics of lumbar disk herniations predict disk regression?

Purpose: To assess whether or not MRI signal characteristics of lumbar disk herniations can predict subsequent disk regression.

Materials And Methods: Medical and radiology records from 1999-2003 were reviewed, and 123 patients who had more than one lumbar MRI during the study interval were identified. Of these, 42 patients had a disk herniation (protrusion, extrusion, or free fragment) identified on their first examination.

The utility of in-phase/opposed-phase imaging in differentiating malignancy from acute benign compression fractures of the spine.

Background And Purpose: Benign and malignant fractures of the spine may have similar signal intensity characteristics on conventional MR imaging sequences. This study assesses whether in-phase/opposed-phase imaging of the spine can differentiate these 2 entities.

Methods: Twenty-five consecutive patients who were evaluated for suspected malignancy (lymphoma [4 patients], breast cancer [3], multiple myeloma [2], melanoma [2], prostate [2], and renal cell carcinoma [1]) or for trauma to the thoracic or lumbar spine were entered into this study.

Location, size, and distribution of mediastinal lymph node enlargement in chronic congestive heart failure.

Purpose: The purpose of this study is to identify the prevalence, location, and size of enlarged mediastinal lymph nodes in patients with chronic congestive heart failure and to correlate the presence of lymph node enlargement with cardiac ejection fraction.

Methods: Sixty-six consecutive, retrospectively identified patients underwent computer tomography (CT) imaging of the thorax as part of a routine work-up prior to cardiac transplantation from 1993 to 1996. CT images of 44 of these patients were independently examined by 3 radiologists for evidence of pulmonary edema, pleural effusions, and the presence, size, and location of lymph nodes >1 cm in short axis.

Evaluation of emergency CT scans of the head: is there a community standard?

Objective: This study was designed to assess the accuracy of general radiologists in the interpretation via teleradiology of emergency CT scans of the head.

Materials And Methods: We studied the interpretations of 716 consecutive emergency CT scans of the head by a group of 15 board-certified general radiologists practicing in the community (as opposed to an academic setting). The scans were sent via teleradiology, and the preliminary interpretations were made.

Oblique reformation in cervical spine computed tomography: a new look at an old friend.

Study Design: Cervical spine computed tomograms were evaluated for neural foraminal stenosis in both the standard axial plane and the oblique reformatted plane.

Objective: To assess whether oblique reformation of cervical spine computed tomograms reduces interobserver variability in the evaluation of neural foraminal stenosis.

Summary Of Background Data: Radiographic assessment of neural foraminal stenosis is subjective, may vary among observers, and can affect surgical planning.

Radiology resident evaluation of head CT scan orders in the emergency department.

Background And Purpose: Prior studies have revealed little difference in residents' abilities to interpret cranial CT scans. The purpose of this study was to assess the performance of radiology residents at different levels of training in the interpretation of emergency head CT images.

Methods: Radiology residents prospectively interpreted 1324 consecutive head CT scans ordered in the emergency department at the University of Arizona Health Science Center.

The solitary pulmonary nodule on chest radiography: can we really tell if the nodule is calcified?

Objective: This study was designed to assess the ability of radiologists to accurately detect calcification within a solitary pulmonary nodule with chest radiography.

Materials And Methods: Thirty-five solitary pulmonary nodules that were examined by both posteroanterior and lateral chest radiography and on thin-section CT were retrospectively identified. Fourteen radiologists blinded to the results of CT assessed the nodules for the presence or absence of calcification using chest radiographs alone.

Gadopentetate dimeglumine as a contrast agent in common carotid arteriography.

Background And Purpose: Despite improvements in noninvasive imaging, some patients with contraindications to iodine-based contrast material still require angiography for the evaluation of carotid stenosis. Our aim was to assess the utility of gadopentetate dimeglumine as an intraarterial contrast agent in common carotid angiography.

Methods: Twelve patients with suspected carotid artery stenosis were enrolled in the study.

Emergency department coverage by academic departments of radiology.

Rationale And Objectives: The purpose of this study was to survey academic radiology departments to determine how emergency radiology coverage is handled and whether there are any prerequisites for those individuals providing this coverage.

Materials And Methods: The authors developed a simple two-page survey and sent it to a total of 608 program directors, chiefs of diagnostic radiology, chairpersons, and chief residents at academic departments of radiology.

Results: Of the 608 surveys sent, 278 (46%) were returned.

Disseminated coccidioidomycosis complicated by vasculitis: a cause of fatal subarachnoid hemorrhage in two cases.

We describe two cases of disseminated coccidioidomycosis that were complicated by fatal subarachnoid hemorrhage. In the first case, a left middle cerebral artery aneurysm and long-segment vasculitis occurred. In the second case, MR imaging revealed an enlarging coccidioidal granuloma at the tip of the basilar artery, and the artery subsequently ruptured.

MR imaging of acute coccidioidal meningitis.

Background And Purpose: Our purpose was to describe the MR imaging findings in patients with acute coccidioidal meningitis.

Methods: Fourteen patients (11 men, three women; 22-78 years old; mean age, 47 years) with coccidioidal meningitis underwent neuroimaging within 2 months of diagnosis. Thirteen patients had MR imaging and one had an initial CT study with a follow-up MR examination 5 months later.

Elevated androgen, brain development and language/learning disabilities in children with congenital adrenal hyperplasia.

Individuals with congenital adrenal hyperplasia (CAH) provide a test population for the theory that elevated testosterone levels alter prenatal brain development and increase the risk of learning disabilities. Eleven subjects with CAH, five of their non-CAH siblings and 16 matched control subjects participated in two studies. The first study documented hand preference, verbal skills and non-verbal skills.

Orbital histiocytosis X.

In three patients with histiocytosis X of bone with orbital involvement, CT scans were reviewed. Consistent findings included a destructive lesion of the lateral wall of the orbit with a large soft-tissue component that extended into the extraconal space, the ocular adnexa, and the infratemporal fossa. The greater wing of the sphenoid was eroded in all cases, with epidural extension into the middle cranial fossa.

Critical carotid artery stenosis: diagnosis, timing of surgery, and outcome.

Purpose: Patients with critical carotid artery stenoses have been considered to be at high risk for carotid artery occlusion necessitating urgent or emergency endarterectomy once the stenosis is identified. Included in this group of patients are those with carotid string sign or atheromatous pseudoocclusion (APO). This review was conducted to determine the impact of the severity of stenosis including APO on the treatment and outcome of patients undergoing carotid endarterectomy.