Wende N. Gibbs

Revised motion estimation algorithm for PROPELLER MRI.

To introduce a new algorithm for estimating data shifts (used for both rotation and translation estimates) for motion‐corrected PROPELLER MRI. The method estimates shifts for all blades jointly, emphasizing blade‐pair correlations that are both strong and more robust to noise.

Diagnosis of congenital unicuspid aortic valve by 64-slice cardiac computed tomography

A 28-year-old man presented to our hospital with 3 days of intermittent, escalating dyspnea and chest tightness. He reported that he often experienced dyspnea when smoking, chewing tobacco, or exerting himself beyond the level of normal daily activity. His discomfort was partially relieved by his albuterol inhaler, which he used ≥10 times per day. As a child, he was told that he had a precordial murmur, but he had not sought medical attention. Five years prior to this evaluation, he was having similar symptoms and was treated with antibiotics. He was told at that time that he had mild asthma. On examination, the patient was mildly dyspneic, with a harsh systolic murmur at the right upper sternal border. Transthoracic echocardiogram revealed left ventricular thickening with normal systolic and diastolic function and a left ventricular ejection fraction of 65%. A peak gradient of >4 meters per second was noted, with a calculated aortic valve area of <0.9 cm2. The morphology of the valve was not clearly seen, but a unicuspid valve was suspected. Transesophageal echocardiogram demonstrated a heavily calcified unicuspid aortic valve with reduced cuspid excursion and moderate to severe aortic regurgitation (Figure ​(Figure1a1a). Preoperative 64-slice computed tomographic coronary angiography (Lightspeed VCT, GE Healthcare) confirmed the valve morphology and demonstrated no significant coronary narrowing (Figure ​(Figure1b1b). Figure Unicuspid aortic valve evaluated with (a) transesophageal echocardiography, (b) computed tomography, and (c) gross pathology. At operation, the valve was found to be unicuspid with one true unfused commissure. The free edge traversed the cusps without contact with the aortic wall (Figure ​(Figure1c1c). The patient received a St. Jude medical mechanical prosthesis, and his postoperative course was uncomplicated. The estimated incidence of unicuspid aortic valve is 0.02% (1–3). During development, the aortic valve is formed from three tubercles, which each develop a cusp and sinus of Valsalva. Fusion of the cusps results in a unicuspid valve. Unicommissural unicuspid valves, as in our case, have one lateral attachment and an eccentric orifice. Acommissural unicuspid valves have no lateral attachment to the aorta.

The effects of SENSE on PROPELLER imaging

To study how sensitivity encoding (SENSE) impacts periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) image quality, including signal‐to‐noise ratio (SNR), robustness to motion, precision of motion estimation, and image quality.

Bilateral lymphadenopathy in a young woman.

A 20-year-old woman presented to the emergency department with bilateral tender neck masses that had been increasing in size for 2 months. Associated symptoms included weakness, headaches, neck pain, dysphagia, and left-sided earache. In the previous week, she had developed a cough productive of white sputum, chest pain, and shortness of breath. She denied fevers, night sweats, and myalgias but did have occasional chills. She had developed a rash on her arms and lower extremities 3 weeks prior, which was now resolving, and tingling in her feet. She had minimal weight loss secondary to decreased appetite over the previous few months. Several weeks prior to admission, she had been diagnosed with mumps. She was also given a 5-day course of azithromycin that did not alleviate her symptoms. She reported that 6 months earlier, her boyfriend and another good friend had been treated for tuberculosis, but she had not been tested. She received standard vaccinations as a child. She denied alcohol, tobacco, and intravenous drug use. Her family history was significant for lung cancer and thyroid disease. She had not recently traveled outside of the United States, and she had been exposed to dogs but not to cats. Physical examination revealed a healthy appearing young woman with significant bilateral cervical lymphadenopathy that was tender to palpation. The skin over the masses was not discolored and did not have draining sinus tracts. Her oropharynx was clear and nonerythematous. Her lungs were clear. She had a resolving rash on her extremities. The remainder of her examination was normal. A posteroanterior and lateral chest radiograph revealed no abnormalities in her lungs. A computed tomography (CT) scan of the neck demonstrated large, bilateral, necrotic lymph nodes extending from the high to low internal jugular lymph node chains (Figure). Figure Contrast-enhanced CT images of the neck. (a) Coronal image demonstrating multiple large necrotic lymph nodes. (b) Coronal image at a more posterior level, showing involvement of nodes in levels 2 to 4. Nodes are centrally hypodense, representing necrosis, ... What are the differential diagnostic considerations? What is the most likely diagnosis? What tests can confirm the diagnosis? DIAGNOSIS: Infectious cervical lymphadenitis, or scrofula, likely caused by M. tuberculosis. The most likely etiology, considering exposures, age, and symptoms, was cervical tuberculous lymphadenitis, or scrofula. However, the broad differential diagnosis of enhancing cervical lymphadenopathy in an adult includes metastatic squamous cell carcinoma, metastatic papillary thyroid carcinoma, lymphoma, tuberculous and nontuberculous mycobacterial lymphadenitis, cat-scratch disease, Kaposis sarcoma, AIDS-related lymphadenopathy, Kimuras disease, Castlemans disease, and Kikuchis disease. Fungal and viral infections, such as Epstein-Barr virus, cytomegalovirus, and rubella, also may present with bilateral diffuse lymphadenopathy. Imaging of the chest, abdomen, and pelvis revealed no systemic lymphadenopathy or other abnormalities. A tuberculin skin test (purified protein derivative [PPD]) was positive. Acid-fast bacilli (AFB) and fungal blood cultures were negative. An HIV antibody test, monospot, and cytomegalovirus polymerase chain reaction (PCR) test were negative. Her angiotensin-con-verting enzyme level was within normal limits, an antinuclear antibody screen was minimally positive at 1:80, her sedimentation rate was elevated at 40 mm/h (reference range, 0–20), and her lactic acid dehydrogenase level was elevated at 248 U/L (reference range, 135–214). Lymph node sampling by fine-needle aspiration showed caseating granulomatous inflammation, but AFB and fungal smears and Mycobacterium tuberculosis (MTB) PCR results were negative. This sample eventually grew pansensitive MTB, also identifiable by MTB probe. A QuantiFERON-TB Gold test was sent and returned with a positive result.

Conventional and Advanced Imaging of Spine Oncologic Disease, Nonoperative Post-treatment Effects, and Unique Spinal Conditions

&NA; In this review, we discuss the imaging features of diseases and conditions ranging from neoplastic to nonoperative post‐treatment effects to unique conditions of the spine. Additionally, advanced imaging may increase diagnostic certainty in cases where conventional imaging characteristics of benign lesions and malignant pathology are variable.

A new MRI tag-based method to non-invasively visualize cerebrospinal fluid flow

PurposeAbnormal cerebrospinal fluid (CSF) dynamics can produce a number of significant clinical problems to include hydrocephalus, loculated areas within the ventricles or subarachnoid spaces as well as impairment of normal CSF movement between the cranial and spinal compartments that can result in a cerebellar ectopia and hydrosyringomyelia. Thus, assessing the patency of fluid flow between adjacent CSF compartments non-invasively by magnetic resonance imaging (MRI) has definite clinical value. Our objective was to demonstrate that a novel tag-based CSF imaging methodology offers improved contrast when compared with a commercially available application.MethodsIn a prospective study, ten normal healthy adult subjects were examined on 3T magnets with time-spatial labeling inversion pulse (Time-SLIP) and a new tag-based flow technique—time static tagging and mono-contrast preservation (Time-STAMP). The image contrast was calculated for dark-untagged CSF and bright-flowing CSF. We tested the results with the D’Agostino and Pearson normality test and Friedman’s test with Dunn’s multiple comparison correction for significance. Separately 96 pediatric patients were evaluated using the Time-STAMP method.ResultsIn healthy adults, contrasts were consistently higher with Time-STAMP than Time-SLIP (p < 0.0001, in all ROI comparisons). The contrast between untagged CSF and flowing tagged CSF improved by 15 to 34%. In both healthy adults and pediatric patients, CSF flow between adjacent fluid compartments was demonstrated.ConclusionsTime-STAMP provided images with higher contrast than Time-SLIP, without diminishing the ability to visualize qualitative CSF movement and between adjacent fluid compartments.

Evaluation of a novel EEG preamplifier.

Summary: The authors performed initial clinical testing of a novel EEG transduction module (ETM), designed to record EEG signals from electrodes with high and unbalanced contact impedances. Twenty patients underwent two consecutive EEG studies. In the first, “experimental” study, electrodes were applied to an unprepared scalp, and the ETM performed initial signal transduction and preamplification. The second, “routine” EEG was acquired in the standard manner, with electrode contact impedances of 5 k&OHgr; or less. Power spectral analysis was performed on all electrode signals from three experimental studies, and all studies were interpreted by three board-certified electroencephalographers. Individual electrode impedances in the experimental studies ranged from 10 to 560 k&OHgr; (mean 129 k&OHgr;). Power spectra on 54 of 57 electrode signals analyzed were free of 60-Hz noise. The majority of experimental studies were technically adequate, and technical limitations were unrelated to the ETM. Interrater reliability of preparation-free and standard EEG interpretation was high. The ETM device is an effective “preparation-free” technology in the setting of a clinical EEG laboratory. It provided easily interpretable EEG signals free of 60-Hz noise, recorded from electrodes with high and unbalanced impedances placed on completely unprepared scalp with minimal electrode paste.