Equilibrium phase contrast-enhanced magnetic resonance angiography of the thoracic aorta and heart using balanced T1 relaxation-enhanced steady-state.

BACKGROUND: Three-dimensional (3D) contrast-enhanced magnetic resonance angiography (CEMRA) is routinely used for vascular evaluation. With existing techniques for CEMRA, diagnostic image quality is only obtained during the first pass of the contrast agent or shortly thereafter, whereas angiographic quality tends to be poor when imaging is delayed to the equilibrium phase. We hypothesized that prolonged blood pool contrast enhancement could be obtained by imaging with a balanced T1 relaxation-enhanced steady-state (bT1RESS) pulse sequence, which combines 3D balanced steady-state free precession (bSSFP) with a saturation recovery magnetization preparation to impart T1 weighting and suppress background tissues. An electrocardiographic-gated, two-dimensional-accelerated version with isotropic 1.1-mm spatial resolution was evaluated for breath-hold equilibrium phase CEMRA of the thoracic aorta and heart. METHODS: The study was approved by the institutional review board. Twenty-one subjects were imaged using unenhanced 3D bSSFP, time-resolved CEMRA, first-pass gated CEMRA, followed by early and late equilibrium phase gated CEMRA and bT1RESS. Nine additional subjects were imaged using equilibrium phase 3D bSSFP and bT1RESS. Images were evaluated for image quality, aortic root sharpness, and visualization of the coronary artery origins, as well as using standard quantitative measures. RESULTS: Equilibrium phase bT1RESS provided better image quality, aortic root sharpness, and coronary artery origin visualization than gated CEMRA (P < 0.05), and improved image quality and aortic root sharpness versus unenhanced 3D bSSFP (P < 0.05). It provided significantly larger apparent signal-to-noise and apparent contrast-to-noise ratio values than gated CEMRA and unenhanced 3D bSSFP (P < 0.05) and provided ninefold better fluid suppression than equilibrium phase 3D bSSFP. Aortic diameter and main pulmonary artery diameter measurements obtained with bT1RESS and first-pass gated CEMRA strongly correlated (P < 0.05). CONCLUSIONS: We found that using bT1RESS greatly prolongs the useful duration of blood pool contrast enhancement while improving angiographic image quality compared with standard CEMRA techniques. Although further study is needed, potential advantages for vascular imaging include eliminating the current requirement for first-pass imaging along with better reliability and accuracy for a wide range of cardiovascular applications.

Quantitative Time-of-Flight Head Magnetic Resonance Angiography of Cerebrovascular Disease.

BACKGROUND: Standard Cartesian time-of-flight (TOF) head magnetic resonance angiography (MRA) is routinely used to evaluate the intracranial arteries, but does not provide quantitative hemodynamic information that is useful for patient risk stratification as well as for monitoring treatment and tracking changes in blood flow over time. Quantitative TOF (qTOF) MRA represents a new and efficient method for simultaneous evaluating the intracranial arteries and quantifying blood flow velocity, but it has not yet been evaluated in patients with cerebrovascular disease. PURPOSE: To evaluate qTOF for simultaneously evaluating the intracranial arteries and quantifying intracranial blood flow velocity in patients with cerebrovascular disease, without the need for a phase contrast (PC) scan. STUDY TYPE: Prospective. SUBJECTS: Twenty-four patients (18 female, 6 male) with cerebrovascular disease. FIELD STRENGTH/SEQUENCES: Head MRA at 3 T using gradient-echo 3D qTOF, standard Cartesian TOF, and PC protocols. ASSESSMENT: Three independent readers assessed arterial image quality using a 4-point scale (1: non-diagnostic, 4: excellent) and artifact presence. Total and component flow velocities obtained with qTOF and PC were measured. STATISTICAL TESTS: Wilcoxon signed-rank tests, Gwet's AC2, intraclass correlation coefficients (ICC) for absolute agreement, Bland-Altman analyses, tests of equal proportions. P values <0.05 were considered statistically significant. RESULTS: Averaged across readers and compared to standard Cartesian TOF, qTOF significantly improved overall arterial image quality (3.8 ± 0.2 vs. 3.6 ± 0.5), image quality at locations of pathology (3.7 ± 0.5 vs. 3.4 ± 0.7), and increased the proportion of evaluations rated without artifacts (63.9% [46/72] vs. 37.5% [27/72]). qTOF significantly agreed with PC for total flow velocity (ICC = 0.71) and component flow velocity (ICC = 0.89). DATA CONCLUSION: qTOF angiography of the head matched or improved upon the image quality of standard Cartesian TOF, reduced image artifacts, and provided quantitative hemodynamic data, without the need for a PC scan. EVIDENCE LEVEL: 2 TECHNICAL EFFICACY: Stage 2.

Elderly-onset pulmonary sarcoidosis: A radiological approach to diagnosis.

BACKGROUND AND AIM: The aim was to compare the radiological and clinical characteristics of sarcoidosis between elderly and non-elderly patients. METHODS: This retrospective observational study was carried out in patients with sarcoidosis. Elderly-onset sarcoidosis was defined as sarcoidosis diagnosed in patients ≥65 years-old. Patients were stratified by age (≥65 years versus <65 years) and radiological and clinical data were compared between age groups. RESULTS: Of the 163 patients, 38 (23.3%) were in the elderly group and 125 (76.7%) were in the non-elderly group. Elderly patients more frequently demonstrated arthralgia (50% vs. 12.8%, p<0.001), coronary artery disease  (15.8% vs. 2.4%, p=0.005), congestive heart failure (13.2% vs. 0.8%, p=0.003), pneumonia (7.9% vs. 0.8%, p=0.04), and pleural fluid (18.4% vs. 0.0%, p<0.001). Clinical remission was significantly more likely in younger patients than in the elderly (76.8% vs. 55.3%, p=0.01). The clinical course to chronic-progressive disease was similar in both groups (p=0.635). Radiologically, lymph nodes measuring 10-25 mm in the short axis (89.5% vs. 72.6%, p=0.032), usual interstitial pneumonia pattern (10.5% vs. 0.8%, p=0.011), and main pulmonary artery diameter above 30 mm (34.2% vs. 16.0%, p=0.014) were significantly more frequent in the elderly group. Elderly patients tended to demonstrate Scadding stage I and II sarcoidosis (39.5% and 31.6%). CONCLUSIONS: Presentation of elderly-onset sarcoidosis appears to differ from young-onset sarcoidosis. Radiologically, lymph node enlargement and the pattern of fibrosis may be distinctive.

Evaluation of MR-Tractography Findings in Hemifacial Spasm Patients Injected with Botulinum Neurotoxin.

Background and Introduction: Botulinum neurotoxin (BoNT) is a potent biological toxin extracted from Clostridium Botulinum bacteria. BoNT injection is mainly used for medical purposes; it is frequently used for cosmetic purposes as well. The hypothesis that frequent application of this treatment modality may also affect the central nervous system constitutes the subject of our study. Objective: We aimed to demonstrate the possible central effects of BoNT in hemifacial spasm patients. Methods and Materials: Diffusion tensor imaging was used for this study. Patients were divided into two groups, and the measured values for each determined bilateral neuroanatomic region were compared within the relevant group. Results: Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values were found to be closer to the pathological values in the right motor cortex and in the left internal capsule areas of the patients who were injected with BoNT into the left side, in the left motor cortex area of the patients who were injected with BoNT into the right side. No significant changes were detected in other regions. Conclusion: Botulinum neurotoxin administration in patients with hemifacial spasms may cause some changes in the central nervous system as well as peripheral effects. In the case of similar studies supporting pathological changes, BoNT treatment modalities or appropriate indications may be reviewed, and regulation on excessive cosmetic use may be in question.

A brief case series of radiation associated myelopathy.

Radiation myelopathy (RM) is a rare but serious complication of radiotherapy. Small vessel ischemia and demyelination are some of the more remarkable indications of RM's pathophysiology. The RM is a diagnosis of exclusion. In the differential diagnosis, infectious causes, tumors, rheumatic diseases, and paraneoplastic syndromes are the main diseases that should be excluded. Contrast-enhanced magnetic resonance imaging (MRI) is a useful method for diagnosis. We present a report on 3 patients diagnosed with radiation myelitis. All the patients presented with late paraparasia and paresthesia. Despite high-dose steroids, hyperbaric oxygen, and physical therapy, there was no clinical improvement at the follow-up one year later.

White Matter Evaluation in Multiple Sclerosis Through Magnetic Resonance Kurtosis Imaging.

OBJECTIVES: To investigate diffusional changes in multiple sclerosis (MS) plaques and non-Gaussian behavior of water diffusion by using diffusional kurtosis imaging (DKI). METHODS: 31 MS patients and 21 controls underwent MRI on a 3T scanner. Mean kurtosis (MK) parametric maps were computed. Region of interest (ROI) was delineated as white matter (WM) in controls and MS plaques and WM in patients. RESULTS: There was no significance of WM kurtosis and skewness parameters among MS group and control group patients p=0.213 and p=0.390, respectively. In MS patients, kurtosis, skewness, maximum intensity, minimum intensity, and median intensity values of WM, Plaque 1, Plaque 2, and Plague 3 were significantly higher at p<0.0001 for all.  Conclusions: DKI may provide more extensive characterization of lesions and WM and may be a sensitive indicator of tissue damage and microstructural change in patients with MS in addition to conventional diffusional evaluations.

Visual Outcome of an Endoscopic Endonasal Transsphenoidal Approach in Pituitary Macroadenomas: Quantitative Assessment with Diffusion Tensor Imaging Early and Long-Term Results.

BACKGROUND: Postoperative visual recovery in patients with pituitary adenoma can be influenced by the duration of symptoms, age, and tumor volume. Diffusion tensor imaging (DTI) allows visualization of white matter structure along with quantitative information. The aims of our study were to predict the visual recovery process in the early and long-term periods and to define the parameters affecting the recovery course. METHODS: A total of 200 patients with pituitary macroadenomas underwent endoscopic transsphenoidal surgery between January 2009 and July 2016. DTI and visual analysis including visual acuity and visual field analyses were performed for these patients at 5 periods, which included 3 years of follow-up. The effects of age, duration of symptoms, and tumor volume on visual recovery were evaluated. RESULTS: Mean tumor volume was calculated as 8871 ± 2758 mm3 and mean symptom duration was 23.41 ± 3.72 weeks. Mean age of the patients was 43.8 ± 8.9 years in the full recovery group and 48.7 ± 15.1 years in the nonrecovery group. Visual field analysis results on a Humphrey visual chart showed a significant linear strong correlation with fractional anisotropy (FA) values and a reverse strong correlation with mean diffusivity (MD) values on DTI magnetic resonance. DTI FA and MD cutoff values for each group were respectively determined as 0.373 and 1386 (×10-6 mm2/second) for the preoperative period, 0.423 and 1383 (×10-6 mm2/second) for the initial period, 0.428 and 1265 (×10-6 mm2/second) for the early period, 0.432 and 1238 (×10-6 mm2/second) for the intermediate period, and 0.437 and 1198 (×10-6 mm2/second) for the late period. CONCLUSIONS: DTI can assess and predict visual recovery after endoscopic transsphenoidal surgery of patients with pituitary macroadenomas causing chiasmal compression. FA values lower than or MD values greater than the cutoff values of the specific period reflect poor prognosis. Tumor volume was found to be the featured parameter that affects visual recovery. The postoperative first year is the most prominent interval evaluating the prognosis of visual recovery.