Biomedical subjects

A H Karantanas

Publications and source records attributed to A H Karantanas.

41 records · Page 3Linked to original sources

PubMedDate not supplied

Comparison of echo planar imaging, gradient echo and fast spin echo MR scans of knee menisci.

In order to reduce the acquisition time, we compared a three-dimensional multi-shot echo-planar imaging (EPI) sequence with fat-suppression with two widely used sequences, the fat-suppressed gradient echo (GRE) and the proton-density weighted turbo spin-echo (FSE) in imaging the menisci of the knee. Sixty patients with various indications were studied prospectively with MRI. The menisci were imaged in the sagittal plane with all three sequences using a 1T MR scanner with 15mT/m gradients. The signal-to-noise ratio (SNR) of bone (b), cartilage (c), and meniscus (m) as well as contrast-to-noise ratio (CNR) and relative contrast (ReCon) between menisci and cartilage and between bone and cartilage were measured. A qualitative analysis was performed on grading of meniscal pathology (0-IV). The imaging accuracy of meniscal pathology was assessed compared to arthroscopy in 13 patients. The EPI provided the highest SNR in cartilage and meniscus (p<0.001), the highest CNR and the highest ReCon between bone and cartilage (p< or =0.001). MR grading of meniscal abnormalities showed overestimation compared to GRE and FSE. The EPI sequence could not be included in the routine protocol in imaging the menisci since the overestimation of meniscal abnormalities could lead to unnecessary arthroscopy.

Adolescent↗

PubMedDate not supplied

MR imaging of intracranial epidermoid tumors: specific diagnosis with Turbo-FLAIR pulse sequence.

The purpose of this study is to present the imaging findings with particular reference to the FLAIR magnetic resonance (MR) pulse sequence, of four patients with epidermoid cysts. In all cases CT showed hypodense lesions with stippled peripheral calcifications and no enhancement. The MR showed low signal intensity lesions in T1-weighted images, high signal intensity in T2-weighted lesions, no or minor enhancement after gadolinium administration and characteristic heterogeneous appearance in FLAIR images. Including the FLAIR sequence in MR imaging, a specific diagnosis can be suggested.

Brain Neoplasms↗

PubMedDate not supplied

Maxillary sinus inflammatory disease: ultrasound compared to computed tomography.

Fifty-six patients (age range, 15-79 yr, average, 37.0+/-18.5 yr), with a clinical and/or radiological diagnosis of acute maxillary sinusitis, were prospectively studied with ultrasound (US) and computed tomography (CT). The imaging finding which supported the diagnosis of acute sinusitis with US was the identification of the hyperechoic posterior antral wall through the hypoechoic inflammation. The findings were compared to CT (3 mm axial sections). The sensitivity of US for maxillary sinus disease was found to be 66.7% and the specificity was 94.9%, which were similar to the plain film ones (65.2 and 96.8%, respectively). The results of the present study suggest US as the method of first choice for acute sinusitis of the maxillary antra, particularly for children and pregnant women.

Acute Disease↗

PubMedDate not supplied

Amyotrophic lateral sclerosis: unilateral T2-shortening on MRI.

Amyotrophic lateral sclerosis (ALS) can cause hyperintense lesions in the corticospinal tract but rarely can also cause T2 shortening in the motor cortex bilaterally. The present case of ALS showed unilateral T2 shortening of the superior parietal lobule without corticospinal tract changes.

Adult↗

PubMedDate not supplied

Single-shot turbo spin-echo MR myelography: comparison with 3D-turbo spin-echo MR myelography and T2-turbo spin-echo at 1 T.

In order to reduce the acquisition time, we compared the single-shot-TSE-MR myelography (MRm) and 3D-TSE-MRm. The T2-TSE sequence was the standard of reference. Fifty patients with low back pain, sciatica or cervical radiculopathy were examined at 1.0 T. The shortest AP diameter of the spinal canal, signal-to-noise ratio (SNR) for CSF and cord, contrast-to-noise ratio (CNR) and relative contrast (ReCon) between CSF and cord were calculated. No statistically significant difference was found between the three sequences with regard to the AP diameter of the spinal canal. A significant difference was found in: (i) SNRcord; (ii) SNRCSF; (iii) SS-TSE-MRm (showed the highest CNR) and (iv) SS-TSE-MRm (showed higher ReCon compared to 3D-TSE-MRm). In conclusion, SS-TSE-MRm can be used alternatively to 3D-TSE-MRm reducing the acquisition time down to only 8 s per image.

Adult↗