scholarly journals A Suggestion of New Slice Thickness Mensuration Using Partial Volume Effect in Magnetic Resonance Imaging

2011 ◽  
Vol 67 (12) ◽  
pp. 1523-1532
Author(s):  
Tetsuya Kimura ◽  
Mitsuji Higashida ◽  
Yasuo Takatsu ◽  
Akio Ogura
Neurosurgery ◽  
2006 ◽  
Vol 59 (3) ◽  
pp. 614-620 ◽  
Author(s):  
Dirk Rasche ◽  
Bodo Kress ◽  
Christoph Stippich ◽  
Ernst Nennig ◽  
Klaus Sartor ◽  
...  

Abstract OBJECTIVE: Most so-called idiopathic trigeminal neuralgias (TN) are caused by neurovascular compression. Does the size of the cerebellopontine cistern play a role in favoring a neurovascular conflict? The aim of this prospective study was to measure the volume of the parapontine cistern in patients with idiopathic TN and to perform a comparison with healthy controls. METHODS: In 25 patients with unilateral idiopathic TN and 17 healthy participants, high-resolution 1.5-T magnetic resonance imaging scans of the parapontine region and the trigeminal nerve were performed. A coronal T2-weighted, true fast imaging steady-state precession sequence with a slice thickness of 0.9 mm was used to define the surrounding cerebrospinal fluid space from the trigeminal root entry zone to Meckel's cave. The volume of the pontomesencephalic cistern was calculated using a standardized method. RESULTS: The mean difference of the volume of the affected and opposite side was 13% in patients with TN. In all patients, a significantly smaller volume of the cistern was found on the affected side (P < 0.01). Healthy controls showed a mean volumetric side difference of 9%, which was not significant (P > 0.05). CONCLUSION: High-resolution magnetic resonance imaging scans are able to demonstrate significant volumetric differences of the pontomesencephalic cistern in patients with unilateral TN. A smaller cistern may be correlated with the occurrence of a neurovascular compression, and these findings support the neurovascular compression theory in idiopathic TN.


Author(s):  
Emil Knut Stenersen Espe ◽  
Bård Andre Bendiksen ◽  
Lili Zhang ◽  
Ivar Sjaastad

Background Magnetic resonance imaging (MRI) of the right ventricle (RV) offers important diagnostic information, but the accuracy of this information is hampered by the complex geometry of the RV. In this project, we propose a novel post-processing algorithm that corrects for partial-volume effects in the analysis of standard MRI cine images of RV mass (RVm), and evaluate the method in clinical and preclinical data. Methods Self-corrected RVm measurement was compared with conventionally measured RVm in 16 patients who showed different clinical indications for cardiac MRI, and in 17 Wistar rats with different degrees of pulmonary congestion. The rats were studied under isoflurane anaesthesia. To evaluate the reliability of the proposed method, the measured end-systolic and end-diastolic RVm were compared. Accuracy was evaluated by comparing preclinical RVm to ex-vivo RV weight (RVw). Results We found that use of the self-correcting algorithm improved reliability compared with conventional segmentation. For clinical data, the limits of agreement (LOAs) were -1.8±8.6g (self-correcting) vs. 5.8±7.8g (conventional) and coefficients of variation (CoVs) were 7.0% (self-correcting) vs. 14.3% (conventional). For preclinical data, LOAs were 21±45mg (self-correcting) vs. 64±89mg (conventional) and CoVs were 9.0% (self-correcting) and 17.4% (conventional). Self-corrected RVm also showed better correspondence with the ex vivo RVw: LOAs were -5±80mg (self-correcting) vs. 94±116mg (conventional) in end-diastole and -26±74mg (self-correcting) vs. 31±98mg (conventional) in end-systole. Conclusions The new self-correcting algorithm improves the reliability and accuracy of RVm measurements in both clinical and preclinical MRI. It is simple, easy to implement and does not require any additional MRI data.


2011 ◽  
Vol 14 (3) ◽  
pp. 501-505 ◽  
Author(s):  
Z. Adamiak ◽  
M. Jaskólska ◽  
H. Matyjasik ◽  
A. Pomianowski ◽  
M. Kwiatkowska

Magnetic resonance imaging of selected limb joints in dogs The presented paper presents updated information concerning magnetic resonance imaging (MRI) of shoulder joint, elbow joint and knee joint in dogs. It describes indications, planes, standard sequences, slice thickness to perform MRI examination of above mentioned joints. Besides general information about basic physics use in magnetic resonance imaging, and practical information about magnetic resonance and it usage in orthopedic examination are given.


2012 ◽  
Vol 2012 ◽  
pp. 1-4 ◽  
Author(s):  
Kanaga Kumari Chelliah ◽  
M. Z. Faizah ◽  
A. A. Dayang ◽  
A. A. Bilkis ◽  
I. Shareena ◽  
...  

Conjoined twins are rare and present a unique challenge to pediatric surgeons and radiologists. An imaging strategy to accurately define anatomic fusion, vascular anomalies, and other associated abnormalities is important for surgical planning and prognostic information. A conjoined female twin with a combined weight of 2.8 kg was born by emergency caeserean. Hence, a computed tomography scan of the thorax and entire abdomen at 1.25 mm slice thickness was performed to delineate the internal structures of the twins. CT-angiography defined specific vascular supply which determined the distribution of shared structures between the twins. An echocardiogram showed four heart chambers with atrioventricular septal defect. To further evaluate the heart chambers, the twin was planned for gated cardiac magnetic resonance imaging. Unfortunately, they succumbed 6 hours apart due to complication of septicemia. Magnetic resonance imaging and CT scan provide excellent anatomic detail, demonstrating organ position, shared viscera, and limited vascular anatomy, whilst angiography defined specific vascular supply, useful in determining the distribution of shared structures between the twins in planning for surgery.


2014 ◽  
Vol 42 (3) ◽  
pp. 801-811 ◽  
Author(s):  
Virginia Mato Abad ◽  
Alicia Quirós ◽  
Roberto García-Álvarez ◽  
Javier Pereira Loureiro ◽  
Juan Álvarez-Linera ◽  
...  

1998 ◽  
Vol 54 (8) ◽  
pp. 947-952 ◽  
Author(s):  
MITSUJI HIGASHIDA ◽  
MASARU YAMAZAKI ◽  
AKIO OGURA ◽  
HIROSHI INOUE ◽  
TAKAHARU HONGOU

2001 ◽  
Vol 7 (S2) ◽  
pp. 626-627
Author(s):  
M.W. Tengowski ◽  
L.W. Hedlund ◽  
D.J. Guyot ◽  
J.E. Burkhardt ◽  
G.A. Johnson

Non-invasive imaging technologies such as magnetic resonance imaging are commonly used in clinical practice. in an experimental setting, it is possible to decrease field of view and pixel size, thereby increase image resolution. We tested this magnetic resonance microscopy (MRM) technique in a theopln lline-induced rat model of reproductive toxicity. The goal of this work was to study the sensitivity of MRM to detect or predict changes in tissue proton (i.e. water) characteristics, and confirm those findings with histology.Male Sprague-Dawley rats were fed either a control or theophylline (1.3-dimethylxanthine. 8000 ppm) diet. Experimental groups of days 8. 16. 24. and 32 animals were imaged with MRM (Figure 1) and tissue morphology confirmed with histology (Figure 2).Tl-weighted images (with and without gadolinium-DTPA contrast. Magnevist®) and T2-weighted images were acquired at 2 T (spin-echo multislice images. 100 μm2 pixel. 300 μm slice thickness).


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