Low Field MRI and Scaphoid Fracture

1995 ◽  
Vol 20 (4) ◽  
pp. 539-542 ◽  
Author(s):  
J. LEPISTÖ ◽  
K. MATTILA ◽  
S. NIEMINEN ◽  
B. SATTLER ◽  
M. KORMANO
Keyword(s):  
Signal Intensity ◽  
Wide Spectrum ◽  
Scaphoid Fracture ◽  
Mr Images ◽  
X Ray ◽  
Scaphoid Fractures ◽  
Low Field ◽  
Bone Bruises ◽  
Traumatic Lesions ◽  
Low Field Mri

18 consecutive patients suspected of and treated for an acute scaphoid fracture were examined by lowfield MRI. This showed 11 fractures while seven scaphoids were considered normal. T1 weighted images showed a fracture as an area of decreased signal intensity. Two radiologically obvious fractures produced normal MR images. These fractures proved to be the result of old trauma. A wide spectrum of additional traumatic lesions in the wrists, not detected by routine X-ray analysis, were also demonstrated. These included seven fragmented triangular fibrocartilages (TFC), torn scapho-lunate ligaments in four cases and one torn triquetro-lunate ligament. Bone bruises of other carpal bones and seven other carpal fractures were also detected. Low field MRI can be used to show scaphoid fractures and allows diagnosis of additional or simulating lesions.

Clinical Assessment of Scaphoid Injuries and the Detection of Fractures

1996 ◽  
Vol 21 (3) ◽  
pp. 341-343 ◽  
Author(s):  
R. Grover
Keyword(s):  
Soft Tissue ◽  
Clinical Assessment ◽  
Tissue Injury ◽  
Wrist Joint ◽  
Scaphoid Fracture ◽  
Soft Tissue Injury ◽  
X Rays ◽  
X Ray ◽  
Scaphoid Fractures ◽  
Prospective Comparison

Difficulty in interpreting X-rays following carpal injury emphasizes the importance of clinical assessment in diagnosing scaphoid fractures. The classical sign of tenderness in the anatomical snuffbox is not specific and leads to many unnecessary out-patient reviews. A prospective comparison was made between anatomical snuffbox, scaphoid tubercle and scaphoid compression tenderness as indicators of scaphoid fracture in 221 patients with suspected scaphoid injury. Swelling was determined by measuring the difference in circumference at the wrist joint to compare between fracture and soft tissue injury. Scaphoid compression tenderness was found to be the most accurate test with a sensitivity of 100% and a specificity of 80%. Swelling of the wrist joint was significantly greater when there was a fracture, compared to soft tissue injury alone, even when the initial X-ray was normal. This was independent of any physiological variation in circumference between dominant and non-dominant sides. Scaphoid compression tenderness is therefore suggested as the most accurate indicator of scaphoid fracture and marked swelling should raise suspicion even if the X-ray is normal.

scholarly journals Does the Low-Field MRI Appearance of Intraosseous STIR Hyperintensity in Equine Cadaver Limbs Change when Subjected to a Freeze-Thaw Process?

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 475
Author(s):  
Georgina C. A. Johnston ◽  
Benjamin J. Ahern ◽  
Solomon M. Woldeyohannes ◽  
Alex C. Young
Keyword(s):  
Signal Intensity ◽  
Statistical Significance ◽  
Metatarsal Bone ◽  
Advanced Imaging ◽  
Freeze Thaw ◽  
Low Field ◽  
Before And After ◽  
Imaging Research ◽  
Low Field Mri ◽  
Short Tau Inversion Recovery

Equine advanced imaging research involving racehorse fetlock pathology commonly uses cadaver limbs and a freeze-thaw process. The presence of short tau inversion recovery (STIR) signal intensity in the distal third metacarpal/metatarsal bone is of particular interest and may be clinically relevant in the diagnosis of horses at risk of fracture. However, little is known about the effect of the freeze-thaw process on the MRI appearance of STIR hyperintensity in these bones. This study compares the low-field MRI appearance of the distal third metacarpal/metatarsal bone from cadaver limbs of Thoroughbreds in race training before and after a freeze-thaw protocol. Blinded and unblinded comparisons were made using objective SNR values and subjective grading. Fifteen cadaver limbs with STIR hyperintensity in the distal third metacarpal/metatarsal bone were included. No overall clinical or statistical significance was detected in STIR signal intensity and distribution after freeze-thaw. Three limbs from one horse had individual changes in STIR hyperintensity that were hypothesized to be attributable to ante-mortem haemodynamic abnormalities caused by anaesthesia. These results indicate that the distribution and intensity of STIR hyperintensity in freeze-thawed cadaver fetlocks can be considered representative of the appearance of pathology in the recently euthanized horse. However, care should be taken with horse selection and handling of the cadaver limbs to ensure reliable appearance of STIR signal after freeze-thaw.

X-Ray Diagnosis of Acute Scaphoid Fractures

2006 ◽  
Vol 31 (1) ◽  
pp. 104-109 ◽  
Author(s):  
G. C. CHEUNG ◽  
C. J. LEVER ◽  
A. D. MORRIS
Keyword(s):  
Retrospective Review ◽  
Scaphoid Fracture ◽  
Initial Presentation ◽  
Alternative View ◽  
X Rays ◽  
X Ray ◽  
Scaphoid Fractures ◽  
Suspected Scaphoid Fracture

In a retrospective review of the radiographs taken for 113 acute scaphoid fractures, each view was assessed for the clarity of demonstration of the fracture. The X-rays on which diagnosis of fracture were made, were taken between 0 and 16 days after injury (mean, 2 days). Whenever a lateral, supinated oblique or elongated view was taken, the fracture was always seen clearly on an alternative view. We recommend the use of four views at initial presentation of suspected scaphoid fracture: PA and lateral to assess carpal alignment, with pronated oblique and ulnar deviated PA to detect the fracture.

A comparative study of the accuracy of ultrasound, X-ray CT and low field MRI in the demonstration of cervical and uterine malignancy

1989 ◽  
Vol 7 (6) ◽  
pp. 677-679 ◽  
Author(s):  
F.W. Smith ◽  
G.R. Cherryman ◽  
A.P. Bayliss ◽  
W.T. Fullerton ◽  
A.N.R. Law ◽  
...  
Keyword(s):  
Comparative Study ◽  
X Ray ◽  
Low Field ◽  
Low Field Mri

Scaphoid Fractures and Nonunions: A Comparison between Panoramic Radiography and Plain X-Rays

1998 ◽  
Vol 23 (3) ◽  
pp. 328-331 ◽  
Author(s):  
J. D. BERNÁ ◽  
F. ABALEDEJO ◽  
M. A. SANCHEZ-CAÑIZARES ◽  
G. CHAVARRIA ◽  
A. PARDO ◽  
...  
Keyword(s):  
Panoramic Radiography ◽  
Scaphoid Fracture ◽  
X Rays ◽  
X Ray ◽  
Scaphoid Fractures ◽  
Diagnostic Potential ◽  
Panoramic Images

This study describes the diagnostic potential of the panoramic X-ray technique in the evaluation of scaphoid fractures and nonunions. Fifty-eight symptomatic wrists were examined using both plain X-rays and the panoramic procedure. The panoramic images showed in detail the line of the scaphoid fracture and nonunion in detail; they revealed four scaphoid fractures and five nonunions that were not shown clearly with plain X-rays. The panoramic technique is a useful complement to plain X-rays for the investigation of scaphoid fractures and nonunions.

Myelographic and low-field magnetic resonance imaging findings in dogs with presumptive acute hydrated non-compressive nucleus pulposus extrusion

2017 ◽  
Vol 181 (22) ◽  
pp. 594-599 ◽  
Author(s):  
Carlos Ros ◽  
Cristian de la Fuente ◽  
Sergio Rodenas ◽  
Rosa Novellas ◽  
Judit Viu ◽  
...  
Keyword(s):  
Nucleus Pulposus ◽  
Lumbar Vertebra ◽  
Cord Compression ◽  
Type I ◽  
Mr Images ◽  
Disc Disease ◽  
Presumptive Diagnosis ◽  
Low Field ◽  
Mri Features ◽  
Low Field Mri

MRI is considered gold standard for the diagnosis of presumptive acute hydrated non-compressive nucleus pulposus extrusions (AHNCNPE). This retrospective study describes the myelographic findings in dogs with AHNCNPE diagnosed by low-field MRI and their association with neurological grade, need of surgical decompression and outcome. Forty-two myelographies (21 dogs with presumptive AHNCNPE, 21 dogs with Hansen type I disc disease herniation) were blindly evaluated. Site of herniation, compression pattern, ratio of length of the lesion to length of the second lumbar vertebra (LL:L2) and degree of spinal cord compression (SCC) were measured on the myelographies of dogs with presumptive AHNCNPE and were compared with the corresponding MRI features. Percentage of extruded volume of nucleus pulposus (VNP) was calculated on MR images. Myelographic interobserver agreement for presumptive diagnosis of AHNCNPE was almost perfect (κ=0.8). Accuracy of myelography to detect site of herniation was 80.9 per cent and to identify extradural compression was 57.1 per cent. Mean SCC was 5.8±2.6 per cent for myelography and 6.6±3 per cent for MRI. Mean LL:L2 ratio was 1.7±0.9 for myelography and 1.2±0.8 for MRI. Mean percentage of extruded VNP was 40±14 per cent, and it was positively associated with neurological grade.

Improved Contrast in Ultra-Low-Field MRI with Time-Dependent Bipolar Prepolarizing Fields: Theory and NMR Demonstrations

2013 ◽  
Vol 20 (3) ◽  
pp. 327-336 ◽  
Author(s):  
Jaakko O. Nieminen ◽  
Jens Voigt ◽  
Stefan Hartwig ◽  
Hans Jürgen Scheer ◽  
Martin Burghoff ◽  
...  
Keyword(s):  
Field Strength ◽  
Time Course ◽  
Signal Strength ◽  
Relaxation Rates ◽  
Resonance Imaging ◽  
New Approach ◽  
Spin Lattice ◽  
Low Field ◽  
Low Field Mri ◽  
Magnetic Resonance Imaging Mri

Abstract The spin-lattice (T1) relaxation rates of materials depend on the strength of the external magnetic field in which the relaxation occurs. This T1 dispersion has been suggested to offer a means to discriminate between healthy and cancerous tissue by performing magnetic resonance imaging (MRI) at low magnetic fields. In prepolarized ultra-low-field (ULF) MRI, spin precession is detected in fields of the order of 10-100 μT. To increase the signal strength, the sample is first magnetized with a relatively strong polarizing field. Typically, the polarizing field is kept constant during the polarization period. However, in ULF MRI, the polarizing-field strength can be easily varied to produce a desired time course. This paper describes how a novel variation of the polarizing-field strength and duration can optimize the contrast between two types of tissue having different T1 relaxation dispersions. In addition, NMR experiments showing that the principle works in practice are presented. The described procedure may become a key component for a promising new approach of MRI at ultra-low fields

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