Improved visualisation of cervix applicators for magnetic resonance-only-guided brachytherapy planning

2014 ◽  
Vol 13 (2) ◽  
pp. 159-165
Author(s):  
Gary P. Liney ◽  
Jenny E. Marsden ◽  
Carl J. Horsfield ◽  
Tom Murray ◽  
David J. Manton ◽  
...  
Keyword(s):  
Cervical Cancer ◽  
Magnetic Resonance ◽  
Soft Tissues ◽  
Spin Echo ◽  
Proton Density ◽  
Tissue Equivalent ◽  
Spin Echo Sequence ◽  
Otsu’S Method ◽  
Magnetic Resonance Imaging Mri ◽  
Dual Echo

AbstractObjectivesCurrent guidelines for image-guided cervical cancer brachytherapy planning recommend both computed tomography (CT) and magnetic resonance imaging (MRI) for adequate visualisation of the applicator and soft tissues, respectively. MRI-only planning would be ideal as it would save time within the patient pathway and avoid the concomitant CT exposures. However, applicator visualisation on MRI is usually achieved using fluid-filled fiducial marker tubes, which can be awkward to use and suffer from unwanted air bubble artefacts. Therefore, a new fiducial-free imaging technique was developed.MethodsA dual echo time (TE) turbo spin echo sequence was used, at 1·5 T, to provide both T2-weighted images (100 ms TE) for tissue visualisation and strongly proton density-weighted images (17 ms TE) for improved applicator visualisation. In-house software was used to automatically segment the applicator in the short TE images (using Otsu's method) and transfer the information to the long TE images to provide a single fused dataset.ResultsThe method was evaluated successfully using titanium applicators in three patient cases and using a plastic applicator in a tissue-equivalent gel phantom.ConclusionsThe dual-echo technique provides a simple and efficient method for improving the visualisation of brachytherapy applicators in cervical cancer MRI images without the need for marker tubes.

scholarly journals Magnetic resonance imaging of the normal dromedary camel tarsus

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Zakriya Ali Al Mohamad ◽  
Usama Hagag ◽  
Mohamed Gomaa Tawfiek ◽  
Ayman El Nahas
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Soft Tissues ◽  
Imaging Modality ◽  
Spin Echo ◽  
Proton Density ◽  
Dromedary Camel ◽  
Resonance Imaging ◽  
Lateral Collateral Ligaments ◽  
Magnetic Resonance Imaging Mri

Abstract Background Magnetic resonance imaging (MRI) is the most versatile and informative imaging modality for the diagnosis of locomotor injuries in many animal species; however, veterinary literature describing the MRI of the dromedary camel tarsus is lacking. Our purpose was to describe and compare the MRI images of twelve cadaveric tarsi, examined in a 1.5 Tesla MRI scanner, with their corresponding anatomical gross sections. Turbo spin-echo (TSE) T1-weighted (T1), T2-weighted (T2), proton density-weighted (PD), and short tau inversion recovery (STIR) sequences were obtained in 3 planes. Tarsi were sectioned in sagittal, dorsal, and transverse planes. MRI images from different sequences and planes were described and compared with the anatomical sections. Results The soft and osseous tissues of the dromedary camel tarsus could be clearly defined on MRI images and corresponded extensively with the gross anatomic sections. The obtained MRI images enabled comprehensive assessment of the anatomic relationships among the osseous and soft tissues of the camel tarsus. Several structure were evaluated that cannot be imaged using radiography or ultrasonography, including the transverse inter-tarsal ligaments, the talocalcaneal ligament, the short dorsal ligament, branches of the short medial and lateral collateral ligaments and the tarsometatarsal ligaments. Specific anatomical features regarding the dromedary camel tarsus were identified, including the fused second and third tarsal bone, an additional bundle of the short medial collateral ligament connecting the talus and metatarsus and the medial and lateral limbs of the long plantar ligament. Conclusions MRI images provided a thorough evaluation of the normal dromedary camel tarsus. Information provided in the current study is expected to serve as a basis for interpretation in clinical situations.

scholarly journals Magnetic resonance imaging of the normal dromedary camel tarsus

2021 ◽  
Author(s):  
Usama Hagag ◽  
Zakriya Ali Almohamad ◽  
Mohamed Gomaa Tawfiek ◽  
Ayman El Nahas
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Soft Tissues ◽  
Imaging Modality ◽  
Spin Echo ◽  
Proton Density ◽  
Dromedary Camel ◽  
Resonance Imaging ◽  
Lateral Collateral Ligaments ◽  
Magnetic Resonance Imaging Mri

Abstract Background: Magnetic resonance imaging (MRI) is the most versatile and informative imaging modality for the diagnosis of locomotor injuries in many animal species; however, veterinary literature describing the MRI of the dromedary camel tarsus is lacking. Our purpose was to describe and compare the MRI images of twelve cadaveric tarsi, examined in a 1.5 Tesla MRI scanner, with their corresponding anatomical gross sections. Turbo spin-echo (TSE) T1-weighted (T1), T2-weighted (T2), proton density-weighted (PD), and short tau inversion recovery (STIR) sequences were obtained in 3 planes. Tarsi were sectioned in sagittal, dorsal, and transverse planes. MRI images from different sequences and planes were described and compared with the anatomical sections.Results: The soft and osseous tissues of the dromedary camel tarsus could be clearly defined on MRI images and corresponded extensively with the gross anatomic sections. The obtained MRI images enabled comprehensive assessment of the anatomic relationships among the osseous and soft tissues of the camel tarsus. Several structure were evaluated that cannot be imaged using radiography or ultrasonography, including the transverse inter-tarsal ligaments, the talocalcaneal ligament, the short dorsal ligament, branches of the short medial and lateral collateral ligaments and the tarsometatarsal ligaments. Specific anatomical features regarding the dromedary camel tarsus were identified, including the fused second and third tarsal bone, an additional bundle of the short medial collateral ligament connecting the talus and metatarsus and the medial and lateral limbs of the long plantar ligament. Conclusions: MRI images provided a thorough evaluation of the normal dromedary camel tarsus. Information provided in the current study is expected to serve as a basis for interpretation in clinical situations.

3D magnetic resonance microscopy of a wounded beech branch

Holzforschung ◽  
2008 ◽  
Vol 62 (3) ◽  
Author(s):  
Primož Oven ◽  
Maks Merela ◽  
Urša Mikac ◽  
Igor Serša
Keyword(s):  
Magnetic Resonance ◽  
Moisture Content ◽  
Spin Echo ◽  
Beech Wood ◽  
Structural Response ◽  
Proton Density ◽  
Protective Mechanism ◽  
High Moisture Content ◽  
High Moisture ◽  
Magnetic Resonance Imaging Mri

Abstract The pruned part of a beech (Fagus sylvatica) branch was imaged by a 3D spin-echo magnetic resonance imaging (MRI) technique to visualize change in structure and water content in the tissues. Proton density-weighted MR images of intact tissues confirmed high moisture content (MC) associated with high MRI signal in the pith, xylem rays and earlywood vessels, as well as in the cambial zone with current annual xylem and phloem increment. MRI images derived from the 3D datasets showed a previously unreported moisture-related structural response of the beech branch to wounding. An extensive wound tissue with a high MRI signal at the wound edge was a conspicuous new structure clearly visualized by 3D MRI. MRI revealed that the xylem at the wound was dehydrated in a cone-shaped pattern extending approximately 4.5 mm deep into the branch. Dehydration was delimited from the underlying sound wood by a layer, corresponding to the reaction zone, of tissue with a high MRI signal and hence high moisture content. Moisture content of these reaction zones in beech determined by MRI were greater than in healthy wood by factors of 1.3–1.8. Accordingly, in the margins of wounded beech wood not only cell wall alterations can be observed, but also an intensive water accumulation, which is probably an integral part of the protective mechanism for the underlying sound wood.

scholarly journals Optimal detection of infratentorial lesions with a combined dual-echo MRI sequence: “PT2”

2016 ◽  
Vol 22 (10) ◽  
pp. 1367-1370 ◽  
Author(s):  
María I Gaitán ◽  
Paulina Yañes ◽  
Pascal Sati ◽  
Carlos Romero ◽  
Daniel S Reich ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Multiple Sclerosis ◽  
Magnetic Resonance ◽  
Image Quality ◽  
Proton Density ◽  
Optimal Detection ◽  
Resonance Imaging ◽  
Magnetic Resonance Imaging Mri ◽  
Dual Echo ◽  
Lesion Conspicuity

Background: The infratentorial compartment is cardinal for multiple sclerosis (MS) diagnosis. T2-weighted (T2) and proton density–weighted (PD) magnetic resonance imaging (MRI) can visualize infratentorial lesions, but only suboptimally. Objective: To combine PD and T2 for better lesion assessment. Methods: T2 and PD from 35 cases were averaged to form “PT2” images. Two raters counted infratentorial lesions and qualitatively assessed their conspicuity. Results: PT2 showed 244 infratentorial lesions, of which 94% and 74% were seen in PD and T2. PT2 received higher grades for image quality and lesion conspicuity ( p < 0.001 for all comparisons). Conclusion: PT2 could improve our ability to diagnose and monitor MS.

scholarly journals Tailored interactive sequences for continuous MR-image-guided freehand biopsies of different organs in an open system at 1.0 tesla (T) – Initial experience

2017 ◽  
Vol 62 (6) ◽  
pp. 557-563 ◽  
Author(s):  
Florian Streitparth ◽  
Christian Althoff ◽  
Martin Jonczyk ◽  
Felix Guettler ◽  
Martin Maurer ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Soft Tissue ◽  
Image Quality ◽  
Spin Echo ◽  
Lesion Size ◽  
Dynamic Imaging ◽  
Proton Density ◽  
Open Magnetic Resonance Imaging ◽  
Vertebral Disc ◽  
Magnetic Resonance Imaging Mri

AbstractObjectives:To assess the feasibility, image quality, and accuracy of freehand biopsies of liver, bone, muscle, vertebral disc, soft tissue, and other lesions using balanced steady-state free precession (SSFP, balanced fast field echo: bFFE), spoiled and nonspoiled gradient echo (FFE), and turbo spin echo (TSE) sequences for interactive continuous navigation in an open magnetic resonance imaging (MRI) system at 1.0 tesla (T).Methods:Twenty-six MR-guided biopsies (five liver, five bone, four muscle, four vertebral disc, one lung, one kidney, one suprarenal gland, and five soft or other tissue) were performed in 23 patients in a 1.0-T open magnetic resonance (MR) scanner (Panorama HFO, Philips Healthcare, Best, the Netherlands). A total of 42 samples were obtained. Depending on lesion size and location, 14–18-gauge MR-compatible biopsy sets with a length of 100 or 200 mm (Somatex Medical, Teltow, Germany), 14–18-gauge MR-compatible semiautomatic biopsy guns with a length of 100 or 150 mm (Invivo, Schwerin, Germany), or 11-gauge MR-compatible bone marrow biopsy needles with a length of 100 mm (Somatex Medical, Teltow, Germany) were employed.Results:All lesions were visible with continuous interactive imaging. Our initial results indicate that bFFE is particularly suitable for fast-moving organs (pulmonary, paracardial); moving organs are targeted better with T1-weighted (T1W) TSE, T1W FFE (liver) or T2-weighted (T2W) TSE (complicated cysts, adrenal glands), and static organs are successfully approached with proton density (PD) (spine) or T1W TSE (peripheral bones, musculoskeletal system). No adverse events related to the use of MRI were obtained. No complications occurred according to the Society of Interventional Radiology (SIR) clinical practice guidelines.Conclusion:Applying tailored interactive dynamic imaging sequences for continuous navigation to liver, bone, muscle, vertebral disc, soft tissue, and other lesions can improve the feasibility, image quality, and interventional accuracy of freehand MR-guided biopsies and may hence reduce the risk of complications.

Magnetic Resonance Imaging in the Diagnosis of Disruption of the Posterior Tibial Tendon

Foot & Ankle ◽  
1987 ◽  
Vol 8 (3) ◽  
pp. 144-147 ◽  
Author(s):  
Ian J. Alexander ◽  
Kenneth A. Johnson ◽  
Thomas H. Berquist
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Soft Tissues ◽  
Diagnostic Technique ◽  
Clinical Findings ◽  
The Body ◽  
Posterior Tibial Tendon ◽  
Resonance Imaging ◽  
Posterior Tibial ◽  
Magnetic Resonance Imaging Mri

Magnetic resonance imaging (MRI), a useful technique of studying soft tissues of the body, can be very effective in assessing the integrity of tendons. Usually a patient with a complete tear of the posterior tibial tendon has characteristic physical findings. In the patient presented, MRI demonstrated a complete disruption of the posterior tibial tendon, despite the absence of the commonly associated clinical findings. In view of the difficulties encountered with attempted tenography of the completely torn posterior tibial tendon, MRI provides a sensitive alternative diagnostic technique.

scholarly journals Magnetic resonance findings in amyotrophic lateral sclerosis using a spin echo magnetization transfer sequence: preliminary report

1999 ◽  
Vol 57 (4) ◽  
pp. 912-915 ◽  
Author(s):  
ANTÔNIO JOSÉ DA ROCHA ◽  
ANTONIO CARLOS MARTINS MAIA JUNIOR ◽  
ROBERTO GOMES NOGUEIRA ◽  
HENRIQUE MANOEL LEDERMAN
Keyword(s):  
Amyotrophic Lateral Sclerosis ◽  
Magnetic Resonance ◽  
Preliminary Report ◽  
Corticospinal Tract ◽  
Spin Echo ◽  
Magnetization Transfer ◽  
Control Group ◽  
Spin Echo Sequence ◽  
Lateral Sclerosis

We present the magnetic resonance (MR) findings of five patients with amyotrophic lateral sclerosis (ALS) using a spin-echo sequence with an additional magnetization transfer (MT) pulse on T1-weighted images (T1 SE/MT). These findings were absent in the control group and consisted of hyperintensity of the corticospinal tract. Moreover we discuss the principles and the use of this fast but simple MR technique in the diagnosis of ALS

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