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.

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.

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 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.

scholarly journals Non-invasive diagnostics in fossils - Magnetic Resonance Imaging of pathological belemnites

2005 ◽  
Vol 2 (2) ◽  
pp. 133-140 ◽  
Author(s):  
D. Mietchen ◽  
H. Keupp ◽  
B. Manz ◽  
F. Volke
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Soft Tissue ◽  
Clinical Diagnostics ◽  
Resonance Imaging ◽  
Non Invasive ◽  
Physiological Processes ◽  
Magnetic Resonance Imaging Mri ◽  
Invasive Diagnostics

Abstract. For more than a decade, Magnetic Resonance Imaging (MRI) has been routinely employed in clinical diagnostics because it allows non-invasive studies of anatomical structures and physiological processes in vivo and to differentiate between healthy and pathological states, particularly of soft tissue. Here, we demonstrate that MRI can likewise be applied to fossilized biological samples and help in elucidating paleopathological and paleoecological questions: Five anomalous guards of Jurassic and Cretaceous belemnites are presented along with putative paleopathological diagnoses directly derived from 3D MR images with microscopic resolution. Syn vivo deformities of both the mineralized internal rostrum and the surrounding former soft tissue can be traced back in part to traumatic events of predator-prey-interactions, and partly to parasitism. Besides, evidence is presented that the frequently observed anomalous apical collar might be indicative of an inflammatory disease. These findings highlight the potential of Magnetic Resonance techniques for further paleontological applications.

Magnetic resonance imaging after frontal sinus surgery with fat obliteration

1995 ◽  
Vol 109 (11) ◽  
pp. 1115-1119 ◽  
Author(s):  
R. Keerl ◽  
R. Weber ◽  
G. Kahle ◽  
W. Draf ◽  
J. Constantinidis ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Connective Tissue ◽  
Frontal Sinus ◽  
Spin Echo ◽  
Sinus Surgery ◽  
Fast Spin Echo ◽  
Fatty Tissue ◽  
Resonance Imaging ◽  
Magnetic Resonance Imaging Mri

AbstractThe obliteration of the frontal sinus via an osteoplastic approach is performed with the aim of achieving a permanent ‘switching off’ by final and conclusive clearing out. For this, freshly harvested abdominal fat has shown itself to be the best clinically. It is possible to demonstrate the vitality of fat transplanted into the frontal sinus without an operation i.e. by a macroscopical and histological examination using magnetic resonance imaging (MRI). The magnetic resonance examinations were carried out on a supraconductive 0.5 T Magnet (Gyroscan T.S.II, Philips Medicine Systems, Eindhoven, Netherlands) with a quadrature (square) head spool. We produced T1-weighted spin echo images (TR: 450–550 ms; TE: 20–25 ms), T2-weighted fast spin echo images or in double-echo technique in transverse orientation (Turbo SE or TR: 2000–2500 ms; TE: 50–90 ms) and short tau inversion recovery (STIR) sequences for fat suppression (TJ: 140 ms; TR: 1400 ms; TE: 30 ms). The fat implanted into the frontal sinus of 11 patients aged 22–65 years, having undergone an osteoplastic frontal sinus operation with obliteration, was examined post-operatively by MRI. Objectives were the time-dependent distribution of portions of vital fatty or connective tissue, the eventual development of necroses or cysts as well as recurrences, inflammatory complications or re-epithelization of the frontal sinus four to 24 months postoperatively. In only six out of 11 cases was vital fatty tissue found. Fatty necrosis occurred five times, whereas in four cases a transformation into granulation tissue and in one case into connective tissue could be seen. All 11 patients were complaint-free. Long-term observations are needed to see if differences in the recurrence rate of frontal sinus disease are dependent on whether the implanted fat remains vital or necrosed and transformed.

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