scholarly journals Visualizing the autonomic and somatic innervation of the female pelvis with 3D MR neurography: a feasibility study

2020 ◽  
Vol 61 (12) ◽  
pp. 1668-1676
Author(s):  
Katja N De Paepe ◽  
David M Higgins ◽  
Iain Ball ◽  
Veronica A Morgan ◽  
Desmond P Barton ◽  
...  
Keyword(s):  
Spin Echo ◽  
Observer Agreement ◽  
Pelvic Nerve ◽  
High Quality ◽  
Mr Neurography ◽  
Pelvic Malignancies ◽  
Pelvic Nerves ◽  
Flow Compensation ◽  
Maximum Intensity Projections ◽  
Radiofrequency Pulse

Background Treatment of female pelvic malignancies often causes pelvic nerve damage. Magnetic resonance (MR) neurography mapping the female pelvic innervation could aid in treatment planning. Purpose To depict female autonomic and somatic pelvic innervation using a modified 3D NerveVIEW sequence. Material and Methods Prospective study in 20 female volunteers (n = 6 normal, n = 14 cervical pathology) who underwent a modified 3D short TI inversion recovery (STIR) turbo spin-echo (TSE) scan with a motion-sensitive driven equilibrium (MSDE) preparation radiofrequency pulse and flow compensation. Modifications included offset independent trapezoid (OIT) pulses for inversion and MSDE refocusing. Maximum intensity projections (MIP) were evaluated by two observers (Observer 1, Observer 2); image quality was scored as 2 = high, 1 = medium, or 0 = low with the sciatic nerve serving as a reference. Conspicuity of autonomic superior (SHP) and bilateral inferior hypogastric plexuses (IHP), hypogastric nerves, and somatic pelvic nerves (sciatic, pudendal) was scored as 2 = well-defined, 1 = poorly defined, or 0 = not seen, and inter-observer agreement was determined. Results Images were of medium to high quality according to both observers agreeing in 15/20 (75%) of individuals. SHP and bilateral hypogastric nerves were seen in 30/60 (50%) of cases by both observers. Bilateral IHP was seen in 85% (34/40) by Observer 1 and in 75% (30/40) by Observer 2. Sciatic nerves were well identified in all cases, while pudendal nerves were seen bilaterally by Observer 1 in 65% (26/40) and by Observer 2 in 72.5% (29/40). Agreement between observers for scoring nerve conspicuity was in the range of 60%–100%. Conclusion Modified 3D NerveVIEW renders high-quality images of the female autonomic and pudendal nerves.

Application of magnetic resonance neurography in the evaluation of patients with peripheral nerve pathology

1996 ◽  
Vol 85 (2) ◽  
pp. 299-309 ◽  
Author(s):  
Aaron G. Filler ◽  
Michel Kliot ◽  
Franklyn A. Howe ◽  
Cecil E. Hayes ◽  
Dawn E. Saunders ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Time Course ◽  
Spin Echo ◽  
Fast Spin Echo ◽  
Mr Neurography ◽  
Magnetic Resonance Neurography ◽  
Cross Sectional ◽  
Content Type ◽  
Direct Nerve ◽  
Fine Print

✓ Currently, diagnosis and management of disorders involving nerves are generally undertaken without images of the nerves themselves. The authors evaluated whether direct nerve images obtained using the new technique of magnetic resonance (MR) neurography could be used to make clinically important diagnostic distinctions that cannot be readily accomplished using existing methods. The authors obtained T2-weighted fast spin—echo fat-suppressed (chemical shift selection or inversion recovery) and T1-weighted images with planes parallel or transverse to the long axis of nerves using standard or phased-array coils in healthy volunteers and referred patients in 242 sessions. Longitudinal and cross-sectional fascicular images readily distinguished perineural from intraneural masses, thus predicting both resectability and requirement for intraoperative electrophysiological monitoring. Fascicle pattern and longitudinal anatomy firmly identified nerves and thus improved the safety of image-guided procedures. In severe trauma, MR neurography identified nerve discontinuity at the fascicular level preoperatively, thus verifying the need for surgical repair. Direct images readily demonstrated increased diameter in injured nerves and showed the linear extent and time course of image hyperintensity associated with nerve injury. These findings confirm and precisely localize focal nerve compressions, thus avoiding some exploratory surgery and allowing for smaller targeted exposures when surgery is indicated. Direct nerve imaging can demonstrate nerve continuity, distinguish intraneural from perineural masses, and localize nerve compressions prior to surgical exploration. Magnetic resonance neurography can add clinically useful diagnostic information in many situations in which physical examinations, electrodiagnostic tests, and existing image techniques are inconclusive.

scholarly journals Sympathetic afferents in the hypogastric nerve facilitate nociceptive bladder activity in cats

2019 ◽  
Vol 316 (4) ◽  
pp. F703-F711 ◽  
Author(s):  
Yan Zhang ◽  
Shun Li ◽  
Todd Yecies ◽  
Tara Morgan ◽  
Haotian Cai ◽  
...  
Keyword(s):  
Bladder Capacity ◽  
Saline Control ◽  
Pelvic Nerve ◽  
Analgesic Agent ◽  
Hypogastric Nerve ◽  
C Fibers ◽  
Pelvic Nerves ◽  
C Fiber ◽  
Bladder Activity

This study in α-chloralose-anesthetized cats revealed a role of hypogastric nerve afferent axons in nociceptive bladder activity induced by bladder irritation using 0.25% acetic acid (AA). In cats with intact hypogastric and pelvic nerves, AA irritation significantly ( P < 0.05) reduced bladder capacity to 45.0 ± 5.7% of the control capacity measured during a saline cystometrogram (CMG). In cats with the hypogastric nerves transected bilaterally, AA irritation also significantly ( P < 0.05) reduced bladder capacity, but the change was significantly smaller (capacity reduced to 71.5 ± 10.6% of saline control, P < 0.05) than that in cats with an intact hypogastric nerve. However, application of hypogastric nerve stimulation (HGNS: 20 Hz, 0.2 ms pulse width) to the central end of the transected nerves at an intensity (16 V) strong enough to activate C-fiber afferent axons facilitated the effect of AA irritation and further ( P < 0.05) reduced bladder capacity to 48.4 ± 7.4% of the saline control. This facilitation by HGNS was effective only at selected frequencies (1, 20, and 30 Hz) when the stimulation intensity was above the threshold for activating C-fibers. Tramadol (an analgesic agent) at 3 mg/kg iv completely blocked the nociceptive bladder activity and eliminated the facilitation by HGNS. HGNS did not alter non-nociceptive bladder activity induced by saline distention of the bladder. These results indicate that sympathetic afferents in the hypogastric nerve play an important role in the facilitation of the nociceptive bladder activity induced by bladder irritation that activates the silent C-fibers in the pelvic nerve.

Diagnosis of acetabular labral tears: Comparison of three-dimensional intermediate-weighted fast spin-echo MR arthrography with two-dimensional MR arthrography at 3.0 T

2013 ◽  
Vol 54 (1) ◽  
pp. 75-82 ◽  
Author(s):  
So Young Park ◽  
Ji Seon Park ◽  
Wook Jin ◽  
Kee Hyung Rhyu ◽  
Kyung Nam Ryu
Keyword(s):  
Spin Echo ◽  
Mr Arthrography ◽  
Three Dimensional ◽  
Observer Agreement ◽  
Fast Spin Echo ◽  
Two Dimensional ◽  
Observer Reliability ◽  
Labral Tears ◽  
Arthroscopic Findings ◽  
Fast Spin

Background Magnetic resonance (MR) arthrography is the ideal imaging modality for the acetabular labrum. Three-dimensional (3D) fast spin-echo (FSE) sequences have similar diagnostic performance as two-dimensional (2D) conventional MR imaging for ligaments, menisci, or bone marrow edema in the knee. Purpose To compare the diagnostic accuracy and inter-observer reliability of 3D intermediate-weighted FSE sequence and 2D FSE sequences for the diagnosis of acetabular labral tears. Material and Methods Institutional review board approval was obtained and informed consent was waived for 45 patients (47 hips) who underwent 3D and 2D MR arthrography and subsequent arthroscopic surgery. The 3D sequences were performed using volumetric intermediate-weighted fast spin-echo imaging with fat suppression (voxel size, 0.6 × 0.6 × 1.2 mm; imaging time, 6 min 38 s). Labral tear was retrospectively and independently evaluated by two radiologists in four areas of the labrum (anterosuperior, posterosuperior, anteroinferior, and posteroinferior) on 3D and 2D FSE sequences. Statistical differences between the sensitivity and specificity of the methods were analyzed with the McNemar test, using arthroscopic findings as the reference standard. Inter-observer agreement was calculated using kappa statistics. Results Arthroscopic findings confirmed labral tears at 40 anterosuperior, 23 posterosuperior, 0 anteroinferior, and 2 posteroinferior quadrants. Sensitivity and specificity were 74% and 89% for 2D FSE sequences, and 78% and 92% for 3D FSE sequences, respectively. Sensitivities and specificities for the methods were not different statistically (P > 0.05). Inter-observer agreement for labral tear was substantial for 2D FSE sequences (k = 0.774) and almost perfect for 3D FSE sequences (k = 0.842). Conclusion 3D intermediate-weighted FSE MR arthrography is excellent for diagnosing acetabular labral tears. Sensitivity, specificity, and inter-observer reliability were similar to conventional 2D MR arthrography. For evaluation of the labrum, 3D FSE MR arthrography is more time-efficient than 2D FSE MR arthrography.

scholarly journals Hyperfine spectroscopy in a quantum-limited spectrometer

2020 ◽  
Vol 1 (2) ◽  
pp. 315-330
Author(s):  
Sebastian Probst ◽  
Gengli Zhang ◽  
Miloš Rančić ◽  
Vishal Ranjan ◽  
Marianne Le Dantec ◽  
...  
Keyword(s):  
Hyperfine Coupling ◽  
Spin Echo ◽  
Electron Spin Echo ◽  
High Sensitivity ◽  
Quantitative Agreement ◽  
High Quality ◽  
Spin Concentration ◽  
Erbium Ions ◽  
Millikelvin Temperatures ◽  
Hyperfine Spectroscopy

Abstract. We report measurements of electron-spin-echo envelope modulation (ESEEM) performed at millikelvin temperatures in a custom-built high-sensitivity spectrometer based on superconducting micro-resonators. The high quality factor and small mode volume (down to 0.2 pL) of the resonator allow us to probe a small number of spins, down to 5×102. We measure two-pulse ESEEM on two systems: erbium ions coupled to 183W nuclei in a natural-abundance CaWO4 crystal and bismuth donors coupled to residual 29Si nuclei in a silicon substrate that was isotopically enriched in the 28Si isotope. We also measure three- and five-pulse ESEEM for the bismuth donors in silicon. Quantitative agreement is obtained for both the hyperfine coupling strength of proximal nuclei and the nuclear-spin concentration.

Synaptic inputs to morphologically identified myenteric neurons in guinea pig rectum from pelvic nerves

1997 ◽  
Vol 273 (1) ◽  
pp. G49-G55 ◽  
Author(s):  
K. Tamura
Keyword(s):  
Morphological Characteristics ◽  
Pelvic Nerve ◽  
Low Frequencies ◽  
Myenteric Neurons ◽  
Synaptic Inputs ◽  
Pelvic Nerves ◽  
Single Spike ◽  
Stimulation Of

Neurobiotin-filled microelectrodes were used to investigate electrical and synaptic behavior and morphological characteristics of rectal myenteric neurons that received synaptic inputs from the pelvic nerves. Stimulation of the pelvic nerve at low frequencies (< 3.3 Hz) evoked nicotinic fast excitatory postsynaptic potentials (fast EPSPs) in 45.3% of rectal neurons. Pelvic fast EPSPs were found in S/type 1, AH/type 2, type 3, or single-spike neurons that had a single long process preferentially projecting in the orad direction. Stimulation of the pelvic nerve at higher frequencies (5–20 Hz) elicited slow membrane excitation in 13.9% of the neurons. They were either AH/type 2 neurons with Dogiel II morphology or S/type 1 neurons with a single long process. Hexamethonium (100 microM) blocked pelvic fast EPSPs more quickly than those evoked by fiber tract stimulation but did not affect slow excitatory response. The results suggested the presence of more than one nicotinic-cholinergic synapse in the pelvic nerve pathway and the possible release of a noncholinergic excitatory substance from the afferent nerve terminals. It is possible that a subpopulation of rectal neurons, which receive a fast EPSP and have a single long process that projects in the orad direction, might be interneurons that mediate the defecation reflex.

scholarly journals Improving acute demyelinating lesion detection: which T1-weighted magnetic resonance acquisition is more sensitive to gadolinium enhancement?

2019 ◽  
Vol 77 (7) ◽  
pp. 485-492
Author(s):  
Lázaro Luiz Faria do AMARAL ◽  
Diego Cardoso FRAGOSO ◽  
Antonio José da ROCHA
Keyword(s):  
Single Dose ◽  
Magnetic Resonance ◽  
Spin Echo ◽  
Magnetization Transfer ◽  
Contrast Ratio ◽  
Accurate Method ◽  
Lesion Detection ◽  
Observer Agreement ◽  
Focal Lesions ◽  
Rapid Acquisition

ABSTRACT Because of the need for a standardized and accurate method for detecting multiple sclerosis (MS) inflammatory activity, different magnetic resonance (MR) acquisitions should be compared in order to choose the most sensitive sequence for clinical routine. Objective To compare the sensitivity of a T1-weighted image to a single dose of gadolinium (Gd) administration both with and without magnetization transfer to detect contrast enhancement in active demyelinating focal lesions. Methods A sample of relapsing-remitting MS patients were prospectively examined separately by two neuroradiologists using a 1.5 Tesla scanner. The outcome parameters were focused on Gd-enhancement detection attributed to acute demyelination. All MR examinations with at least one Gd-enhancing lesion were considered positive (MR+) and each lesion was analyzed according to its size and contrast ratio. Results Thirty-six MR examinations were analyzed with a high inter-observer agreement for MR+ detection (k coefficient > 0.8), which was excellent for the number of Gd-enhancing lesions (0.91 T1 spin-echo (SE), 0.88 T1 magnetization transfer contrast (MTC) sequence and 0.99 magnetization-prepared rapid acquisition with gradient-echo (MPRAGE). Significantly more MR+ were reported on the T1 MTC scans, followed by the T1 SE, and MPRAGE scans. Confidently, the T1 MTC sequence demonstrated higher accuracy in the detection of Gd-enhancing lesions, followed by the T1 SE and MPRAGE sequences. Further comparisons showed that there was a statistically significant increase in the contrast ratio and area of Gd-enhancement on the T1 MTC images when compared with both the SE and MPRAGE images. Conclusion Single-dose Gd T1 MTC sequence was confirmed to be the most sensitive acquisition for predicting inflammatory active lesions using a 1.5 T magnet in this sample of MS patients.

Functional differences between afferent fibers in the hypogastric and pelvic nerves innervating female reproductive organs in the rat

1993 ◽  
Vol 69 (2) ◽  
pp. 533-544 ◽  
Author(s):  
K. J. Berkley ◽  
A. Robbins ◽  
Y. Sato
Keyword(s):  
Spinal Cord ◽  
Dorsal Root ◽  
Reproductive Tract ◽  
Nerve Fibers ◽  
Pelvic Nerve ◽  
Hypogastric Nerve ◽  
Afferent Fibers ◽  
Pelvic Nerves ◽  
Different Parts ◽  
Stimulation Of

1. The uterus, cervix, and vaginal canal are innervated by afferent fibers in the hypogastric and pelvic nerves. Four studies compared the innervation territory and sensitivity to peripheral stimuli of the two sets of fibers in adult virgin rats. 2. Innervation territory was studied anatomically by injecting different fluorescent dyes into different parts of the reproductive, lower urinary, and lower digestive tracts and examining retrogradely labeled neurons in dorsal root ganglia. It was also studied electrophysiologically in anesthetized rats by summing potentials evoked in branches of the two nerves by electrical stimulation of different parts of the reproductive tract. 3. In both studies sensory innervation of the reproductive tract shifted from the pelvic to the hypogastric nerve (i.e., shifted entry into the spinal cord from the L6-S1 to the T13-L3 dorsal root ganglia, respectively) as the dye or stimulating electrode shifted from the vaginal entrance to the uterine horns, with fibers from both nerves densely innervating the cervix region (i.e., entering the spinal cord through both sets of ganglia). The anatomic results suggested that the regions innervated by fibers in one nerve might also be innervated by a small component of normally quiescent fibers in the other nerve. 4. Response sensitivity was studied electrophysiologically by simultaneously recording multiunit activity in branches of the hypogastric and pelvic nerves in two ways. First, in intact, anesthetized rats, activity was recorded during mechanical stimulation of the reproductive tract (distension of the vagina and uterus, probing the cervix). Second, in an in vitro organ preparation of the uterus and vagina, activity was recorded during chemical stimulation through the uterine artery with bradykinin, serotonin, NaCN, CO2, and KCl. 5. Pelvic nerve fibers were markedly more sensitive than hypogastric nerve fibers to uterine and cervical mechanostimulation. Similarly, pelvic nerve fibers were more likely to respond or responded more vigorously than hypogastric nerve fibers to all chemical stimuli (except KCl). 6. These results provide strong evidence that afferent fibers in the pelvic and hypogastric nerves of nulliparous adult rats subserve different functions in reproduction and sensation. Pelvic nerve fibers seem closely tied to sensory and behavioral processes associated with mating and conception, whereas hypogastric fibers seem closely tied to pregnancy and nociception, with fibers in both nerves serving functions during parturition.

Flow compensation for the fast spin echo triple-echo Dixon sequence

2011 ◽  
Vol 29 (2) ◽  
pp. 293-299 ◽  
Author(s):  
Kaining Shi ◽  
Russell Low ◽  
Ken-Pin Hwang ◽  
Shanglian Bao ◽  
Jingfei Ma
Keyword(s):  
Spin Echo ◽  
Fast Spin Echo ◽  
Flow Compensation ◽  
Fast Spin
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