The authors are especially indebted to nurses Paola Garavello and Giulia Melara, for their valuable assistance during the examinations.

Procedures involving human subjects have been performed according to the National Guidelines of the Italian Radiological Society
1. Patient preparation
<ol>
	<li>Help patients to fill in a form which provides information on their history, current symptoms, treatments (either medical or surgical), and prior medical records, if any.</li>
	<li>Obtain each patient&#39;s written consent before beginning the examination.</li>
	<li>Clearly explain in advance the characteristics and purpose of the procedure, including the performance of various maneuvers such as squeezing, straining, and rectal emptying.</li>
	<li>Give information on the duration (average time: 25 min) of the procedure and the need for the insertion of a small catheter into the anal canal for contrast administration (acoustic gel).</li>
	<li>Ask the patients to empty their bladder in the toilet just before starting the examination. 
	NOTE: On the basis of the patients&#39; histories and presenting symptoms, tailor the procedure to each single case with regard to the amount of contrast administered and the number of scan planes and pulse sequences used.</li>
</ol>
2. Diagnostic room and facilities
<ol>
	<li>Keep a trolley inside the area of the diagnostic room, equipped with all necessary instruments and supplies, including gloves, syringes, a catheter, lubricant jelly, acoustic gel, etc. (see Table of Materials).</li>
</ol>
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/58534/58534fig1.jpg" /> 
Figure 1: Supplies. This picture shows (A) a trolley with supplies for the MR examination and (B) the dilution of acoustic gel with water (50/30 mL per syringe) in the area adjacent to the diagnostic room before the administration. <a href="https://jove.unicartagenaproxy.elogim.com/files/ftp_upload/58534/58534fig1large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<ol start="2">
	<li>Ask the patient to lay on the diagnostic table of the MR scanner in the left lateral position (Sims&#39; position). Gently insert the catheter into the rectum and administer the contrast administration (acoustic coupling gel) until the patient experiences a characteristic desire to evacuate (the average amount is 250 mL). Turn the patient in the supine position afterward.</li>
	<li>Adjust the absorbent pad beneath the buttocks, and wrap around the patient&#39;s pelvis a surface phased-array coil for the image acquisition. 
	NOTE: In case of anticipated sensation, urgency, discomfort, or involuntary leakage, interrupt the injection and register the total volume injected before the leakage, as well as the volume leaked.</li>
</ol>
3. Technique and image acquisition
<ol>
	<li>Acquire a localizer scout scan in the coronal, axial, and sagittal planes (TFE T1 pulse sequence, TR of 8 ms, TE of 5 ms, flip angle (FA) of 25&#176;, thickness of 15 mm, and the number of images: 5-11) to mark the boundaries of the region of interest (ROI).</li>
	<li>Then, obtain three subsequent dynamic series in the midsagittal plane (see Table 1, series 1: TR/TE of 2.7/1.3 ms; FA of 45&#176;) centered over the anorectal junction, with the patient at rest, squeezing his/her anal sphincter, and straining (10 s each).</li>
	<li>Thereafter, instruct the patient to start - at will - the movement of rectal emptying, and notice when it starts (by acoustic device) to allow the simulatenous acquisition of images over an entire time cycle of 58 s (see Table 1, series 1: TR/TE of 2.7/1.3 ms; FA of 45&#176;; thickness of 35 mm; acquisition time of 58 s). 
	NOTE: If necessary, repeat the series until obtaining an adequate stream of contrast.</li>
	<li>Repeat the latter sequence in the coronal plane (see Table 1, series 2: TR/TE of 2.8/1.3 ms; FA of 45&#176;; thickness of 35 mm; acquisition time of 58 s) while the patient is expelling the residual rectal contrast.</li>
	<li>Then, instruct the patient to perform a steady-state Valsalva maneuver without interruption for 9 s.</li>
	<li>Taking the sagittal images acquired during the rectal emptying as a reference, select three horizontal planes in the axial plane (see Figure 3) to image the levator hiatus as follows: the first at the midsymphysis (level I), the second tangent to the inferior border of the symphysis (level II), and the third at the point of the maximal bulging of the anterior rectal wall (level III). 
	NOTE: The reason for the above is to include most relevant anatomical areas inside and outside the hiatus boundaries of both sexes in the ROI: bladder base, urethra, vagina, cervix, perineal body, anorectal junction, endopelvic fascia, and fat recesses (female), or bladder base, retropubic space, prostate, seminal vesicles, Denonvilliers&#39; fascia, anorectal junction, mesorectal fascia, and presacral space (male).</li>
	<li>Acquire a horizontal 1 cm-thick section in the axial plane (see Table 1, series 3: TR/TE of 3/1.5 ms; FA of 45&#176;; thickness of 10 mm; acquisition time of 9 s) from each level during the Valsalva maneuver, leaving the patient a 60 s interval between two subsequent maneuvers to relax.</li>
	<li>Finally, acquire static T2-weighted images when at rest in the axial, sagittal, and coronal planes (see Table 1, series 4, 5, and 6: TR/TE of 3649-4656/100; FA of 90&#176;; thickness/gap of 4/0.4 mm; acquisition time of 3:00-3:44 min) to provide a complete evaluation of the pelvic anatomy. 
	NOTE: Refer to Table 1 for the technical settings.</li>
</ol>
<img alt="Table 1" src="/files/ftp_upload/58534/58534table1v2.jpg" /> 
Table 1: Technical settings for MR defecography, using a 1.5 T scanner and an external coil.
4. Image analysis and measurements
<ol>
	<li>To measure the position of the pelvic organs when at rest and while straining, from midsagittal dynamic MR images in the analysis software, go to the list of toolbar options positioned at the top of the screen and hover over Annotation Tools.</li>
	<li>Then, click on the arrow and select Ruler to obtain a linear measurement in millimeters of the vertical distance of the bladder neck, uterine cervix, prostate base, seminal vesicles, and rectal floor from two reference lines, as follows: express the distances by negative (proximal) or positive (distal) numbers relative to the hymen plane (female) or to a horizontal line drawn tangent to the inferior border of the symphysis pubis (male).</li>
</ol>
<img alt="Figure 2" class="xfigimg" src="/files/ftp_upload/58534/58534fig2.jpg" /> 
Figure 2: Reference lines for pelvic organ descent on midsagittal MR images. (A) A 61-year-old woman with a rectal descent of &#62;10 cm below the hymen plane (yellow line) and sigmoidocele. (B) A 42-year-old man with rectal intussusception and a descent of &#62;3 cm below the lower border of the symphysis pubis (yellow line). bl = bladder; sp = symphysis pubis; ut = uterus; r = rectum; p = prostate. <a href="https://jove.unicartagenaproxy.elogim.com/files/ftp_upload/58534/58534fig2large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<ol start="3">
	<li>To measure the hiatal anterior/posterior and transverse diameter (in millimeters) from the axial static and dynamic images, repeat the same selection of linear measurements described in steps 4.1-4.2 and calculate the distance from the pubic symphysis to the anterior margin of the puborectalis sling and the distance between the medial borders of the levator ani muscle.</li>
	<li>To measure the hiatal area (in square centimeters) when at rest and during maximum strain, click again on Annotation Tools and choose Free-ROI to select a free-hand contour-tracing technique (see Figure 3).</li>
	<li>Depict the internal area of the levator ani muscle and express the differences between resting and straining measurements as absolute values and an increase in percentage from sections of the same level identified by the recognition of bony landmarks, namely the symphysis pubis and the ischial tuberosities (level 2). 
	NOTE: Register any impingement of the organs within the levator ani hiatus and refer, for organ prolapse definition and grading, to the standards recommended by the international committee on pelvic organ prolapse14,15 and to the traditional &#34;HMO&#34; MRI classification system of pelvic organ prolapse described by Comiter&#160;et al.9.</li>
</ol>
<img alt="Figure 3" class="xfigimg" src="/files/ftp_upload/58534/58534fig3.jpg" /> 
Figure 3: Method for levator ani hiatus imaging and area measurement. (A) A selection of three axial scan sections from a midsagittal image taken relative to the midsymphysis pubis (level 1), tangent to its lower border (level 2), and at the maximal bulging of the anterior rectal wall (level 3) during rectal emptying. (B) An example of an asymmetric area measured when at rest from level 2 with the free-hand contour-tracing method in a 52-year-old woman with a focal defect of the right pubococcygeus muscle (arrow). s = symphysis pubis; bl = bladder; r = rectum.The left panel = a sagittal view;the right panel = a coronal view.The area values are expressed in square centimeters.1 = first level; 2 = second level; 3 = third level. <a href="https://jove.unicartagenaproxy.elogim.com/files/ftp_upload/58534/58534fig3large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>

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A prospective study in a group of 50 patients complaining of defecatory difficulties.</a> Diseases of the Colon &amp; Rectum. 36 (5), 430-438 (1993).</li><li>Maglinte, D. D. T., Kelvin, F. M., Fitzgerald, K., Hale, D. S., Benson, J. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Association+of+compartment+defects+in+pelvic+floor+dysfunction.">Association of compartment defects in pelvic floor dysfunction.</a> American Journal of Roentgenology. 172 (2), 439-444 (1999).</li><li>Dietz, H. P., Jarvis, S. K., Vancaillie, T. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+assessment+of+Levator+muscle+strength:+a+validation+of+three+ultrasound+techniques.">The assessment of Levator muscle strength: a validation of three ultrasound techniques.</a> International Urogynecology Journal and Pelvic Floor Dysfunction. 13 (3), 156-159 (2002).</li><li>Dietz, H. P., Shek, C., Clarcke, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biometry+of+the+pubovisceral+muscle+and+levator+hiatus+by+three-dimensional+pelvic+floor+ultrasound.">Biometry of the pubovisceral muscle and levator hiatus by three-dimensional pelvic floor ultrasound.</a> Obstetrics &amp; Gynecology. 25 (6), 580-585 (2005).</li><li>Yang, A., Mostwin, J. L., Rosenhein, N. B., Zerhouni, E. 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The authors have nothing to disclose.

This method has an overt advantage over pelvic examinations that are limited to the assessment of the urogenital hiatus in only females. In contrast, the method presented here examines the entire levator ani hiatus in both sexes. Moreover, although easily examined by palpation by the gynecologist, the female hiatus can be calculated only approximately with a ruler, to produce the area of an oval1. Similarly, an advantage does exist over 2- and 3-D TPUS4,<sup clas...

Pelvic organ prolapse (POP) develops when the forces acting inside the boundaries of levator ani hiatus are no longer counteracted by those outside, leading to abnormal enlargement and organ impingement. Several factors are responsible for the disease, including ligaments, fascia, or muscular tonic activity. Whatever the mechanism involved, the increased hiatus size has been credited with a reliable index to assess the inability to keep it closed. Usually, the status of pelvic support is determined in women during a pelvic examination1 by observing the location of the cervix, vaginal apex, and vaginal walls during the Valsalva maneuver. However, the inaccuracy of the method, combined with a failure to identify all involved sites2,3 and sex-related constrictions (female only), has led clinicians and researchers to seek alternative methods, namely diagnostic imaging.
Current methods for determining hiatus size include transperineal ultrasonography (TPUS)4,5 and, more recently, magnetic resonance imaging (MRI). Unfortunately, existing methods of performing the examination and measurement of individual parameters vary greatly among researchers6,7,8,9,10,11,12,13, making a comparison of study results difficult. Moreover, significant differences still exist in the definition and terminology of the most common pelvic descent processes, as well as in the classification and quantification of the adopted systems14,15.
This study highlights the advantages of MRI over other methods and describes the technical details and diagnostic criteria for the quantification of POP in patients of both sexes. In particular, the description focuses on the quantification of pelvic organs descent and levator ani hiatus enlargement when straining, with the patient supine, to demonstrate that the lack of a vertically oriented MR system16,17 (i.e., gravity will not adversely affect the detection of various changes associated with POP).

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>MR scanner</td>
			<td>Philips Medical Systems, High Tech Campus&#160; 37, 5656 AE, Eindhoven, 
			The Netherlands</td>
			<td></td>
			<td>Description: 1.5 T horizontally oriented, Multiva model, SENSE XL Torso coil 
			Procedure: Position the patient in the left lateral decubitus on the diagnostic table with the coil warpped around the pelvis</td>
		</tr>
		<tr>
			<td>Catheter</td>
			<td>Convatek ltd, First avenue Deeside, Flintshire CH5 2NU 
			UK</td>
			<td></td>
			<td>Description: Sterile vaginal catheter, 16 ch,180 mm long, 3 mm wide 
			Procedure: Gently insert the lubricated tip inside the anal canal for contrast administration with patients in the left side position</td>
		</tr>
		<tr>
			<td>Holder</td>
			<td>Kartell Plastilab, Artiglas Srl, Via Carrara Padua, Italy</td>
			<td></td>
			<td>Description: Universal test-tube holder with multiple 13-mm holes 
			Procedure: Put 3 empty syringes vertically inside the holes with the outlet cone down</td>
		</tr>
		<tr>
			<td>Syringe</td>
			<td>Pikdare Srl, Via Saldarini Catelli 10 , 22070 Casnate con Bernate (Como) Italy</td>
			<td></td>
			<td>Description: Sterile, latex free,60 mL graduated transparent cylinder, catheter cone 
			Procedure: Fill with contrast, adjust the plunger and connect to the catheter</td>
		</tr>
		<tr>
			<td>Contrast</td>
			<td>Ceracarta SpA, Via Secondo Casadei 14 47122 Forl&#236; 
			Italy</td>
			<td></td>
			<td>Description: Eco supergel not irritant, water soluble, salt free 
			Procedure: Dilute the content of each syringe adding 30 mL of tap water to 50 mL of acustic gel</td>
		</tr>
		<tr>
			<td>Mixer device</td>
			<td>Kaltek Srl, Via del Progresso 2 Padua 
			Italy</td>
			<td></td>
			<td>Description: Kito-Brush for endovaginal sampling 
			Procedure: Rotate one full turn 10-20 times until obtaining an homogeneous gel</td>
		</tr>
		<tr>
			<td>Pad</td>
			<td>Fater SpA, Via A. Volta 10, 65129 Pescara 
			Italy</td>
			<td></td>
			<td>Description: Pad for incontinent subjects 
			Procedure: Wrap around patient&#39;s pelvis to collect any material and prevent diagnostic table contamination</td>
		</tr>
		<tr>
			<td>Lubricant</td>
			<td>Molteni farmaceutici, Localit&#224; Granatieri Scandicci (Florence) 
			Italy</td>
			<td></td>
			<td>Description: Luan gel 1% 
			Procedure: Apply on the tip of catheter before insertion</td>
		</tr>
		<tr>
			<td>Apron</td>
			<td>Mediberg Srl, via Vezze 16/18 Calcinate 24050 (Bergamo) 
			Italy</td>
			<td></td>
			<td>Description: Kimono 
			Procedure: Put on counteriwise (opening back) to maintain patient&#39;s dignity</td>
		</tr>
		<tr>
			<td>Gloves</td>
			<td>Gardening Srl, Via B. Bosco 15/10 16121 Genova 
			Italy</td>
			<td></td>
			<td>Description: Nitrile, latex free, no talcum powdered 
			Procedure: Wear during contrast preparation and catheter insertion; change regularly to prevent cross contamination</td>
		</tr>
	</tbody>
</table>

quantification of levator ani hiatus enlargement by magnetic resonance imaging in males and females with pelvic organ prolapse

Here we present a protocol to examine the levator ani hiatus in males and females with pelvic organ prolapse, during the Valsalva maneuver and while evacuating acoustic gel, using a horizontally oriented 1.5 T magnetic resonance (MR) scanner. On midsagittal images, the vertical distance of pelvic organs is measured in millimeters relative to the hymen plane (female) and to the lower border of the symphysis pubis (male), preceded by - (above) or + ( below) signs. On axial images, the levator ani area is calculated in square centimeters with a free-hand tracing method from three key images, passing through the midsymphysis (level I), tangential to the lower border of the symphysis (level II), and at the maximal anterior rectal wall bulging (level III). Areas at rest and strained are compared to find evidence of a percentage of increase. The purpose is to provide objective evidence of the maximal extent of pelvic organs descent and hiatus enlargement without the interference of foreign objects or the examiner&#39;s proximity, so as to overcome the limitations of pelvic examination and transperineal sonography (i.e., subjectivity and sex-related limitations [female only]).

Between 2012 and 2018, this protocol has been successfully adopted in three different diagnostic centers in Italy at an average cumulative rate of 30 &#177; 4 exams per month, using the same 1.5 T MR scanner model and technical settings (see Table 1 and Table of Materials). During this period, over 2,000 examinations have been performed in patients of both sexes for the following three main disease categories: pelvic organ prolapse and evacuation disturba...

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Quantification of Levator Ani Hiatus Enlargement by Magnetic Resonance Imaging in Males and Females with Pelvic Organ Prolapse

Here we present a protocol to standardize the measurement of the levator ani hiatus size&#160;by magnetic resonance imaging. The purpose is to extract biomechanical inferences from image analysis by comparing resting and straining values in patients of both sexes with pelvic prolapse, using consistent anatomical bony landmarks.

Here we present a protocol to examine the levator ani hiatus in males and females with pelvic organ prolapse, during the Valsalva maneuver and while ...

quantification-levator-ani-hiatus-enlargement-magnetic-resonance

Universidad de Cartagena UDEC

Research

JoVE Journal

Medicine

9.3K Views.  Iniziativa Medica. Here we present a protocol to standardize the measurement of the levator ani hiatus size by magnetic resonance imaging. The purpose is to extract biomechanical inferences from image analysis by comparing resting and straining values in patients of both sexes with pelvic prolapse, using consistent anatomical bony landmarks.

Video: Quantification of Levator Ani Hiatus Enlargement by Magnetic Resonance Imaging in Males and Females with Pelvic Organ Prolapse

Magnetic Resonance Derived Myocardial Strain Assessment Using Feature Tracking

Purpose: An accurate and practical method to measure parameters like strain in myocardial tissue is of great clinical value, since it has been shown, that strain is a more sensitive and earlier marker for contractile dysfunction than the frequently used parameter EF. Current technologies for CMR are time consuming and difficult to implement in clinical practice. Feature tracking is a technology that can lead to more automization and robustness of quantitative analysis of medical images with less time consumption than comparable methods.
Methods: An automatic or manual input in a single phase serves as an initialization from which the system starts to track the displacement of individual patterns representing anatomical structures over time. The specialty of this method is that the images do not need to be manipulated in any way beforehand like e.g. tagging of CMR images.
Results: The method is very well suited for tracking muscular tissue and with this allowing quantitative elaboration of myocardium and also blood flow.
Conclusions: This new method offers a robust and time saving procedure to quantify myocardial tissue and blood with displacement, velocity and deformation parameters on regular sequences of CMR imaging. It therefore can be implemented in clinical practice.

An accurate and practical method to measure parameters like strain in myocardial tissue is of great clinical value, since it has been shown, that strain is a more sensitive and earlier marker for contractile dysfunction than the frequently used parameter EF.

Purpose: An accurate and practical method to measure parameters like strain in myocardial tissue is of great clinical value, since it has been shown, that ...

Magnetic Resonance Imaging Quantification of Pulmonary Perfusion using Calibrated Arterial Spin Labeling

This demonstrates a MR imaging method to measure the spatial distribution of pulmonary blood flow in healthy subjects 
during normoxia (inspired O2, fraction (FIO2) = 0.21) hypoxia (FIO2 = 0.125), and hyperoxia 
(FIO2 = 1.00). In addition, the physiological responses of the subject are monitored in the MR scan environment. MR images 
were obtained on a 1.5 T GE MRI scanner during a breath hold from a sagittal slice in the right lung at functional residual capacity. An arterial 
spin labeling sequence (ASL-FAIRER) was used to measure the spatial distribution of pulmonary blood flow 1,2 and a multi-echo fast 
gradient echo (mGRE) sequence 3 was used to quantify the regional proton (i.e. H2O) density, allowing the quantification 
of density-normalized perfusion for each voxel (milliliters blood per minute per gram lung tissue). 
With a pneumatic switching valve and facemask equipped with a 2-way non-rebreathing valve, different oxygen concentrations 
were introduced to the subject in the MR scanner through the inspired gas tubing. A metabolic cart collected expiratory gas via expiratory tubing. Mixed expiratory O2 and CO2 concentrations, oxygen consumption, carbon dioxide production, respiratory exchange ratio, 
respiratory frequency and tidal volume were measured. Heart rate and oxygen saturation were monitored using pulse-oximetry. 
Data obtained from a normal subject showed that, as expected, heart rate was higher in hypoxia (60 bpm) than during normoxia (51) or hyperoxia (50) and the arterial oxygen saturation (SpO2) was reduced during hypoxia to 86%. Mean ventilation was 8.31 L/min BTPS during hypoxia, 7.04 L/min during normoxia, and 6.64 L/min during hyperoxia. Tidal volume was 0.76 L during hypoxia, 0.69 L during normoxia, and 0.67 L during hyperoxia. 
Representative quantified ASL data showed that the mean density normalized perfusion was 8.86 ml/min/g during hypoxia, 8.26 ml/min/g during normoxia and 8.46 ml/min/g during hyperoxia, respectively. In this subject, the relative dispersion4, an index of global heterogeneity, was increased in hypoxia (1.07 during hypoxia, 0.85 during normoxia, and 0.87 during hyperoxia) while the fractal dimension (Ds), another index of heterogeneity reflecting vascular branching structure, was unchanged (1.24 during hypoxia, 1.26 during normoxia, and 1.26 during hyperoxia). 
Overview. This protocol will demonstrate the acquisition of data to measure the distribution of pulmonary perfusion noninvasively under conditions of normoxia, hypoxia, and hyperoxia using a magnetic resonance imaging technique known as arterial spin labeling (ASL). 
Rationale: Measurement of pulmonary blood flow and lung proton density using MR technique offers high spatial resolution images which can be quantified and the ability to perform repeated measurements under several different physiological conditions. In human studies, PET, SPECT, and CT are commonly used as the alternative techniques. However, these techniques involve exposure to ionizing radiation, and thus are not suitable for repeated measurements in human subjects.

A MR imaging method to study the distribution of pulmonary blood flow under a variety of physiological conditions, in this case exposure to three different inspired oxygen concentrations: hypoxia, normoxia, and hyperoxia, is described. This technique utilizes human pulmonary physiology research techniques in an MR scanning environment.

This demonstrates a MR imaging method to measure the spatial distribution of pulmonary blood flow in healthy subjects 
during normoxia (inspired O2, ...

Tracking the Mammary Architectural Features and Detecting Breast Cancer with Magnetic Resonance Diffusion Tensor Imaging

Breast cancer is the most common cause of cancer among women worldwide. Early detection of breast cancer has a critical role in improving the quality of life and survival of breast cancer patients. In this paper a new approach for the detection of breast cancer is described, based on tracking the mammary architectural elements using diffusion tensor imaging (DTI). 
The paper focuses on the scanning protocols and image processing algorithms and software that were designed to fit the diffusion properties of the mammary fibroglandular tissue and its changes during malignant transformation. The final output yields pixel by pixel vector maps that track the architecture of the entire mammary ductal glandular trees and parametric maps of the diffusion tensor coefficients and anisotropy indices. 
The efficiency of the method to detect breast cancer was tested by scanning women volunteers including 68 patients with breast cancer confirmed by histopathology findings. Regions with cancer cells exhibited a marked reduction in the diffusion coefficients and in the maximal anisotropy index as compared to the normal breast tissue, providing an intrinsic contrast for delineating the boundaries of malignant growth. Overall, the sensitivity of the DTI parameters to detect breast cancer was found to be high, particularly in dense breasts, and comparable to the current standard breast MRI method that requires injection of a contrast agent. Thus, this method offers a completely non-invasive, safe and sensitive tool for breast cancer detection.

We describe how to obtain parametric and vector maps of the diffusion tensor of the breast using magnetic resonance imaging. The protocol and final output following imaging processing are tailored for tracking breast architectural features and detecting breast malignancy.

Breast cancer is the most common cause of cancer among women worldwide. Early detection of breast cancer has a critical role in improving the quality of ...

Quantitative Magnetic Resonance Imaging of Skeletal Muscle Disease

Quantitative magnetic resonance imaging (qMRI) describes the development and use of MRI to quantify physical, chemical, and/or biological properties of living systems. Neuromuscular diseases often exhibit a temporally varying, spatially heterogeneous, and multi-faceted pathology. The goal of this protocol is to characterize this pathology using qMRI methods. The MRI acquisition protocol begins with localizer images (used to locate the position of the body and tissue of interest within the MRI system), quality control measurements of relevant magnetic field distributions, and structural imaging for general anatomical characterization. The qMRI portion of the protocol includes measurements of the longitudinal and transverse relaxation time constants (T1 and T2, respectively). Also acquired are diffusion-tensor MRI data, in which water diffusivity is measured and used to infer pathological processes such as edema. Quantitative magnetization transfer imaging is used to characterize the relative tissue content of macromolecular and free water protons. Lastly, fat-water MRI methods are used to characterize fibro-adipose tissue replacement of muscle. In addition to describing the data acquisition and analysis procedures, this paper also discusses the potential problems associated with these methods, the analysis and interpretation of the data, MRI safety, and strategies for artifact reduction and protocol optimization.

Neuromuscular diseases often exhibit a temporally varying, spatially heterogeneous, and multi-faceted pathology. The goal of this protocol is to characterize this pathology using non-invasive magnetic resonance imaging methods.

Quantitative magnetic resonance imaging (qMRI) describes the development and use of MRI to quantify physical, chemical, and/or biological properties of ...

Simultaneous PET/MRI Imaging During Mouse Cerebral Hypoxia-ischemia

Dynamic changes in tissue water diffusion and glucose metabolism occur during and after hypoxia in cerebral hypoxia-ischemia reflecting a bioenergetics disturbance in affected cells. Diffusion weighted magnetic resonance imaging (MRI) identifies regions that are damaged, potentially irreversibly, by hypoxia-ischemia. Alterations in glucose utilization in the affected tissue may be detectable by positron emission tomography (PET) imaging of 2-deoxy-2-(18F)fluoro-&#7429;-glucose ([18F]FDG) uptake. Due to the rapid and variable nature of injury in this animal model, acquisition of both modes of data must be performed simultaneously in order to meaningfully correlate PET and MRI data. In addition, inter-animal variability in the hypoxic-ischemic injury due to vascular differences limits the ability to analyze multi-modal data and observe changes to a group-wise approach if data is not acquired simultaneously in individual subjects. The method presented here allows one to acquire both diffusion-weighted MRI and [18F]FDG uptake data in the same animal before, during, and after the hypoxic challenge in order to interrogate immediate physiological changes.

The method presented here uses simultaneous positron emission tomography and magnetic resonance imaging. In the cerebral hypoxia-ischemia model, dynamic changes in diffusion and glucose metabolism occur during and after injury. The evolving and irreproducible damage in this model necessitates simultaneous acquisition if meaningful multi-modal imaging data are to be acquired.

Dynamic changes in tissue water diffusion and glucose metabolism occur during and after hypoxia in cerebral hypoxia-ischemia reflecting a bioenergetics ...

Cardiac Magnetic Resonance Imaging at 7 Tesla

CMR at an ultra-high field (magnetic field strength B0&#160;&#8805; 7 Tesla) benefits from the signal-to-noise ratio (SNR) advantage inherent at higher magnetic field strengths and potentially provides improved signal contrast and spatial resolution. While promising results have been achieved, ultra-high field CMR is challenging due to energy deposition constraints and physical phenomena such as transmission field non-uniformities and magnetic field inhomogeneities. In addition, the magneto-hydrodynamic effect renders the synchronization of the data acquisition with the cardiac motion difficult. The challenges are currently addressed by explorations into novel magnetic resonance technology. If all impediments can be overcome, ultra-high field CMR may generate new opportunities for functional CMR, myocardial tissue characterization, microstructure imaging or metabolic imaging. Recognizing this potential, we show that multi-channel radio frequency (RF) coil technology tailored for CMR at 7 Tesla together with higher order B0 shimming and a backup signal for cardiac triggering facilitates high fidelity functional CMR. With the proposed setup, cardiac chamber quantification can be accomplished in examination times similar to those achieved at lower field strengths. To share this experience and to support the dissemination of this expertise, this work describes our setup and protocol tailored for functional CMR at 7 Tesla.

The sensitivity gain inherent to ultrahigh field magnetic resonance holds promise for high spatial resolution imaging of the heart. Here, we describe a protocol customized for functional cardiovascular magnetic resonance (CMR) at 7 Tesla using an advanced multi-channel radio-frequency coil, magnetic field shimming and a triggering concept.

CMR at an ultra-high field (magnetic field strength B0&#160;&#8805; 7 Tesla) benefits from the signal-to-noise ratio (SNR) advantage inherent at higher ...

Phase Contrast Magnetic Resonance Imaging in the Rat Common Carotid Artery

Phase contrast magnetic resonance imaging (PC-MRI) is a noninvasive approach that can quantify flow-related parameters such as blood flow. Previous studies have shown that abnormal blood flow may be associated with systemic vascular risk. Thus, PC-MRI can facilitate the translation of data obtained from animal models of cardiovascular diseases to pertinent clinical investigations. In this report, we describe the procedure for measuring blood flow in the common carotid artery (CCA) of rats using cine-gated PC-MRI and discuss relevant analysis methods. This procedure can be performed in a live, anesthetized animal and does not require euthanasia after the procedure. The proposed scanning parameters yield repeatable measurements for blood flow, indicating excellent reproducibility of the results. The PC-MRI procedure described in this article can be used for pharmacological testing, pathophysiological assessment, and cerebral hemodynamics evaluation.

The overall goal of this procedure is to measure the blood flow in the rat common carotid artery by using noninvasive phase contrast magnetic resonance imaging.

Phase contrast magnetic resonance imaging (PC-MRI) is a noninvasive approach that can quantify flow-related parameters such as blood flow. Previous ...

Anogenital Distance and Perineal Measurements of the Pelvic Organ Prolapse (POP) Quantification System

Anogenital distance (AGD) is a sexually dimorphic attribute, twice longer in males than in females, and a marker of intrauterine hormonal environment. Interest in AGD measurements is increasing due to mounting evidence on their potential clinical implications. A parallel set of perineal measurements, the Pelvic Organ Prolapse Quantification System (POP-Q), include similar, but not exactly the same, landmarks: the perineal body (PB) and the genital hiatus (GH) lengths. However, clinical reproducibility of both perineal measurements and their usefulness to describe perineal anthropometry needs to be elucidated. To our knowledge, there is no publication in video format showing the methodology of these measurements. The main objective of this work is to show how to properly perform perineal anthropometry, including measurements of the AGD in its two variants [anoclitoral (AGDAC) and anofourchette (AGDAF)], genital hiatus (GH) and perineal body (PB). Moreover, we explored if there were differences in these measurements in women with and without Pelvic Organ Prolapse (POP). We research whether the anthropometric characteristics of the perineum, such as AGD (which is determined prenatally), may be altered in these women and be an independent etiological factor for pelvic floor dysfunction. We show two different ways of measuring perineal lengths, as they might be quite comparable. Our suggestion is that unifying perineal measurements could be useful for clinical and biomedical investigation. More studies are needed in order to compare GH and PB measurements and its AGD counterparts to analyze which procedures are more reproducible with less intra and interobserver variability.

Anogenital Distance and Perineal Measurements of the Pelvic Organ Prolapse POP Quantification System

This manuscript describes the procedures to perform anogenital distance (AGD) and perineal measurements standardized by the Pelvic Organ Prolapse Quantification System (POP-Q): perineal body (PB) and genital hiatus (GH). These measurements are compared in women with and without pelvic organ prolapse.

Anogenital distance (AGD) is a sexually dimorphic attribute, twice longer in males than in females, and a marker of intrauterine hormonal environment. ...

Human Fetal Blood Flow Quantification with Magnetic Resonance Imaging and Motion Compensation

Magnetic resonance imaging (MRI) is an important tool for the clinical assessment of cardiovascular morphology and heart function. It is also the recognized standard-of-care for blood flow quantification based on phase contrast MRI. While such measurement of blood flow has been possible in adults for decades, methods to extend this capability to fetal blood flow have only recently been developed.
Fetal blood flow quantification in major vessels is important for monitoring fetal pathologies such as congenital heart disease (CHD) and fetal growth restriction (FGR). CHD causes alterations in the cardiac structure and vasculature that change the course of blood in the fetus. In FGR, the path of blood flow is altered through the dilation of shunts such that the oxygenated blood supply to the brain is increased. Blood flow quantification enables assessment of the severity of the fetal pathology, which in turn allows for suitable&#160;in utero&#160;patient management and planning for postnatal care.
The primary challenges of applying phase contrast MRI to the human fetus include small blood vessel size, high fetal heart rate, potential MRI data corruption due to maternal respiration, unpredictable fetal movements, and lack of conventional cardiac gating methods to synchronize data acquisition. Here, we describe recent technical developments from our lab that have enabled the quantification of fetal blood flow using phase contrast MRI, including advances in accelerated imaging, motion compensation, and cardiac gating.

Here we present a protocol for measuring fetal blood flow rapidly with MRI and retrospectively performing motion correction and cardiac gating.

Magnetic resonance imaging (MRI) is an important tool for the clinical assessment of cardiovascular morphology and heart function. It is also the ...

Magnetic Resonance Imaging of Multiple Sclerosis at 7.0 Tesla

The overall goal of this article is to demonstrate a state-of-the-art ultrahigh field (UHF) magnetic resonance (MR) protocol of the brain at 7.0 Tesla in multiple sclerosis (MS) patients. MS is a chronic inflammatory, demyelinating, neurodegenerative disease that is characterized by white and gray matter lesions. Detection of spatially and temporally disseminated T2-hyperintense lesions by the use of MRI at 1.5 T and 3 T represents a crucial diagnostic tool in clinical practice to establish accurate diagnosis of MS based on the current version of the 2017 McDonald criteria. However, the differentiation of MS lesions from brain white matter lesions of other origins can sometimes be challenging due to their resembling morphology at lower magnetic field strengths (typically 3 T). Ultrahigh field MR (UHF-MR) benefits from increased signal-to-noise ratio and enhanced spatial resolution, both key to superior imaging for more accurate and definitive diagnoses of subtle lesions. Hence, MRI at 7.0 T has shown encouraging results to overcome the challenges of MS differential diagnosis by providing MS-specific neuroimaging markers (e.g., central vein sign, hypointense rim structures and differentiation of MS grey matter lesions). These markers and others can be identified by other MR contrasts other than T1 and T2 (T2*, phase, diffusion) and substantially improve the differentiation of MS lesions from those occurring in other neuroinflammatory conditions such as neuromyelitis optica and Susac syndrome. In this article, we describe our current technical approach to study cerebral white and grey matter lesions in MS patients at 7.0 T using different MR acquisition methods. The up-to-date protocol includes the preparation of the MR setup including the radio-frequency coils customized for UHF-MR, standardized screening, safety and interview procedures with MS patients, patient positioning in the MR scanner and acquisition of dedicated brain scans tailored for examining MS.

Here, we present a protocol to acquire magnetic resonance (MR) images of multiple sclerosis (MS) patient brains at 7.0 Tesla. The protocol includes preparation of the setup including the radio-frequency coils, standardized interview procedures with MS patients, subject positioning in the MR scanner and MR data acquisition.

The overall goal of this article is to demonstrate a state-of-the-art ultrahigh field (UHF) magnetic resonance (MR) protocol of the brain at 7.0 Tesla in ...