Name: quantification of levator ani hiatus enlargement by magnetic resonance imaging in males and females with pelvic organ prolapse
Uploaded: 2019-04-17T13:00:00
Description: Watch this Scientific Journal Video about Quantification of Levator Ani Hiatus Enlargement by Magnetic Resonance Imaging in Males and Females with Pelvic Organ Prolapse at JoVE.com

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 p...

<ol>
	<li>DeLancey, J. O. L., Hurd, W. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Size+of+the+urogenital+hiatus+in+the+levator+ani+muscles+in+normal+women+and+women+with+pelvic+organ+prolapse.">Size of the urogenital hiatus in the levator ani muscles in normal women and women with pelvic organ prolapse.</a> Obstetrics &amp; Gynecology. 91 (3), 364-368 (1998).</li><li>Siproudhis, L., Ropert, A., Vilotte, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=How+accurate+is+clinical+examination+in+diagnosing+and+quantifying+pelvirectal+disorders?+A+prospective+study+in+a+group+of+50+patients+complaining+of+defecatory+difficulties.">How accurate is clinical examination in diagnosing and quantifying pelvirectal disorders? 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. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pelvic+floor+descent+in+women:+dynamic+evaluation+with+fast+MR+imaging+and+cinematic+display.">Pelvic floor descent in women: dynamic evaluation with fast MR imaging and cinematic display.</a> Radiology. 179 (1), 25-33 (1991).</li><li>Lienemann, A., Anthuber, C., Baron, A., Kohz, P., Reiser, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dynamic+MR+colpocystorectography+assessing+pelvic+floor+descent.">Dynamic MR colpocystorectography assessing pelvic floor descent.</a> European Radiology. 7 (8), 1309-1317 (1997).</li><li>Healy, J. C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Patterns+of+prolapse+in+women+with+symptoms+of+pelvic+floor+weakness:+assessment+with+MR+imaging.">Patterns of prolapse in women with symptoms of pelvic floor weakness: assessment with MR imaging.</a> Radiology. 203 (1), 77-81 (1997).</li><li>Comiter, C. V., Vasavada, S. P., Barbaric, Z. L., Gousse, A. E., Raz, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Grading+pelvic+prolapse+and+pelvic+floor+relaxation+using+dynamic+magnetic+resonance+imaging.">Grading pelvic prolapse and pelvic floor relaxation using dynamic magnetic resonance imaging.</a> Urology. 54 (3), 454-457 (1999).</li><li>Kelvin, F. M., Maglinte, D. D. T., 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=Female+pelvic+organ+prolapse:+a+comparison+of+triphasic+dynamic+MR+imaging+and+triphasic+fluoroscopic+cystocolpoproctography.">Female pelvic organ prolapse: a comparison of triphasic dynamic MR imaging and triphasic fluoroscopic cystocolpoproctography.</a> American Journal of Roentgenology. 174 (1), 81-88 (2000).</li><li>Pannu, H. K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dynamic+MR+imaging+of+pelvis+organ+prolapse:+spectrum+of+abnormalities.">Dynamic MR imaging of pelvis organ prolapse: spectrum of abnormalities.</a> RadioGraphics. 20 (6), 1567-1582 (2000).</li><li>Hoyte, L., Ratiu, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Linear+measurements+in+2-dimen&#172;sional+pelvic+floor+imaging:+the+impact+of+slice+tilt+angles+on+measurement+reproducibility.">Linear measurements in 2-dimen&#172;sional pelvic floor imaging: the impact of slice tilt angles on measurement reproducibility.</a> American Journal of Obstetrics and Gynecology. 185 (3), 537-544 (2001).</li><li>Tunn, R., DeLancey, J. O. L., Quint, E. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Visibility+of+pelvic+organ+support+system+structures+in+magnetic+resonance+images+without+an+endovaginal+coil.">Visibility of pelvic organ support system structures in magnetic resonance images without an endovaginal coil.</a> American Journal of Obstetrics and Gynecology. 184 (6), 1156-1163 (2001).</li><li>Bump, R. C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+standardization+of+terminology+of+female+pelvic+organ+prolapse+and+pelvic+floor+dysfunction.">The standardization of terminology of female pelvic organ prolapse and pelvic floor dysfunction.</a> American Journal of Obstetrics and Gynecology. 175 (1), 10-17 (1996).</li><li>Haylen, B. T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+inter-national+Urogynecological+Association+(IUGA)+/+International+Continence+Society+(ICS)+Joint+Report+on+the+Terminology+for+Female+Pelvic+Floor+Dysfunction.">An inter-national Urogynecological Association (IUGA) / International Continence Society (ICS) Joint Report on the Terminology for Female Pelvic Floor Dysfunction.</a> Neurology and Urodynamics. 29 (1), 4-20 (2009).</li><li>Fielding, J. R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=MR+imaging+of+pelvic+floor+continence+mechanisms+in+the+supine+and+sitting+positions.">MR imaging of pelvic floor continence mechanisms in the supine and sitting positions.</a> American Journal of Roentgenology. 171 (6), 1607-1610 (1998).</li><li>Bertschinger, K. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dynamic+MR+imaging+of+the+pelvic+floor+performed+with+patient+sitting+in+an+open-magnet+unit+versus+with+patient+supine+in+a+closed-magnet+unit.">Dynamic MR imaging of the pelvic floor performed with patient sitting in an open-magnet unit versus with patient supine in a closed-magnet unit.</a> Radiology. 223 (2), 501-508 (2002).</li><li>Piloni, V., Ambroselli, V., Nestola, M., Piloni, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantification+of+levator+ani+(LA)+hiatus+enlargement+and+pelvic+organs+impingement+on+Valsalva+maneuver+in+parous+and+nulliparous+women+with+obstructed+defecation+syndrome+(ODS):+a+biomechanical+perspective.">Quantification of levator ani (LA) hiatus enlargement and pelvic organs impingement on Valsalva maneuver in parous and nulliparous women with obstructed defecation syndrome (ODS): a biomechanical perspective.</a> Pelviperineology. 35 (1), 25-31 (2016).</li><li>Piloni, V., Pierandrei, G., Pignalosa, F., Galli, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fusion+imaging+by+transperineal+sonography/magnetic+resonance+in+patients+with+fecal+blockade+syndrome.">Fusion imaging by transperineal sonography/magnetic resonance in patients with fecal blockade syndrome.</a> EC Gastroenterology and Digestive System. 5 (1), 11-16 (2018).</li><li>Piloni, V., Bergamasco, M., Melara, G., Garavello, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+clinical+value+of+magnetic+resonance+defecography+in+males+with+obstructed+defecation+syndrome.">The clinical value of magnetic resonance defecography in males with obstructed defecation syndrome.</a> Techniques in Coloproctology. 22 (3), 179-190 (2018).</li><li>Chanda, A., Unnikrishnan, V. U., Roy, S., Ricther, H. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Computational+modeling+of+the+female+pelvic+support+structures+and+organs+to+understand+the+mechanisms+of+pelvic+organ+prolapse:+a+review.">Computational modeling of the female pelvic support structures and organs to understand the mechanisms of pelvic organ prolapse: a review.</a> Applied Mechanics Reviews. 67 (4), 040801-040814 (2015).</li><li>Rostaminia, G., Abramowitch, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Finite+element+modeling+in+female+pelvic+floor+medicine:+a+literature+review.">Finite element modeling in female pelvic floor medicine: a literature review.</a> Current Obstetrics and Gynecology Reports. 4 (2), 125-131 (2015).</li></ol>

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...

Watch this Scientific Journal Video about Quantification of Levator Ani Hiatus Enlargement by Magnetic Resonance Imaging in Males and Females with Pelvic Organ Prolapse at JoVE.com

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 ...

This method of ours is simultaneous visualization of pelvic organ dissent and the impediment on the reg-i-tory under the effect of a intra-abdominal vector focus. I like, during a physical examination and the three deep perineal ultrasound. The images our required during pre-rectal emptying.And without the embarrassment due to the facility of the examiner. Demonstrating the procedure will be Giulia Melara, nurse. And Andrea Chiapperin and Mattia Bergamasco, technicians.Both from my laboratory. Before beginning the examination, place a trolley inside the diagnostic room, equipped with all the necessary instruments and supplies;including gloves, syringes, a catheter, lubricant jelly and acoustic. Help the patient fill in a form that provides information on their history, current symptoms, treatments and prior medical records, if any.After obtaining written consent, clearly explain the characteristics and purpose of the procedure including the performance of various examination maneuvers, such as squeezing, straining and rectal emptying, to the patient. Informing the patient of the, on average, 25 minute duration of the procedure and the need for the insertion of a small catheter into the anal canal for contrast administration. Ask the patient to empty their bladder.Then, ask the patient to wear an apron and direct the patient to the diagnostic room. Next, help the patient lay on the diagnostic table of the magnetic resonance scanner, in the left lateral position and gently insert the catheter into the rectum, for administration of the rectal contrast until the patient experiences a characteristic desire to evacuate. After rectal filling, help the patient turn to the supine position and adjust the absorbent pad beneath the buttocks.Then, wrap a surface phased array around the patient's pelvis for the image acquisition. When the patient is in position, acquire a localizer scout scan in the coronal, axial and sagittal planes in the magnetic resonance imaging or MRI Imager to mark the boundaries of the region of interest. Next, obtain three subsequent, dynamic series scans in the mid-sagittal plane, centered over the anal rectal junction, with the patient at rest and squeezing their anal sphincter for 10 seconds per strain.After the last anal rectal junction scan has been obtained, instruct the patient to begin the movement of rectal emptying;initiating the simultaneous acquisition of images over an entire 58-second cycle upon acoustic device indication of the evacuation. While the patient is expelling the residual rectal contrast, repeat the imaging sequence in coronal plane, before instructing the patient to perform a steady state Valsalva maneuver, without interruption for nine seconds. Using the sagittal images acquired during the rectal emptying, as a reference, select three horizontal planes in the axial plane to image the levator hiatus;first at the mid symphysis, second, tangent to the inferior border of the symphysis, and third, at the point of the maximal bulging of the anterior rectal wall.Acquire a horizontal, one-centimeter thick section in the axial plane, from each level, during the Valsalva maneuver. Leaving the patient at 30 to 60 second interval between subsequent maneuvers, to relax. Then acquire static, T2-weighted images with the patient at rest in the axial, sagittal and coronal planes, to provide a complete evaluation of the pelvic anatomy.To measure the position of the pelvic organs at rest and while straining, from the mid-sagittal dynamic MRI images and the analysis software, open the list of toolbar options, positioned at the top of the screen and hover over annotation tools. Click the arrow and select ruler to obtain a linear measurement in millimeters of the vertical distance of the bladder neck, uterine cervix, prostate base, sentinel vesicles and rectal floor, from two reference lines. To measure the hiatal and interior posterior and transverse diameter in millimeters;from the axial static and dynamic images, repeat the same linear measurements and calculate the distance from the pubic symphysis to the anterior margin of the pubo-rectalis sling.And the distance between the medial borders of the levator ani muscle. To measure the hiatal area when at rest and during maximum strain in square centimeters, select annotation tools and free region of interest to select a free-hand contour tracing technique. Then draw a border around the internal area of the the levator ani muscle and express the differences between the resting and straining measurements, as absolute values.And an increase in percentage from the symphysis pubis and the ischial tuberosities. Between 2012 and 2018, this protocol has been successfully adopted in three different diagnostic centers in Italy at an average cumulative rate of about 30 exams per month;using the same MRI scanner model and technical parameters. Although pelvic organ prolapse is more common in females, it also occurs in male patients.Regardless of sex, levator ani hiatus ballooning during straining has emerged as the most reliable index of the disease. And it's area can easily be quantified with axial dynamic MR pelvic imaging for disease screening, compared to the size of the hiatus when at rest. Interestingly, the actual enlargement of the hiatus when straining, cannot be predicted based on its size when at rest.As demonstrated in a previous study, in New-la Paris and Paris women, whose at rest values did not correlate with those during the Valsalva maneuver. It is important to tailor the examination for each individual. So as to obtain the maximum information from the vibration.Particularly in cases of chronic pelvic pain and sexual dysfunction. This protocol paves the way for future investigation and cor-ri-gation;with the pressure status and the rectal neuro-physilogical test. This pelvic organ displacement and there, dramatical deformities by MRI in a quantitative manner, will help investigating the mechanism by which pelvic organ prolapse develops.

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

Research

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Medicine

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, ...

Noninvasive Assessment of Cardiac Abnormalities in Experimental Autoimmune Myocarditis by Magnetic Resonance Microscopy Imaging in the Mouse

Myocarditis is an inflammation of the myocardium, but only ~10% of those affected show clinical manifestations of the disease. To study the immune events of myocardial injuries, various mouse models of myocarditis have been widely used. This study involved experimental autoimmune myocarditis (EAM) induced with cardiac myosin heavy chain (Myhc)-&#945; 334-352 in A/J mice; the affected animals develop lymphocytic myocarditis but with no apparent clinical signs. In this model, the utility of magnetic resonance microscopy (MRM) as a non-invasive modality to determine the cardiac structural and functional changes in animals immunized with Myhc-&#945; 334-352 is shown. EAM and healthy mice were imaged using a 9.4 T (400 MHz) 89 mm vertical core bore scanner equipped with a 4 cm millipede radio-frequency imaging probe and 100 G/cm triple axis gradients. Cardiac images were acquired from anesthetized animals using a gradient-echo-based cine pulse sequence, and the animals were monitored by respiration and pulse oximetry. The analysis revealed an increase in the thickness of the ventricular wall in EAM mice, with a corresponding decrease in the interior diameter of ventricles, when compared with healthy mice. The data suggest that morphological and functional changes in the inflamed hearts can be non-invasively monitored by MRM in live animals. In conclusion, MRM offers an advantage of assessing the progression and regression of myocardial injuries in diseases caused by infectious agents, as well as response to therapies.

This study demonstrates the successful establishment of magnetic resonance microscopy imaging as a non-invasive tool to assess the cardiac abnormalities in mice affected with autoimmune myocarditis. The data indicate that the technique can be used to monitor the disease-progression in live animals.

Myocarditis is an inflammation of the myocardium, but only ~10% of those affected show clinical manifestations of the disease. To study the immune events ...

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.