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Mri breast,indication,contra,prtocol,techniq,curves

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Information about Mri breast,indication,contra,prtocol,techniq,curves
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Published on March 14, 2014

Author: ProffQen

Source: slideshare.net

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MRI of the breastMRI of the breast Contraindications:Contraindications:  the usual contraindications to MRI, including thethe usual contraindications to MRI, including the presence of cardiac pacemakers, cochlear implants, andpresence of cardiac pacemakers, cochlear implants, and other metallic objects in the body,other metallic objects in the body,  women who are unable to lie prone to be positionedwomen who are unable to lie prone to be positioned within the breast coil,within the breast coil,  those with very large body habitus who cannot fit intothose with very large body habitus who cannot fit into the bore of the magnet orthe bore of the magnet or  whose breasts cannot be accommodated within thewhose breasts cannot be accommodated within the breast coil,breast coil,  those with extreme claustrophobia.those with extreme claustrophobia.

TimingTiming Normal breast parenchyma mayNormal breast parenchyma may enhance asymmetrically or in nodularenhance asymmetrically or in nodular pattern in premenopausal patternpattern in premenopausal pattern.. Scheduling of MR examination duringScheduling of MR examination during 7-20 days of menstrual cycle has been7-20 days of menstrual cycle has been useful because parenchymaluseful because parenchymal enhancement may be less intenseenhancement may be less intense during this timeduring this time..

MRI techniqueMRI technique  breast MRI should be performed usingbreast MRI should be performed using dedicated breast surface coilsdedicated breast surface coils..  Most of these are designed such that the patient liesMost of these are designed such that the patient lies prone with the breasts dependant within the coil.prone with the breasts dependant within the coil.  Most studies are based on examinations performedMost studies are based on examinations performed with 1 to 1.5 T magnetswith 1 to 1.5 T magnets  Some coils are equipped with the capability ofSome coils are equipped with the capability of applying compression to the breast .applying compression to the breast .

Imaging protocolImaging protocol  There is no standardization of breast MRI protocols.There is no standardization of breast MRI protocols.  Unilateral or bilateral imaging, 2D or 3D acquisition, and scanning in theUnilateral or bilateral imaging, 2D or 3D acquisition, and scanning in the sagittal, axial, or coronal planes can be performed with or withoutsagittal, axial, or coronal planes can be performed with or without compression.compression.  Bilateral scanningBilateral scanning allows both breasts to be evaluated in a single session andallows both breasts to be evaluated in a single session and also allows comparison of the enhancement patterns between the two breasts.also allows comparison of the enhancement patterns between the two breasts.  Sequences that are acquired in a short periodSequences that are acquired in a short period of time allow for theof time allow for the acquisition of several postcontrast scans before lesions are renderedacquisition of several postcontrast scans before lesions are rendered undetectable because of lesion washout or enhancement of surroundingundetectable because of lesion washout or enhancement of surrounding normal parenchyma, which occurs over time. Several postcontrast scansnormal parenchyma, which occurs over time. Several postcontrast scans allow for analysis of the enhancement kinetics of lesions.allow for analysis of the enhancement kinetics of lesions.  Sequences with longer acquisition timesSequences with longer acquisition times provide higher spatial resolution,provide higher spatial resolution, allowing for analysis of lesion morphology, but only a limited number ofallowing for analysis of lesion morphology, but only a limited number of useful postcontrast scans can be obtained and the kinetics of enhancementuseful postcontrast scans can be obtained and the kinetics of enhancement cannot be readily determined.cannot be readily determined.  In general,In general, 3D sequences with T1-weighting, high resolution, thin slice3D sequences with T1-weighting, high resolution, thin slice thickness, and no gapthickness, and no gap are preferred for optimum sensitivity.are preferred for optimum sensitivity.

 Acquiring images in the sagittal or axial plane moreAcquiring images in the sagittal or axial plane more closely reproduces the positioning of the mediolateralclosely reproduces the positioning of the mediolateral and craniocaudal mammographic views, respectively,and craniocaudal mammographic views, respectively, and may facilitate correlation between MRI andand may facilitate correlation between MRI and mammographic findings.mammographic findings.  Fat suppressionFat suppression is desirable to enable identification ofis desirable to enable identification of small enhancing lesions that might otherwise besmall enhancing lesions that might otherwise be obscured by surrounding fatty tissue.obscured by surrounding fatty tissue.  Subtraction techniquesSubtraction techniques can also be performed tocan also be performed to facilitate identification of enhancing foci but arefacilitate identification of enhancing foci but are potentially limited by patient motion betweenpotentially limited by patient motion between sequences.sequences.

Morphologic criteriaMorphologic criteria Enhancing lesions on breast MRI examinations should be evaluated byEnhancing lesions on breast MRI examinations should be evaluated by their:their:  distribution,distribution,  shape,shape,  margins,margins,  enhancement characteristics.enhancement characteristics. Morphologic features associated with malignancy on MRI examinationsMorphologic features associated with malignancy on MRI examinations are similar to those associated with malignancy on mammography.are similar to those associated with malignancy on mammography. This includesThis includes::  irregular shapeirregular shape  irregular or spiculated margins.irregular or spiculated margins.  rim enhancement,rim enhancement,  heterogeneous internal enhancement,heterogeneous internal enhancement,  ductal distribution.ductal distribution.

Enhancement criteriaEnhancement criteria  There are basically three types of enhancement curves associatedThere are basically three types of enhancement curves associated with breast lesions seen on MRI. These curves assess the initialwith breast lesions seen on MRI. These curves assess the initial slope of enhancement, occurring generally within the first 2slope of enhancement, occurring generally within the first 2 minutes after contrast administration, and later enhancementminutes after contrast administration, and later enhancement behavior.behavior.  The three types of curves :The three types of curves :  In the Type I (progressive) curve, enhancement continues toIn the Type I (progressive) curve, enhancement continues to increase with each postcontrast sequence.increase with each postcontrast sequence.  In the Type II (plateau) curve, enhancement levels off after theIn the Type II (plateau) curve, enhancement levels off after the first postcontrast scan.first postcontrast scan.  In the Type III (washout) curve, enhancement decreases afterIn the Type III (washout) curve, enhancement decreases after the initial rise.the initial rise.  Although the Type I curve is usually associated with benignAlthough the Type I curve is usually associated with benign entities and the Type III curve with malignancy, there is overlap.entities and the Type III curve with malignancy, there is overlap.

INDICATIONSINDICATIONS  MRI preoperative is most useful in breast cancer patientsMRI preoperative is most useful in breast cancer patients with:with:  mammographically dense breastsmammographically dense breasts  those with large (T2 and T3) tumorsthose with large (T2 and T3) tumors  those with invasive lobular carcinomathose with invasive lobular carcinoma  Scar versus tumor. Post operative scar can enhance up to 6 m.Scar versus tumor. Post operative scar can enhance up to 6 m. With radiation up to 18-24 m fortunately recurrence happensWith radiation up to 18-24 m fortunately recurrence happens after this interval.after this interval.  Screening for:Screening for: high +family historyhigh +family history proved genetic mutation .proved genetic mutation . previous biopsy of atypia or LL in situ.previous biopsy of atypia or LL in situ.

IndicationIndication  Determination of local extent :Determination of local extent : size ,number, locationsize ,number, location multifocality , multicentricity.multifocality , multicentricity. incidental contralateral cancers seen in 3-6%incidental contralateral cancers seen in 3-6% chest wall invasion.chest wall invasion.  Assessment of residual tumor:Assessment of residual tumor: appears as seroma with enhancing rim.appears as seroma with enhancing rim.

indicationindication  Assessment of recurrent disease:Assessment of recurrent disease: Sensetivity of mammography is 55-70%Sensetivity of mammography is 55-70% recurrence= enhancementrecurrence= enhancement fibrosis = no enhancement.fibrosis = no enhancement.

indicationsindications Other uses for breast MRIOther uses for breast MRI  evaluation of possible rupture of silicone breastevaluation of possible rupture of silicone breast implantsimplants  evaluation of pectoralis muscle invasion in womenevaluation of pectoralis muscle invasion in women with large or posteriorly located tumorswith large or posteriorly located tumors  identification of an occult primary in women whoidentification of an occult primary in women who present with axillary metastases from breast cancerpresent with axillary metastases from breast cancer but a negative physical examination and negativebut a negative physical examination and negative mammogrammammogram  monitoring response to treatment in women withmonitoring response to treatment in women with locally advanced tumors who are being treated withlocally advanced tumors who are being treated with neoadjuvant chemotherapyneoadjuvant chemotherapy

ConclusionConclusion  MR imaging should not substitute for problemMR imaging should not substitute for problem solving mammography or US.solving mammography or US.  Although MR is sensitive for cancer , benign andAlthough MR is sensitive for cancer , benign and malignant features overlap.malignant features overlap.  MR imaging shown to contribute to patient careMR imaging shown to contribute to patient care by providing information not attainable withby providing information not attainable with other imaging methods .other imaging methods .

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