Radiología de mama

Generalidades• En pacientes

asintomáticos: mamografía de control

• En pacientes con signos y síntomas: imagenología diagnóstica de mama

• Incluye la mamografía y estudios adicionales

• Objetivo primario es detectar el carcinoma de mama

• Objetivo secundario: Evaluación de enfermedad benigna como quistes, infección, complicación de implantes y trauma

Generalidades

• Mujeres mayores de 50 años se ven beneficiadas por la mamografía periódica

• Ha reducido hasta en 30% la mortalidad en este grupo de pacientes

• En pacientes más jóvenes el parénquima es más denso y nodular

• Esto disminuye la sensibilidad para la detección de carcinoma

• Lleva a más resultados falsos negativos y falsos positivos.

Generalidades• La mamografía ha sido

utilizada desde 1980, siendo el ultrasonido la técnica de soporte más usada durante este tiempo

• La mayor contribución del ultrasonido ha sido la efectividad para distinguir lesiones quísticas de las sólidas

• El ultrasonido ha ayudado así a disminuir el número de cirugías innecesarias por quistes simples asintomáticos que no requieren intervención

• El ultrasonido junto con la mamografía también es usado para caracterizar las lesiones como benignas, indeterminadas o sospechosas

Generalidades

• La resonancia magnética es útil en pacientes seleccionados

• La toma de biopsia por aguja fina guiada por imagen se ha convertido en el procedimiento de primera línea para el diagnóstico de lesiones indeterminadas de la mama

Técnica• La mamografía de control

siempre incluye dos tomas: craneocaudal (CC) y mediolateral oblicua (MLO)

• La MLO muestra la mayor parte del tejido mamario incluidos el cuadrante superior externo y la cola de Spence

• Se hacen en total 4 tomas

Carcinoma ductal in situCraneocaudal MLO

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women the breast parenchyma is more often dense andnodular. This condition decreases the sensitivity for detec-tion for carcinoma and leads to more false-negative andfalse-positive results.

Besides a decrease in mortality, a second benefit of earlierdiagnosis is that patients with breast carcinoma are affordedmore treatment options; lumpectomy with radiation therapyis an option to mastectomy in many patients.

Mammography has been in common use since about1980, and breast ultrasonography has been the most oftenused adjunctive technique during this time. The major con-tribution of ultrasonography has been its effectiveness in dis-tinguishing cystic lesions from solid masses. Sonography has,therefore, helped to avoid unnecessary surgery, becauseasymptomatic simple cysts do not require intervention. Ul-trasonography, together with mammography, is also used tohelp characterize solid lesions as benign, indeterminate, orsuspicious.

Magnetic resonance (MR) imaging of the breast can beused in selected patients. Image-guided needle biopsy of thebreast has become the first-line procedure for diagnosis of in-determinate lesions of the breast, with surgical biopsy beingreserved for special cases. Nuclear medicine and contrast in-

jection studies (ductography) are occasionally used underspecial circumstances with specific indications.

TECHNIQUE AND NORMAL ANATOMY

" Film-screen and Digital Radiography(Radiomammography)

The film-screen mammogram is created with x-rays, radi-ographic film, and intensifying screens adjacent to the filmwithin the cassette; hence the term film-screen mammogra-phy. The digital mammogram is created using a similar sys-tem, but replacing the film and screen with a digital detector.

The routine examination consists of two views of eachbreast, the craniocaudal (C-C) view and the mediolateraloblique (MLO) view, with a total of four films. The C-C viewcan be considered the “top-down” view, and the MLO an an-gled view from the side (Figures 5-1, 5-2). The patient un-dresses from the waist up and stands for the examination,leaning slightly against the mammography unit. The technol-ogist must mobilize, elevate, and pull the breast to place asmuch breast tissue as possible on the surface of the film cas-sette holder. A flat, plastic compression paddle is then gently

PART 2

BA! Figure 5-1. (A) Positioning of the patient for the craniocaudal view of the mammogram. (B) Positioning of thepatient for the mediolateral oblique view of the mammogram.

Técnica• La paciente debe estar

descubierta desde la cintura y de pie durante la realización del estudio

• Se debe de inclinar ligeramente al frente contra la unidad de mamografía

• El radiólogo debe mover y elevar la mama para colocarla de tal manera que se haga la toma de la mayor cantidad de tejido mamario

Craneocaudal

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women the breast parenchyma is more often dense andnodular. This condition decreases the sensitivity for detec-tion for carcinoma and leads to more false-negative andfalse-positive results.

Besides a decrease in mortality, a second benefit of earlierdiagnosis is that patients with breast carcinoma are affordedmore treatment options; lumpectomy with radiation therapyis an option to mastectomy in many patients.

Mammography has been in common use since about1980, and breast ultrasonography has been the most oftenused adjunctive technique during this time. The major con-tribution of ultrasonography has been its effectiveness in dis-tinguishing cystic lesions from solid masses. Sonography has,therefore, helped to avoid unnecessary surgery, becauseasymptomatic simple cysts do not require intervention. Ul-trasonography, together with mammography, is also used tohelp characterize solid lesions as benign, indeterminate, orsuspicious.

Magnetic resonance (MR) imaging of the breast can beused in selected patients. Image-guided needle biopsy of thebreast has become the first-line procedure for diagnosis of in-determinate lesions of the breast, with surgical biopsy beingreserved for special cases. Nuclear medicine and contrast in-

jection studies (ductography) are occasionally used underspecial circumstances with specific indications.

TECHNIQUE AND NORMAL ANATOMY

" Film-screen and Digital Radiography(Radiomammography)

The film-screen mammogram is created with x-rays, radi-ographic film, and intensifying screens adjacent to the filmwithin the cassette; hence the term film-screen mammogra-phy. The digital mammogram is created using a similar sys-tem, but replacing the film and screen with a digital detector.

The routine examination consists of two views of eachbreast, the craniocaudal (C-C) view and the mediolateraloblique (MLO) view, with a total of four films. The C-C viewcan be considered the “top-down” view, and the MLO an an-gled view from the side (Figures 5-1, 5-2). The patient un-dresses from the waist up and stands for the examination,leaning slightly against the mammography unit. The technol-ogist must mobilize, elevate, and pull the breast to place asmuch breast tissue as possible on the surface of the film cas-sette holder. A flat, plastic compression paddle is then gently

PART 2

BA! Figure 5-1. (A) Positioning of the patient for the craniocaudal view of the mammogram. (B) Positioning of thepatient for the mediolateral oblique view of the mammogram.

Técnica• Una paleta de plástico plana es

colocada delicada pero firmemente para comprimir la mama en una capa lo más delgada posible

• Esta compresión logra la inmovilización durante la exposición y dispersión de las sombras del tejido mamario sobre un área más amplia

• Permitiendo así una mejor visualización de las estructuras MLO

!RADIOLOGY OF THE BREAST 131

but firmly lowered onto the breast surface to compress thebreast into as thin a layer as possible. This compressionachieves both immobilization during exposure and disper-sion of breast tissue shadows over a larger area, thereby permitting better visual separation of imaged structures.Compression may be uncomfortable, and may even be

painful in a small proportion of patients. However, most pa-tients accept this level of discomfort for the few seconds re-quired for each exposure, particularly if they understandthe need for compression and know what to expect duringthe examination. Mammography has proved to be morecost-effective, while maintaining resolution high enough to

CHAPTER 5

A

B

! Figure 5-2. (A) Normal bilateral cran-iocaudal views. (B) Normal bilateralmediolateral oblique views. This patientshows a moderate amount of residualfibroglandular density, having a mixedpattern of dense and fatty areas of thebreast.

Vista CC bilateral normal

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but firmly lowered onto the breast surface to compress thebreast into as thin a layer as possible. This compressionachieves both immobilization during exposure and disper-sion of breast tissue shadows over a larger area, thereby permitting better visual separation of imaged structures.Compression may be uncomfortable, and may even be

painful in a small proportion of patients. However, most pa-tients accept this level of discomfort for the few seconds re-quired for each exposure, particularly if they understandthe need for compression and know what to expect duringthe examination. Mammography has proved to be morecost-effective, while maintaining resolution high enough to

CHAPTER 5

A

B

! Figure 5-2. (A) Normal bilateral cran-iocaudal views. (B) Normal bilateralmediolateral oblique views. This patientshows a moderate amount of residualfibroglandular density, having a mixedpattern of dense and fatty areas of thebreast.

Vista MLO bilateral normal

Técnica• La sensibilidad de la

mamografía es entre el 85% y el 95%

• La sensibilidad está limitada por tres factores: la naturaleza del parénquima, la técnica durante el estudio y la naturaleza del carcinoma de mama

• Algunos carcinomas se localizan bien definidos como masas redondas o como calcificaciones pequeñas pero brillantes y son fácilmente detectadas

• Otras, sin embargo, están poco definidas, irregulares e imitan tejido mamario normal

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demonstrate early malignant lesions, than any other breast im-aging technique. In its present state of evolution, however, thesensitivity of radiomammography ranges from 85% to 95%.

Limitations

Sensitivity is limited by three factors: (1) the nature of breastparenchyma, (2) the difficulty in positioning the organ forimaging, and (3) the nature of breast carcinoma.

The Nature of Breast ParenchymaVery dense breast tissue may obscure masses lying within ad-jacent tissue. Masses are more easily detected in a fatty breast.

PositioningA technologist performing mammography must include asmuch breast tissue as possible in the field of view for eachimage. The x-ray beam must pass through the breast tangen-tially to the thorax, and no other part of the body should in-trude into the field of view, so as to not obscure any part ofthe breast. This requires both a cooperative patient and askilled technologist. If a breast mass is located in a portion ofthe breast that is difficult to include in the image, mammog-raphy may fail to demonstrate the lesion. Also, because ofthese practical considerations, routine mammography is notperformed in markedly debilitated patients.

The Nature of Breast CarcinomaSome breast carcinomas are seen as well-defined roundedmasses or as tiny, but bright, calcifications, and are easily de-tected. Others, however, may be poorly defined and irregular,mimicking normal breast tissue. Rarely, still others may haveno radiographic signs at all.

For these reasons, it must be remembered that mammog-raphy has significant limitations in detection of carcinoma. Itcannot be overemphasized that any suspicious finding onbreast physical examination should be evaluated further, evenif the mammogram shows no abnormality. Occasionally, ad-ditional imaging may reveal an abnormality, but if not, short-term close clinical follow-up or biopsy is warranted.

Normal Structures

Normal breast is composed mainly of parenchyma (lobules andducts), connective tissue, and fat. Lobules are drained by ducts,which arborize within lobes. There are about 15 to 20 lobes inthe breast. The lobar ducts converge upon the nipple.

ParenchymaThe lobules are glandular units and are seen as ill-defined,splotchy opacities of medium density. Their size varies from1 to several millimeters, and larger opacities result from con-glomerates of lobules with little interspersed fat. The breastlobes are intertwined and are therefore not discretely identi-fiable. This parenchymal tissue is contained between the pre-mammary and retromammary fascia.

The amount and distribution of glandular tissue arehighly variable. Younger women tend to have more glandular

PART 2

B

A

! Figure 5-3. (A) Normal mammograms of fatty breasts.(B) Normal mammograms of dense breasts. Note the extreme variation of the normal breast parenchymal pattern between patients. A small carcinoma would bemuch more difficult to detect in the patient with densebreasts than in the patient with fatty breasts.

tissue than do older women. Glandular atrophy begins infer-omedially, and residual glandular density persists longer inthe upper outer breast quadrants. However, any pattern canbe seen at any adult age (Figure 5-3).

Diferencia en la densidad del tejido

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demonstrate early malignant lesions, than any other breast im-aging technique. In its present state of evolution, however, thesensitivity of radiomammography ranges from 85% to 95%.

Limitations

Sensitivity is limited by three factors: (1) the nature of breastparenchyma, (2) the difficulty in positioning the organ forimaging, and (3) the nature of breast carcinoma.

The Nature of Breast ParenchymaVery dense breast tissue may obscure masses lying within ad-jacent tissue. Masses are more easily detected in a fatty breast.

PositioningA technologist performing mammography must include asmuch breast tissue as possible in the field of view for eachimage. The x-ray beam must pass through the breast tangen-tially to the thorax, and no other part of the body should in-trude into the field of view, so as to not obscure any part ofthe breast. This requires both a cooperative patient and askilled technologist. If a breast mass is located in a portion ofthe breast that is difficult to include in the image, mammog-raphy may fail to demonstrate the lesion. Also, because ofthese practical considerations, routine mammography is notperformed in markedly debilitated patients.

The Nature of Breast CarcinomaSome breast carcinomas are seen as well-defined roundedmasses or as tiny, but bright, calcifications, and are easily de-tected. Others, however, may be poorly defined and irregular,mimicking normal breast tissue. Rarely, still others may haveno radiographic signs at all.

For these reasons, it must be remembered that mammog-raphy has significant limitations in detection of carcinoma. Itcannot be overemphasized that any suspicious finding onbreast physical examination should be evaluated further, evenif the mammogram shows no abnormality. Occasionally, ad-ditional imaging may reveal an abnormality, but if not, short-term close clinical follow-up or biopsy is warranted.

Normal Structures

Normal breast is composed mainly of parenchyma (lobules andducts), connective tissue, and fat. Lobules are drained by ducts,which arborize within lobes. There are about 15 to 20 lobes inthe breast. The lobar ducts converge upon the nipple.

ParenchymaThe lobules are glandular units and are seen as ill-defined,splotchy opacities of medium density. Their size varies from1 to several millimeters, and larger opacities result from con-glomerates of lobules with little interspersed fat. The breastlobes are intertwined and are therefore not discretely identi-fiable. This parenchymal tissue is contained between the pre-mammary and retromammary fascia.

The amount and distribution of glandular tissue arehighly variable. Younger women tend to have more glandular

PART 2

B

A

! Figure 5-3. (A) Normal mammograms of fatty breasts.(B) Normal mammograms of dense breasts. Note the extreme variation of the normal breast parenchymal pattern between patients. A small carcinoma would bemuch more difficult to detect in the patient with densebreasts than in the patient with fatty breasts.

tissue than do older women. Glandular atrophy begins infer-omedially, and residual glandular density persists longer inthe upper outer breast quadrants. However, any pattern canbe seen at any adult age (Figure 5-3).

Mamografía normal de mamas grasas

Mamografía normal de mamas densas

Anatomía normal• Las mamas normales

están compuestas de parénquima (lóbulos y ductos), tejido conectivo y grasa

• Los lóbulos son drenados por los ductos, los cuales arborizan a los primeros

• Normalmente encontramos de 15 a 20 lóbulos en la mama

• Los ductos lobares convergen hacia el pezón

• Los lóbulos son unidades glandulares vistas como manchas opacas de densidad media mal definidas

Anatomía normal• Su tamaño varía de uno a

varios milímetros y opacidades mayores son el resultado de conglomerados de lóbulos con poca grasa intermedia

• Los lóbulos mamarios están entrelazados y por ello no identificables de manera discreta

• Este tejido parenquimatoso está contenido entre las fascias retromamaria y la premamaria

• La cantidad y distribución deltejido glandular es altamente variable. Mujeres jóvenes tienen un tejido más glandular que las mujeres de mayor edad

Anatomía normal• La atrofia glandular inicia

interomedial y densidad glandular residual persiste por más tiempo en los cuadrantes superiores externos

• Sin embargo, cualquier patrón de tejido puede ser visto a cualquier edad adulta

• Junto con los elementos glandulares, el parénquima consiste de tejido ductal

• Sólo los ductos mayores son visibles en la mamografía y son reconocibles en la región subareaolar como estructuras lineares engrosadas de densidad media convergiendo hacia el pezón

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Along with glandular elements, the parenchyma con-sists of ductal tissue. Only major ducts are visualizedmammographically, and these are seen in the subareolar re-gion as thickened linear structures of medium density con-verging on the nipple.

Connective TissueTrabecular structures, which are condensations of connec-tive tissue, appear as thin (!1 mm) linear opacities ofmedium to high density. Cooper’s ligaments are the sup-porting trabeculae over the breast that give the organ itscharacteristic shape, and are thus seen as curved linesaround fat lobules along the skin-parenchyma interfacewithin any one breast (Figure 5-4).

FatThe breast is composed of a large amount of fat, which is lu-cent, or almost black, on mammograms. Fat is distributed inthe subcutaneous layer, in among the parenchymal elementscentrally, and in the retromammary layer anterior to the pec-toral muscle (Figure 5-4).

Lymph NodesLymph nodes are seen in the axillae and occasionally in thebreast itself (Figure 5-4).

VeinsVeins are seen traversing the breast as uniform, linear opaci-ties, about 1 to 5 mm in diameter (Figure 5-4).

ArteriesArteries appear as slightly thinner, uniform, linear densitiesand are best seen when calcified, as in patients with athero-sclerosis, diabetes, or renal disease.

SkinSkin lines are normally thin and are not easily seen withoutthe aid of a bright light for film-screen mammograms. Vari-ous processing algorithms with digital mammography allowbetter visualization of the skin.

Screening Mammography

The standard mammogram (along with appropriate history-taking) makes up the entire screening mammogram. The indi-cation for this examination is the search for occult carcinoma inan asymptomatic patient. Physical examination by the patient’sphysician, known as the clinical breast examination (CBE), is anindispensable element in complete breast screening. Althoughthe American Cancer Society no longer recommends routinebreast self-examination (BSE), particular attention should bepaid to lumps identified by the patient as new or enlarging.Such patients should be referred for diagnostic mammography.Table 5-1 includes guidelines for frequency.

Diagnostic Mammography

The diagnostic mammogram begins with the two-view stan-dard mammogram. Additional maneuvers are then used as

CHAPTER 5

A

Lymph node

Vein

Pectoral muscleFat (dark, orradiolucent)Fibroglandulartissue (light, orradiopaque)

Nipple

Cooper’s (suspensory)ligament

B! Figure 5-4. (A) Mediolateral oblique view of normal breast. (B) Line drawing with identification of normal structuresvisible in part (A).Anatomía normal

Ganglio

Vena

M. pectoral

Grasa (radiolúcida)

Tejido fibroglandular (radiopaco)

PezónLigamento suspensorio

de Cooper

Anatomía normal• Las estructuras

trabeculares que son condensaciones de tejido conectivo, aparecen como opacidades lineares delgadas (<1mm) de media a alta densidad

• Los ligamentos de Cooper son trabéculas de soporte de la mama que le dan al órgano su forma característica y de esa manera son vistas como líneas curvas alrededor de lóbulos de grasa a lo largo de la interface entre piel y parénquima

Anatomía normal• La mama está compuesta de gran

cantidad de grasa, la cual es lúcida o casi negra en la mamografía

• La grasa está distribuida en una capa subcutánea entre los elementos parenquimatosos de manera central y una capa retromamaria anterior al músculo pectoral

• Los ganglios linfáticos son vistos en la axila y ocasionalmente en la misma mama

• Las venas se visualizan atravesando la mama como opacidades uniformes y lineares de entre 1 y 5 mm de diámetro

• Las arterias aparecen como densidades uniformes ligeramente más delgadas y son reconocidas facilmente calcificadas en pacientes con ateroesclerosis, diabetes mellitus o enfermedad renal

• Las lineas de la piel son normalmente delgadas y dificilmente reconocibles

Mamografía de control

• La indicación para este examen es la búsqueda de carcinoma oculto en pacientes asintomáticos

• El examen clínico de la mama realizado por el médico es un elemento indispensable en el estudio completo de la mama

Mama premenopáusica con tejido fibroglandular denso

Mamografía diagnóstica• La mamografía

diagnóstica inicia con el mamograma estandar de dos vistas

• Está indicada en masas palpables o signo o síntoma (retracción del pezón, descarga del pezón, etc) así como anormalidad en la mamografía de control

Cancer invasivo (flecha)

Clasificación según BI-RADS y manejo sugerido

Categoría BI-RADS Evaluación Manejo clínico recomendado

0 Evaluación incompleta Revisar estudios previos y/o realizar imagen adicional

1 Negativo Continuar con revisión de rutina

2 Hallazgo benigno Continuar con revisión de rutina

3 Hallazgo probablemente benigno

Realizar mamografía a 6 meses, post. cada 6 a 12 meses por 1 o 2 años

4 Sospecha de anormalidad Realizar biopsia

5 Sospecha alta de malignidad Biopsia y tratamiento

6 Malignidad comprobada por biopsia

Asegurarse de que se completa el tratamiento

Implantes• En caso de implantes de

mama se requiere de técnicas especializadas para visualizar de la mejor manera el tejido residual dado que los implantes obscurecen grandes áreas de la mama durante la mamografía de rutina

• Las técnicas especiales como la de Eklund desplaza los implantes posteriormente mientras el tejido mamario es jalado anteriormente tanto como sea posible

Ultrasonografía• Está indicada en el hallazgo de una

masa detectada mediante mamografía cuya naturaleza es indeterminada, en una masa palpable no detectable mediante mamografía, en una masa palpable en paciente menor de la edad recomendada para la mamografía y como guía para una intervención

• La US es una técnica altamente confiable para diferenciar quistes de masas sólidas

• Si los criterios para determinar un quiste se cumplen, el diagnóstico es 99.9% preciso

• Limitantes de la US son la habilidad del radiólogo además de que proyecta solo una porción de la mama en un momento determinado

• La piel, fascias premamarias y retromamarias, trabéculas, paredes de ductos y vasos y fascia pectoral son identificadas claramente como estructuras lineares

• Los lóbulos de grasa y glandulares son ovales, de diversos tamaños y realtivamente hipoecóicos contra el tejido conectivo circundante

• Quistes simples son anaecóicos y tienen paredes delgadas y suaves

!RADIOLOGY OF THE BREAST 135

implants, and (7) evaluating difficult (dense or fibrous) breasts.In addition, the technology for MR-guided breast biopsies is in-creasingly available.

The patient lies prone on the scanner table, and a special-ized coil surrounds the breasts. Depending on the clinicalquestion, a varying number of pulse sequences are performedto evaluate the breasts or the composition of a suspicious le-sion. Scan times can range from 30 minutes to over an hour.

MRI can show whether a lesion is solid or contains fat orfluid. Dynamic scanning after administration of intravenouscontrast shows whether structures enhance and at what rate.Cancers classically enhance rapidly with subsequent “wash-out.” For instance, a lesion that enhances relatively rapidlyon dynamic exam (think neovascularity) is more concerningfor malignancy. If more than one suspicious lesion is identi-fied, the relative proximity of these lesions can determinewhether a patient would be a good candidate for lumpec-tomy rather than mastectomy. The wide field of view allowsstaging by evaluating the axillary and internal mammarynodes. Figure 5-6 shows an enhancing cancerous tumor.

Although MRI is quite sensitive (good for detecting dis-ease), it is relatively nonspecific. This is due to the overlap-ping imaging characteristics of both benign and malignantprocesses. Like cancer, some benign breast structures showenhancement, although usually with a slower rate.

Because of the relatively low specificity, screening withMRI is best used in patients with a higher probability of

disease. The 2007 American Cancer Society recommenda-tions include annual MRI breast screening of patients with alifetime risk of 20% or greater.

Normal Structures

Tissues are differentiated by their pattern of change on dif-ferent pulse sequences. The skin, nipple and areola, mam-mary fat, breast parenchyma, and connective tissue arenormally seen, in addition to the anterior chest wall, in-cluding musculature, ribs and their cartilaginous portions,and portions of internal organs. Small calcifications are notvisible, and small solid nodules may not be detected. Cysticstructures are well seen. Normal implants appear as cysticstructures with well-defined walls. Their location is deep tothe breast parenchyma or subpectoral, depending on thesurgical technique that was used to place the implants. In-ternal signal varies and depends on implant contents, eithersilicone or saline.

" DuctographyDuctography, or galactography, uses mammographic imag-ing with contrast injection into the breast ducts. The indica-tion for use is a profuse, spontaneous, nonmilky nippledischarge from a single duct orifice. If these conditions arenot present, the ductogram is likely to be of little help. The

CHAPTER 5

A

Dermis

Cooper’sligament

Subcutaneous fat

Fibroglandular tissue

Retromammary fatPectoral muscle

Pleura Rib, in cross-section

B! Figure 5-5. (A) Ultrasonographic image of a portion of normal breast. (B) Line drawing identifying normal structuresvisible on the sonographic image.Ultrasonografía

Dermis

Grasa retromamaria

Tejido fibroglandular

Grasa subcutánea

Músculo pectoral

Ligamento de Cooper

PleuraCostila

Imagen de ultrasonido mostrando una masa anecóica con pared posterior bien definida, característico de un

quiste

Absceso mamario con probable carcinoma concomitante

Mastopatía fibroquística

MRI• Indicada en la estadificación y

planeación de tumores, búsqueda de un tumor primario en pacientes que presentan ganglios linfáticos axilares cancerosos, en la evaluación de la respuesta de la quimioterapia, para diferenciar la recurrencia de un tumor de cambios post-tratamiento, vigilancia de pacientes de alto riesgo, evaluación de implantes y

para evaluar tejido mamario muy denso y fibroso

• La MRI puede mostrar si la lesión es sólida o si contiene grasa o líquido

• A pesar de que la MRI es bastante sensitiva es relativamente inespecífica

• Esto es por la sobreposición de las características de procesos benignos y malignos

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purpose is to reveal the location of the ductal system in-volved. The cause of the discharge is frequently not identi-fied. Occasionally, an intraluminal abnormality is seen, butfindings have low specificity.

The patient lies in supine position while the dischargingduct is cannulated with a blunt-tipped needle or catheterunder visual inspection and with the aid of a magnifyingglass. A small amount of contrast material (usually not morethan 1 mL) is injected gently by hand into the duct. Severalmammographic images are then made. The procedure re-quires about 30 minutes and is not normally painful.

Normal Structures

Just deep to the opening of the duct on the nipple, the duct ex-pands into the lactiferous sinus. After a few millimeters, theduct narrows again and then branches as it enters the lobe con-taining the glands drained by this ductal system. The normalcaliber of the duct and its branches is highly variable, but nor-mal duct walls should be smooth, without truncation or abruptnarrowing. With high-pressure injection, the lobules, as well ascystically dilated portions of ducts and lobules, may opacify.

" Image-Guided Needle Aspiration and Biopsy

The indications for needle aspiration and biopsy of breast le-sions are varied and are variably interpreted by radiologistsand referring physicians. Two categories are discussed here.

The first indication is aspiration of cystic lesions to con-firm diagnosis, to relieve pain, or both. Nonpalpable cysts re-quire either ultrasound or mammography to be seen. A fineneedle (20- to 25-gauge) usually suffices to extract the fluid.The cystic fluid is not routinely sent for cytology unless it is bloody.

The second indication concerns solid lesions. Needlebiopsy is used in this case (1) to confirm benignity of a lesioncarrying a low suspicion of malignancy mammographically,(2) to confirm malignancy in a highly suspicious lesion priorto initiating further surgical planning and treatment, and (3) to evaluate any other relevant mammographic lesion forwhich either follow-up imaging or surgical excision is a lessdesirable option for further evaluation.

Guidance for needle biopsy can be accomplished withstereotactic mammography, ultrasound, and MR. Imaging

PART 2

A B! Figure 5-6. (A) Mammogram showing dense breast tissue. (B) MRI of same breast showing enhancing cancer inotherwise minimally enhancing breast.Mamografía con tejido denso (Izquierda), MRI de misma mama mostrando cáncer (derecha)

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purpose is to reveal the location of the ductal system in-volved. The cause of the discharge is frequently not identi-fied. Occasionally, an intraluminal abnormality is seen, butfindings have low specificity.

The patient lies in supine position while the dischargingduct is cannulated with a blunt-tipped needle or catheterunder visual inspection and with the aid of a magnifyingglass. A small amount of contrast material (usually not morethan 1 mL) is injected gently by hand into the duct. Severalmammographic images are then made. The procedure re-quires about 30 minutes and is not normally painful.

Normal Structures

Just deep to the opening of the duct on the nipple, the duct ex-pands into the lactiferous sinus. After a few millimeters, theduct narrows again and then branches as it enters the lobe con-taining the glands drained by this ductal system. The normalcaliber of the duct and its branches is highly variable, but nor-mal duct walls should be smooth, without truncation or abruptnarrowing. With high-pressure injection, the lobules, as well ascystically dilated portions of ducts and lobules, may opacify.

" Image-Guided Needle Aspiration and Biopsy

The indications for needle aspiration and biopsy of breast le-sions are varied and are variably interpreted by radiologistsand referring physicians. Two categories are discussed here.

The first indication is aspiration of cystic lesions to con-firm diagnosis, to relieve pain, or both. Nonpalpable cysts re-quire either ultrasound or mammography to be seen. A fineneedle (20- to 25-gauge) usually suffices to extract the fluid.The cystic fluid is not routinely sent for cytology unless it is bloody.

The second indication concerns solid lesions. Needlebiopsy is used in this case (1) to confirm benignity of a lesioncarrying a low suspicion of malignancy mammographically,(2) to confirm malignancy in a highly suspicious lesion priorto initiating further surgical planning and treatment, and (3) to evaluate any other relevant mammographic lesion forwhich either follow-up imaging or surgical excision is a lessdesirable option for further evaluation.

Guidance for needle biopsy can be accomplished withstereotactic mammography, ultrasound, and MR. Imaging

PART 2

A B! Figure 5-6. (A) Mammogram showing dense breast tissue. (B) MRI of same breast showing enhancing cancer inotherwise minimally enhancing breast.

Ductografía• La ductografía o

galactografía usa imagenes mamográficas con injección de contraste en los ductos de la mama

• La indicación se realiza en caso de una descarga profusa, espontánea no lechosa de un sólo orificio ductal del pezón

• Su objetivo es mostrar la ubicación del sistema ductal involucrado

• La causa de descarga es frecuentemente no identificable

• Ocasionalmente se puede hallar alguna anormalidad pero es bastante inespecífico

Ductograma craniocaudal (IZ) y MLO (derecha) mostrando una masa (flechas) posterior al pezón y delineada por contraste, el

cual también llena las estructuras ductales proximales

Bibliografía• Freimanis, Rita. Ayoub, Joseph. Radiología de mama.

Capítulo 5. Radiología básica. 2da. Edición. Mc. Graw Hill. Carolina del Norte, USA. Páginas129-138

• Schwartz S., Shires G., Spencer F. La Mama. Principios de Cirugía 9ª Edición Capítulo 17. 2011. Interamericana McGraw-Hill.

• BI-RADS Classification for Management of Abnormal Mammograms, Margaret M. Eberl, MD, MPH, Chester H. Fox, MD, Stephen B. Edge, MD, Cathleen A. Carter, PhD, and Martin C. Mahoney, MD, PhD, FAAFP. (J Am Board Fam Med 2006;19:161– 4.

www.sapiensmedicus.org