Vagina 12

12.1 Anatomy

12.2 Imaging Appearance of the Vagina

12.3. Congenital Malformations

12.4. Benign Lesions

12.4.1 Bartholin’s Gland Cysts

12.4.2 Condylomata Acuminata

12.4.3 Gartner’s Duct Cysts 281 12.4.4 Infl ammatory Conditions of the Vagina 282 12.4.5 Crohn’s Disease

12.4.6 Trauma

12.4.7 Benign Tumors of the Vagina 283 12.5 Malignant Tumors of the Vagina

12.5.1 Secondary Vaginal Malignancies

12.5.2 Primary Vaginal Malignancies

12.5.2.1 Background 283

12.5.2.2 MR Imaging 286 12.5.2.3 Staging 286

12.5.2.4 MR Appearance After Radiotherapy 287 12.5.2.5 MR Appearance After Surgery 290 12.5.2.6 Residual and Recurrent Tumor 290 12.5.2.7 Lymph Nodes 290

References 290

U. Zaspel, MD

Institut für Radiologie (Campus Mitte), Charité – Universitäts- medizin Berlin, Charitéplatz 1, 10117 Berlin, Germany B. Hamm, MD

Professor and Chairman, Institut für Radiologie (Campus Mitte), Klinik für Strahlenheilkunde (Campus Virchow-Klini- kum und Campus Buch), Charité – Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany

The vagina is a fi bromuscular sheath-like structure connecting the external genitals with the uterus. It is lined with nonkeratinizing squamous epithelium and is 8–12 cm long. The vagina protects the internal geni- tal organs against ascending infections, forms part of the birth canal, and receives the penis in copulation.

The proximal third of the vagina is at the level of the lateral vaginal fornices, the middle third at the level of the urinary bladder base, and the lower third at the level of the urethra. The anterior and posterior walls of the vagina are usually pressed together by the surrounding soft tissue, which ensures functional mechanical closure.

On axial sections, this results in a shape that resembles the letter H (see Fig. 12.3a). The concertina barrier-like arrangement of the muscular layer of the vaginal wall and an abundance of elastic fi bers in the subepithelial and adventitial connective tissue layer enable extreme passive extension and active contraction. The squamous epithelium of the vagina is highly susceptible to hor- monal effects. The epithelium consists of up to 30 cell layers in women of reproductive age but of only a few layers in childhood and after menopause. The vagina is supplied with blood through the descending branch of the uterine artery as well as through branches from the rectal, vesical, and pudendal arteries. Lymph is drained from the vagina to the iliac, sacral, and para-aortic nodes from the upper two thirds and to inguinal and anorectal nodes from the lower third and vestibule.

12.2

Imaging Appearance of the Vagina

On axial CT scans, the vagina is diffi cult to differenti-

ate from the urethra (Fig. 12.1) and it is not possible

to distinguish the vaginal epithelium/mucus from the

layers of the vaginal wall.

Fig. 12.1a–c. CT anatomy of the normal vagina. a,b CT. c Sag- ittal CT reconstruction. CT anatomy of the vagina – middle third at the level of the urinary bladder (a) and distal third at the level of the urethra (b). The vagina has the same density as the walls of the bladder, urethra, and rectum and can be distinguished from these structures on CT by the presence of a small fat layer. For differentiation of the vagina, it is also helpful if the bladder is fi lled with urine and the rectum is fi lled with air

a

b

c

Fig. 12.2a,b. MR anatomy of the normal vagina on FS T1-weighted images. a,b T1-weighted images with fat sat in axial and sagit- tal orientation. On T1-weighted images, the vagina is of a similar signal intensity as the walls of the urinary bladder, urethra, and rectum. Thus, the vagina can only be localized indirectly between the fi lled bladder and the air-fi lled rectum

a b

Fig. 12.3a,b. MR anatomy of the normal vagina on T2-weighted images. a,b T2-weighted images in axial and sagittal orienta- tion. T2-weighted MR images allow differentiation of the three layers forming the vaginal wall (arrows). The innermost layer, the vaginal mucosa, is of high signal intensity; the middle layer, the muscularis, is of low signal intensity; and the outer layer, consisting of paravaginal fatty tissue and the venous plexus, is of high signal intensity. On transverse images, the vagina has an H-shaped appearance (arrow). The vagina is located between the urethra anteriorly and rectum posteriorly

a b

Fig. 12.5. MR anatomy of the normal vaginal fornices on T2- weighted images. T2-weighted image in sagittal orientation.

The uterine cervix protrudes into the vagina, forming the pos- terior vaginal fornix (open arrow) and the somewhat smaller anterior vaginal fornix (arrow)

Insertion of a tampon is not necessary for ade- quate evaluation and may even distort vaginal anat- omy (Fig. 12.6a). Instead, evaluation can be improved by fi lling and distending the vagina with ultrasound gel (Fig. 12.6b).

Hormone intake not only alters the thickness of the vaginal epithelium and the vaginal mucus but also affects the signal characteristics on MR images.

Before the onset of menstruation, the vagina has lower signal intensity on T2-weighted images and a very thin central epithelial/fl uid layer of high signal intensity. In women of reproductive age, the contrast between the vaginal mucosa and the wall is highest during the early proliferative phase. In this phase, the vaginal wall has a low signal intensity on T2-weighted images with a central stripe of high signal intensity (epithelium and mucus) (Fig. 12.7a, b). During the secretory phase, the central stripe shows moderate widening while there is a simultaneous increase in the signal of the vaginal wall, which makes it more diffi cult to distinguish these two layers. In post- menopausal women without hormonal replacement, the vagina has a low signal intensity on T2-weighted images and the central stripe of high signal inten- sity is very thin (Fig. 12.7c, d). In postmenopausal women on estrogen substitution, the vagina has the same appearance as during the proliferative phase in premenopausal women.

Fig. 12.4a,b. MR anatomy of the normal vagina on contrast-enhanced images. a,b T1-weighted images with fat sat after ad- ministration of Gd-DTPA in axial and sagittal orientation. After contrast medium administration, two layers of the vaginal wall (arrow) can be distinguished, a low-signal-intensity inner mucosa with intraluminal secretion and a contrast-enhancing muscularis and the outer venous plexus, which are of high signal intensity

a b

Fig. 12.7a–d. Pre- and postmenopausal vaginal anatomy. T2-weighted images in sagittal and axial orientation. A premenopausal (a,b) and a postmenopausal (c,d) woman: Two-layered appearance of the wall of the vagina (open arrows) is demonstrated in the postmenopausal woman. The low-signal-intensity muscularis layer and the high-signal-intensity paravaginal fatty tissue can be distinguished. Hypoplasia of the mucosa, which is just barely visible as high-signal-intensity stripe in sagittal orientation (c,d). Compare the thick high-signal-intensity vaginal mucosa in premenopausal age (a,b) (arrows)

a c

b d

Fig. 12.6a,b. Intravaginal tampon and gel fi lling of the vagina. a T2-weighted image in sagittal orientation. Distortion of the va- gina through an intravaginal tampon (asterisk). The tampon does not improve evaluation of vaginal morphology. b T2-weighted image in sagittal orientation. Gel fi lling unfolds the vagina and fornix (asterisk). The uterus is retrofl exed

a b

12.3.

Congenital Malformations

The upper third of the vagina develops from the mül- lerian ducts, which descend during embryonic life and also give rise to the uterus, uterine cervix, and fallopian tubes. This is why vaginal malformations are typically associated with other developmental anomalies of the müllerian ducts. The lower and middle thirds of the vagina develop as a result of embryologic interactions between the müllerian ducts and the urogenital sinus.

The close proximity to the wolffi an duct (also known as the mesonephric duct) explains the association of vaginal malformations with renal anomalies. Congeni- tal vaginal malformations are agenesis, duplication, and vaginal septa. Congenital absence (Fig. 12.8) and hypoplasia of the vagina are rare and are typically part of the Mayer-Rokitansky-Küster-Hauser (MRKH) syn- drome. MRI shows a rudimentary vagina, often with concurrent hypoplasia of the uterus. Because agenesis of the vagina may be associated with renal agenesis or ectopic kidneys, the kidneys should always be included in the examination.

A longitudinal vaginal septum (Fig. 12.9) occurs as a consequence of incomplete fusion of the mülle- rian ducts or resorption failure of the vaginal septum.

This anomaly is also typically associated with other malformations of the müllerian ducts [septate uterus, bicornuate uterus, uterus didelphys (Fig. 12.9), cervi- cal duplication] [2].

Fibrous horizontal vaginal septa can occur any- where in the vagina as a result of defective fusion of the descending müllerian ducts and ascending uro- genital sinus. A horizontal septum causes primary amenorrhea, abdominal pain, an abdominal mass, or dyspareunia. MR imaging shows the vagina to be distended with retained secretion and allows evalua- tion of the location and thickness of the membrane for planning the surgical approach. Ectopic ureters inserting into the vagina are another anomaly but they are typically diagnosed by excretory urography.

In general, patients with vaginal malformations can be examined by hysterosalpingography, ultrasonog- raphy, or MRI [3]. MRI provides a good overview of pelvic anatomy in patients with suspected congenital malformations of the vagina or other structures of the urogenital tract and is very helpful in planning surgi- cal measures for treating vaginal malformations [4].

12.4.

Benign Lesions

12.4.1

Bartholin’s Gland Cysts

Bartholin’s gland cysts are among the most common incidental fi ndings in the posterolateral portion of the lower vagina (Fig. 12.10).

Fig. 12.8a,b. Agenesis of uterus and vagina. a,b T2-weighted images in axial and sagittal orientation. (Reproduced with permis- sion from [13])

a b

The cysts develop when secretion is retained in the ducts of the vulvovaginal glands opening in the area of the vestibule. Bartholin’s cysts are characterized on T2-weighted MR images as cystic lesions of high signal intensity with a delicate and sharply delineated wall.

On T1-weighted images, they are of intermediate to high signal intensity, depending on the protein content.

Large cysts can cause symptoms with walking and sit- ting. As a complication Bartholin’s cysts may develop infl ammation and form an abscess. As a consequence those symptomatic cysts are treated by a wide incision of the glandular duct (marsupialization).

12.4.2

Condylomata Acuminata

Condylomata acuminata are papillomas caused by the human papilloma virus and are the most common benign tumors of the vulva but rarely occur within

the vagina. They are usually diagnosed by inspec- tion, which may be supplemented by colposcopy and biopsy as required.

12.4.3

Gartner’s Duct Cysts

Gartner’s duct cysts are another malformation of the vagina [3]. They develop as retention cysts from remnants of the wolffi an duct system and typically occur in the anterolateral portion of the vagina and vulva (Fig. 12.11).

Gartner’s duct cysts vary in size from a few milli- meters to several centimeters and may occur in large numbers. Small Gartner’s duct cysts are asymptomatic and may be detected incidentally while larger cysts can compress the vagina or urethra. T1- and T2-weighted MR images depict cystic lesions with a delicate wall and high signal intensity due to their high protein content.

Fig. 12.9a–c. Uterus didelphys. T2-weighted images in transverse and coronal orientation. Good visualization of the duplicated uterus (a) and the two fl uid-fi lled vaginas (b,c)

a

c

b

12.4.4

Infl ammatory Conditions of the Vagina

Infections of the vagina are frequent and may be caused by a wide variety of pathogens (viruses, bac- teria, fungi). MRI is rarely needed to diagnose vaginal infection. There may be thickening of the vaginal wall and vaginal secretion may be increased. Vaginal infl am- mation is associated with an increased signal intensity of the vaginal mucosa or of the entire vaginal wall on T2-weighted and STIR images. Contrast-enhanced T1-weighted images show more marked enhancement with a higher signal of the vaginal wall.

12.4.5

Crohn’s Disease

Crohn’s disease is a chronic inflammatory condi- tion that may occur in any part of the gastroin- testinal tract but commonly involves the terminal ileum or right colon frame. Gynecologic involve- ment with inflammation of the organs of the true pelvis or of the vulva is not uncommon. Another manifestation are fistulas between the vagina and the colon or rectum [5]. MRI is the method of choice for the diagnostic evaluation of pelvic fis- tulas.

Fig. 12.11a,b. Gartner’s duct cyst. T2-weighted images in sagittal and transverse orientation. Depiction of a Gartner’s duct cyst (arrows) in the anterolateral portion of the right vagina

a b

Fig. 12.10a,b. Bartholin’s duct cyst. a T2-weighted image in sagittal orientation. Thin walled cyst (arrow) of the right wall at the vestibule of the vagina

a b

include lipoma, fi broma, and neurofi broma. They may be pedunculated and protrude from the vagina.

12.5

Malignant Tumors of the Vagina

12.5.1

Secondary Vaginal Malignancies

Secondary tumors account for about 80% of all vagi- nal malignancies. Direct tumor spread from adjacent organs such as the urinary bladder, vulva, uterine cervix (Fig. 12.12), or rectum is not uncommon. More-

12.5.2.1 Background

Most primary vaginal malignancies are carcinomas.

Vaginal carcinoma is rare, accounting for 1%–2 % of the malignant tumors of the female genital tract. Their incidence is 0.5/100,000 women. The major histologic type is squamous epithelial carcinoma, which makes up over 90% of all primary vaginal malignancies.

Vaginal cancer typically occurs in women aged 50–70 years. About 4% of vaginal cancers are adenocarci- nomas. This histologic type mostly affects younger women from 17 to 32 years of age. Vaginal sarcoma in the form of leiomyosarcoma or fi brosarcoma is rare [6]. Embryonal rhabdomyosarcoma (Fig. 12.14) is the

Fig. 12.12a,b. Cervical cancer invading the vagina. T2-weighted images in axial and sagittal orientation. Cervical cancer invading the proximal third of the posterior vaginal wall (arrows)

a b

Fig. 12.13. Vaginal metastasis of malig- nant melanoma. Contrast enhanced CT.

An unspecifi c mass with inhomogeneous contrast enhancement in the vagina is shown. The right levator ani muscle (arrow) can not be well delineated sug- gesting tumor involvement. (Figure courtesy of Dr. Forstner)

Fig. 12.14a–c. Botry- oid sarcoma. Sagittal, transaxial, and coronal T2-weighted images in a 2-year-old girl. A multiseptated mass with numerous thin septations causes extensive enlarge- ment of the vagina which extends up to the level of the promontorium

a c

b

diethylstilbestrol. Furthermore, it has been shown that there is an association with tumors of the cervix or vulva and status post hysterectomy [8]. Vaginal cancer typically involves the proximal third and the posterior wall of the vagina [6]. Early vaginal cancer is asymptomatic. More advanced tumors may cause painless vaginal bleeding or contact bleeding, vaginal discharge, dysuria, and dyspareunia.

The growth pattern of vaginal tumors includes the whole spectrum from exophytic and papillomatous, through infi ltrating, to ulcerating forms. The tumor primarily extends by direct spread to the paracolpium, parametria, vulva, uterine cervix, and rectovaginal and vesicovaginal septa. Fistulas are not infrequent when there is tumor invasion of the rectum and bladder.

Lymphatic spread of tumors involving the proximal two thirds of the vagina is to the lymph nodes along the external and common iliac arteries, and the abdominal aorta. Vaginal tumors in the lower third of the vagina

exenteration with adjuvant radiotherapy. Patients in whom distant metastases outside the pelvis are pres- ent are treated by chemotherapy.

Table 12.1. Staging of vaginal cancer according to FIGO and TNM criteria

FIGO TNM

0 Tis Cis

I T1 Tumor confi ned to vagina

II T2 Tumor invades paravaginal tissues but does not extend to pelvic wall

III T3 Tumor extends to pelvic wall

IVa T4 Tumor invades bladder and rectum, tumor extends beyond the true pelvis

IVb M1 Distant metastasis

N1 Pelvic lymph node metastasis

N2 Unilateral inguinal lymph node metastasis N3 Bilateral inguinal lymph node metastasis

Fig. 12.15a,b. Regional lymph node stations. a Vaginal cancer of the proximal two thirds of the vagina drains into the pelvic lymph node stations. b The inguinal lymph nodes are the fi rst lymph node stations invaded by vaginal cancer of the distal third of the vagina. (Reproduced with permission from [14])

a b

12.5.2.2 MR Imaging

MRI has its most important diagnostic role in staging vaginal cancer that has been confi rmed by colposcopy and biopsy. Staging by MRI serves to determine local tumor extent and to classify the cancer according to TNM and FIGO criteria [9]. In addition, MRI allows assessment of inguinal and pelvic lymph nodes. Because the signal intensity of vaginal tumors, except for vaginal melanoma, is unspecifi c, MRI does not allow differentia- tion of the different primary and secondary malignan- cies involving the vagina and thus cannot replace histo- logic diagnosis [10]. The protocol recommended for MR imaging of vaginal cancer is summarized in Table 12.2.

Table 12.2. MRI sequences recommended for imaging of vagi- nal cancer

Sequence T2w TSE PD TSE T1w TSE Contrast- enhanced T1w TSE Sagittal

Transverse

Transverse Sagittal Transverse

Sagittal Transverse Area

imaged

Uterus to pelvic fl oor

Aortic bifurca- tion to groin

Uterus to pelvic fl oor

Uterus to pelvic fl oor

Prior to MR imaging, patients are administered a spasmolytic agent to reduce intestinal motility, e.g. 2 ml Buscopan

(40 mg butylscopolamine). Distention of the vagina, e.g. by fi lling with ultrasound gel, may improve diagnostic assessment. In women with an oblique ori- entation of the vagina, angulation of the transverse T2- weighted sequence perpendicular to the axis of the vagina will improve evaluation of anatomy and tumor extent.

On T2-weighted images, vaginal tumors have an intermediate to high signal intensity, enabling their differentiation from the low-signal-intensity muscu- lar vaginal wall (Fig. 12.16).

On T1-weighted images, a vaginal tumor is identi- fi ed as a contour deformity of the vagina and not by a difference in signal intensity. Following administra- tion of a contrast medium, most vaginal tumors display more marked signal enhancement than the vaginal wall (Fig. 12.14c,d). Because vaginal tumors may show a marginal infl ammatory reaction, their extent may be overestimated [9]. Moreover, it may be diffi cult to dif- ferentiate cervical cancer and tumors of the proximal vagina when there is invasion of both organs. In such cases, the tumor often arises from the organ containing the largest tumor mass. However, only biopsy enables

reliable differentiation in such cases and between pri- mary and secondary vaginal tumors in general. An exception are vaginal melanomas which show a distinct signal behavior that depends on their composition such as presence of intralesional hemorrhage or pigments.

Melanin is paramagnetic and shortens relaxation times, resulting in a higher signal on T1-weighted images and a lower signal on T2-weighted images. There is no para- magnetic effect amelanotic melanomas.

12.5.2.3 Staging

Stage T1 vaginal cancer is confi ned to the vagina (Fig. 12.17). T2-weighted images show a hyperintense disruption of the low-signal-intensity muscular vaginal wall. To exclude cancer growth beyond the vagina, it is important to differentiate the tumor from the fatty layer surrounding the vagina. The differentiation of tumor and fat may be easier on T1-weighted images because there is superior contrast between low-signal-intensity tumor and high-signal-intensity fat. On T2-weighted images, on the other hand, both tumor and paravaginal fat with its rich venous network have a high signal inten- sity. However, this is not a reliable criterion because the fatty layer surrounding the vagina is very thin.

Stage II tumors are characterized by invasion of paravaginal fatty tissue, which is seen as a blurred and irregular delineation of the vaginal wall (Figs. 12.16, 12.18, 12.19). Larger tumors extending beyond the vagina are seen as low-signal-intensity lesions sur- rounded by hyperintense paravaginal tissue on T1- weighted images. On T2-weighted images both the vaginal tumor and the paravaginal tissue have a high signal intensity and are diffi cult to distinguish.

In stage III disease with tumor extension to the pelvic sidewall (Fig. 12.20), muscular infi ltration of the pelvic wall is best appreciated on T2-weighted images.

Muscle is of a lower signal intensity and can thus be differentiated from the high-signal-intensity tumor.

Other important muscles that need to be evaluated are the levator ani, piriform, and internal obturator mus- cles. Invasion of the internal anal sphincter muscle can be evaluated on coronal T2-weighted images.

Stage IV vaginal cancer is characterized by invasion of the bladder and rectum (Fig. 12.21), which is identi- fi ed as a disruption of the low-signal-intensity muscu- lar layer of these organs on T2-weighted images.

Fistulas can be identifi ed on contrast-enhanced

T1-weighted images. They are characterized by more

pronounced contrast enhancement and there may be

a central signal void in the fi stula canal.

12.5.2.4

MR Appearance After Radiotherapy

Edematous and infl ammatory reactions of the vagina that persist for up to about 6 months after radiother- apy are associated with an increased signal intensity of the vaginal wall on T2-weighted images. The observed increase in signal intensity is directly proportion to the total radiation dose administered and always occurs above a threshold dose of 45 Gy. The mode of admin-

istration (percutaneous radiation, brachytherapy) appears not to affect the degree of signal change. Irra- diated tissue also shows increased enhancement after contrast medium administration. About 6 months after completion of radiotherapy, fi brosis leads to a decreased signal intensity of the vagina on T1- and T2-weighted images and there is again less pronounced contrast medium enhancement [11]. A rare complication of radiotherapy is vaginal stenosis with subsequent devel- opment of serometra or hematometra (Fig. 12.22).

Fig. 12.16a–d. Vaginal cancer. a,b T2-weighted images in sagittal and axial orientation. FIGO stage II vaginal cancer of inter- mediate signal intensity (status post hysterectomy). There is tumor throughout the anterior wall of the distal vagina (arrows).

Tumor extension to the urethra (open arrow). c,d T1-weighted images with fat sat after administration of Gd-DTPA in axial and sagittal orientation. Contrast medium administration does not improve delineation of the cancer

a c

b d

Fig. 12.19a–c. Vaginal cancer. a T2-weighted image in sagittal orientation. b T2-weighted image with fat sat in axial orientation. c T1-weighted image with fat sat after administration of Gd-DTPA in axial orientation. a Status post hysterectomy for leiomyomas of the uterus. Vaginal cancer (arrows) of in the proximal two thirds of the vagina with infi ltration of the vaginal wall. Accessory fi nding: air inclusion in the urinary bladder after catheterization. b,c Fairly good differentiation of the solid tumor (arrows) from the high-signal-intensity venous plexus. There is no obvious infi ltration of the paracolpal fat. (Figure courtesy of Dr. Forstner) Fig. 12.17. FIGO stage I. Vaginal cancer is limited to the vagina.

(Reproduced with permission from [14])

Fig. 12.18. FIGO stage II. Tumour involves the paravaginal tis- sue but does not extend to the pelvic wall. (Reproduced with permission from [14] )

c a

b

Fig. 12.20. FIGO stage III. Cancer extends to the pelvic wall.

(Reproduced with permission from [14])

Fig. 12.21. FIGO stage IV. Tumour involves the mucosa of the bladder or rectum or extends beyond the true pelvis. (Repro- duced with permission from [14])

Fig. 12.22a,b. Vaginal stenosis. T2-weighted images in axial and sagittal orientation. Vaginal stenosis in the proximal third of the va- gina after radiotherapy. There is hematometra (a) and hematosalpinx (b) (short arrows). (Reproduced with permission from [13])

a b

12.5.2.5

MR Appearance After Surgery

The postoperative appearance varies with the type of surgery performed. Shortly after surgery, scars are characterized by a high signal intensity on T2- weighted images and there is abnormally increased contrast enhancement on T1-weighted images due to postoperative edema formation and neovasculariza- tion. These reactive changes are diffi cult to distin- guish from residual or recurrent tumor in the early postoperative phase [12].

12.5.2.6

Residual and Recurrent Tumor

With its intrinsic high soft-tissue contrast, MRI is the method of choice for demonstrating residual tumor or tumor recurrence. Moreover, MRI allows identi- fi cation of radiation-induced changes of the organs of the true pelvis. Postoperative scars or postactinic changes can be differentiated from recurrent or residual tumor on MR images on condition that the examination is performed at least 6 months after the end of therapy. This interval is necessary because acute reactive increases in signal due to edema and infl ammation immediately after irradiation or sur- gery cannot be differentiated from vital tumor tissue.

After about 6 months, the vagina has returned to its normal low signal intensity on T2-weighted images and residual or recurrent tumor can be identifi ed as a high-signal-intensity disruption of the vaginal wall [12]. Recurrent tumor has an increased signal intensity on T2-weighted images and typically shows an inhomogeneous structure. On contrast-enhanced images, recurrent tumor is characterized by a higher signal enhancement compared with surrounding tissue. However, the examiner must be aware that even after 6 months following radiation or surgery, increased signal intensities may be due to postthera- peutic reactive changes. In such cases, a dynamic con- trast-enhanced fast GRE study may be helpful. Here, recurrent or residual tumor will show signifi cantly earlier and more pronounced contrast enhancement than scar tissue. As in pretherapeutic staging, con- trast-enhanced T1-weighted images are helpful to identify possible invasion of the bladder or rectum by recurrent or residual tumor. Tumor invasion of these organs is indicated by circumscribed areas of abnormally increased contrast enhancement in the wall. As in preoperative staging, muscular infi ltration is best seen on T2-weighted images.

Ultrasonography and CT have only a limited role in detecting recurrent or residual vaginal tumor because they rely on the confi guration of the lesion as the only criterion. The sensitivity of both modalities is too low for differentiation of tumor from posttherapeutic changes and for the detection of small tumors. The accuracy of the clinical examination is also limited, in particular when postoperative scar tissue is present.

12.5.2.7 Lymph Nodes

Imaging of the inguinal, pelvic, and, where necessary, para-aortic lymph node stages by means of MRI/

CT may provide additional information for primary therapeutic decision making. Although the inguinal lymph nodes are easily accessible to palpation, pal- pation has a poor sensitivity in detecting inguinal lymph node metastasis. Evaluation for lymph node metastasis is clinically relevant before surgery and before primary or adjuvant radiotherapy. Moreover, a considerable proportion of recurrent vaginal tumors arise from lymph node metastases. The criteria for lymph node imaging are described in Chapter 14.

References

1. Hricak H, Chang YC, Thurnher S (1988) Vagina: evalua- tion with MR imaging. Part I. Normal anatomy and con- genital anomalies. Radiology 169:169–174

2. Haddad B, Louis-Sylvestre C, Poitout P, Paniel BJ (1997) Longitudinal vaginal septum: a retrospective study of 202 cases. Eur J Obstet Gynecol Reprod Biol 74:197–199 3. Carrington BM, Hricak H, Nuruddin RN, Secaf E, Laros

RK, Jr., Hill EC (1990) Mullerian duct anomalies: MR imaging evaluation. Radiology 176:715–720

4. Pellerito JS, McCarthy SM, Doyle MB, Glickman MG, DeCherney AH (1992) Diagnosis of uterine anomalies:

relative accuracy of MR imaging, endovaginal sonogra- phy, and hysterosalpingography. Radiology 183:795–800 5. Feller ER, Ribaudo S, Jackson ND (2001) Gynecologic

aspects of Crohn’s disease. Am Fam Physician 64:1725–

1728

6. Creasman WT (2005) Vaginal cancers. Curr Opin Obstet Gynecol 17:71–76

7. Piura B, Rabinovich A, Yanai-Inbar I (2002) Primary malignant melanoma of the vagina: case report and review of literature. Eur J Gynaecol Oncol 23:195–198 8. Merino MJ (1991) Vaginal cancer: the role of infectious

and environmental factors. Am J Obstet Gynecol 165:1255–

1262

9. Lopez C, Balogun M, Ganesan R, Olliff JF (2005) MRI of

vaginal conditions. Clin Radiol 60:648–662