Pelvic anomaly

Arrest of labor with the necessity of performing secondary cesarean section is a major cause of maternal morbidity and mortality. The fetus is likewise affected hy prolonged labor. Pelvimetry is performed to identify those women in whom an attempt at vaginal delivery is likely to fail due to a narrow pelvis or pelvic anomaly. Hence, the clinical significance of pelvimetry depends on how the following questions are answered ... 

Only 0.5%-l% of all pregnant women have such obvious pelvic anomalies that absolute cephalopelvic disproportion is highly likely. The risk of abso-... 

Table6.1. Suggested guidelines (Nievelstein et al. 1998b) for MR protocol for neonates and infants with anorectal malformations (based on a 1-T or 1.5-T magnet using ahead coil for neonates and a phased arraybody coil for older children). Axial and coronal planes should be angled to be parallel and perpendicular to the pelvic floor. Imaging of the spinal cord and kidneys is only necessary if associated anomalies are suspected...

Magnetic resonance (MR) imaging is suitable for assessing female infertility, as infertility typically results from benign processes in women of reproductive age. The causes of female infertility include ovulatory disorders (i.e., pituitary adenoma and polycystic ovarian syndrome), disorders of the fallopian tubes (i.e., hydrosalpinx and pelvic inflammatory disease), uterine disorders (i.e.,mullerian duct anomaly, aden-omyosis, and leiomyoma), and pelvic endometriosis. 

Other indications are rarer. Imaging of urethral malformation or trauma remains based on the voiding part of VCU. Patients with cloacal anomalies, ambiguous genitalia, or imperforate anus can be explored. On the other hand, the role of VCU in investigating pelvic or bladder tumors has decreased since the advent of cystoscopy and MRI. 

Anomalies of renal position and rotation are well demonstrated by the high resolution anatomic images. Horseshoe and ectopic kidneys can be easily separated from the background and overlying tissues. Pelvic kidneys in particular, which often are significantly smaller than the normally positioned kidney, are well demonstrated with MR urography (Fig. 1.2.13). Hypoplastic kidneys associated with ureteric ectopia and supernumerary kidneys, which have been difficult to demonstrate with other imaging modalities, can usually be demonstrated even if there is minimal renal function. 

The contralateral kidney may be abnormal in up to 50% of patients (Malek et al. 1971). There is a 10% incidence of contralateral renal agenesis. In up to 70% of children with pelvic kidney there is associated VUR (Kramer and Kelalis 1984). In most cases of renal ectopy the adrenal gland is in normal position. Genital anomalies were found ranging from 15% of males to 75% of females (Thompson and Pace 1937 Downs et al. 1973). Skeletal anomalies occur in up to 50% of children, cardiovascular lesions were found in 9 out of 21 children (Malek et al. 1971) and gastrointestinal abnormalities in one-third of patients (Ritchey 1992). 

Daneman A, Alton DJ (1991) Radiographic manifestations of renal anomalies. Radiol Clin North Am 29 351-363 Downs RA, Lane JW, Burns E (1973) Solitary pelvic kidney its clinical implications. Urology 1 51-56 Evans WP, Resnick MI (1981) Horseshoe kidney and urolithiasis. J Urol 125 620-621... 

Fig. 5.5. MR imaging of bilateral infundibulo-pelvic stenosis. T2-weighted sequence. The anomaly is associated with a right megaureter and with a segmental ureteral cystic dilatation to the left ureter...

Pediatric radiologists will commonly come across mUllerian duct anomalies at two different stages of a girl s life. In neonates diagnostic requests encompass evaluation of a palpable abdominal mass and delineation of associated genital malformation in urogenital sinus anomalies. In adolescent girls delay in puberty or primary amenorrhea as well as pelvic... 

The diagnosis of cloacal malformation includes a wide spectrum of pelvic and perineal anomalies. Associated malformations of the inner genitalia and urinary tract need to be considered. 

For all other anomalies, especially multicystic dysplastic kidney, renal ectopia, or unilateral agenesis, the workup should also include US and eventually a VCU in order to detect ipsi- or contralateral VUR, which would require prophylactic chemotherapy (AxiYEHetal. 1993 Flack and Bellinger 1993 Selzman and Elder 1995 Ismaili et al. 2005). Also of interest is to search for associated genital anomalies on pelvic ultrasound (Table 13.5) (Riccabona et al. 2006). 

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