Role of endorectal prostate MRI in patients with initial suspicion of prostate cancer

PURPOSE

To evaluate the role of conventional endorectal prostate MRI in patients with initial suspicion of prostate cancer.

MATERIALS AND METHODS

Ethics board approval was received for this retrospective study of 87 men who underwent 1.5-Tesla conventional prostate MRI with a combination of endorectal and body phased-array coils for suspected prostate cancer before their first systematic 12-core TRUS-guided biopsy. Three radiologists independently analyzed the images, dividing the prostate into 12 regions corresponding to the biopsy scheme and scoring each region for the presence of prostate cancer on a 5-point scale. Results were analyzed by prostate region. ROC analysis was done and descriptive statistics were calculated. The negative predictive value, specificity, sensitivity and positive predictive value were calculated using dichotomized scores (benign tissue = scores of 1 and 2; malignant tissues = scores of 3, 4, and 5).

RESULTS

Biopsy revealed cancer in 47/87 patients (26 low-grade [Gleason score 6]; 21 high-grade [Gleason score ≥ 3 + 4]), and 184/1044 cores (77 low-grade and 107 high-grade) with a median of 3 positive cores per cancer patient (range 1 – 12). The areas under ROC curves were 0.65 – 0.67 for cancer detection by region overall and 0.75 – 0.76 for the detection of high-grade cancer by region. Statistic figures for the detection of all cancers/high-grade cancers by region were as follows: negative predictive value, 87.4 – 88.2 %/92.6 – 93.1 %; specificity, 72.3 – 79.4 %/71.5 – 79.8 %; sensitivity, 49.5 – 54.8 %/62.6 – 69.2 %; and positive predictive value, 29.3 – 34.0 %/29.4 – 34.7 %.

CONCLUSION

In patients with suspected prostate cancer, negative MRI findings indicate the absence of high-grade prostate cancer on subsequent TRUS-guided 12-core biopsy with high probability. However, agreement between conventional 1.5-T endorectal prostate MRI and systematic 12-core TRUS-guided biopsy for the detection of prostate cancer appears to be moderate.

Role of endorectal prostate MRI in patients with initial suspicion of prostate cancer

PURPOSE

To evaluate the role of conventional endorectal prostate MRI in patients with initial suspicion of prostate cancer.

MATERIALS AND METHODS

Ethics board approval was received for this retrospective study of 87 men who underwent 1.5-Tesla conventional prostate MRI with a combination of endorectal and body phased-array coils for suspected prostate cancer before their first systematic 12-core TRUS-guided biopsy. Three radiologists independently analyzed the images, dividing the prostate into 12 regions corresponding to the biopsy scheme and scoring each region for the presence of prostate cancer on a 5-point scale. Results were analyzed by prostate region. ROC analysis was done and descriptive statistics were calculated. The negative predictive value, specificity, sensitivity and positive predictive value were calculated using dichotomized scores (benign tissue = scores of 1 and 2; malignant tissues = scores of 3, 4, and 5).

RESULTS

Biopsy revealed cancer in 47/87 patients (26 low-grade [Gleason score 6]; 21 high-grade [Gleason score ≥ 3 + 4]), and 184/1044 cores (77 low-grade and 107 high-grade) with a median of 3 positive cores per cancer patient (range 1 - 12). The areas under ROC curves were 0.65 - 0.67 for cancer detection by region overall and 0.75 - 0.76 for the detection of high-grade cancer by region. Statistic figures for the detection of all cancers/high-grade cancers by region were as follows: negative predictive value, 87.4 - 88.2 %/92.6 - 93.1 %; specificity, 72.3 - 79.4 %/71.5 - 79.8 %; sensitivity, 49.5 - 54.8 %/62.6 - 69.2 %; and positive predictive value, 29.3 - 34.0 %/29.4 - 34.7 %.

CONCLUSION

In patients with suspected prostate cancer, negative MRI findings indicate the absence of high-grade prostate cancer on subsequent TRUS-guided 12-core biopsy with high probability. However, agreement between conventional 1.5-T endorectal prostate MRI and systematic 12-core TRUS-guided biopsy for the detection of prostate cancer appears to be moderate.

Changes in the MRI morphology of the stress continence control system after TVT (tension-free vaginal tape) insertion

OBJECTIVE

Magnetic resonance imaging (MRI) was used to investigate whether tension-free vaginal tape (TVT) insertion (according to Ulmsten) leads to morphologic changes of the stress continence control system.

METHODS

Twenty women (mean age 53.4 years) with clinically and urodynamically proven stress urinary incontinence without prolapse were examined by MRI before and 13 months after TVT insertion.

RESULTS

Postoperative MRI showed a signal intensity loss of the suburethral portion of the endopelvic fascia in the area of the anterior vaginal wall in 9/20 women with additional signal loss of the paraurethral portion of the fascia in 3/20 women. No morphologic changes of the levator ani muscle and the urethra were seen postoperatively.

CONCLUSIONS

TVT insertion does not damage the structures of the stress continence control system or impact on their topographic relationships. MRI identified no excessive scar formation resulting from integration of the TVT.

Histopathologische Qualität von Prostatastanzzylindern: Vergleich einer MR-kompatiblen Biopsienadel mit einer im Ultraschall eingesetzten ferromagnetischen Biopsienadel

PURPOSE

The histopathologic quality of core biopsy specimens obtained via MRI-guided prostate biopsy using a 16G MR-compatible needle was compared to that of biopsies obtained via ultrasound-guided biopsy using a conventional 18G stainless steel biopsy needle.

MATERIAL AND METHODS

A retrospective analysis was performed for a total of 247 transrectal prostate biopsy specimens obtained from 32 patients. A total of 117 tissue cores were obtained from 15 patients (PSA of 10.8 ng/ml, age 64 years) who underwent an MRI-guided prostate biopsy using a 16G (1.7 mm) MR-compatible biopsy needle made of titanium alloy. The remaining 130 tissue cores were obtained from 17 patients (PSA of 6.7 ng/ml, age 68 years) who underwent a transrectal ultrasound-guided prostate biopsy using an 18G (1.3 mm) ferromagnetic stainless steel biopsy needle. The length and width of the histologic sections prepared from the tissue cores were measured to calculate the area. The histopathologic quality of the specimens was assessed microscopically using tissue fragmentation, the presence of crush artifacts, and the overall accessibility as criteria. Each of these features was assigned a score from 0 to 3. All 3 features contributed equally to the overall score which ranged from 0 (no tissue) to 9 (optimal quality).

RESULTS

The overall quality scores assigned to the biopsies obtained with a 16G MR-compatible needle and an 18G ferromagnetic needle can be considered to be equivalent to a mean difference between patient related median scores of the specimens of - 0.05 (95 % confidence interval [- 0.46; 0.36]) and a given equivalence limit of 1. The MRI biopsies showed more tissue fragmentation (p = 0.001) but fewer crush artifacts (p = 0.022) while the accessibility did not differ significantly between the two needle types (p = 0.064). There was also no significant difference in the calculated areas of the tissue cores (p = 0.236). According to the different calibers of the biopsy needles, the lengths (p = 0.008) and widths (p = 0.000) of the biopsy specimens differed significantly.

CONCLUSIONS

The core biopsy specimens obtained with an MR-compatible 16G titanium alloy biopsy needle are of the same histopathologic quality as specimens obtained with a ferromagnetic 18G stainless steel needle.

Visibility of the polypropylene tape after tension-free vaginal tape (TVT) procedure in women with stress urinary incontinence: comparison of introital ultrasound and magnetic resonance imaging in vitro and in vivo

OBJECTIVE

To determine whether introital sonography and magnetic resonance imaging (MRI) after TVT (tension-free vaginal tape) insertion can depict the polypropylene tape, and thus be used for patient follow-up.

METHODS

The study comprised an experimental part, which investigated in-vitro visualization of the polypropylene tape in a model (phantom), and a clinical part, in which 20 women (mean age, 53.4 years) with clinically and urodynamically proven stress urinary incontinence without prolapse were investigated by introital ultrasound and MRI before and 13 months after the TVT procedure.

RESULTS

In the phantom, the polypropylene tape was depicted with a low signal intensity by MRI and as a highly echogenic structure by ultrasound. In the clinical study, introital ultrasound in a mediosagittal orientation depicted the vaginal tape in all patients: it was located under either the midurethra (n = 16) or the lower urethra (n = 4), and in either the muscular coat of the urethra (n = 8) or in the urethrovaginal space (n = 12), the tape was either flat (n = 6) or curled up (n = 14), and there was no retropubic visualization of the tape. Overall, depiction by MRI was limited, and was poorer in comparison with ultrasound, especially when the tape had a sub- or paraurethral location. Retropubically, however, MRI identified the tape near the periosteum of the pubic bone (55% of cases), in the retropubic space (37.5% of cases), or near the bladder wall (7.5% of cases).

CONCLUSION

Sonography is recommended for evaluation of the suburethral and paraurethral tape portions, while MRI is suitable for retropubic evaluation after the TVT procedure.

Complex genital malformation in a female with congenital adrenal hyperplasia: evaluation with magnetic resonance imaging

This is a case of complex genital malformation in a young patient with congenital adrenal hyperplasia. The magnetic resonance imaging (MRI) findings included ostium of the vagina into the urethra (common urogenital opening), prostate-like tissue surrounding the urethra, and hyperplasia of the left adrenal gland. The report provides information on the clinical findings, the MRI examination, including the applied sequences and the MR findings, and gives an overview of the disease pattern and its frequency of occurrence.

Pathogenesis of urethral funneling in women with stress urinary incontinence assessed by introital ultrasound

OBJECTIVE

The incidence of urethral funneling (UF) seen in women with stress urinary incontinence (SUI) during straining is reported to range from 18.6% to 97.4%. Its morphologic basis is unknown. The aim of the present study was to determine whether SUI patients with and without UF differ in terms of history, urodynamic results and magnetic resonance imaging (MRI) findings.

PATIENTS AND METHODS

Fifty-four women (mean age 52 +/- 11 years) with a history of SUI confirmed by clinical and urodynamic findings were included in the study. UF was demonstrated by introital ultrasound performed at a bladder filling volume of 300 mL during maximal straining. MRI for assessment of the urethra, levator ani muscle and endopelvic fascia was performed using axial proton-density-weighted sequences.

RESULTS

UF was demonstrated by introital ultrasound in 59% of the patients with SUI (Group 1) and was absent in 41% (Group 2). There were no differences between the two groups in mean age (P = 0.208), the incidence of mild prolapse of the anterior vaginal wall (Aa, Ba; stage I; P = 0.741), and urodynamic parameters (urethral closure pressure at rest; P = 0.507). The percentages of nulliparous and parous women were 22% and 78% in Group 1 and 54% and 46% in Group 2 (P = 0.013). The two groups did not differ in the MRI demonstration of morphologic defects of the urethra, levator ani muscle and endopelvic fascia or of combined defects.

CONCLUSIONS

The results of the present study did not elucidate the pathogenesis of UF. The demonstration of UF crucially depends on the examination technique employed.

Morphology of the suburethral pubocervical fascia in women with stress urinary incontinence: a comparison of histologic and MRI findings

To correlate MRI with histologic findings of the suburethral pubocervical fascia in women with urodynamic stress incontinence. Thirty-one women with urodynamically proven stress urinary incontinence without relevant prolapse underwent preoperative MRI. Tissue specimens obtained from the pubocervical fascia were examined immunohistochemically (types I and III collagen, smooth muscle actin) and the results compared with the MRI findings. MRI demonstrated an intact pubocervical fascia in 61.3% of the cases and a fascial defect in 38.7%. A fascial defect demonstrated by MRI was associated with a decrease in actin (P<0.09) and an increase in collagen III (P<0.01) compared to an intact fascia. In women with stress urinary incontinence, smooth muscle actin in the pubocervical fascia is decreased, changed in structure, and replaced by type III collagen. MRI allows evaluation of the pubocervical fascia and its morphologic changes.

Differentiation of Prostate Cancer from Normal Prostate Tissue in an Animal Model: Conventional MRI and Dynamic Contrast-enhanced MRI

PURPOSE

To differentiate orthotopically implanted prostate cancer from normal prostate tissue using magnetic resonance imaging (MRI) and Gd-DTPA-BMA-enhanced dynamic MRI in the rat model.

MATERIAL AND METHODS

Tumors were induced in 15 rats by orthotopic implantation of G subline Dunning rat prostatic tumor cells. MRI was performed 56 to 60 days after tumor cell implantation using T1-weighted spin-echo, T2-weighted turbo SE sequences, and a 2D FLASH sequence for the contrast medium based dynamic study. The interstitial leakage volume, normalized permeability and the permeability surface area product of tumor and healthy prostate were determined quantitatively using a pharmacokinetic model. The results were confirmed by histologic examination.

RESULTS

Axial T2-weighted TSE images depicted low-intensity areas suspicious for tumor in all 15 animals. The mean tumor volume was 46.5 mm(3). In the dynamic study, the suspicious areas in all animals displayed faster and more pronounced signal enhancement than surrounding prostate tissue. The interstitial volume and the permeability surface area product of the tumors increased significantly by 420 % (p < 0.001) and 424 % (p < 0.001), respectively, compared to normal prostate tissue, while no significant difference was seen for normalized permeability alone.

CONCLUSION

The results of the present study demonstrate that quantitative analysis of contrast-enhanced dynamic MRI data enables differentiation of small, slowly growing orthotopic prostate cancer from normal prostate tissue in the rat model.

MRT zur Problemlösung beim Nachweis des Prostatakarzinoms

Prostate cancer is the most common malignancy in males. Men aged 50 and older are recommended to undergo an annual digital rectal examination (DRE) and determination of prostate-specific antigen (PSA) in serum for early detection. However, prostate biopsies guided by transrectal ultrasound (TRUS) come up negative for cancer in many patients despite having PSA levels above 4 ng/ml. T2-weighted Magnetic Resonance Imaging (MRI) is able to represent the prostate including the surrounding anatomy and depict suspicious areas of low intensity within a high-intensity peripheral zone. MRI has a higher sensitivity for detecting prostate carcinomas than DRE and TRUS in patients having an elevated PSA value and a negative core biopsy. However, its specificity is poor since other abnormalities such as prostatic intraepithelial neoplasia (PIN), prostatitis, scars, or haemorrhage have a similar MRI appearance. The use of additional techniques such as MR spectroscopy and contrast-enhanced dynamic MRI improves sensitivity, but in particular it improves the specificity of tumor detection. Newly developed biopsy devices enable the performance of targeted biopsies in areas that appear suspicious in the MRI.

[Cross-section diagnosis of tumors of the kidney and prostate gland: CT and MRI]

Computed tomography (CT) and magnetic resonance imaging (MRI) underwent significant technical advances in the past ten years, especially in the diagnostic evaluation of renal tumors. Either modality can perform unenhanced and contrast enhanced imaging with high resolution display of three-dimensional data sets of the entire abdomen including the arterial and the parenchymatous perfusion phase after injection of contrast medium. Multiplanar reconstructions of these three-dimensional data allow the display in any chosen orientation. The maximum intensity projection can create CT and MR angiograms. For the diagnosis of renal tumors, both modalities offer the possibility of a detailed visualization of both the parenchyma and the arterial and venous vessels, leading to an efficient preoperative work-up. For the MRI diagnosis of the prostate cancer, the achievable accuracy depends on the applied coil technique and on the available clinical information as well as on the experience of the examiner. For the preoperative MRI staging of prostate cancer, the accuracy has been stated to be between 51 % and 97 %.

[MRI of prostate cancer using three different coil systems: image quality, tumor detection, and staging]

PURPOSE

To compare three MRI coil systems in terms of image quality, delineation of prostate cancer, and tumor staging.

MATERIALS AND METHODS

49 patients with prostate cancer underwent MRI at 1.5 Tesla using a combination of an endorectal coil with a phased-array body coil (combination coil) prior to radical prostatectomy. Images were reconstructed from the data sets acquired with the endorectal coil alone and from those acquired with the combined coil. In addition, 19 patients of the study patients were examined with the body phased-array coil alone without the endorectal coil. The prostate was imaged at a slice thickness of 3 mm using axial and coronal T 2 -weighted sequences and an axial T 1 -weighted sequence. Preoperative analysis of all images acquired was done to determine the accuracy of MRI in local staging of prostate cancer. An additional retrospective analysis served to compare the different coil systems in terms of overall image quality, delineation and localization of the tumor, and criteria for local staging of prostate cancer.

RESULTS

Preoperative analysis showed MRI to have an accuracy of 59 % in local tumor staging. Retrospective coil-by-coil analysis demonstrated image quality and tumor delineation to be best for the combination coil and the endorectal coil. Regarding the staging criteria for transcapsular tumor extension and infiltration of adjacent organs, a significant advantage of the combination coil compared to the endorectal coil was identified only for the criterion of smooth bulging. In addition, the endorectal coil and the combination coil were found to be superior to the body phased-array coil in assessing 15 of 17 criteria for local tumor staging but the differences were not significant.

CONCLUSION

In view of the achieved superior image quality, the combination coil or the endorectal coil is the preferred method for staging prostate cancer.

[Use of state-of-the-art ultrasound techniques in diagnosing sarcoidosis of the salivary glands (Heerfordt's syndrome)]

AIM

The parotid gland is a rare site of sarcoidosis (6% of all cases). The role of state-of-the-art ultrasound techniques in the diagnostic assessment of parotid sarcoidosis (Heerfordt's syndrome) is presented.

PATIENTS AND METHODS

Four patients (three male, one female; aged 31-42 years) with inconclusive parotid swelling associated with fever and uveitis were referred for diagnostic assessment by the ENT outpatient service over a 1 year period. High-resolution ultrasound (US) was performed using the SONOLINE Elegra system with a 7.5-MHz wide-band transducer and various, special US techniques (tissue harmonic imaging, photopic imaging, color-coded duplex US, and power Doppler). Diagnoses were confirmed in all cases by puncture and histology.

RESULTS

Two patients with typical lung findings (stage I and II sarcoidosis) and two patients without known sarcoidosis showed an inhomogeneous nodular appearance of the clinically enlarged salivary glands at US. Duplex US demonstrated hypervascularization in three cases and moderate, inhomogeneous vascularization in one. In comparison to plain B-mode scanning, optimal visualization of the hypodense, nodular, structural changes was achieved using contrast-enhancing techniques. All patients underwent US-guided puncture for determining the etiology of parotitis. Histology demonstrated granulomatous epitheloid cell inflammation.

CONCLUSION

An inhomogeneous nodular appearance of the parenchyma of enlarged parotid glands with areas of hypervascularization, which is optimally depicted by state-of-the-art US techniques, should suggest Heerfordt's syndrome as a possible differential diagnosis.

[Image quality and detection of pathology by ultrasound: comparison of B-mode ultrasound with photopic imaging and tissue harmonic imaging alone and in combination]

PURPOSE

To determine the accuracy of photopic imaging (PI) in detecting pathology by ultrasound (US) and to assess the image quality in direct comparison with conventional B-mode ultrasound and tissue harmonic imaging (THI).

MATERIAL AND METHODS

Fifty-two patients underwent US examination, among them 29 patients for abdominal assessment and 23 for otolaryngological assessment. A total of 208 freeze frames, 52 B-mode scans each with and without THI and 52 B-mode scans each with and without PI, were assessed by three readers, who determined the presence of pathology on a scale of 1 (definitely abnormal) to 5 (definitely normal). All 52 patients underwent US follow-up within six weeks. The results were confirmed by CT in 30 patients and by histology in five cases. Image quality and different color encodings of each technique were rated on a ranking scale of 1 (optimal) to 4 (poor). The different US techniques were compared in terms of image quality, diagnostic accuracy, and color encoding using McNemar's test and ROC analysis.

RESULTS

The results for image quality were as follows: B-scan 3.9; THI 1.9; PI 2.8; and THI plus PI 1.5 (each p < 0.05). The following AUCs (Area under Curve, presence of pathology) were calculated: 0.925, 0.990, and 0.990 for B-mode US, THI, and PI, respectively (not significant), and 0.994 for THI plus PI (significant compared to B-mode scan). The different color encodings were rated as follows: reddish brown 1.6, gray 1.9, blue 3.1, and green 3.6 (each p < 0.05).

CONCLUSION

For ultrasound examinations, PI in combination with THI improves the image quality and conspicuity of pathology.

[Ultrasound at the bedside: does a portable ultrasound device save time?]

AIM

To prospectively determine whether the use of a portable ultrasound device results in a detectable reduction of the time required for acute ultrasound (US) assessment at the bedside.

MATERIALS AND METHODS

A total of 125 patients underwent US at the bedside, among them 68 for abdominal assessment, 12 patients for chest or soft-tissue evaluation, and 45 patients with vascular disease. Five different US systems equipped with 3.5 MHz and 7.5 MHz wide-band transducers were compared in terms of overall examination time including transport, setting up and disassembling, switching on and off as well as initializing the device (but without writing of the report). The following ultrasound systems were used: the portable SonoSite 180 (SonoSite, Germany) as well as the mobile units Masters/Gateway 2000 (Diasonics, USA), Tosbee (Toshiba, Japan), PowerVision 7000 (Toshiba, Japan), and SONOLINE Elegra (Siemens AG, Germany).

RESULTS

The portable ultrasound device significantly reduced the examination time per patient to a mean 16 +/- 4 min from 26 +/- 5 min for the mobile units (p < 0.05). This result was predominantly affected by the time required for switching on and initializing the device as well as the duration of positioning at the bedside and to a lesser extent by elevator waiting time.

CONCLUSION

The overall time required for performing an ultrasound examination at the bedside can be considerably reduced if a portable device is used instead of a mobile system.

Diagnosis of Heerfordt's syndrome by state-of-the-art ultrasound in combination with parotid biopsy: a case report

The parotid gland is rarely affected by sarcoidosis (6% of all cases). If there is initial parotitis, and other major symptoms include fever, uveitis, or facial paralysis, the condition is referred to as Heerfordt's syndrome. The case presented here describes the diagnostic work-up and differentiation of swelling of the parotid gland by employing state-of-the-art ultrasound techniques in a 33-year-old patient with Heerfordt's syndrome. Color-coded duplex ultrasound demonstrated hypervascularization. Tissue harmonic and photopic imaging ultrasound additionally depicted hypoechoic, septated structural lesions of the glandular parenchyma with an optimized contrast. Since such structural changes are not a specific sonographic criterion for sarcoidosis, ultrasound-guided biopsy was performed for further clarification of the etiology of parotitis and for excluding lymphoma. In conclusion, state-of-the-art ultrasound with the option of obtaining a biopsy at low risk is a useful procedure for diagnosing unclear pathology of the parotid gland with rapid histological confirmation.

Magnetic resonance imaging of atherosclerotic plaques using superparamagnetic iron oxide particles

Experimental data show accumulation of superparamagnetic iron oxide (SPIO) particles in atherosclerotic plaques. SPIO uptake occurred in plaques, suggesting an increased endothelial permeability and macrophage infiltrates as signs of inflammatory plaque activity. We incidentally observed SPIO uptake in aortic and arterial wall segments in patients who had originally received the magnetic resonance (MR) contrast agent for staging lymph node metastases. Twenty patients (19 male, 1 female; mean age, 64; range, 41-78 years) with bladder or prostate cancer underwent MR imaging (MRI) using a T2*-weighted high-resolution gradient-echo sequence prior to and 24-36 hours after intravenous injection of 2.6 mg of Fe/kg of SPIO (Sinerem). The aorta, both common external and internal iliac, as well as both superficial femoral arteries, were retrospectively analyzed for atherosclerotic wall changes. One patient was excluded. A positive finding was defined as an area of pronounced signal loss on postcontrast images clearly confined to the arterial wall, which was absent in the precontrast examination or increased in size. Such a finding was observed in one to three arteries in 7 of the 19 patients. The pronounced signal loss in the wall of the aorta and pelvic arteries seen in part of an elderly patient population after intravenous SPIO administration strongly suggests that this contrast agent accumulates in human atherosclerotic plaques.

[Contribution of MRI in diagnosis of urinary stress incontinence without concomitant urogenital prolapse]

PURPOSE

To detect pathomorphological changes of the pelvic floor, the vagina, and the urethra by MR imaging in patients with stress urinary incontinence in the absence of organ descent compared with findings in 10 healthy controls.

MATERIALS AND METHODS

The study included 10 healthy controls and 38 patients with stage II urinary incontinence showing no urge symptoms but a pathological stress profile on urodynamic testing. The subjects underwent MR imaging with a phased-array coil at 1.5 T in addition to urodynamic testing and gynecological examination. The following sequences were used: axial and coronal PD-weighted TSE sequences with a FOV of 20 cm and a section thickness of 4 mm; axial STIR sequence. Sagittal T2-weighted HASTE sequences were acquired during pelvic floor contraction, relaxation, and straining maneuvers.

RESULTS

In 22/38 cases pathomorphological changes were found by MR imaging. The pathomorphological changes were classified as lateral defects (n = 14) if the musculofascial connection between the levator muscle and the lateral vaginal wall or the butterfly shape of the vagina was absent and as central (n = 16) if changes were detected in the urethral wall. Defects of the pelvic floor muscles were detected in 8 cases. No underlying changes were identified in 16/38 cases.

CONCLUSION

In cases of female urinary incontinence, MR imaging of the pelvic floor can detect pathomorphological changes, which are difficult to identify by clinical examination. MR imaging currently does not allow the detection of morphological changes in all forms of female urinary stress incontinence.

Sexual function and testicular perfusion after inguinal hernia repair with mesh

BACKGROUND

Open tension-free techniques of hernia repair using synthetic meshes revealed an excellent patient comfort with low recurrence rates. The influence of the resulting fibrosis on testicular perfusion and sexual function is still unclear.

METHODS

In a prospective observation study testicular volume, perfusion, and sexual function was investigated before plug and patch repair, after 3 months, and every 6 months thereafter. Testicular volume and perfusion was examined by a standardized scrotal ultrasound and duplex sonography. Sexual function was assessed by a validated anonymized questionnaire.

RESULTS

Seventy-three patients were included and follow-up examinations by questionnaire and sonography, respectively, were completed in 73 and 68 patients after 3 months, 51 and 43 after 6, and 24 and 14 after 12 months. Preoperative testicular volume and flow volume was comparable between the side of hernia and the contralateral side (average 10.2 +/- 4.8 cm3 versus 9.8 +/- 5.3, respectively) and showed no significant differences during follow-up. In 11 (15%) patients with preexisting disorders sexual function was normalized postoperatively. Ten (14%) other patients (3 of them with neuralgia pain) described limitations of sexual activity due to inguinal pain (n = 4; 6%) or a loss of sensitivity in the inguinal area (n = 6; 8%) after the procedure. Among these, sexual function recovered spontaneously within 12 months postoperatively in 6 patients (2 with inguinal pain, 4 with loss of sensitivity). In all other patients sexual function showed no changes after inguinal hernia repair.

CONCLUSIONS

So far there is no evidence for a significant impairment of the cord structures and the sexual function after inguinal hernia repair in the plug and patch technique.

Sectional depiction of the pelvic floor by CT, MR imaging and sheet plastination: computer-aided correlation and 3D model

The structures of the pelvic floor are clinically important but difficult to assess. To facilitate the understanding of the complicated pelvic floor anatomy on sectional images obtained by CT and MR imaging, and to make the representation more vivid, a computer-aided 3D model was created from a male and a female torso to develop a teaching tool. A male and a female cadaver torso were investigated by means of CT, MR imaging, and serial-section sheet plastination. A 3D reconstruction of the pelvic floor and adjacent structures was performed by fusion of CT and MR imaging data sets with sheet plastination sections. Corresponding sections from all three methods could be compared and visualized in their 3D context. Sheet plastination allows distinction of connective tissue, muscles, and pelvic organs down to a microscopic level. In combination with CT, MR imaging, and sheet plastination a 3D model of the pelvic floor offers a better understanding of the complex pelvic anatomy. This knowledge may be applied in the diagnostic imaging of urinary incontinence or prolapse and prior to prostate surgery.

[Diagnosis of urethral diverticula and periurethral masses]

AIM

To give recommendations for the standard diagnostic assessment of urethral diverticula and periurethral masses based on an evaluation of our results and a survey of the recent literature.

METHODS

Group I (1981-1993) included 47 women in whom urethral diverticula (n = 34), periurethral cysts (n = 11), and periurethral leiomyomas (n = 2) were diagnosed and the results compared with the intraoperative findings. Diagnostic work-up comprised history taking, vaginal palpation, introitus ultrasound, double-balloon urethrography (DBU), voiding cystourethroscopy (VCU), excretion urography (EU), and urethrocystoscopy. Group II (1994-1996) included 12 women with urethral diverticula who were examined by DBU, 2D and 3D introitus ultrasound. The diagnostic accuracy of the different methods was assessed.

RESULTS

Group I: The diagnostic accuracy in identifying urethral diverticula was 85.3% for palpation, 61.5% for introitus ultrasound, 93.8% for DBU, 37.5% for EU, and 30.0% for urethrocystoscopy. Of all imaging modalities used, only introitus ultrasound depicted periurethral cysts and leiomyomas. Group II: The DBU, 2D and 3D introitus ultrasound had a diagnostic accuracy of 100% in identifying urethral diverticula.

CONCLUSIONS

Introitus ultrasound should be used as the basic diagnostic tool in clinically suspected urethral diverticula or periurethral masses and additional DBU should be restricted to cases with inconclusive findings.

[MRI of the prostate after combined radiotherapy (afterloading and percutaneous): histopathologic correlation]

AIM

To identify the MRI changes of the prostate after combined (high-dose rate interstitial with external beam) radiotherapy for, localized prostate cancer and to correlate the findings with histology in order to determine the value of MR imaging in the follow-up of these patients.

MATERIAL AND METHODS

Twenty-three patients underwent MR imaging at 1.5 T between 6 and 24 months after completion of combined radiotherapy. The prostate was imaged with axial and coronal T2-weighted sequences and axial T1-weighted sequences before and after intravenous administration of Gd-DTPA. Quadrant or sextant biopsy was performed in all cases and three patients with proven persistence of the tumor underwent salvage prostatectomy. The MRI findings were compared with the biopsy results or the large-area sections.

RESULTS

On T2-weighted images the fibrotically changed peripheral zone was hypointense while persistent tumor tissue showed hyperintensity. Solid tumors were depicted when they had a diameter of 1 cm or more. Persistent tumors of the diffuse multifocal type escaped detection. Contrast-enhanced T1-weighted imaging yielded no additional information. The accuracy in detecting persistent tumor was 74%.

CONCLUSIONS

Histopathologic changes seen after combined radiotherapy correlate with the findings on T2-weighted MR images. MR imaging cannot replace follow-up by routine biopsy. Its only role is assessing local operability in cases found to have increasing PSA levels during follow-up. Further studies are needed to determine the role of MR imaging in this patient population.

[The staging of bladder tumors in MRT: the value of the intravesical application of an iron oxide-containing contrast medium in combination with high-resolution T2-weighted imaging]

AIM

To investigate superparamagnetic iron oxide (SPIO) particles as intravesically applied contrast material in combination with high-resolution T2-weighted MR imaging for the diagnostic assessment of urinary bladder tumors.

METHODS

A prospective study was performed in 40 patients with suspected urinary bladder tumors who underwent MR imaging with a body phased-array coil at 1.5 T. Prior to imaging, a SPIO-containing solution (179.2 mg Fe/l) was instilled into the bladder. All patients were examined with T2-weighted, half-fourier acquired single shot turbo spin echo sequences and T1-weighted fast low angle shot sequences in 3 planes as well as a T2-weighted turbo spin echo sequence (TSE) using a 512 matrix. An additional gadolinium-enhanced dynamic study was performed in 33 patients. All patients underwent transurethral resection of the bladder or cystectomy.

RESULTS

The combination of intravesically applied SPIO particles and a high-resolution T2-weighted TSE sequence depicted intravesical tumors as small as 4 mm. A reliable identification of the different layers of the bladder wall was possible in 5 cases only. The T2-weighted TSE sequence allowed the correct determination of the depth of infiltration in 29 of 36 patients with urothelial cancer by assessing the inner and outer boundary of the urinary bladder wall. This sequence had a diagnostic accuracy of 81% compared to 84% for the dynamic study (26/31).

CONCLUSION

Even small tumors could be identified with the T2-weighted TSE sequence after intravesical administration of SPIO particles but it was not possible to reliably differentiate the layers of the bladder wall. The results suggest that a dynamic MR imaging study cannot be dispensed with in patients with urinary bladder cancer.

[Results of CT-guided puncture biopsies in the abdominal and pelvic regions]

Results of 285 abdominal and pelvic CT-monitored biopsies are presented. 81.6% of the histological biopsies (n = 46) were evaluable (39.1% right positive, 43.5% right negative, 4.35% suspect). In 13% no definite findings were made. For the cytologic examinations and those due to an abscess 44.8% led to a right positive diagnosis and 23.8% gave a true negative finding. In 4.2% of the cases a suspect finding was given. 28% of all cytological evaluations were not definite. The complication rate was 1%.