Magnetic resonance imaging for stress incontinence: evaluation of patients before and after surgical correction

OBJECTIVE: The purpose of this study was to evaluate the accuracy of magnetic resonance imaging (MRI) in the pre and postoperative assessment of stress urinary incontinence. METHODS: Fifteen female patients with clinical evidence of stress urinary incontinence were included in this prospective study. All the patients underwent MRI in the supine position both preoperatively and postoperatively. For imaging, we used a 1.0 T magnet, T2-weighted images were obtained in the midline sagittal plane with patients at rest. Images were evaluated for anatomical stress urinary incontinence alterations, such as the increased distance between the pubococcygeal line and the bladder base and the posterior urethro-vesical angle and the urethral inclination angle changes. Wilcoxon signed rank test allowed comparisons of pre and postoperative results. RESULTS: Compared with postoperative measurements, the bladder base was lowered significantly by an average of 9.4+/-4.0 mm (P<0.01), posterior urethro-vesical angle was significantly increased by an average of 127.8+/-11.4 degrees (P<0.01), and the urethral inclination angle was significantly increased by an average of 54.9+/-10.1 degrees (P<0.01) preoperatively. CONCLUSION: Our results suggest that MRI can play a major role in the preoperative and postoperative assessment of stress urinary incontinence. It can reliably detect anatomical urinary incontinence alterations. MRI should be considered in failed surgery, complex prolapse, and in differentiating genuine stress incontinence resulting from malposition of the bladder neck from stress incontinence due to intrinsic urethral damage.     

Effect of exercise induced hyperlactatemia on the biodistribution and metabolism of iodine-123-15-(p-iodophenyl)-3-R,S-methyl pentadecanoic acid in normal volunteers

We have evaluated the biodistribution and metabolism of iodine-123-15-(p-iodophenyl)-3-R,S-methyl pentadecanoic acid (BMIPP) in the presence of increased lactate levels induced by short-term heavy exercise. Five healthy male subjects received 159 MBq (±13 MBq) ¹²³I-BMIPP at rest and a week later after they performed a maximal exercise test using a bicycle ergometer. Planar and tomographic images were obtained with a dual-head gamma camera up to 4 h after administration of the tracer. Multiple blood samples were taken at different time points for blood clearance, substrate concentration measurements and for HPLC analysis of metabolites. The exercise test did not alter plasma glucose and non-esterified fatty acid concentrations, but blood lactate increased from 1.12 mmol/l at rest to 9.26 mmol/l with maximal exercise. After exercise, BMIPP showed a significantly faster plasma clearance than at rest and the production of PIPA, the end metabolite of BMIPP oxidation, was reduced. Activity in the heart was similar after exercise and at rest on planar images 15 min after injection (4.83±0.50%ID vs 4.80±0.43%ID, P=NS), although the myocardium-to-cavity activity ratio, as determined on the SPET images 20 min after tracer injection, was slightly increased after the exercise test (4.20±0.63 vs 3.78±1.34 at rest, P=NS). Significantly increased activity was observed in a leg muscle region of interest after exercise (4.98±0.50%ID vs 3.93±0.44%ID at rest, P=0.02). Between early and late images, tracer washout from the myocardium increased from 20.72% at rest to 36.72% after exercise (P<0.05), but was unchanged for liver and leg muscles. The metabolic and physiological alterations induced by exercise do not degrade image quality of BMIPP scintigraphy. On the contrary, exercise-induced hyperlactatemia seems to enhance myocardium-to-cavity activity ratios on SPET images, although this effect does not reach statistical significance in this small group of normal subjects. These findings further support the robustness of BMIPP SPET in varied metabolic environments. Received 7 June and in revised form 7 August 1999     

盆底MRI在女性压力性尿失禁诊疗中的应用价值

目的 探讨盆底MRI在女性压力性尿失禁(SUI)诊疗中的应用价值。方法 前瞻性收集2017年1月至2019年1月首都医科大学附属北京朝阳医院的SUI组和对照组受试者,部分SUI患者行尿道中段悬吊带术(TVT)治疗。受试者均行盆底动态MRI检查(静息相及力排相),对SUI组尿道、膀胱颈功能及盆腔器官脱垂进行定性、定量诊断,分析SUI组TVT术后尿道移动角度、膀胱颈及尿道开放、盆底器官脱垂程度变化。采用独立样本t检验(正态分布)或秩和检验(偏态分布)比较对照组和SUI组患者计量资料的差异,采用χ2检验比较计数资料的差异。结果 对照组25例,SUI组33例,31例行TVT治疗,其中12例于术后3~ 6个月复查盆底MRI,纳入术后观察。力排相下,SUI组较对照组,功能尿道长度、尿道移动角度、H线、M线、膀胱漏斗征、尿道开放和膀胱脱垂的差异有统计学意义(P<0.05)。膀胱漏斗征及尿道开放征术前、后的差异有统计学意义(P<0.05)。TVT术后SUI患者的膀胱脱垂程度减小,子宫脱垂程度增大,但差异无统计学意义(P>0.05);TVT术后SUI患者的尿道长度增加,尿道移动角度减小,但差异无统计学意义(P>0.05)。结论 盆底MRI能准确评估SUI盆底功能;TVT术后对尿道支持结构薄弱及盆底器官脱垂无明显改善。     

Feasibility of synchrotron radiation computed tomography on rats bearing glioma after iodine or gadolinium injection

The purpose of this work was to demonstrate the feasibility of a new imaging technique called synchrotron radiation computed tomography (SRCT). This technique leads to a direct assessment of the in vivo concentration of an iodine- or gadolinium-labeled compound. Rats bearing C6 glioma were imaged by MRI prior to the SRCT experiment. The SRCT experiments were performed after a 1.3 g I/kg (n = 5) or a 0.4 g Gd/kg (n = 5) injection. Finally, brains were sampled for histology. The SRCT images exhibited contrast enhancement at the tumor location. Ten minutes after injection, iodine and gadolinium tissular concentrations were equal to 0.80 ( ± 0.40) mg/cm³ and 0.50 ( ± 0.10) mg/cm³, respectively in the peripheral area of the tumor (respective background value: 0.20 ± 0.02 to 0.10 ± 0.01). Correlation to MRI and histology revealed that the contrast uptake occurred in the most vascularized area of the tumor. The present study summarizes the feasibility of in vivo SRCT to obtain quantitative information about iodine and gadolinium-labeled compounds. Beyond brain tumor pathology, the SRCT appears as a complementary approach to MRI and CT, for studying iodine- and gadolinium-labeled compounds by the direct achievement of the tissular concentration value in the tissue. Received: 8 September 1999; Revised: 3 May 2000; Accepted: 4 May 2000     

Magnetic resonance imaging in assessment of stress urinary incontinence in women: Parameters differentiating urethral hypermobility and intrinsic sphincter deficiency

AIM: To define the magnetic resonance imaging (MRI) parameters differentiating urethral hypermobility (UH) and intrinsic sphincter deficiency (ISD) in women with stress urinary incontinence (SUI).METHODS: The static and dynamic MR images of 21 patients with SUI were correlated to urodynamic (UD) findings and compared to those of 10 continent controls. For the assessment of the urethra and integrity of the urethral support structures, we applied the high-resolution endocavitary MRI, such as intraurethral MRI, endovaginal or endorectal MRI. For the functional imaging of the urethral support, we performed dynamic MRI with the pelvic phased array coil. We assessed the following MRI parameters in both the patient and the volunteer groups: (1) urethral angle; (2) bladder neck descent; (3) status of the periurethral ligaments, (4) vaginal shape; (5) urethral sphincter integrity, length and muscle thickness at mid urethra; (6) bladder neck funneling; (7) status of the puborectalis muscle; (8) pubo-vaginal distance. UDs parameters were assessed in the patient study group as follows: (1) urethral mobility angle on Q-tip test; (2) Valsalva leak point pressure (VLPP) measured at 250 cc bladder volume; and (3) maximum urethral closure pressure (MUCP). The UH type of SUI was defined with the Q-tip test angle over 30 degrees, and VLPP pressure over 60 cm H₂O. The ISD incontinence was defined with MUCP pressure below 20 cm H₂O, and VLPP pressure less or equal to 60 cm H₂O. We considered the associations between the MRI and clinical data and UDs using a variety of statistical tools to include linear regression, multivariate logistic regression and receiver operating characteristic (ROC) analysis. All statistical analyses were performed using STATA version 9.0 (StataCorp LP, College Station, TX).RESULTS: In the incontinent group, 52% have history of vaginal delivery trauma as compared to none in control group (P < 0.001). There was no difference between the continent volunteers and incontinent patients in body habitus as assessed by the body mass index. Pubovaginal distance and periurethral ligament disruption are significantly associated with incontinence; periurethral ligament symmetricity reduces the odds of incontinence by 87%. Bladder neck funneling and length of the suprapubic urethral sphincter are significantly associated with the type of incontinence on UDs; funneling reduced the odds of pure UH by almost 95%; increasing suprapubic urethral sphincter length at rest is highly associated with UH. Both MRI variables result in a predictive model for UDs diagnosis (area under the ROC = 0.944).CONCLUSION: MRI may play an important role in assessing the contribution of hypermobility and sphincteric dysfunction to the SUI in women when considering treatment options.     

盆底三维超声判断压力性尿失禁患者盆底功能损伤和疗效的价值

目的 探讨盆底三维超声在压力性尿失禁患者盆底功能损伤和疗效判断中的应用价值.方法 选取40例产后压力性尿失禁患者纳入本次实验作为观察组,另选择同期产后40例正常产妇纳入本次实验作为对照组,观察组产后接受盆底康复治疗,2组均接受盆底三维超声检查,统计并比较2组盆底功能(盆底裂孔面积、膀胱尿道后角以及膀胱颈至耻骨联合下缘的...     

Non-invasive estimation of myocardial efficiency using positron emission tomography and carbon-11 acetate – comparison between the normal and failing human heart

The clearance kinetics of carbon-11 acetate, assessed by positron emission tomography (PET),can be combined with measurements of ventricular function for non-invasive estimation of myocardial oxygen consumption and efficiency. In the present study, this approach was applied to gain further insights into alterations in the failing heart by comparison with results obtained in normals. We studied ten patients with idiopathic dilated cardiomyopathy (DCM) and 11 healthy normals by dynamic PET with ¹¹C-acetate and either tomographic radionuclide ventriculography or cine magnetic resonance imaging. A ”stroke work index” (SWI) was calculated by: SWI = systolic blood pressure × stroke volume/body surface area. To estimate myocardial efficiency, a ”work-metabolic index” (WMI) was then obtained as follows: WMI = SWI × heart rate/k(mono), where k(mono) is the washout constant for ¹¹C-acetate derived from mono-exponential fitting. In DCM patients, left ventricular ejection fraction was 19%±10% and end-diastolic volume was 92±28 ml/m² (vs 64%±7% and 55±8 ml/m² in normals, P<0.001). Myocardial oxidative metabolism, reflected by k(mono), was significantly lower compared with that in normals (0.040±0.011/min vs 0.060± 0.015/min; P<0.003). The SWI (1674±761 vs 4736± 895 mmHg × ml/m²; P<0.001) and the WMI as an estimate of efficiency (2.98±1.30 vs 6.20±2.25×10⁶ mmHg × ml/m²; P<0.001) were lower in DCM patients, too. Overall, the WMI correlated positively with ejection parameters (r=0.73, P<0.001 for ejection fraction; r=0.93, P<0.001 for stroke volume), and inversely with systemic vascular resistance (r=–0.77; P<0.001). There was a weak positive correlation between WMI and end-diastolic volume in normals (r=0.45; P=0.17), while in DCM patients, a non-significant negative correlation coefficient (r=–0.21; P=0.57) was obtained. In conclusion non-invasive estimates of oxygen consumption and efficiency in the failing heart were reduced compared with those in normals. Estimates of efficiency increased with increasing contractile performance, and decreased with increasing ventricular afterload. In contrast to normals, the failing heart was not able to respond with an increase in efficiency to increasing ventricular volume. The present data support the usefulness of the WMI for non-invasive characterization of cardiac efficiency and may serve as a background for improved evaluation of medical therapy for heart failure. Received 10 August and in revised form 3 November 1999     

Clinical evaluation of no-carrier-added meta-[123I]iodobenzylguanidine for myocardial scintigraphy

In clinical and research studies, images obtained using carrier-added meta-[¹²³I]iodobenzylguanidine (c.a. [¹²³I]MIBG) have shown quite variable quality, with varying levels of uptake in lung, liver and mediastinum; this is a significant problem for quantification of the myocardial uptake by means of region ratios. First experimental and preliminary human data in respect of no-carrier-added (n.c.a.) [¹²³I]MIBG are indicative of improved imaging quality. The aim of the present study was to evaluate the clinical value of myocardial scintigraphy with n.c.a. [¹²³I]MIBG in patients with tachyarrhythmias. The study population comprised 24 patients with tachyarrhythmogenic diseases routinely studied by cardiac single-photon emission tomography (SPET) with [¹²³I]MIBG. Twelve of the 24 patients were studied with c.a. [¹²³I]MIBG (seven females and five males; mean age 42±13 years, range 20–60 years), whereas the other 12 were studied with n.c.a. [¹²³I]MIBG (ten females, two males; mean age 41±11 years, range 18–60 years, P=NS). For quantification of the specific uptake in the different organs, count ratios were calculated on SPET images acquired 4 h p.i. Visual analysis of all [¹²³I]MIBG scans showed improved image quality (improved contrast between heart and neighbouring organs) in n.c.a. studies as compared with c.a. studies. A significantly higher heart/left atrial blood ratio was found in the n.c.a. studies as compared with the c.a. studies (10.3±3.2 vs 5.3±1.3, P=0.0003); furthermore, significantly higher heart/lung and heart/liver ratios (2.5±0.6 vs 1.5±0.3, P=0.0002, and 0.8±0.2 vs 0.6±0.1, P=0.0006, respectively) were obtained in the c.a. studies, whereas lung/left atrial blood and liver/left atrial blood ratios showed no significant differences (4.2±1.3 vs 3.6±1.1, P=0.39, and 13.7±5.2 vs 9.6±2.2, P=0.21, respectively). In conclusion, the use of n.c.a. [¹²³I]MIBG yields a significantly higher myocardial uptake associated with improvement in contrast between the heart and neighbouring organs and is therefore superior to the commercially available c.a. [¹²³I]MIBG for use in clinical and research studies of the myocardial presynaptic sympathetic nervous system. Furthermore, our data indicate that for quantification the use of a left atrial blood reference region of interest, which is only available on SPET studies, is to be recommended. Received 22 September and in revised form 2 November 1999     

Peripheral sympathetic dysfunction in patients with Parkinson’s disease without autonomic failure is heart selective and disease specific

The study was undertaken to investigate by means of iodine-123-labelled metaiodobenzylguanidine (MIBG) scintigraphy the peripheral sympathetic function in patients with Parkinson’s disease (PD) without autonomic failure and in patients with related neurodegenerative diseases with parkinsonism. Seventy patients (33 men and 37 women, mean age 63±9.7 years) with parkinsonism and ten control subjects underwent MIBG scintigraphy. Of these 70 patients, 41 were diagnosed as having idiopathic PD, 9 multiple system atrophy (MSA), 6 progressive supranuclear palsy (PSP) and 2 corticobasal degeneration (CBD); the remaining 12 were diagnosed as having neurodegenerative disease with parkinsonism (P-nism) that did not meet the diagnostic criteria of any specific disease. Cardiac planar and tomographic imaging studies and subsequent whole-body imaging were performed 20 min and 3 h after the injection of 111 MBq MIBG. The early MIBG heart to mediastinum (H/M) ratio in PD (1.61±0.29) was significantly lower than that in the control group (2.24±0.14, P<0.01), P-nism (2.15±0.31, P<0.01), MSA (2.08±0.31, P<0.05) and PSP (2.30±0.24, P<0.01). The delayed H/M ratio in PD (1.47±0.34) was also significantly lower than that in the control group (2.37±0.14, P<0.01), P-nism (2.13±0.38, P<0.01), PSP (2.36±0.36, P<0.01) and MSA (2.17±0.36, P<0.01). In patients with PD, early and delayed H/M ratios were significantly decreased in disease stages I, II and III (established using the Hoehn and Yahr criteria) as compared with control subjects, and there were no significant differences among the stages. Only PD showed a significantly higher washout rate (WR) than that in the control subjects (27%±8.0% vs 11%±4.2%, P<0.01). Early and delayed uptake ratios of the lung, parotid gland, thyroid gland, liver and femoral muscles in each of the patient groups were not significantly different from those in control subjects. Only the early and delayed uptake ratios of the lower leg muscles in MSA were significantly lower than those in the control group (P<0.05). In conclusion: In patients with PD without autonomic failure, only cardiac MIBG uptake was severely reduced in the earliest phase of the disease (stage I). Parkinsonian syndromes other than PD did not demonstrate significant reduction in MIBG uptake in any organs except for the lower legs in MSA. In patients with PD without autonomic failure, reduction in MIBG uptake occurs selectively in the heart; this is considered to be a specific finding for PD and useful for the differential diagnosis of the parkinsonian syndromes. Received 13 September and in revised form 29 December 1999     

Chondrosarcoma of the hyoid bone

The CT and MRI findings in a case of chondrosarcoma of the hyoid bone are reported. Although chondrosarcoma is the second most common primary malignant bone tumor, only 10 % of chondrosarcomas occur in the head and neck region. The hyoid bone is a rare site of involvement with only seven cases reported previously. Received: 19 February 1999; Revised: 19 April 1999; Accepted: 11 May 1999     

四维盆底超声在电刺激联合生物反馈结合盆底肌锻炼治疗压力性尿失禁疗效评估中的价值

目的:探讨四维盆底超声在电刺激联合生物反馈盆底肌锻炼治疗压力性尿失禁(SUI)疗效评估中的价值.方法:选择60例SUI患者,电刺激联合生物反馈盆底肌锻炼3个月后分析治疗效果;并于治疗前后采用经会阴四维盆底超声记录患者肛提肌裂孔面积、裂孔左右径、肛提肌厚度、膀胱颈移动度、膀胱尿道后角及尿道内口漏斗形成率.结果:治疗后,肛...     

Influence of exercise rehabilitation on myocardial perfusion and sympathetic heart innervation in ischaemic heart disease

Exercise rehabilitation improves the clinical status in ischaemic heart disease. The purpose of this study was to assess the influence of exercise rehabilitation on myocardial perfusion and sympathetic heart innervation. Sixteen patients with ischaemic heart disease and previous myocardial infarction were investigated by means of exercise/rest tetrofosmin and metaiodobenzylguanidine (MIBG) exercise/rest single-photon emission tomography (SPET) studies, before and 6 months after starting an exercise rehabilitation programme. Tomograms were divided into 15 segments, and these were grouped into five myocardial anatomical regions. Regional uptake of both tracerswas quantified and expressed as a percentage of maximumpeak activity. The percentage ≤55% was chosen to evaluate defect size, and the results were expressed as a percentage of left ventricular mass. Areas with perfused and denervated myocardium and areas with ischaemic myocardium were calculated. In addition, regions with <75% of peak activity in the exercise perfusion study at baseline were divided into two groups according to whether there was an increase in peak activity of >10% (representing reversible regional defects) or an increase of <10% (representing fixed regional defects) in the rest study. These percentages were compared with the percentages obtained in the innervation study, and with the percentages obtained in exercise/rest perfusion and innervation studies performed 6 months after starting rehabilitation. Myocardial perfusion defects were significantly smaller than myocardial innervation defects before and 6 months after starting exercise rehabilitation. The area of ischaemia 6 months after starting exercise rehabilitation was significantly smaller than that before rehabilitation (0.31%± 1.4% vs 1.4%±1.6%, P<0.01). The size of innervation defects and the area of perfused and denervated myocardium did not show significant differences between the two studies performed before and 6 months after starting exercise rehabilitation. In reversible regional defects the percentage of peak activity was significantly increased 6 months after starting exercise rehabilitation in exercise and rest studies (P<0.001), while in fixed regional defects it was significantly increased only in exercise studies (P<0.001). There was no significant change in the regional MIBG percentages. We conclude that in ischaemic heart disease, exercise rehabilitation over a period of 6 months improves myocardial perfusion, but does not cause changes in sympathetic myocardial innervation. Received 12 August and in revised form 17 November 1999     

Quantitative assessment of regional myocardial blood flow using oxygen-15-labelled water and positron emission tomography: a multicentre evaluation in Japan

Recently, a method has been proposed for the quantitative measurement of regional myocardial blood flow (MBF) using oxygen-15-labelled water and positron emission tomography (PET). A multicentre project was organized with the intention of evaluating the accuracy of this method, particularly as a multicentre clinical investigative tool. Each of seven institutions performed PET studies on more than five normal volunteers following a specified protocol. The PET study included a transmission scan, a ¹⁵O-carbon monoxide static scan and a ¹⁵O-water dynamic scan, thereby yielding MBF values which should have been independent of the spatial resolution of the PET scanner employed. Fifty-three subjects (aged 20–63 years, mean±SD 36±12 years) were studied at rest, and 31 of these subjects were also studied after dipyridamole in five institutions. Inter-institution consistency and intra-subject variation in MBF values were then evaluated. MBF averaged for all subjects was 0.93±0.34 ml min^–1 g^–1 at rest and 3.40±1.73 ml min^–1 g^–1 after the administration of dipyridamole, and the flow reserve (defined as the ratio of the two MBF values) was 3.82±2.12; these values are consistent with previous reports. Resting MBF values were significantly correlated with the heart rate–blood pressure product (RPP) (y=0.31+6.56E^-5 x, P<0.010), and RPP was in resting MBF observed in all institutions was well explained by the age-dependent RPP. No significant difference was observed in resting MBF among the institutions. Except in one institution, no significant difference was seen in dipyridamole MBF or myocardial flow reserve. No significant difference was found among the myocardial segments. Regional variation was reasonably small in five institutions, but was not acceptable in two institutions, which was attributed to the scanner performance. These observations suggest that the ¹⁵O-water PET technique is useful for a multicentre clinical study if the PET scanner can provide time-activity data with good count statistics. Received 25 April and in revised form 30 August 1999     

Comparison of colpocystourethrorectography and transrectal ultrasonography in the assessment of female urinary incontinence

In order to investigate the diagnostic reliability of transrectal US in the study of female urinary incontinence, the authors compared the static images obtained by means of colpocystourethrorectography with the ones obtained with transrectal US. The study population included 30 patients suffering from urinary incontinence. US images were obtained both at rest and during Valsalva's maneuver, some minutes before cystourethrography and employing part of its preparation (vesical filling with 250 cc of iodine contrast medium and positioning of a metallic bead chain in the urethra). On static images obtained with cystourethrography and transrectal US both at rest and during Valsalva, 4 parameters were evaluated: anterior and posterior vesical angles, urethral axis angle, and distance between symphysis pubis and urethral-vesical junction. As for posterior vesical angle, urethral axis angle, and symphysis-junction distance, the statistical comparison of the results did non demonstrate any significant differences. Anterior vesical angle was not included because it is too difficult to measure by transrectal US. In our experience, transrectal US was capable of yielding accurate information similar to that obtained with colpocystourethrorectography.     

MR appearance of parasymphyseal insufficiency fractures of the os pubis

 Objective. To clarify the MRI features of parasymphyseal insufficiency fractures of the os pubis. Design and patients. MRI was performed in four postmenopausal women with parasymphyseal insufficiency fractures. The diagnosis was confirmed with plain films in every patient. T1-weighted and T2-weighted images were obtained in four patients using a 1.5-T unit. Postcontrast T1-weighted imaging was also done in three patients. Results and conclusions. MRI of pubic parasymphyseal insufficiency fracture characteristically demonstrates a hyperintense mass lesion with a hypointense rim on T2-weighted imaging, showing peripheral and septal enhancement after contrast administration. It is important to have this entity in mind in patients with osteoporosis, especially in patients with a history of pelvic irradiation for malignant disease, so as not to misinterpret it as a chondroid tumor or bone metastasis.     

Cough urethrocystography: the best radiological evaluation of female stress urinary incontinence?

Urethrocystography and simultaneous urethrocystometry were performed on 40 women with primary urinary incontinence. The posterior urethrovesical angle, inclination angle, urethropelvic angle, and an orifice descent angle, not earlier described, were measured on radiographs obtained at rest, during coughing and during straining. The orifice descent angle was used to describe the descent of the internal urethral orifice in the cough radiographs, and was the only measurement that provided a significant correlation with urethrocystometry. The other angles measured, and radiographs obtained at rest or during straining were not useful in the evaluation of female stress urinary incontinence. The authors conclude that the best imaging method for the evaluation of female stress urinary incontinence is urethrocystography employing a single lateral view taken during coughing, with measurement of the orifice descent angle.     

CT and MR findings in neoplastic perineural spread along the vidian nerve

The aims of this article are to describe the findings of perividian tumor spread and to compare the accuracy of MRI and CT in diagnosing perineural metastasis along the vidian nerve. Moreover, the frequency of perividian metastasis in patients with head and neck cancer was evaluated. The CT and MR examinations of 98 consecutive untreated patients with histologically proven head and neck cancer were retrospectively reviewed. We considered as criteria for perineural tumor spread along the vidian nerve the following CT and MR findings: For CT (a) enlargement of the pterygoid canal, (b) erosion of its bony wall, and (c) obliteration of its normal fatty content; and for MR (a) enlargement of the vidian nerve, (b) enhancement of the nerve, and (c) obliteration of fat, particularly in the anterior part of the pterygoid canal. Ten patients met the selected criteria for perineural metastasis, which was bilateral in 3 patients, with a total of 13 vidian metastases. The CT scans demonstrated unilateral involvement of the vidian nerve in 9 patients. The MRI scans showed 13 perineural metastases. In 3 patients MR scans demonstrated involvement of four vidian nerves that appeared normal on CT examinations. The diagnostic difference between CT and MRI was statistically significant (Fisher's exact test; p = 0.04). Perineural spread along the vidian nerve is an event more frequent than previously reported and must be investigated with a careful imaging technique. Although a major limitation of our study is the lack of histological proof, the MR finding of a significant enhancement of the nerve, whether enlarged or normal in size, could be considered very suggestive of this kind of metastatic spreading, particularly if associated with simultaneous involvement of the neighboring structures (pterygopalatine fossa, foramen lacerum, trigeminal branches, etc.). Received: 5 January 1999; Revision received 11 May 1999; Accepted: 17 June 1999     

MRI evaluation of soft tissue hydatid disease

Infestation in soft tissue by Echinococcus granulosus is not a common disease, and its diagnosis is based on clinical, laboratory data and radiological findings. The aim of our retrospective study is to give an overview of the different signs and patterns shown by MRI that can be useful in characterizing soft tissue hydatid disease. The MRI images obtained in seven patients with soft tissue and subcutaneous hydatidosis were reviewed. Typical signs of hydatidosis were multivesicular lesions with or without hypointense peripheral ring (“rim sign”). Related to the presence and absence, respectively, of viable scolices in the microscopic exam, daughter cysts were presented either as high signal intensity or low signal intensity on T2-weighted images. Low-intensity detached layers within the cyst and peripheral enhancement with gadolinium-DTPA were also presented. Atypical signs were presented in an infected muscular cyst, a subcutaneous unilocular cyst and several unilocular cysts. Knowledge of the different patterns in MRI of soft tissue hydatid disease can be useful in diagnosing this entity. We observed that the “rim sign” is not as common as in other locations, and in addition, MRI seems to be of assistance when evaluating the vitality of the cysts. Received: 27 July 1998; Revision received: 11 March 1999; Accepted: 23 April 1999     

MRI of the fingers in patients with systemic scleroderma. Early results of contrast-enhanced examinations on a dedicated MRI system

Purpose. To estimate disease activity in patients with systemic sclerosis using contrast-enhanced MRI of the skin. Material and Methods. In a pre-study, sequences of a low-field (0.2 T) scanner (Artoscan, Esaote, Genova, Italy) were optimized for detection of intravenous contrast (0.1 mmol/l Gd-DTPA) in six patients with the autoimmune disease systemic scleroderma. Based on the results of the pre-study, 17 patients with scleroderma (7 sclerotic/10 active inflammatory disease) were scanned using gradient-spoiled 3D GRE sequences (FA 90 °, TR 100 ms, TE 18 ms), which had been established as most sensitive for intravenous contrast. Contrast enhancement of the skin was determined quantitatively by contrast-to-noise ratios (CNR), comparing post- to pre-contrast and dynamic scans (for 6 min, 1 acquisition/min). Patients in the chronic state with sclerodactylia and active inflammation of the hands were considered separately and compared to a control group (n = 10) matched according to age. Results. CNR increase after intravenous contrast was significantly higher in patients with active disease (86 ± 16 % increase) than sclerosing disease (29 ± 3 %, p < 0.05) and the control group (4 ± 2 %, p < 0.05). The dynamic examination showed a significantly slower decrease after the peak rise in the first minute in patients with active disease (CNR 15.4 ± 0.7 to 14.2 ± 1.4) than in those with chronic disease (14.1 ± 0.5 to 11.3 ± 0.9, p < 0.05). Discussion. Capillary leakage is the most likely explanation for the increased enhancement in patients with active scleroderma. Using sequences optimized for contrast detection, disease activity in the course of scleroderma and response to therapy can be determined by MRI in the future.      

Testicular function after radioiodine therapy for thyroid carcinoma

Radiotherapy can cause infertility in both men and women. However, few data are available concerning the effects of radioiodine therapy for thyroid carcinoma on testicular function. We investigated 25 men (age 23–73 years) with differentiated thyroid carcinoma in a longitudinal prospective trial. Follicle-stimulating hormone (FSH), inhibin B, luteinising hormone (LH) and testosterone were measured before (n=25) and 3 months (n=11), 6 months (n=18), 12 months (n=22), and 18 months (n=18) after radioiodine therapy [radioiodine dose (mean ± SEM): 9.8±0.89 GBq]. Before therapy, FSH was 5.4±0.77 IU/l; it increased significantly (P<0.001) to 21.3±2.4 IU/l after 6 months and fell to 7.4±1.3 IU/l after 18 months (normal range: 1.8– 9.2 IU/l). Inhibin B was significantly decreased (P<0.001) from 178±25.3 pg/ml before therapy to 22.2±5.5 pg/ml after 3 and 29.4±5.7 pg/ml after 6 months and rose to 154±23.3 pg/ml after 18 months (normal range 75– 350 pg/ml). LH and testosterone were within the normal range during the whole study (1.6–9.2 IU/l and 10.4–34.7 nmol/l, respectively). LH was significantly increased (P<0.001) from 2.8±0.33 IU/l before therapy to 5.9±0.69 IU/l 6 months after therapy and then fell slowly to 4.0±0.45 IU/l after 18 months. Total testosterone was significantly increased (P<0.01) from 12.8±0.99 nmol/l at baseline to 19.8±1.7 nmol/l after 12 months and 19.6±1.7 nmol/l after 18 months. The testosterone/LH ratio (normal range: 3.3–17.9 nmol/IU) fell from 5.8±0.66 nmol/IU to 3.0±0.36 nmol/IU after 3 months (P<0.01); it remained close to the latter value after 6 months (3.4±0.49 nmol/IU) and then rose to 5.5± 0.6 nmol/IU after 18 months. In conclusion, 3 and 6 months after radioiodine therapy all patients showed elevated FSH and decreased inhibin B levels, reflecting severely impaired spermatogenesis. At the same time a compensated insufficiency of the Leydig cell function was observed. Eighteen months after the last radioiodine therapy, mean values of gonadal function had completely recovered. Received 5 October and in revised form 27 December 1999