Emergent MRI utilizing a 5-inch surface coil to evaluate for acute penile fracture

MR imaging is useful in rapidly detecting penile fractures and in guiding surgical planning. Electronic Publication     

阴茎癌MRI表现(附20例分析)

目的 探讨阴茎癌的MRI影像学特点.方法 选取我院确诊的20例阴茎癌影像学资料并分析其影像学特点.结果 20例阴茎癌,病理均为鳞癌,4例(4/20,20％)位于阴茎头,10例(10/20,50％)位于冠状沟,4例(4/20,20％)位于包皮,2例(2/20,10％)位于双侧阴茎海绵体.2例(2/20,10％)广泛转移(...     

Renal angiomyolipoma: comparison of MRI and CT results for diagnosis

The aim of this study was to compare the potentials of MRI and CT for characterising renal angiomyolipomas. MRI and CT examinations of 13 adult patients with renal angiomyolipoma were reviewed. Pathological correlation was available for ten patients who underwent nephrectomy or tumourectomy. Negative CT density numbers were demonstrated in 10 cases. MRI depicted high signal intensity areas suggesting fat in 11 cases. A haemorrhagic component was by both CT and MRI in 4 cases and was confirmed by surgery. Fat suppression imaging was performed in 3 cases and confirmed the presence of fat. We conclude that identification of angiomyolipomas can be achieved by MRI, but compared with CT, MRI is more expensive and less available. Therefore MRI should be performed when CT results are equivocal and when direct multiplanar images are necessary for a precise tumour localisation of multiple angiomyolipomas. Correspondence to: M. F. Bellin     

Sports-related muscle injuries of the lower extremity: MR imaging appearances

Sports-related injuries of the lower extremity are frequent. Before magnetic resonance (MR) imaging was available, ultrasound, radionuclide scintigraphy and computed tomography were used to evaluate muscle trauma. Although relatively inexpensive, these imaging modalities are limited by their low specificity. The high degree of soft tissue contrast and multiplanar capability of MR imaging, allow direct visualization as well as characterization of traumatic muscle lesions. This pictorial review highlights the spectrum of traumatic muscle lesions on MRI, with emphasis on its typical appearances. Received: 8 May 1998; Revision received: 31 August 1998; Accepted: 23 September 1998     

Reconstructed anterior cruciate ligaments using patellar tendon ligament grafts: diagnostic value of contrast-enhanced MRI in a 2-year follow-up regimen

We analyzed prospectively the diagnostic efficacy of contrast-enhanced MRI following anterior cruciate neoligament (ACL) reconstruction. One hundred fifty-six MR examinations were performed 2, 12, 52, 76, and 104 weeks post-operatively on 68 patients with ACL transplants. Sagittal, parasagittal, and coronal images using unenhanced T1- and T2-weighted spinecho sequences, and post-contrast images utilizing T1-weighted spinecho and fat-saturated sequences, were acquired. Results were correlated with those of the pivot shift, Lachman, and a mechanical test. The MR examination criteria included morphological analysis, signal intensity, transplant contrast enhancement, secondary signs (e.g., elongation of normal ligaments), and comparison with clinically standardized test results. Two weeks post-operatively all neoligaments showed homogeneous low signal intensity on T1- and T2-weighted spinecho sequences indistinguishable from that of normal cruciate or patellar ligaments [contrast-to-noise ratio (C/N) on T1: 1.6], with a 9% percentile enhancement. At 12-52 weeks, signal intensity increased (C/N: 6.7), with a mean 50% percentile enhancement. The 1-year follow-up allowed no definite assessment of the neoligament's course. At 76 and 104 weeks, significant decrements in signal intensity (C/N: 3.0) and ligamentous percentile enhancement (25%) occurred. All patients tested displayed stable transplants 2 years post-operatively. Contrast-enhanced MRI allows accurate evaluation of morphology and function up to 3 months postoperatively and 1-2 years following ACL reconstructive surgery.     

高频超声诊断闭合性阴茎损伤的临床价值

目的探讨高频超声诊断闭合性阴茎损伤的声像图特点及临床价值。方法对22例临床手术或随访证实的闭合性阴茎损伤患者临床资料及超声图像进行回顾性分析。结果闭合性阴茎损伤的高频超声图像清晰、典型,常可见白膜及海绵体连续性中断、海绵体血肿、阴茎皮下血肿、尿道回声连续性中断等特征,能准确显示病变的部位、范围及血供情况。结论高频超声检查简单、高效、非侵入性,在闭合性阴茎损伤诊断中具有较高的临床价值,可作为闭合性阴茎损伤影像学检查的首选方法。     

The occipitotemporal vein: a cadaver,MRI and CT study

The author studied a superficial temporal vein running anteroposteriorly within the occipitotemporal sulcus, the occipitotemporal vein, which, when prominent, could be thought to simulate a venous angioma on MRI. A cadaver (n=50), MRI (n=200), and CT (n=50) study was undertaken to examine the incidence, detectibility, size, location, and drainage of the occipitotemporal vein. It was an approximately 3 mm wide, 2–5 cm long structure. It was present in 83% of the cadavers (52% bilaterally), and clearly identifiable on 73% of the MRI (43% bilaterally), and 8% of the CT studies. In 18% of the cadavers the vein was totally absent, and it was not seen in 27% of the MRI examinations. The occipitotemporal vein can be distinguished from a venous angioma by its particular location and course, and by lack of intraluminal bright signal on spin-echo T2-weighted and/or contrast-enhanced T1-weighted images. In addition, venous angiomas are usually intraparenchymal, whereas the occipitotemporal vein is a superficial vessel.     

MR多种成像技术在原发性骨质疏松椎体骨折鉴别诊断中的应用

目的 :探讨MR多种成像技术对鉴别原发性骨质疏松椎体骨折与其它原因所致病理性骨折的价值。方法 :对14例原发性骨质疏松椎体压缩骨折和 2 0例转移瘤所致骨折患者行MRI检查 ,成像序列均包括SET1 WI、FSET2 WI、STIR、DWI和增强SET1 WI抑脂序列 ,分析病变椎体在不同MR成像序列上的信号表现 ,计算病变区的强化比率、ADC值和骨髓对比率 ,进行统计学分析。结果 :SET1 WI、FSET2 WI、STIR和增强扫描上病变椎体横形分层样信号、椎体后上角后突及前后径增加、附件信号异常、邻近椎间盘信号增高、局部软组织肿块及椎管内结构受累在两组间发生率差异明显 ,骨质疏松骨折与转移瘤所致骨折的ADC值无显著性差异 (P >0 .0 5 ) ,两者强化比率和骨髓对比率有显著性差异 (P <0 .0 1)。结论 :MR多种成像技术联合应用对原发性骨质疏松椎体骨折与其它原因所致病理性骨折的鉴别可提供很大帮助     

Color Doppler appearance of penile cavernosal-spongiosal communications in patients with normal and impaired erection

Our objective was to investigate prevalence and Doppler characteristics of penile cavernosal-spongiosal communications (CSC). These vessels are either anastomoses connecting the cavernosal arteries with the urethral arterial network or afferent vessels to the corpus spongiosum. Sixty-one consecutive patients underwent penile color Doppler US. Waveform changes in CSC were evaluated in comparison with changes in the cavernosal artery. Eighteen of 61 patients had normal erection, 17 of 61 had arterial insufficiency, and 26 of 61 had veno-occlusive dysfunction. Resistance index (RI) in CSC was significantly lower than in cavernosal arteries in all patients and increased during phases 1-2 (positive diastolic flow). Peak systolic velocity (PSV) in CSC was significantly higher in the patients with veno-occlusive dysfunction. During cavernosal phase 4 (diastolic flow reversal) CSC of patients with normal erection or with arterial insufficiency disappeared, underwent markedly reduced diastolic flow, or had systolic flow inversion. Conversely, low resistance flow was appreciable in CSC of patients with veno-occlusive dysfunction who reached phase 4. During phase 5 (systolic peak reduction) all CSC disappeared. Color Doppler US allows evaluation of CSC both in patients with normal and impaired erection.     

MR evaluation of brachial plexus injuries

Summary Ten cases of brachial plexus injury were subjected to magnetic resonance (MR) to demonstrate the roots, trunks, divisions or cord abnormalities. Both normal and abnormal brachial plexuses were imaged in sagittal, axial, coronal and axial oblique planes. Myelography, using water soluble contrast agents, was performed in seven cases. MR demonstrated one traumatic meningocele, one extradural cerebrospinal fluid (CSF) collection, trunk and/or root neuromas in four, focal root fibrosis in two and diffuse fibrosis in the remaining two cases. Results of MR were confirmed at surgery in four cases with neuromas, while myelography was normal in two and was not carried out in the remaining two. In two cases, where MR demonstrated diffuse fibrosis of the brachial plexus, myelography showed C7 and T1 traumatic meningocele in one and was normal in the other. Both these patients showed excellent clinical and electrophysiological correlation with MR findings and in one of them surgical confirmation was also obtained. In the other two cases with focal nerve root fibrosis, myelography was normal in one and showed a traumatic meningocele in another. Operative findings in these cases confirmed focal root fibrosis but no root avulsion was observed although seen on one myelogram. Focal fibrosis, however, was noted at operation in more roots than was observed with MR. Initial experience suggests that MR may be the diagnostic procedure of choice for complete evaluation of brachial plexus injuries.     

Non-visualization of sentinel lymph nodes in penile carcinoma

Purpose The purpose of this study was to analyse the incidence and cause of non-visualization of sentinel lymph nodes on preoperative lymphoscintigrams for penile cancer and its implications for further management.Methods Preoperative lymphoscintigraphy was performed after injection of ^99mTc-labelled nanocolloid in 123 clinically node-negative penile carcinoma patients. Anterior dynamic lymphoscintigraphy was performed during 20 min immediately after tracer injection. Subsequently, 5-min anterior and lateral static images were obtained 30 min and 2 h post injection.Results Lymphatic drainage to both groins was seen in 98 patients (79%), unilateral drainage in 23 patients (19%) and no drainage at all in two patients (2%). Thus, in 27 (11%) of 246 groins, no sentinel node was visualized. The amount of administered tracer dose was associated with non-visualization (p=0.01). Unilateral drainage was initially interpreted as a normal physiological phenomenon. After the occurrence of a tumour-positive node in a non-visualized groin, we explore non-visualized groins by blue dye mapping and intraoperative palpation. Sentinel nodes were retrieved in four out of eight such groins, of which one contained metastasis.Conclusion In penile carcinoma patients, preoperative lymphoscintigraphy visualizes a sentinel node in 89% of groins. Visualization depends on the administered tracer dose. It is worthwhile to explore non-visualized groins. Sentinel nodes can be intraoperatively identified in more than half of these cases.     

Fundamentals and hemodynamics of penile erection

Human penile erection is a complex phenomenon mediated through the coordinated interaction among the nervous, vascular, and musculosystems. For social and ethical reasons, the mechanism and hemodynamics of this essential human function remained speculative and controversial for many years. In the past decade, however, advances in technology, together with a marked increase in clinical and research activity, have resolved some of the controversy and have provided a better understanding of erectile physiology. In this essay, we will review traditional concepts, as well as the new and exciting findings from many different research centers, concerning the physiologic mechanisms of penile erection that involve the arterial, venous, and nervous systems.     

三叉神经鞘瘤的MRI 诊断

分析三叉神经鞘瘤的ＭＲＩ表现。方法搜集病理证实的三叉神经鞘瘤６例,其中并发神经纤维瘤病２例,均行ＭＲ平扫及增强检查。结果肿瘤ＭＲ表现以哑铃状骑跨征为主,肿瘤大多为实性,边界清楚,有完整的包膜肿瘤呈等。混杂或长Ｔ１、长Ｔ２信号,注射Ｇｄ－ＤＴＰＡ后性病灶呈均匀强化,整性病灶呈环状强化。结论ＭＲＩ以其特有的多方位断层,多参数成像对三叉神经鞘瘤的定位,定性诊断具有很高的准确性。     

MRI during fast infusion of Gd-DTPA: results in hepatic and pancreatic enhancement

The authors describe the results obtained with dynamic MRI of the parenchymal organs during the infusion of contrast agents. Thirteen patients with hepatic and pancreatic lesions were studied. RASE sequences were characterized by TR of 260 ms, TE of 16 ms, NEX 1, matrix 128 × 256. Infusion of the contrast agent started 15 s prior to the beginning of the pulse sequence and continued throughout the pulse sequence (25 s). In this way, a continuous inflow of contrast agent in abdominal organs was expected during the acquisition time. The conventional dose of Gd-DTPA was employed (0.1 mmol/kg).The results demonstrate a highly relevant pancreatic enhancement in the early arterial phase of perfusion, with values of SE/N of 18.1 versus 8.5 in the subsequent sequence. However, in the liver the perfusion study did not improve the parenchymal enhancement, with values of 9.3 versus 15.3 in the late phase. There was no improvement of hypontense lesion detections in the liver, while the hypervascular lesions were visualized with a high signal intensity in the early perfusion study, disappearing in the later sequences. Correspondence to: P. Pavone     

Shortcomings and pitfalls of ocular MRI

Summary MRI was performed in 41 patients with ocular lesions: 27 cases of malignant melanoma, 5 of haemorrhage, 3 of choroidal metastasis, 3 of senile disciform macular degeneration, 2 retinoblastomas and 1 hamartoma. On MRI 5 small lesions (<2 mm thick): 1 melanoma, the 3 metastases and the hamartoma, were not seen. All the malignant melanomas visualised were hyperintense compared to the vitreous on T1-weighted images. On T2-weighted images 24 of 26 lesions were hypointense compared to the vitreous. The remaining two lesions were almost isointense, corresponding to amelanotic lesions. These MRI features did not differ significantly from those of retinoblastomas, senile disciform macular degeneration or subacute choroidal haemorrhage. Major shortcomings of MRI in lesions of the globe lie in a lack of spatial resolution and poor specificity of the findings.     

脊椎骨髓炎的MRI诊断

目的确定MRI对脊椎骨髓炎的诊断价值.方法对26例经临床或手术病理证实的脊椎骨髓炎的MR影像表现进行回顾性分析.MR检查方法为矢状位和轴位常规SE序列T1WI及T2WI,Gd-DTPA T1WI.结果26例患者中,单纯脊椎骨髓炎3例,相邻椎体及椎间盘受累9例,相邻椎体,椎间盘及椎旁软组织受累12例,合并硬膜外脓肿2例.病变椎体和椎间盘MRI表现为长T1、长T2信号,椎旁软组织呈等T1、长T2信号.病变椎体、椎间盘和椎旁软组织影可见不同程度的异常强化.结论MRI对脊椎骨髓炎的早期诊断和指导治疗具有重要意义.     

Chronic lymphocytic leukemia: Changes in bone marrow composition and distribution assessed with quantitative MRI

The purposes of this study were (α) to determine the prevalence of bone marrow abnormalities in patients with chronic lymphocytic leukemia (CLL) using quantitative MR assessment of axial marrow composition and peripheral marrow distribution; (b) to assess the agreement between both quantitative MR methods and compare their sensitivities to detect marrow alterations; and (c) to correlate MR findings with clinical and laboratory parameters. Twenty-nine consecutive patients with biopsy-proven CLL were investigated on a .5-T MR imager to determine bulk T1 relaxation times of the vertebral bone marrow and proportion of proximal femur surface area occupied by nonfatty marrow on coronal T1-weighted MR images of one hip. Of the 29 patients, 12 (41%) had abnormal increase in lumbar marrow T1 values (>600 msec) and 16 (55%) had increased proportion of surface area occupied by non-fatty marrow in the proximal femur (>+1 SD compared to normal values determined in sex- and age-matched healthy subjects). The results of both quantitative MR methods were normal in 12 patients and abnormal in 11 patients (agreement, 79%). Patients with alterations in peripheral marrow distribution had significantly higher T1 relaxation times (P = .001) than those with normal peripheral marrow. Patients with abnormal marrow composition or distribution at MRI had significantly higher blood and marrow lymphocytosis than patients without these features. In conclusion, the agreement between both quantitative MR methods suggests a parallelism between changes in axial marrow composition and in peripheral marrow distribution in patients with CLL. The limits of quantitative MRI in CLL must be kept in mind, because quantitative MR methods failed to detect leukemic marrow infiltration in 41% of patients.     

Magnetic resonance diagnosis of traumatic penile fracture

PURPOSE: To report our experience with MRI in the preoperative evaluation of patients with traumatic penile fractures. MATERIALS AND METHODS: Between January 1998 and December 2001, we performed MRI examinations on five patients (aged 29-48 years; mean age 40 years) with suspected traumatic fracture of the penis occurred during sexual intercourse. In all cases, T1-weighted SE, T2-weighted FSE and GRE sequences in the axial, coronal and sagittal planes were acquired. The study was performed without IV administration of paramagnetic contrast agents and in conditions of detumescence. A small-sized surface coil was used in four cases and a body coil was used in one case. All patients had suspected penile fracture with indications for surgical repair. The MR examination was performed within 12 to 48 hours of the trauma and was requested to aid surgical planning. RESULTS: The MR image quality was adequate in all cases. The examination documented unilateral rupture of the corpus cavernosum in all patients. This finding was associated with haematoma located both subcutaneously and inside the corpus cavernosum itself. In no case was there rupture of both corpora cavernosa. In only one patient was there a suspicion of injuries to the urethral corpus spongiosum, which was confirmed by surgery along with the other MR findings. DISCUSSION AND CONCLUSIONS: Many imaging methods are available to evaluate traumatic penile lesions: ultrasound, colour-Doppler ultrasound, urethrography, cavernosography, angiography and MRI. In agreement with the literature, our experience shows that MRI is useful in evaluating penile injuries owing to its multiplanar capabilities, its good spatial resolution and its excellent tissue contrast resolution. These characteristics enabled a more adequate surgical approach. In our view, MRI can be regarded as an emerging method to obtain helpful diagnostic information, with no risks for the patient.