Normal penile anatomy and abnormal penile conditions: evaluation with MR imaging

The appearance of the normal penis and of a variety of penile abnormalities on magnetic resonance (MR) images was studied in 55 patients with either medium (0.35 T) or high (1.5 T) magnetic field strengths. Penile morphologic characteristics with anatomic detail of the corpora cavernosa and corpus spongiosum were demonstrated in each patient. MR images clearly displayed congenital anomalies (n = 6), penile prostheses (n = 7), fibrous tissue or hematoma due to trauma (n = 8), and fibrous plaque in Peyronie disease (n = 3). MR imaging also demonstrated urethral (n = 6) and penile (n = 5) neoplasms and allowed tumor staging, thus facilitating the surgical approach.     

MR imaging in pediatric airway obstruction

Magnetic resonance (MR) imaging of the trachea was performed in 27 children with congenital tracheal narrowing. The diagnoses included aortic arch anomalies (n = 7), innominate artery compression (n = 13), pulmonary artery compression (n = 5), and tracheomalacia (n = 2). Demonstration of the trachea and the surrounding tissue and vessels on MR images allowed the evaluation of the cause of tracheal compression and the degree and location of collapse. Patients were examined with MR imaging if the cause of airway obstruction was still unclear after bronchoscopy. It is concluded that MR imaging is a well suited modality for characterizing tracheal narrowing without using ionizing radiation or intravenous contrast medium.     

Imaging findings in patients with clinical anophthalmos.

PURPOSETo review the intracranial and facial imaging features in children with congenital anophthalmos.METHODSWe retrospectively studied eight children with anophthalmos with respect to intraorbital, intracranial, and craniofacial anomalies (six had CT examinations, including the face, orbits, and brain, and four had MR imaging, including the orbits and brain).RESULTSThree patients had primary bilateral anophthalmos on CT (n = 1) and MR (n = 3) studies. In these patients, MR images showed hypoplasia of the optic chiasm and posterior visual pathways (n = 3), agenesis (n = 1) or dysgenesis of the corpus callosum (n = 2), and a mass in the tuber cinereum region (n = 1). One patient had incontinentia pigmenti. Five patients had unilateral anophthalmos on CT (n = 5) and MR (n = 1) studies. One of these patients had a contralateral congenital cystic eye and one had contralateral severe microphthalmia and absent optic chiasm. All had craniofacial anomalies that consisted of midline facial clefts (n = 2) and concomitant hemifacial hypoplasia (n = 2). One had a craniosynostosis. All five had normal-appearing brains.CONCLUSIONPatients with bilateral anophthalmos represent a distinct group from those with unilateral anophthalmos. In our patients, bilateral anophthalmos was associated with absence of the optic chiasm, diminished size of the posterior optic pathways, and agenesis or dysgenesis of the corpus callosum. Patients with unilateral anophthalmos had severe craniofacial anomalies. Imaging of the face is helpful in patients with unilateral anophthalmos.     

MRI及超声对先天性阴道畸形及处女膜闭锁的诊断分析

目的:探讨先天性阴道畸形及处女膜闭锁的MRI及超声影像表现,分析其特点,提高对该病的认识。方法:12例经临床证实的先天性阴道畸形和处女膜闭锁病例,对其MRI、超声影像资料进行回顾性分析,分别计算准确率,应用卡方检验统计两者准确率差异性。结果:先天性阴道畸形(7例),为副中肾管发育畸形,先天性无阴道畸形伴痕迹子宫或无子宫2例,为Mayer-Rokitansky-Kstner-Hauser(MRKH)综合征;阴道斜隔综和征2例,超声误诊1例;阴道闭锁2例,其中1例为宫颈发育不良伴阴道闭锁;阴道横隔1例;处女膜闭锁5例。MRI诊断准确率为100%(12/12),超声诊断准确率为83.3%(10/12),两者统计学无明显差异(P0.05),但MRI检查较超声准确率高。结论:先天性阴道畸形和处女膜闭锁的MRI及超声影像表现有一定特征,超声可作为首选的筛查检查方法,进一步MRI检查可以提高诊断准确率。     

Tear of the peroneus longus tendon: MR imaging features in nine patients

PURPOSE: To determine the magnetic resonance (MR) imaging features that characterize tear of the peroneus longus tendon at the midfoot. MATERIALS AND METHODS: Medical records and MR images in nine patients with a tear of the middle segment of the peroneus longus tendon were retrospectively reviewed. All nine patients had undergone routine ankle MR imaging; three had undergone additional oblique coronal MR imaging. Surgical proof of a tear was available for three patients. RESULTS: Partial tear was present in four patients, and complete tear was present in five. Partial tears were characterized by heterogeneous signal intensity and thickening of the tendon. Complete tears were characterized by discontinuity of the tendon. Additional findings included fluid in the tendon sheath (n = 6), marrow edema of the lateral calcaneal wall (n = 3), enlarged peroneal tubercle (n = 3), and tear of the peroneus brevis tendon (n = 2). The extent of the tear was better assessed with oblique coronal MR images. CONCLUSION: The characteristic MR imaging appearance of complete or partial tear of the middle portion of the peroneus longus tendon includes foci of increased signal intensity in the distal tendon, morphologic alterations, and/or discontinuity of tendon. Bone marrow edema along the lateral calcaneal wall may be suggestive of the diagnosis. Additional oblique coronal midfoot MR images may help in assessment of the extent of the tear.     

Focal nodular hyperplasia of the liver: MR imaging and pathologic correlation in 37 patients.

Thirty-seven patients with 48 lesions of focal nodular hyperplasia (FNH) underwent preoperative magnetic resonance (MR) examination and surgical resection. Sixteen lesions were imaged at 0.5 T with T1- and T2-weighted spin-echo sequences; 32 lesions were imaged at 2 T with T1-and T2-weighted spin-echo and gradient-recalled-echo sequences. Contrast material-enhanced MR imaging was performed in 20 lesions. MR imaging failed to depict six tumors that were less than 3 cm in diameter. Typical appearance was present in 18 of the 42 (43%) lesions seen at MR. Atypical lesion features included no scar (n = 15), hypointense scar on T2-weighted images (n = 7), pseudocapsule (n = 6), strong hyperintense lesion on T2-weighted images (n = 3), diffuse hyperintensity on T1-weighted images (n = 3), and heterogeneous lesion (n = 1). Comparison between findings at MR imaging and at histopathologic examination was performed in 38 lesions: There was good correlation between presence and size of the scar on both examinations. In 13 of 20 (65%) of the hyperintense scars on T2-weighted images, edema was prominent, whereas in five of the seven (71%) hypointense scars on T2-weighted images, edema was absent or low.     

Fluid-attenuated inversion-recovery MR imaging in acute and subacute cerebral intraventricular hemorrhage.

BACKGROUND AND PURPOSE: Fluid-attenuated inversion-recovery (FLAIR) MR imaging may show subarachnoid hemorrhage (SAH) with high sensitivity. We hypothesized that the FLAIR technique is effective and reliable in the diagnosis of cerebral intraventricular hemorrhage (IVH). METHODS: Two observers evaluated the 1.5-T MR fast spin-echo FLAIR images, T1- and T2-weighted MR images, and CT scans of 13 patients with IVH and the FLAIR images of 40 control subjects. RESULTS: IVH appeared bright on the FLAIR images obtained during the first 48 hours and was of variable appearance at later stages. FLAIR MR imaging detected 12 of 13 cases of IVH; no control subjects were falsely thought to have IVH (92% sensitivity, 100% specificity). However, IVH could not be fully excluded in the third ventricle (20%, n = 8) or in the fourth ventricle (28%, n = 11) on some control images because of CSF pulsation artifacts. Two cases had CT-negative IVH seen on FLAIR images. One case had FLAIR-negative IVH seen by CT. Although the sensitivities of conventional MR imaging (92%) and CT (85%) were also high, FLAIR imaging showed IVH more conspicuously than did standard MR imaging and CT in 62% of the cases (n = 8). FLAIR was as good as or better than CT in showing IVH in 10 cases (77%). FLAIR images showed all coexisting SAH. CONCLUSION: FLAIR MR imaging identifies acute and subacute IVH in the lateral ventricles with high sensitivity and specificity. In cases of subacute IVH, conventional MR imaging complements FLAIR in detecting IVH. The usefulness of the FLAIR technique for detecting third and fourth ventricular IVH may be compromised by artifacts. Blood hemoglobin degradation most likely causes the variable FLAIR appearance of IVH after the first 48 hours.     

Vagina: evaluation with MR imaging. Part II. Neoplasms

The potential of magnetic resonance (MR) imaging in the detection of vaginal tumors and the assessment of their extent was evaluated retrospectively in 87 patients in whom primary, metastatic, or recurrent vaginal cancer was clinically suspected. MR findings were compared with the results of surgery and/or biopsy. Results of histopathologic study verified a normal vagina in 51 patients, benign cysts in two, primary tumor in four, metastatic cancer in 22, and recurrent tumor in eight. MR imaging demonstrated the two benign cysts, correctly depicting their size and location, and demonstrated and enabled correct staging of the four primary tumors. MR accuracy for demonstrating metastatic cancer was 92%, sensitivity was 95%, and specificity was 90%. Tumor extension to the vagina was reliably excluded (negative predictive value = 97%), but false-positive interpretations occurred (positive predictive value = 84%) primarily because inflammation (n = 2) and congestion (n = 2) could not be distinguished from tumor invasion. An additional role of MR imaging was the ability to differentiate tumor from fibrotic tissue in patients with suspected recurrent vaginal carcinoma. The overall accuracy of MR imaging for recurrent vaginal cancer was 82% (14 of 17).     

Acute spontaneous spinal epidural hematomas.

BACKGROUND AND PURPOSE: Although previous reports have characterized MR imaging features of spinal epidural hematomas (EDH), few cases have been reported during the acute or hyperacute phase within the first 48 hours. Our goal in this investigation was to correlate the MR imaging features of acute (< or =48 hours) spontaneous EDH with clinical management and outcome. METHODS: Eight patients with acute spontaneous EDH (five men and three women; age range, 31-81 years) underwent MR imaging at 1.5 T (T1-weighted, n = 8; T1-weighted after the administration of 0.1 mmol/kg contrast material, n = 6; T2-weighted, n = 8; and T2-weighted, n = 4). The interval from symptom onset to hospital admission ranged from immediate to 5 days. Two neuroradiologists reviewed the MR images for signal characteristics, contrast enhancement, and cord compression. Treatment and clinical outcome were correlated with the imaging findings. RESULTS: The EDH were located in the cervical (n = 3), cervicothoracic (n = 2), thoracolumbar (n = 2), and lumbar (n = 1) regions. On T1-weighted images, the signal intensity of the EDH was isointense to spinal cord in five cases, hyperintense in two cases, and hypointense in one case and did not correlate with time to imaging. Isointensity on T1-weighted images persisted for 5 days in one case. On T2-weighted images, all EDHs were hyperintense with focal, heterogeneous hypointensity. Cord compression was severe in six patients, moderate in one patient, and minimal in one patient. Four cases were treated conservatively with complete resolution or improvement of symptoms within 1 to 3 weeks. CONCLUSION: MR imaging findings were useful in establishing the diagnosis of EDH but did not influence management or predict outcome in this series. Heterogeneous hyperintensity to cord with focal hypointensity on T2-weighted images should suggest the diagnosis of acute spinal EDH. Severity of neurologic impairment had the greatest impact on management and outcome. Nonoperative treatment may be successful in cases with minimal neurologic deficits, despite cord compression revealed by MR imaging.     

MR imaging of rotator cuff tears: is there a diagnostic benefit of shoulder exercise prior to imaging

The purpose of this study was to determine if shoulder exercise prior to MR imaging accentuates findings related to rotator cuff tears. In 32 consecutive patients undergoing MR imaging to evaluate the rotator cuff, after routine MR examination, the joint was moved by active or passive exercise (circumduction, including abduction, if possible) in an attempt to redistribute any joint fluid. The exercise was performed according to pain tolerance and for no longer than 4 minutes. The coronal oblique fast spin-echo T2-weighted images of these patients performed before exercise were reviewed by consensus agreement of two musculoskeletal radiologists who were blinded to clinical information. The appearance of the rotator cuff tendons and the distribution of fluid in the glenohumeral joint were determined. The identical postexercise MR images then were placed alongside the corresponding preexercise MR images, and a direct comparison of findings was made with regard to any change in the appearance of the rotator cuff or joint fluid by consensus opinion of the same two radiologists. Five patients (five shoulders) could not perform exercise because of pain. In the remaining 27 patients (27 shoulders), changes in the location of joint fluid were seen when the preexercise and postexercise images were reviewed together, the diagnosis of partial rotator cuff tear (n = 8) was changed to normal in two cases, and the diagnosis of partial tear was made with more confidence in one case. The diagnoses of normal rotator cuff (n = 16) and complete rotator cuff tear (n = 3) were unchanged. Eight patients had arthroscopy; in each of these, the preexercise and postexercise images showed similar results, and proved to be correct surgically (six normal, one partial rotator cuff tear, and one complete rotator cuff tear). Although postexercise MR images show changes in the distribution of joint fluid when compared to preexercise images, the diagnostic benefits of the postexercise images in the analysis of the rotator cuff appear to be limited.     

MR appearance of rhinoscleroma.

BACKGROUND AND PURPOSE: We describe the MR imaging appearance of rhinoscleroma, an endemic, chronic, granulomatous disease whose causative agent is Klebsiella rhinoscleromatis. METHODS: The study included 15 patients (nine males and six females; mean age, 25 years; range, 13-36 years) with rhinoscleroma. MR imaging was performed in all patients. The signal intensity of the nasal masses was compared with that of fat, muscle, and CSF on both T1- and T2-weighted images. All cases were proved by histopathologic examination. RESULTS: The nasal masses were bilateral and symmetrical (n = 6), asymmetrical (n = 4), or unilateral (n = 5). They extended through the anterior nares (n = 9) or posterior choana into the nasopharynx (n = 3). They obstructed the ostiomeatal units with retained secretions in the related sinuses (n = 10). On T1-weighted images, rhinoscleroma showed striking (n = 9) or mild (n = 6) high signal intensity relative to muscle and CSF, but less hyperintensity than fat. On T2-weighted images, the nasal masses showed homogeneous high signal intensity (n = 10) or heterogeneous high signal intensity associated with hypointense foci (n = 5). They were hyperintense relative to fat and muscle, but less hyperintense than CSF. CONCLUSION: The hypertrophic stage of rhinoscleroma has characteristic mild to marked high signal intensity on both T1- and T2-weighted MR images.     

MR of hereditary hemorrhagic telangiectasia: prevalence and spectrum of cerebrovascular malformations.

PURPOSEOur goal was to describe the prevalence and types of cerebral vascular malformations (CVMs) seen with MR imaging in patients with hereditary hemorrhagic telangiectasia (HHT).METHODSWe reviewed retrospectively the brain MR images of 184 consecutive patients with HHT. Catheter angiography was performed in 17 patients with CVMs detected on MR images.RESULTSMR imaging revealed 63 CVMs in 42 patients. Classic arteriovenous malformations (n = 10) had a conspicuous network of vessels with flow voids and enlarged adjacent pial vessels. Apparent venous malformations (n = 5) were best seen after administration of contrast material as a prominent vessel coursing through normal brain parenchyma. Indeterminate vascular malformations (n = 48) had a spectrum of appearances characterized by variable combinations of heterogeneous signal intensity, enhancement, or hemosiderin. Angiography in 17 patients revealed 47 CVMs. Forty-six were arteriovenous malformations (AVMs), including 25 CVMs not seen with MR imaging and 21 CVMs that by MR criteria included 8 AVMs and 13 indeterminate vascular malformations. Angiography confirmed 1 venous malformation seen with MR imaging but failed to detect 3 indeterminate lesions revealed by MR imaging.CONCLUSIONMR imaging of a large cohort of consecutive patients with HHT revealed a CVM prevalence of 23% (42/184). Most CVMs (48/63) have an atypical appearance for vascular malformations on MR images. Angiographic correlation suggests that MR imaging underestimates the prevalence of CVMs and that the majority of indeterminate CVMs, despite their variable MR appearance, are AVMs.     

Cerebral MR imaging in uninfected children born to HIV-seropositive mothers and perinatally exposed to zidovudine

BACKGROUND AND PURPOSE: Mitochondrial dysfunction has been reported in HIV-negative children perinatally exposed to zidovudine, a drug often used in HIV-seropositive mothers during pregnancy. The purpose of this study was to determine the incidence of cerebral MR imaging findings in HIV-uninfected children exposed to zidovudine who present with unexplained neurologic symptoms. METHODS: Two expert groups conducted a systematic, retrospective review of all cerebral MR images available in a multicentric, nationwide French prospective cohort of children born to HIV-seropositive mothers to identify imaging abnormalities. Experts were blinded to each others' interpretations, to the children's neurologic symptoms, and to laboratory evidence of mitochondrial dysfunction. The incidence of abnormalities was determined and compared with the neurologic presentation and laboratory evidence of mitochondrial dysfunction. RESULTS: MR images from 49 HIV-uninfected children (mean age, 26 months) were available for study. All children were perinatally exposed to zidovudine. Twenty-two had probable or established mitochondrial dysfunction according to their symptoms and laboratory data. Twenty-seven children without mitochondrial dysfunction presented with unexplained neurologic symptoms (n = 14) or nonneurologic symptoms (n = 7), and six were asymptomatic. Sixteen of 22 MR images in children with mitochondriopathy were considered abnormal in both independent analyses. Diffuse hyperintensity in the supratentorial white matter (n = 9) and in the tegmentum pons (n = 9) were the most frequent anomalies. Imaging abnormalities were often multifocal (n = 10) and sometimes associated with necrotic areas (n = 3) and volume loss (n = 8). Although 19 of 27 MR images of children without mitochondrial dysfunction were mainly normal, abnormal images were observed in five of 14 children with unexplained neurologic symptoms and in three of six asymptomatic children. CONCLUSION: Images observed in children with antiretroviral-induced mitochondrial dysfunction are similar to those observed in congenital mitochondrial diseases. These images were also observed in symptomatic or asymptomatic children without evidence of systemic mitochondrial dysfunction.     

MR imaging features of infiltrating lobular carcinoma of the breast: histopathologic correlation

OBJECTIVE: Our study aimed to correlate the dynamic contrast-enhanced MR appearance of infiltrating lobular carcinoma of the breast with histopathologic findings. MATERIALS AND METHODS: We retrospectively reviewed the high-resolution, fat-suppressed and dynamic contrast-enhanced MR images of 13 of 20 women diagnosed with pathologically proven infiltrating lobular carcinoma of the breast. Twelve of the 13 women presented with breast symptoms and underwent mammography. Five of the women also had breast sonography. MR imaging was performed for evaluation of disease extent before the patients underwent modified radical mastectomy (n = 11) or lumpectomy (n = 2). Three experienced radiologists reviewed the MR scans. The tumor pattern types described on imaging were correlated with a detailed analysis of the pathology. RESULTS: We found three patterns of infiltrating lobular carcinoma on MR imaging. The tumor pattern on imaging correlated with pathologic tumor morphology. We found the following patterns of infiltrating lobular carcinoma: a solitary mass with irregular margins (n = 4) that corresponded to the same appearance at pathology; multiple lesions, either connected by enhancing strands (n = 6) or separated by nonenhancing intervening tissue (n = 2), that correlated with the pathologic appearance of noncontiguous tumor foci, with malignant cells streaming in single-file fashion in the breast stroma or small tumor aggregates separated by normal tissue; and enhancing septa only, which were correlated with the histopathologic appearance of tumor cells streaming in the breast stroma (n = 1). CONCLUSION: Infiltrating lobular carcinoma may be detected on MR imaging as solitary or multiple lesions that correspond to tumor morphology on pathologic examination. The appearance of multiple lesions or of enhancing fibroglandular breast elements on MR imaging is suggestive of infiltrating lobular carcinoma.     

Morning Glory syndrome. MR imaging.

We present two cases of the Morning Glory Syndrome (MGS), with the most detailed MR images to date of this rare congenital optic nerve dysplasia. Though the embryology of this syndrome remains controversial, we feel the MR appearance can be diagnostic of the non-familial syndrome and be reliably distinguished from the similar appearing optic disc coloboma, which may be genetically inherited. MR imaging also allows the most sensitive detection and characterization of any associated intracranial anomalies, thus enabling more accurate determination of prognosis for the patient and their family.     

Newly developed hepatocellular carcinoma (HCC) in chronic liver disease: MR imaging findings before the diagnosis of HCC

PURPOSE: The purpose of this work was to describe the initial magnetic resonance (MR) imaging findings obtained before an imaging diagnosis of overt hepatocellular carcinoma (HCC) in the chronically damaged liver. METHODS: One hundred fifty-two newly diagnosed HCCs diagnosed by dynamic computed tomography (n = 111) or by MR imaging (n = 41), in addition to digital subtraction hepatic arteriography, in 96 patients were subjected to analysis of their MR imaging features within the previous 2 years. RESULTS: Ninety-seven (64%) HCC cases showed no focal lesions distinguishable from background hepatic parenchyma in MR images taken before the indication of typical HCC. The remaining 55 (36%) lesions were readily identified in earlier images and were categorized into 3 groups: nonhypervascular lesions (category I, n = 6), lesions with partially hypervascular foci of "nodule-within-nodule" appearance (category II, n = 12), and homogeneously hypervascular and/or T2-weighted hyperintense lesions (category III, n = 37). The size and doubling time of category III lesions (0.7 cm, 154 days) were smaller and shorter than those of the other lesions (1.2 cm, 377 days). CONCLUSIONS: Before the imaging diagnosis of HCCs, the premalignant or early malignant lesions can be found on the prior MR images just in the minority of the lesions in the cirrhotic liver.     

Right lobe living donor liver transplantation: preoperative evaluation of the donor with MR imaging

OBJECTIVE: The purpose of this study was to report our experience in preoperative evaluation of right hepatic lobe donors with a comprehensive MR examination and to compare abdominal MR images, MR cholangiograms, and MR angiograms with findings at surgery, intraoperative cholangiography, and digital subtraction angiography. MATERIALS AND METHODS: Twenty-eight right hepatic lobe donors underwent preoperative evaluation with MR imaging, MR cholangiography, and MR angiography. Two abdominal radiologists independently and randomly reviewed these studies. Points of assessment included focal and diffuse liver disease, calculation of right lobe volumes, depiction of the biliary tract and ductal anomalies, and depiction of the liver vasculature and vascular anomalies. Comparison was made with intraoperative cholangiograms (n = 20) and digital subtraction angiograms (n = 28). RESULTS: MR imaging revealed and characterized focal liver lesions in eight of 28 patients. Calculated right lobe volumes agreed with surgically determined volumes within 7% for reviewer 1 and within 15% for reviewer 2. Intrahepatic bile ducts were depicted completely with MR cholangiography in 25 of 28 patients and with intraoperative cholangiography in nine of 20 patients. MR cholangiography revealed ductal anomalies in six patients. MR imaging and MR angiography depicted the portal veins more completely than digital subtraction angiography. MR imaging and MR angiography correctly excluded portal venous anomalies in all patients and revealed surgically confirmed accessory hepatic veins in six of 28 patients. Angiographically confirmed arterial anomalies were correctly detected in three of 28 patients by at least one reviewer on MR imaging and MR angiography. CONCLUSION: MR imaging, MR cholangiography, and MR angiography provide a comprehensive, accurate means of evaluating donors for factors that may preclude or complicate right hepatic lobe donation.     

Diffusion-weighted MR imaging offers no advantage over routine noncontrast MR imaging in the detection of vertebral metastases

BACKGROUND AND PURPOSE: Diffusion-weighted MR imaging of the spine has been used to differentiate benign from pathologic vertebral body compression fractures. We sought to determine the utility of diffusion-weighted MR imaging in the detection of vertebral metastases and to compare it with conventional noncontrast T1- and T2-weighted MR imaging. METHODS: Fifteen patients with metastases to the spine were studied using conventional MR imaging and diffusion-weighted imaging. Blinded review of all images was undertaken, and patients were categorized according to whether they had focal or multiple lesions. The signal intensity of the lesions was compared on T1-, T2- (fast spin-echo), and diffusion-weighted images. RESULTS: In five patients with focal disease, metastases were hypointense on T1-weighted images; hypointense (n = 2), isointense (n = 1), or hyperintense (n = 2) on T2-weighted images; and hypointense (n = 3) or hyperintense (n = 2) on diffusion-weighted images with respect to presumed normal bone marrow. In 10 patients with disease in multiple sites, all lesions were hypointense on T1-weighted images; hypointense (n = 2), isointense (n = 4), hyperintense (n = 2), or mixed (n = 2) on T2-weighted images; and hypointense (n = 5), hyperintense (n = 3), or mixed (n = 2) on diffusion-weighted images with respect to presumed normal bone marrow. CONCLUSION: As used in this study, diffusion-weighted MR imaging of the spine showed no advantage in the detection and characterization of vertebral metastases as compared with noncontrast T1-weighted imaging, but was considered superior to T2-weighted imaging.     

Adult intussusception detected at CT or MR imaging: clinical-imaging correlation.

PURPOSE: To determine the clinical presentation in cases of adult intussusception demonstrated at computed tomography (CT) or magnetic resonance (MR) imaging and to correlate the imaging appearance with clinical diagnosis. MATERIALS AND METHODS: Retrospective review of CT and MR images and clinical records of all patients with an intussusception demonstrated on CT or MR images from January 1, 1991, through April 30, 1998. RESULTS: Thirty-three patients had one or more intussusceptions demonstrated on CT (n = 30) or MR (n = 3) images. Twenty-nine patients had enteroenteric intussusceptions, and four had intussusceptions involving the colon. Ten patients (30%) had a neoplastic lead point, including all four of the intussusceptions involving the colon (benign mass, n = 3; malignant mass, n = 7). In 23 cases (70%), no neoplastic lead point was identified. A variety of causes were implicated in these cases, with 16 cases (48%) classified as idiopathic. Enteric intussusceptions in the nonneoplastic group were shorter in length (median, 4 vs 10.8 cm; P = .002), smaller in diameter (median, 3 vs 4 cm; P = .002), and less likely to be associated with obstruction (4.3% vs 50%; P = .02). CONCLUSION: Less than one-third of adult intussusceptions demonstrated at CT or MR imaging were caused by a neoplastic lead point. Almost half of adult cases in this series were idiopathic.     

快速MRI对胎儿中枢神经系统先天畸形的诊断价值与超声对照研究

目的 探讨快速MRI对胎儿中枢神经系统先天畸形的诊断价值并与超声（US）对照。方法 对48例孕妇产前行US和MRI检查，胎儿尸检及出生后随访检查证实中枢神经系统畸形22例，共26处。于US检查后3d内行胎儿颅脑脊柱及胸腹部MR扫描，并与US诊断结果和尸检及随访结果进行比较。结果 引产后尸检发现17处畸形，出生后随访检查证实9处畸形，共26处（无脑畸形6处、脊柱裂2处、脑膜脑膨出3处、先天性脑积水7处、前脑无裂畸形1处、脑穿通畸形3处、蛛网膜囊肿2处、脉络丛囊肿2处），US诊断24处，准确率92．3％（24／26），误、漏诊各1处，假阳性率3．8％（1／26），漏诊率为3．8％（1／26），MRI诊断23处，准确率88．5％，误诊1处，假阳性率3．8％（1／26），漏诊2处，漏诊率为7．7％（2／26）。比较2种方法差异无统计学意义（X^2=0．22，P〉0．05）。但快速MRI视野大，运动伪影少，组织分辨率高，能清楚显示脑灰白质、脑室系统、脑沟裂、蛛网膜下腔、脊柱等中枢神经系统解剖结构。结论 MRI对胎儿中枢神经系统先天畸形具有较高的诊断价值，可作为胎儿中枢神经系统先天畸形的一种重要的影像学诊断手段。