Evaluation of focal hepatic masses: a comparative study of MRI and CT

We evaluated suspected hepatic lesions in 30 patients using both nongated spin-echo magnetic resonance imaging (MRI) on a 0.35 T superconducting magnet and contrast-enhanced dynamic incremental computed tomography (CT). In the 27 patients with focal lesions, both modalities detected abnormalities in 26 patients. Liver lesions were equally well demonstrated using MRI and CT in 15 patients, better demonstrated by CT in 11 patients, and better demonstrated by MRI in 1 patient. Small lesions (<2 cm) were much better demonstrated using CT than MRI; this was significant when knowledge of the precise extent of disease was necessary for planning surgical therapy or for evaluating response to chemotherapy. Five patients had significant extrahepatic disease detected by CT; MRI identified extrahepatic abnormalities in only 2 of these 5 patients. We conclude that at the current time CT is more useful than nongated spin-echo MRI in the evaluation of suspected hepatic masses.     

腰骶椎管闭合不全超声检查的应用

目的 :观察超声在腰骶椎管闭合不全合并脊髓栓系综合征中诊断和术后随访的价值。方法 :6 8例患者进行腰骶椎管超声检查 ,同时有脊髓造影 CT或磁共振 (MRI)确诊并经手术证实进行对比评价 ;对术后 30例随访超声观察。结果 :超声可同样检查 CT或 MRI显示本症的特征 ,低位脊髓、脊髓背移、椎管内脂肪瘤或囊性脊椎裂的病变异常 ;同时超声尚能检查出脊髓远端动态脉跳搏动消失。超声诊断正确率为 85 .3%。术后随访 30例中有 3例可能术后粘连致再栓系。结论 :超声可作为无损伤早期初筛诊断 ,尤为可疑婴幼儿和儿童的应用 ,并可术后随访     

肝肾间隙巨大占位病灶来源器官的影像鉴别研究

目的：利用循证医学（Evidence-Based Medicine）的原理，综合几种影像诊断方法的优势，提高肝肾间隙病灶来源诊断水平。资料与方法：采用B超、彩色多普勒血流图（CDFI）和能量图（CDE），结合CT、MRI影像手段，对35例肝肾间隙巨大肿块的定位征象进行回顾性研究。并利用循证医学原理进行分析。结果：31例超声检查者均可检测到肝肾等脏器间相对运动，23例受检CDFI和CDE中19例示增粗的肿瘤供血血管并显示其起始方向，CT、MRI受检者全部可显示病灶全貌。综合超声、CT、MRI、DSA影像手段，对32例肝肾间隙的巨大肿块来源能作出正确定位。结论：利用几种影像诊断方法的优势，于临床工作中循证，有益于评价各种影像学获得的最好的证据，确立肝肾间隙巨大占位病灶的来源。     

Diagnostic imaging in cancer.

Screening chest radiographs do not reduce mortality from lung cancer. Should an incidental noncalcified pulmonary parenchymal nodule be discovered, chest CT will demonstrate one third of such patients to, in fact, have the multiple nodules of metastatic disease. CT is very helpful to guide fine needle aspiration biopsy of lung lesions and to assist in evaluation for resectability. MR can be helpful in special circumstances, including the definition of the extent of paravertebral, superior sulcus, and diaphragmatic lesions. Endorectal ultrasound is not sensitive enough to function as a screening tool for prostate cancer but is used routinely to guide biopsies. CT and MR are rarely helpful in staging this disease. Given the highly characteristic trait of bone metastasis in prostate cancer, a bone scan is mandatory in all patients. Double contrast barium enema can be used as an adjunct or alternative to sigmoidoscopy for colorectal cancer screening, in the preoperative evaluation of patients, and in postoperative surveillance. CT and MR can detect macroscopic adenopathy and liver metastases; CT is generally the preferred study. Screening mammography can have a major impact in reducing breast cancer mortality. It is recommended that a baseline study be obtained at age 35. Annual or biannual examinations should commence at age 40. Any palpable lesion, whether or not it is demonstrated mammographically, must be subjected to biopsy. Ultrasound is the most useful initial imaging study for evaluating pelvic masses. MR will, on occasion, identify the origin of a mass not determinable from ultrasound scan. MR is particularly valuable to identify parametrial spread (inoperability) of cervical cancer, and has been underused for this purpose. Surgery remains the mainstay for the staging of ovarian and endometrial cancer, although CT can be helpful to identify macroscopic relapse, ascites, or liver metastases. Bone scan and liver CT remain the standard procedures for detecting metastases in these respective organ systems. MR can be invaluable in the imaging of epidural metastasis and spinal cord compression in patients with vertebral metastatic disease. Contrast-enhanced MR is more sensitive than contrast-enhanced CT for detecting brain metastases, but the latter remains a useful tool. Chest CT can improve the detection of pulmonary metastases when this is of crucial importance.     

Adrenal and pseudoadrenal masses: CT and US findings

Computed tomography (CT) is currently the imaging modality of choice for assessing the morphology of the adrenal glands in adult patients. Much useful information can be gained using CT in disease processes which primarily involve one or both of the adrenal glands, such as adenomas, as well as in entities which secondarily affect the adrenals, such as pituitary or metastatic disease. The size and configuration of the glands can be readily determined, and masses may be detected. We discuss CT of normal and abnormal adrenal glands with sonographic (US) and pathological correlation, when available. Entities which may mimic adrenal abnormalities are emphasized. Relative advantages of US over CT in the pediatric patient are discussed.     

超声造影在肝恶性肿瘤介入治疗疗效评估中的应用价值

目的观察肝恶性肿瘤介入治疗后超声造影表现,并与其他影像学方法比较,评估其对介入治疗疗效判定的临床应用价值。方法评估介入治疗疗效66例次,病灶78个,介入治疗后均行超声造影检查及同期CT/MRI/DSA检查(超声造影前后2周内),包括经肝动脉插管栓塞化疗(TACE)38例次46个病灶,射频(RF)消融治疗13例次15个病灶,经皮乙醇注射(PEI)治疗15例次17个病灶。超声造影显像将病灶分为有增强和无增强两类。结果介入治疗后,超声造影显示44个病灶(56.4%)动脉相局部增强区,34个病灶无增强。同期CT/MRI/DSA诊断41个病灶(52.6%)有肿瘤复发/残存,以后者为对照,实时谐波超声造影评估肝恶性肿瘤介入治疗疗效的敏感性为87.8%,特异性为78.4%,符合率为83.3%。TACE、RF、PEI三种肝脏恶性肿瘤治疗方式中,超声造影对TACE治疗后疗效评估的敏感性、特异性及符合率最高,分别为92.0%,85.7%,89.1%。结论超声造影可以作为肝脏恶性肿瘤介入治疗疗效评估的可靠方法,且更适于TA-CE治疗后的疗效评价。     

B超、CT与MRI诊断胆管结石的比较研究

目的 比较B超、CT与MRI各成像序列对胆管结石的诊断价值.方法 23例临床拟诊胆管结石的患者行B超和MRI检查,其中10例行同期CT扫描.最后诊断均经手术或经内镜逆行胰胆管造影(ERCP)证实.依据影像诊断报告结果总结B超、CT与MRI诊断胆管结石的准确性,并通过回顾性分析CT与MRI脉冲序列图像探讨各种技术的优缺点.结果 23例病人中,22例有胆管结石,1例手术中未见胆管内结石.B超诊断结石12例,其中1例假阳性,诊断准确度48%(11/23).CT诊断结石8例,假阴性2例,诊断准确度80%(8/10).MRI诊断结石20例,其中1例假阳性,诊断准确度83%(19/23).在MRI各序列中,磁共振胰胆管造影(MRCP)显示胆管结石最直观,轴位T2WI与T1WI是MRCP的有益补充.结论 诊断胆管结石时,B超可作为初步筛查方法.CT与MRI的诊断准确性较高,且后者多序列多方向的成像能力可补充B超与CT的不足.     

MR imaging of the pleura and chest wall

Evaluation of pleural and chest-wall disease begins with a chest radiograph. In many cases, further evaluation of the chest wall and pleura requires cross-sectional imaging with CT scan or MR imaging. MR imaging is reserved for specific cases of tumors, infections, pleural effusions, and masses. The superior soft-tissue contrast of MR imaging is useful in evaluating the extent of infections and tumors involving the pleura and chest wall. The multiplanar capability of MR imaging aids in the evaluation of chest wall and pleural abnormalities, particularly in the apical regions.     

Fetal magnetic resonance imaging

Ultrafast magnetic resonance imaging (MRI) sequences have changed the use of MRI to evaluate fetal abnormalities. Currently, the best application is the evaluation of suspected brain abnormalities found on ultrasound. MRI differentiates the various types of fetal ventriculomegaly. Superior posterior fossa visualization allows differentiation of Dandy-Walker malformation from a large cisterna magna. Anomalies of the corpus callosum can be seen. MRI also is valuable in the evaluation of fetal giant neck masses for planning delivery of the baby and surgery for life-threatening airway obstruction. In the chest, MRI differentiates masses such as diaphragmatic hernia, cystic adenomatoid malformation, and sequestration, and it aids in planning fetal surgery because MRI directly visualizes the position of the lung, liver, and bowel.     

Applications of magnetic resonance imaging to gynecology

The advent of MRI has improved the ability of the diagnostic radiologist to provide useful clinical information to the practicing gynecologist. Although US remains the screening procedure of choice for evaluation of the uterus and adnexa because of its relative safety and low cost, MRI is now considered the next imaging step. In a woman with pelvic pain, MRI can accurately identify adenomyosis, enumerate and localize uterine fibroids, and provide more accurate identification of endometriosis and cystic teratomas of the ovary than US. Although MRI should not be used as a screening procedure for diagnosing endometrial or cervical carcinoma, it can aid in patient management by determining the extent of myometrial or cervical invasion by endometrial carcinoma and can be used to calculate tumor volume in patients with cervical carcinoma. Early studies suggest that MRI may be helpful in distinguishing between long-term radiation fibrosis and tumor recurrence in such patients. MRI findings may be highly indicative of the presence of ovarian malignancy, but the procedure adds little to CT or US findings. Nevertheless, MRI is superior in the localization of pelvic masses and is often indicated in clarifying the origin of a mass as uterine or ovarian.     

Amebic abscess of the liver manifested by “hemoptysis”: US,CT, and MRI findings

Ultrasonographic (US), computed tomographic (CT), and magnetic resonance imaging (MRI) findings of a patient suffering from an amebic abscess of the liver complicated by a bronchohepatic fistula are presented. Subsequent to US, CT provided the specific diagnosis. Multiplanar MRI was valuable to directly visualize the secondary diaphragmatic rupture and the bronchohepatic fistula.     

超声和MRI在胎儿中枢神经系统畸形诊断中的对比应用

目的对比分析超声和MRI在胎儿中枢神经系统畸形诊断中的应用价值。方法在超声检出的529例中枢神经系统畸形胎儿中,有62例于超声检查后48h内接受产前MRI检查。此62例患者均经引产后尸检、尸体影像学检查或分娩后随访证实。将超声、MRI及随访结果进行对比分析。结果MRI与超声诊断结果一致39例(62.9%),MRI较超声提供更多诊断信息19例(30.6%),超声较MRI提供更多诊断信息3例(4.8%),MRI不能提供有效诊断信息1例(1.6%)。结论对于脑室扩张、颅内囊性病变、颅内团状异常回声、后颅窝异常及全前脑的评价MRI优于超声;而对于颈枕部肿块或囊性包块及开放性神经管缺陷的评价,MRI未见明显优势。超声检查仍是胎儿中枢神经系统畸形筛查的首选方法。在超声检查基础上进一步行MRI检查,有助于弥补超声检查的不足,甚至更正超声诊断,可作为产前胎儿检查的重要手段。     

Comparison of MR imaging and CT in the evaluation of renal masses

The present status of magnetic resonance imaging (MRI) in the evaluation of renal masses, especially as compared to computed tomography (CT) is discussed based on our experience and on a review of the literature. It is already apparent that simple renal cysts, hemorrhagic cysts, and fatty renal masses are well demonstrated by MRI. However, other modalities, and particularly CT, have similar degrees of accuracy, are more widely available, and are less expensive. So, currently, MRI has not been proven to be an optional screening method for detection of renal masses. At present, the major clinical uses of MRI are (1) the staging of renal carcinoma, in which MRI appears slightly superior to CT, (2) in patients with known contraindications to the use of iodinated contrast medium, (3) in patients with suspected renal carcinomas in which results from other imaging modalities are atypical or indeterminate, and (4) when sagittal or coronal imaging is desirable.     

The usefulness of ultrasound colour-Doppler twinkling artefact for detecting urolithiasis compared with low dose nonenhanced computerized tomography

This prospective study evaluates the usefulness of the twinkling artefact (TA) seen on colour-Doppler ultrasound (US) in diagnosing urolithiasis. US and standard computed tomography (CT) were performed blinded on 105 patients. B-mode US and colour-Doppler used separately and in combination showed 55% sensitivity and 99% specificity (positive predictive value [PPV] 67% and negative predictive value [NPV] 98%). Of CT verified stones, 61% were ≤3 mm. TAs were present in 74% of the B-mode stones (43% of all CT verified stones). Patients with CT verified stone disease had significantly more TAs in other foci than the stone(s) found on CT, suggestive of microlithiasis. In conclusion, colour-Doppler TA is a helpful supplement for detecting urolithiasis when CT is contraindicated. In addition, US can be valuable in monitoring stones left to pass without intervention if they have presented a TA. CT, US and US with colour-Doppler TA can be useful as complementary techniques for detecting stones.     

Computed tomographic and magnetic resonance features of gynecologic abnormalities in women presenting with acute or chronic abdominal pain

Advances in technology and improved availability have led to increased use of computed tomography (CT) and magnetic resonance imaging (MRI) to evaluate women presenting to the emergency department or to their primary care provider with abdominal and/or pelvic pain. Computed tomographic examinations are often performed to evaluate the presence of appendicitis or renal stone disease. However, gynecologic abnormalities are frequently identified on these examinations. Although ultrasound remains the primary modality by which complaints specific to the pelvis are evaluated, in many instances, CT and MRI imaging occurs before sonographic evaluation.Historically, because of cost, radiation exposure, and relative ease of use, ultrasound examinations have preceded all other imaging modalities when evaluating pelvic disorders. However, as CT and MRI technology have improved, their use in diagnosing causes of pelvic pain has become equal to that of ultrasound. In some cases, primarily because of historic comfort with sonographic evaluation, gynecologic abnormalities originally diagnosed on CT or MRI may be immediately and unnecessarily reevaluated by ultrasound.For a woman in her reproductive years, the most common adnexal masses are physiological cysts, endometriomas, and cystic teratomas. Although lesions are often asymptomatic and incidentally detected, they can present with pain, and they increase the risk of ovarian torsion. Common causes of chronic pelvic pain in this population include leiomyomata and adenomyosis. In postmenopausal women, ovarian carcinoma, which often does not present clinically until a late stage, has to be included in the differential diagnosis of adnexal masses.If a gynecologic pathology is discovered on CT or MRI, an immediate follow-up ultrasound need not be pursued if the lesion can be characterized as benign, needing immediate surgical intervention, or a variant of normal anatomy. If, on the other hand, findings demonstrate a mass that either is uncharacteristic of a benign lesion, has an indeterminate risk for malignancy, or demonstrates suspicious characteristics for malignancy (such as enhancing mural nodules), further evaluation by serial ultrasound, biochemical marker, and/or CT or MRI is warranted.The purpose of this review is to present a series of commonly encountered gynecologic abnormalities with either CT or MR to make radiologists more familiar with gynecologic pathology on CT and MRI.     

Use of chest sonography in acute-care radiology

Diagnosis of acute lung disease is a daily challenge for radiologists working in acute-care areas. It is generally based on the results of chest radiography performed under technically unfavorable conditions. Computed tomography (CT) is undoubtedly more accurate in these cases, but it cannot always be performed on critically ill patients who need continuous care.The use of thoracic ultrasonography (US) has recently been proposed for the study of acute lung disease. It can be carried out rapidly at the bedside and does not require any particularly sophisticated equipment. This report analyzes our experience with chest sonography as a supplement to chest radiography in an Emergency Radiology Unit. We performed chest sonography – as an adjunct to chest radiography – on 168 patients with acute chest pathology. Static and dynamic US signs were analyzed in light of radiographic findings and, when possible, CT. The use of chest US improved the authors' ability to provide confident diagnoses of acute disease of the chest and lungs.     

Magnetic resonance imaging of the kidneys and adrenals

Renal and adrenal anatomy, both normal and abnormal, are well depicted by MRI. Although MRI is not a sensitive modality for detection of renal cell carcinoma, it has clinical utility for evaluation of vascular involvement or direct extension of neoplasm into adjacent organs when CT findings are equivocal. Use of signal characteristics has not been useful in differentiating simple from complex cystic renal masses or among the various causes of medical renal disease and renal transplant failure. Similarly, signal characteristics are not sufficiently reliable for differentiating benign from malignant adrenal masses. MRI is useful, however, for detection and localization of pheochromocytomas. MRI plays a major role in imaging of children with neuroblastoma and Wilms' tumor and may obviate other, often more invasive, examinations in these cases.     

The role of coronary CT in the assessment and diagnosis of patients with chest pain

The role of cardiac computed tomography (CT) in the assessment and management of patients with suspected cardiac chest pain has been formally recognised in NICE guidance 95. When the technique and patient selection are appropriate, cardiac CT is a valuable diagnostic tool, particularly for patients with a low to intermediate pre-test probability of coronary artery disease. The physician must be aware of the implications of the recent guidelines; hence, we present an illustrated synopsis on the current technique and the indications for the use of calcium scoring and cardiac CT in the assessment and management of patients with suspected cardiac chest pain.     

Magnetic resonance imaging of the pediatric head and neck

Although the bulk of pediatric head and neck lesions are adequately evaluated by computed tomography (CT) alone, magnetic resonance imaging (MRI) provides valuable additional information in those lesions that are difficult to resolve on CT, and it is almost essential for assessment of possible intracranial extension of disease. The ability of MRI to show intrinsic characteristics of mass lesions can help direct therapeutic decisions. It should be utilized early in the imaging evaluation of most vascular lesions, including juvenile nasal angiofibroma and vascular malformations, in suspected neurogenic tumors, and as an adjunct in those cases where CT does not adequately demonstrate the extent or true nature of a lesion.     

CT Imaging of the Pericardium

Pericardial disease can be challenging to diagnose, and imaging can play a useful role in confirming or even suggesting the diagnosis. Computed tomography (CT) is a particularly appealing option for investigating pericardial disease in many patients because the differential diagnosis for symptoms of acute pericarditis or constrictive pericarditis often includes other diseases which are also well assessed with CT. In addition, many patients will have findings of pericardial disease manifest on CT imaging for other suspected diseases, and these findings can be missed if careful attention is not paid to the pericardium. CT also can play an important role in evaluating specific pericardial lesions, such as cysts, tumors, and abscesses. We will review findings of various pericardial diseases on CT with illustrative cases.