MRI of the pediatric shoulder: nontraumatic lesions

Magnetic resonance imaging is an established technique for imaging the shoulder because it demonstrates clearly the articular surfaces, medullary canal and the extra-articular soft tissues which can be affected in shoulder disorders. The value of MR imaging in the evaluation of the traumatized shoulder has been described [1]; however, few cases of MR imaging in nontraumatic disorders in children have been reported. We reviewed the findings in 55 children undergoing MRI of the shoulder for nontraumatic conditions and included selected cases showing a broad range of imaging findings.     

Magnetic resonance imaging in 80 cases of orbital tumors

Magnetic resonance imaging (MRI) is a new medical imaging technique which has been used in evaluating ocular and orbital diseases in recent years. Owing to the high resolution of soft tissues and lesions, it is superior to ultrasound and computed tomography in the localization and characterization of an orbital tumor in diagnosis. In this paper, we analysed 80 cases of MR images of orbital tumors by which all the lesions were detected. Benign or malignant disorders were recognized in 59 cases and complete tumors with accurate localization were shown in 79 cases. The principles of MRI, signal intensity of various tumors and the indications of MRI were discussed.     

Accuracy of seven different tests for the diagnosis of Helicobacter pylori infection and the impact of H2-receptor antagonists on test results

The financial burden for the evaluation of patients for acoustic neuroma in an otolaryngology practice is substantial. Patients with sudden sensorineural hearing loss represent a portion of that population seen with unilateral, asymmetric auditory symptoms who require investigation for acoustic neuroma. For these patients, gadolinium-enhanced magnetic resonance imaging is the diagnostic gold standard. Auditory brain stem response testing has been used in the past as a screening test for acoustic neuroma, but its apparent sensitivity has fallen as the ability to image smaller acoustic neuromas has improved. Fast spin echo magnetic resonance imaging techniques without gadolinium have been shown to be as effective in the detection of acoustic neuroma as contrast-enhanced magnetic resonance imaging. Limited nonenhanced fast spin echo magnetic resonance imaging now provides an inexpensive alternative for high-resolution imaging of the internal auditory canal and cerebellopontine angle. Fast spin echo magnetic resonance imaging can now be done at a cost approximating auditory brain stem response testing while providing the anatomic information of contrast-enhanced magnetic resonance imaging. Cost analysis was done in the cases of 58 patients with sudden sensorineural hearing loss by comparing the costs for routine workup and screening of acoustic neuroma with the cost of fast spin echo magnetic resonance imaging with the use of screening protocols based on literature review. The potential cost savings of evaluating patients with sudden sensorineural hearing loss with fast spin echo magnetic resonance imaging for acoustic neuroma was substantial, with a 54% reduction in screening costs. In an era of medical economic scrutiny, fast spin echo magnetic resonance imaging has become the most cost-effective method to screen suspected cases of acoustic tumors at our institution by improving existing technology while reducing the cost of providing that technology and eliminating charges for impedance audiometry, auditory brain stem response testing, and contrast-enhanced magnetic resonance imaging.     

Detection of the first recurrence during intensive follow-up of breast cancer patients

BACKGROUND: Breast cancer patients are routinely followed after primary treatment. Many intensive diagnostic methods (tumor markers, chest X-ray, mammography, liver echography, bone scans) are performed periodically. However, it remains to be determined how often attempts should be made to detect the first recurrence of breast cancer by these methods. METHODS: To evaluate the effect of imaging diagnosis and tumor markers, we analyzed methods of detection of first recurrence sites during intensive follow-up of breast cancer patients. RESULTS: Of 550 female patients who had been surgically treated between July 1992 and December 1996, 65 recurrent cases had been diagnosed as of December 1997. Thirty cases (46%) had been found as a result of symptoms related to the site of recurrence and 14 cases (22%) were detected by physical examination. In the remaining 21 cases (32%), detection was by other methods: in eight cases by imaging diagnosis, in three cases based on abnormal tumor markers and in 10 cases by imaging diagnosis and abnormal tumor markers. Twenty-nine cases (45%) followed every 1-3 months had presented with symptoms at routine or interval appointments. There was a significant difference between first recurrence sites (loco-regional, bone and viscera) and the methods of detection (symptoms, physical examination and other diagnostic methods) (P < 0.0001). However, no statistical difference in overall survival after operation was observed between the 30 cases found as a result of symptoms and the 35 cases detected by physical examination or other diagnostic methods. CONCLUSIONS: Taken together with ASCO's surveillance guidelines (J Clin Oncol 1997;15:2149-56), intensive follow-up of breast cancer patients should be limited to high-risk breast cancer patients, especially those who enter randomized clinical trials. A careful history and physical examination are in practice indicated every 3-6 months for 3 years and then every 6 months for the following 2 years.     

Apropos of a case of acute pancreatitis revealing cystic dilatation of the common bile duct

Dilatation of the common bile duct is rarely caused by cystic formations. Though the pathogenesis is uncertain, congenital disorders have been suggested. Most cases are observed in small children (80% female predominance) with only 20% of the cases reported in adults. Clinical signs vary. Recurrent acute pancreatitis has been reported but is rare. New imaging techniques using CT-scan cholangiography and sometimes MR cholangiography have greatly improved the diagnostic approach. MR of the bile ducts is a recent noninvasive technique enabling an analysis of the biliopancreatic ducts without contrast injection into the bile. To our knowledge, cystic dilatation of the common bile duct has not been previously reported in the literature. We report an interesting case in a 25-year-old woman who developed an episode of acute pancreatitis during the post partum period. We describe the clinical aspects and the different imaging findings, including magnetic resonance cholangiography results.     

Crescent-shaped necrosis: a new imaging sign suggestive of stromal tumor of the small bowel

We report three cases of unsuspected stromal tumors of the small bowel (STSB). These cases were diagnosed preoperatively by sonography, the imaging was completed for some with barium studies, computed tomography, magnetic resonance imaging, or angiography. To our knowledge, the use of this noninvasive technique for detecting this type of tumor has not been described in the literature. Moreover, we believe that some sonographic findings such as crescentic tumoral necrosis may appear highly suggestive of STSB.     

Quantitative analyses for facial nerve MR imaging

It is clear, from our clinical experience, that the facial nerve in patients with facial palsy is enhanced on magnetic resonance (MR) imaging after intravenous administration of gadolinium diethylenetriamine. However, some problems with clinical reliability persist. There have been reports that normal facial nerves often show enhancement on MR imaging. We also question whether there are any differences in the degree of enhancement between Bell's palsy and Ramsay Hunt syndrome. To solve these problems, analyses were conducted using a personal computer by means of digital image-processing to measure the gray scale levels of enhanced facial nerves on MR imaging films. Seventeen cases of Bell's palsy, eight cases of Ramsay Hunt syndrome and fourteen normal subjects whose facial nerves showed enhancement on MR imaging were selected for the analyses. The concept of a facial nerve/whole image ratio (F/W ratio), analyzing the degree of enhancement of the facial nerve quantitatively, is introduced in this paper. The F/W ratio is the ratio of the gray scale level of the facial nerve region to the highest gray scale level in the skull at the MR imaging film. When the F/W ratios of these subjects were analyzed, no significant differences were found between Bell's Palsy and Ramsay Hunt syndrome in the degree of enhancement; facial palsy cases showed quantitatively larger F/W ratios than normal subjects.     

Incidental lung carcinoma detected at CT in patients selected for lung volume reduction surgery to treat severe pulmonary emphysema

OBJECTIVE: Ovarian vein thrombosis (OVT) is a pathologic entity classically considered a postpartum complication and only rarely associated with other disease processes. Before modern imaging methods, diagnosis was primarily made clinically or at exploratory surgery. Our objective was to show that with CT and sonographic imaging, OVT can be detected in atypical clinical situations and that the condition may also be occult. CONCLUSION: Only two of six cases at our institution fit the classic picture of postpartum infection complicated by OVT. The other four cases occurred in conjunction with other pathologic conditions, one of which has not to our knowledge been previously associated with OVT. The diagnosis was not clinically suspected in these four cases. On CT and sonography, OVT was detected incidentally, because clinical symptoms were atypical or absent. Such atypical presentations of OVT pose a clinical dilemma as to appropriate management.     

Benign solitary fibrous tumour of the pre-sacral space: MRI findings

Benign solitary fibrous tumour, a rare mesenchymal tumour of adults, usually arises from the pleura. Only a few cases have been reported in the retroperitoneum and, to our knowledge, there has been no report of its imaging features. We describe the MRI features of benign solitary fibrous tumour arising from the pre-sacral space.     

Stimulation of endothelial angiotensin-converting enzyme by morphine via non-opioid receptor mediated processes

A 63-year-old woman complained of acute swelling and pain in her ankle at 15 months, after fixation of a talar neck fracture with poly-L-lactide rods. Roentgenographic and laboratory data revealed no abnormalities, but T1-weighted magnetic resonance imaging showed a diffuse area of low intensity in the talus. After nonweightbearing for 1 month, local findings had disappeared and the area of low intensity shown by magnetic resonance imaging had decreased without surgical treatment. Although there have been some reports of aseptic swelling or synovitis after fixation of a fracture with polyglycolide rods or screws, there has been no report of such cases with poly-L-lactide rods or screws.     

射频联合131I治疗失分化甲状腺癌的临床研究

Objective:The aim of this study was to explore clinical efficiency of radio frequency combined with 131I therapy for dedifferentiated thyroid carcinoma. Methods:All patients have been treated by radiofrequency connected with 131I in 29 cases of dedifferentiated thyroid carcinoma which performed radionuclide imaging and Ig array of blood serum before and after therapy, respectively. Results:There were 4 (4/29) positive cases of radionuclide imaging before treatment and 19 (19/29)cases 2 weeks after therapy, 25 (25/29) cases of overall efficacy and 15 (15/29) curative cases. Conclusion:Radiofrequency connected with 131I improve clinical efficacy of 131I treatment for dedifferentiated thyroid cancer of thyroid in view of higher absorbing 131I of thyroid cancerous cell.     

Knee problems--imaging techniques

Standard radiographs still represent the standard imaging method in knee abnormalities. Major advantages include high spatial resolution, low cost, high availability and standardized imaging technique. Because there is an increasing pressure on the cost of health care, additional imaging should only be employed based on a working hypothesis. In most cases MR imaging is most suitable for further diagnosis. In internal knee derangements MR imaging has been shown to have a high negative predictive value, thus obviating unnecessary surgery. MR imaging also is the imaging method of choice in the detection and follow-up of arthritis, in the detection, staging and follow-up of malignant neoplasms, and in the detection of occult fractures. Ultrasonography is useful in the characterization of superficial soft-tissue abnormalities, but has not gained high acceptance in searching for internal derangements of the knee. Scintigraphy is competing with MR imaging in the early detection of bone abnormalities and for follow-up. However, it is less expensive and can be employed for the evaluation of multilocular processes. CT has a limited role in the evaluation of complex fractures mainly of the tibial plateau.     

Biliodigestive fistulae. Apropos 2 cases with opposite symptomatology

Biliodigestive fistulas are the most frequent internal biliary fistulas and occur when a calculus or neoplasia perforates the wall of the biliary tract of intestine at any point. Symptoms vary given that completely asymptomatic cases have been reported in which the findings of a biliodigestive fistula was completely coincidental, but there are also cases in which the severe clinical conditions at onset require immediate surgery. The Authors report two cases with opposing symptoms and underline the importance of diagnostic imaging in the preoperative analysis. They also underline that a correct therapeutic approach is fundamentally important in these cases.     

Imaging of tendons--adaptation, degeneration, rupture

Tendon imaging is mainly performed with ultrasonography (US) and magnetic resonance imaging (MRI) and has been improved within the last years because of technical advancements and a better understanding of tendon pathology. Several concepts concerning the etiology and the course of tendon diseases have influenced image interpretation and vice versa. Adaptive mechanisms within the tendon tissue against stress can be observed mainly on histologic specimens and not macroscopically or with in-vivo imaging. Degeneration may occur in the form of tendinitis, peritendinitis, enthesitis, or myotendinal junction abnormality. Distinct imaging findings exist for most of these forms. Many concepts that have been developed to explain tendon degeneration have been applied on virtually all tendons in the human body. They can be grouped into those which focus on hypovascularization, on biomechanical overload, and on degeneration secondary to other underlying disease. Tendon rupture seems, in many cases, to be the final stage of tendinitis. From this point of view, imaging may be used to predict the risk of tendon rupture together with other intrinsic and with extrinsic parameters. These considerations result in the concept of the "vulnerable zone" and of the "critical phase" in which tendon ruptures may predominantly occur.     

Hepatic artery aneurysm rupture: case report, imaging findings, and literature review

Hepatic artery aneurysm rupture is a rare condition that requires urgent diagnosis and treatment in order to avoid a potentially fatal outcome. The clinical presentation is often non-specific. The classic triad of abdominal pain, gastrointestinal hemorrhage, and obstructive jaundice occurs in less than one-third of cases. Physical examination is rarely helpful since bruits, masses or pulsations are infrequent. Radiologic imaging provides the best tool to early diagnosis. Angiography has historically been the gold standard of diagnosis and is needed prior to radiologic intervention. Computerized tomography, doppler ultrasound and even magnetic resonance imaging have all demonstrated visceral artery aneurysms with success. Conventional treatment has included surgical ligation and resection. More recently transcatheter embolization or even percutaneous transhepatic injection of thrombin has been successfully performed by the interventional radiologist. This article discusses the clinical presentation, imaging findings, and review of the literature of this elusive entity.     

Imaging of mediastinal lymph nodes: CT, MR, and FDG PET

The evaluation of mediastinal lymph nodes is an important aspect of staging in patients with non-small cell lung cancer. Anatomic imaging of lymph nodes with computed tomography (CT) and magnetic resonance (MR) imaging has been limited by the relatively low sensitivity and specificity of these techniques. Advances in physiologic imaging of mediastinal lymph nodes with 2-[fluorine-18] fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) have resulted in improved diagnostic accuracy in the determination of nodal status. Despite the limitations of CT, this technique still plays an important role by aiding in the selection of the most appropriate procedure for staging, by guiding biopsy, and by providing anatomic information for visual correlation with FDG PET images. At present, anatomic MR imaging of lymph nodes is primarily a problem-solving tool for cases with inconclusive CT results. Physiologic MR imaging with iron oxide is an exciting area of investigation, and the accuracy of this technique is being assessed in clinical trials. Anatomic and physiologic imaging techniques should be considered complementary rather than competitive imaging strategies.     

Localization of abnormal parathyroid glands of the mediastinum with MR imaging

PURPOSE: To determine the sensitivity of magnetic resonance (MR) imaging for preoperative localization of abnormal parathyroid glands in the mediastinum and to compare the sensitivity of MR imaging with those of scintigraphy and ultrasonography (US). MATERIALS AND METHODS: The prospective sensitivity of MR imaging was compared with those of thallium-technetium scintigraphy and US in 25 patients in whom the abnormal gland was located in the mediastinum at surgery. RESULTS: MR imaging had a much higher sensitivity (22 of 25 cases [88%]) than did scintigraphy (11 of 19 cases [58%]) or US (three of 24 cases [12%]). The most common locations for the mediastinal gland were intrathymic (eight of 25 cases) and paraesophageal (six of 25 cases) sites. CONCLUSION: MR imaging should be considered the modality of choice for preoperative localization in this group of patients.     

Bilateral renal cell carcinoma in a horseshoe kidney: preoperative assessment with MRI and digital subtraction angiography

Renal cell carcinoma in a horseshoe kidney is an unusual entity. To our knowledge, only 123 cases have been published to date. We report the first bilateral case of two clear-cell carcinomas in an asymmetrically fused kidney. Optimum preservation of renal function after radical tumor removal requires accurate preoperative imaging. Since the vascular supply in fusion anomalies is extremely variable, angiography is mandatory. Magnetic resonance imaging was most suitable to predict the tumor extent and localization, because it simultaneously gave the most comprehensive anatomical overview of the malformation.     

Use of magnetic resonance imaging scanning in adrenocortical carcinoma with vena caval involvement

We report on 2 cases of an adrenocortical carcinoma with vena caval involvement. Preoperative evaluation included a magnetic resonance imaging (MRI) scan confirming the presence of vena caval involvement. Extremely precise detail of the vena caval tumor thrombus was very helpful in preparing for the surgical extirpation. MRI detail far outweighed what was seen on the computed tomography scan and venacavogram. The MRI scan correlated exactly with what was found surgically. Although MRI scanning has been used to evaluate renal tumors with vena caval extension, few cases have been reported with similar adrenal tumors.     

MR imaging of small hepatocellular carcinoma (< or = 20 mm)--correlation with vascularity and histological features

We have evaluated the efficacy of magnetic resonance (MR) imaging for detecting hepatocellular carcinoma less than 20 mm in diameter (sHCC). This study involved 72 cases of sHCC tumors which were also investigated by angiography and histology. These cases were retrospectively examined for correlations between tumor stain (vascularity) on angiography, histological features (fat deposition, clear cells and the grade of differentiation) and the findings on T1 and T2 weighted MR imaging. The sHCC detection rate by MR imaging was 73.6% (53 cases) and by angiography was 59.7% (43 cases). Thirty-five cases were detected both the MR imaging and by angiography. The main MR imaging patterns were hypo to isointense on T1 weighted images (T1WI) and hyperintense on T2 weighted images (T2WI) in 22 cases, and hyperintense on both T1WI and T2WI in 7. In 18 cases which were not demonstrated by tumor staining on angiography, the main MR imaging patterns were hyperintense on T1WI and isointense on T2WI in 14. The histological features included fat deposition in 22 cases, 20 cases of which were hyperintense on T1WI, and 10 of these 20 were hyperintense on both T1WI and T2WI. Fat deposition was marked in 9. According to the grade of differentiation, 23 of the 26 cases with well differentiated HCC tumors were hyperintense on T1WI, and 21 of the 27 cases with moderately to poorly differentiated HCC were hypo to isointense on T1WI and hyperintense on T2WI. sHCC was visualized by MR imaging, reflecting vascularity, fat deposition and the grade of differentiation. In particular, MR imaging is useful for a differential diagnosis between the well differentiated HCC and the moderately to poorly differentiated HCC, and useful for the diagnosis of an early HCC.