Undisclosed and undetected foreign bodies during MRI screening resulting in a potentially serious outcome

The risks associated with performing magnetic resonance imaging (MRI) examinations in patients with ferromagnetic foreign bodies are well known. Accordingly, screening procedures are implemented to identify items that may pose hazards to patients and other individuals before allowing them to enter the MRI system room. This report describes a patient who, despite undergoing proper MRI screening procedures, did not disclose the presence of ferromagnetic foreign bodies, which resulted in a potentially serious outcome.     

Cystic lymphangioma in the adult: an unusual axillary mass

Magnetic resonance imaging (MRI) has rapidly become an effective technique for the diagnosis and localization of most musculoskeletal diseases. Because MRI lacks ionizing radiation and has superior soft tissue contrast as compared with computed tomography without the need for intravenous contrast material, MRI is emerging as the study of choice for soft tissue masses. This report describes the use of MRI in the evaluation of an unusual axillary soft tissue mass in an adult, a cystic lymphangioma.     

Primary retroperitoneal teratoma in the adult: correlation of MRI features with CT and pathology

Primary benign teratoma of the retroperitoneum is a rare tumor in the adult population. Only one case with an MRI examination has been reported in the English literature. This paper describes the CT and MRI features of a retroperitoneal teratoma in a 24-year-old male and discusses the value of MRI in the diagnosis and the preoperative imaging of such a tumor.     

Superior laryngeal nerve paresis and paralysis

Superior laryngeal nerve paresis and paralysis are relatively common but often difficult to diagnose with certainty. They are most commonly caused by viral infections, though other etiologies must be considered. A thorough history and physical examination, including strobovideolaryngoscopy and laryngeal electromyography, are needed for definitive diagnosis. It is essential to establish the diagnosis accurately to differentiate an apparent superior laryngeal nerve paresis from other conditions, such as myasthenia gravis. Laryngeal electromyography is used to confirm clinical impressions, as a guide for therapy, and as one measure of recovery. In our experience, accurate and early diagnosis assure the best phonatory outcome by directing therapy that will prevent or eliminate compensatory vocal abuses, which may themselves lead to even more serious vocal injury.     

Applications of spectral analysis in medical ultrasonography.

Spectral analysis of ultrasonic reflections from biological tissues can be used to determine basic tissue parameters for use in differential diagnosis. This paper describes the use of the technique under circumstances encountered in several types of clinical examinations. The applications are illustrated with results obtained from laboratory measurements with a system now being employed in a clinical evaluation programme. The test objects studied simulate tissues with planar boundaries, tissues with heterogeneous interior structure, and tissues causing acoustic 'shadowing' of posterior regions.     

Idiopathic dilatation of the pulmonary artery: report of four cases.

Idiopathic dilatation of the pulmonary artery (IDPA) is a rare congenital disease which is usually detected fortuitously on chest x-ray, thus radiologists must be aware of this clinical entity. This report describes four cases to which Magnetic Resonance Imaging (MRI) played a major role in diagnosing IDPA and in detecting the concomitant findings observed in this disease. MRI is a non-invasive procedure with many advantages for the accurate and reproducible measurement of artery structures, which makes it the preferred option for combined use with echocardiography in the diagnosis and follow-up of patients with IDPA.     

Prolonged bone marrow T1-relaxation in acute leukaemia. In vivo tissue characterization by magnetic resonance imaging

In vivo tissue characterization by measurement of T1- and T2-relaxation processes is one of the greatest potentials of magnetic resonance imaging (MRI). This may be especially useful in the evaluation of bone marrow disorders as the MRI-signal from bone marrow is not influenced by the overlying osseous tissue. Nine patients with acute leukaemia, one patient with myelodysplastic syndrome, and ten normal volunteers were included in the study. The T1- and T2-relaxation processes were measured in the lumbar spine bone marrow using a wholebody superconductive MR-scanner operating at 1.5 Tesla. In the patients MRI was done at the time of diagnosis and during follow-up of chemotherapy and related to bone marrow biopsies taken within three days of the MRI. At the time of diagnosis T1-relaxation time was increased two to three times in the patients (range 0.7-3.0 sec.) compared to the controls (range 0.38-0.60 sec.). No significant difference was seen in the T2-relaxation process. In relation to chemotherapy T1 decreased towards the normal range in the patients who obtained complete remission, whereas T1 remained prolonged in the patients who did not respond successfully to the treatment. The results indicate that MRI may be a non-invasive clinically useful tool in the evaluation of acute leukaemia especially as a follow-up control of chemotherapy.     

Current and Emerging Concepts in Muscle Tension Dysphonia: A 30-Month Review

The modern theory of hoarseness is that there are multifactorial etiologies contributing to the voice problem. The hypothesis of this study is that muscle tension dysphonia is multifactorial with various contributing etiologies. METHODS: This project is a retrospective chart review of all patients seen in the Voice Speech and Language Service and Swallowing Center at our institution with a diagnosis of muscle tension (functional hypertensive) dysphonia over a 30-month period. A literature search and review is also performed regarding current and emerging concepts of muscle tension dysphonia. RESULTS: One hundred fifty subjects were identified (60% female, 40% male, with a mean age of 42.3 years). Significant factors in patient history believed to contribute to abnormal voice production were gastroesophageal reflux in 49%, high stress levels in 18%, excessive amounts of voice use in 63%, and excessive loudness demands on voice use in 23%. Otolaryngologic evaluation was performed in 82% of patients, in whom lesions, significant vocal fold edema, or paralysis/paresis was identified in 52.3%. Speech pathology assessment revealed poor breath support, inappropriately low pitch, and visible cervical neck tension in the majority of patients. Inappropriate intensity was observed in 23.3% of patients. This set of multiple contributing factors is discussed in the context of current and emerging understanding of muscle tension dysphonia. CONCLUSIONS: Results confirm multifactorial etiologies contributing to hoarseness in the patients identified with muscle tension dysphonia. An interdisciplinary approach to treating all contributing factors portends the best prognosis.     

Diagnostic utility of tumor vascularity on magnetic resonance imaging of the breast

The objective of this study was to examine the relation of tumor vascularity on magnetic resonance imaging (MRI) with differential diagnosis malignant from benign lesions and tumor invasiveness in breast carcinoma. Forty-nine patients with breast cancer or benign lesion (median 49 yrs) were examined with dynamic MRI. Scanning of the entire breast was performed at 1.5 T with a three-dimensional fast spin echo sequence, using an original polarity altered spectral and spatial selective acquisition (PASTA) technique for fat suppression. Subsequently 0.1 mmol/Kg Gd-DTPA was administered and 3-6 images were obtained. The presence or absence of intratumoral, marginal and peritumoral vascularity on MRI was recorded. The excised specimen was histopathologically examined for the size of lesion, the presence and extent of local invasion. Tumor size on MRI correlated closely with the size at morphologic examination (r = 0. 96). Intratumoral (p = 0.04), marginal (p = 0.05) and peritumoral vascularity (p = 0.01) were less common in benign than in malignant lesions. Among the latter, intratumoral (p = 0.01) and marginal (p = 0.03) vascularity were more common in invasive carcinomas than in DCIS. In the subset of invasive carcinomas (n = 31); however, the tumors exhibiting intratumoral vascularity were markedly larger (p = 0.03). The presence of intratumoral and marginal vascularity on MRI can help predict both the differential diagnosis malignant from benign lesions and the presence tumor invasion in breast carcinomas.     

Granulomatous hepatitis: MRI findings.

The purpose of this study was to describe the magnetic resonance imaging findings of granulomatous hepatitis on T1-weighted, T2-weighted and postgadolinium images. Eight patients with histopathological diagnosis of granulomatous hepatitis were evaluated in this study. MRI examinations included precontrast T1-weighted breath-hold spoiled gradient echo, breathing independent STIR sequences, and T1-weighted breath-hold spoiled gradient-echo sequence following after i.v. gadolinium administration in arterial, intermediate and late phases. Diffuse nodular liver involvement was visualized in all patients. Nodules were consistent with granulomas and were 0.5-4.5 cm in diameter. Caseating granulomas were intermediate and high signal on T2-weighted, low signal on T1-weighted images. They revealed no enhancement in two patients, and enhanced in one patient. Noncaseating granulomas revealed intermediate signal on T1, and T2-weighted images and increased enhancement on arterial phase images with persisting enhancement in late phase images. Portal lymph nodes were visible in five patients. Splenomegaly was present in five patients. Granulomatous hepatitis has spectrum of MRI features, to be considered in differential diagnosis with other diffuse nodular liver pathologies.     

Cardiac Metastatic Melanoma Investigated by Magnetic Resonance Imaging

There is a high rate of cardiac involvement in malignant melanoma (MM), but such cardiac metastases are usually diagnosed late. This report describes four cases with different clinical presentations of MM cardiac involvement that were investigated by magnetic resonance imaging (MRI). The MM cardiac involvement was asymptomatic in one case, detected because of a superior vena cava syndrome in a second, and because a tamponade in the remaining two cases. MRI permitted the diagnosis of cardiac metastases of MM, which was not made by echocardiography in one case. By precisely detecting the extent of the tumors, MRI was a great help in management, especially when an isolated cardiac metastasis was suitable for surgical ablation (two cases). Because both clinical signs and transthoracic echocardiogram are not very sensitive for diagnosing MM myocardial involvement, MRI can help provide such a diagnosis and ensure better treatment-monitored decisions.     

Gadolinium- and superparamagnetic-iron-oxide-enhanced MR findings of intrapancreatic accessory spleen in five patients

Purpose

The purposes of this study were to describe dynamic gadolinium-enhanced magnetic resonance imaging (MRI) findings of intrapancreatic accessory spleen(s) (IPAS) in five patients and to show how superparamagnetic iron oxide (SPIO) enhancement can be used for definite characterization in two cases.

Materials and Methods

An MRI database was searched for patients who had pancreatic tail lesions with imaging features compatible with IPAS between June 2005 and July 2007. Five (four male, one female) patients (age: mean±S.D., 58±9.8 years; range, 50–75 years) were identified. All patients were examined with standard gadolinium-enhanced MRI protocol. Additionally, two patients were examined with SPIO-enhanced MRI protocol. All MRI examinations were retrospectively and blindly evaluated by two radiologists for the predetermined findings, and their final diagnoses were noted.

Results

One pancreatic tail lesion was detected in each patient. All of these lesions were single, focal, well-marginated and located within 3 cm of the distal tail of the pancreas. The mean size (mean±S.D.) of the lesions was (2.02±0.64)×(1.72±0.42) cm², and all lesions had a rounded morphology. The signal intensity of all lesions was similar to that of the spleen on all sequences, including precontrast, postgadolinium and post-SPIO sequences. The reviewers confidently diagnosed IPAS in two patients who had SPIO-enhanced MRI. In the remaining three patients, the reviewers favored the diagnosis of IPAS based on the findings of standard gadolinium-enhanced MRI; however, they could not definitively exclude the other differential diagnoses.

Conclusion

The discovery of a well-marginated, rounded mass in the distal aspect of the tail of the pancreas with signal intensity features of the spleen on all precontrast and postgadolinium sequences suggests the diagnosis of IPAS. However, SPIO-enhanced MRI can be used to characterize the lesion and to establish the definite diagnosis of IPAS in case of clinical doubt.     

A combined analysis and magnetic resonance imaging technique for computerised automatic measurement of cartilage thickness in the distal interphalangeal joint

It is well known that magnetic resonance imaging (MRI) contrast can be controlled, albeit sometimes at the expense of image resolution and signal-to-noise ratio, and most studies of articular joints have used a single MRI protocol, which is optimised for subjective image analysis. Inevitably that single protocol frequently compromises the detection of one or another of the boundaries between which any measurement must be made. This paper describes an alternative approach in which the criteria for computerised edge detection necessary for fully automated measurement of cartilage thickness are used to define the MRI acquisition parameters. This necessitates the combined use of two MRI sequences, one optimised for the cartilage-bone boundary, and the other for cartilage-synovial fluid. This provides a highly effective combination and its efficacy is demonstrated for the distal interphalangeal joint of a range of asymptomatic adults.     

Primary epiploic appendagitis: MRI findings

Primary epiploic appendagitis (PEA) occurs secondary to inflammation of an epiploic appendage, and is considered to be a rare cause of acute abdomen. In this case report, we describe the magnetic resonance imaging (MRI) findings of PEA correlated with computed tomographic (CT) findings. MRI findings included an oval shaped fat intensity mass with a central dot on T1- and T2-weighted images, which possessed an enhancing rim on postgadolinium T1-weighted fat saturated images. The lesion was best visualized on postcontrast T1-weighted fat saturated images. MRI findings of PEA should be considered in the differential diagnosis with the other causes of acute abdominal pain.     

基于AI+MRI的影像诊断的样本增广与批量标注方法

训练样本是所有领域人工智能（AI）研发的关键因素.目前，基于人工智能+磁共振成像（AI+MRI）的影像诊断存在着训练样本的有效标注数量和类型无法满足研发需求的瓶颈问题.本文利用临床MRI设备对志愿者或阳性病例进行正常或重点病灶区的定量扫描，获取高分辨率各向同性的纵向弛豫时间（T₁）、横向弛豫时间（T₂）、质子密度（Pd）和表观扩散系数（ADC）等物理信息的多维数据矩阵，作为原始数据.开发虚拟MRI技术平台，对原始数据（相当于数字人体样本）进行虚拟扫描，实现不同序列不同参数下的多种类磁共振图像输出.选择感兴趣组织具有最好边界区分度的图像种类，经有经验的影像医生对其进行手动勾画并轨迹跟踪形成三维MASK标注矩阵，作为其他种类图像的图像勾画标注模板，从而实现低成本、高效率的MRI样本增广和批量标注.该平台以临床少量阳性病例作为输入，进行样本增广和标注，极大地减少AI对实际扫描样本的要求，降低了影像医生的精力和时间投入，极大地节省了成本，并输出了数量足够的磁共振图像，为基于AI+MRI的影像诊断研发提供低成本的训练数据解决方案.     

Magnetic resonance imaging as an adjunct to sonography in the evaluation of the female pelvis

Magnetic resonance imaging (MRI) of the pelvis is generally considered to be most beneficial in those cases where the pelvic sonogram is limited or equivocal. All cases that underwent both sonographic and MRI examinations at our institution for the evaluation of the female pelvis in the past two years were retrospectively reviewed. We reviewed the sonographic and MRI reports and the subsequent clinical management in the 41 cases that had both studies to assess whether MRI contributed to the clinical management decision. Both studies were interpreted independently based upon the known clinical and laboratory data available at the time. MRI was obtained in 21 cases because the sonogram was suboptimal or inconclusive. In the other 20 cases it was obtained for additional information, even though the sonogram was diagnostic. Of the 21 inconclusive sonographic studies, MRI established or clarified the diagnosis in all cases. Of the 20 studies where MRI was obtained for additional information, MRI added useful data that helped contribute to the clinical management of 11 patients. MRI is an important adjunct to pelvic sonography. It established, clarified, or added significant data in 78% of cases.     

The diagnostic role of gadolinium enhanced MRI in distinguishing between acute medullary bone infarct and osteomyelitis

The objective of the study was to evaluate the diagnostic utility of contrast enhanced magnetic resonance imaging (MRI) for distinguishing between acute medullary bone infarct and osteomyelitis. There were 11 patients (age 6-34 years) presented to our institution between December 1994 and February 1998 with a clinical differential diagnosis of acute bone infarct versus osteomyelitis and inconclusive radiographs were imaged using MRI. All but one received i.v. gadolinium. Nine of the patients had homozygous Sickle Cell disease (SCD) and two had Systemic Lupus Erythematosus (SLE), the latter requiring chronic methylprednisolone. Osteomyelitis was confirmed either by biopsy alone or by the combination of Gallium(67) scan in conjunction with positive blood cultures and clinical resolution following antibiotics. Infarcts without osteomyelitis were confirmed either by biopsy or resolution of symptoms without antibiotic therapy. All patients had at least six months clinical follow-up. The results found that seven of nine patients with SCD had acute infarct only. One patient with SCD had osteomyelitis only. Three patients (two SLE and one SCD) had both acute-on-chronic infarcts and superimposed osteomyelitis, one with an adjacent soft tissue abscess. Accurate distinction between infarct and osteomyelitis was impossible for one patient with SLE who did not receive contrast. All other cases were correctly diagnosed prospectively based on distinct patterns of MRI contrast enhancement. In all adult patients, acute infarcts demonstrated thin, linear rim enhancement on MRI while osteomyelitis revealed more geographic and irregular marrow enhancement. Two of four cases of osteomyelitis also demonstrated subtle cortical defects with abnormal signal traversing marrow and soft tissue. The single pediatric patient demonstrated elongated, serpiginous central medullary enhancement with periostitis. We concluded that the pattern of MR contrast enhancement may allow accurate distinction between acute infarct and osteomyelitis, or recognition of osteomyelitis superimposed on bone infarction.     

Amyotrophic lateral sclerosis with predominant pyramidal signs -- early diagnosis by magnetic resonance imaging

OBJECTIVE: To evaluate the role of magnetic resonance imaging (MRI) in the early diagnosis of amyotrophic lateral sclerosis (ALS) with predominant upper motor neuron (UMN) signs in the initial stage of the disease. PATIENTS AND METHOD: Two patients with ALS were found to have spastic quadriparesis with no wasting or fasciculation in the limbs in the early stage of the disease. Both were subjected to MRI of the head and cervical spine to look for any specific diagnostic feature. Both of them were followed with clinical evaluation and electroneuromyography (ENMG) for the definitive diagnosis of ALS. RESULTS: Magnetic resonance imaging showed selective degeneration of the pyramidal tracts in the contiguous axial cuts from subcortical white matter to cerebral peduncles. The finding was more visible in the coronal section. In addition, there was T1 hyperintensity visible along the anterior aspect of the spinal cord in the cervical region. These findings were suggestive of ALS, the diagnosis that was subsequently confirmed by serial clinical follow-up and ENMG. CONCLUSION: It is difficult to diagnose ALS in the early stage of the disease especially if the pyramidal signs predominate over the lower motor neuron (LMN) signs; MRI might be useful in such cases.     

The development of a three-dimensional T1 image calculation program in proportion to the DICOM data of any marketing clinical MRI systems

Contrast media such as gadolinium-diethlene-triamine pentaacetic acid (Gd-DTPA) is used for MRI. Recently there have been some reports about diagnosis using contrast media for the MRI T(1) image for the quantitative evaluation of articular cartilage degeneration. This may be a useful method to evaluate the lesion of the articular cartilage or to confirm therapeutic progress. Whether or not contrast is used, the use of the calculated T(1) image is effective for the quantitative evaluation of the degeneration of knee joint cartilage. However, our system copes with the format of every MRI image even if software of the calculated T(1) image isn't often prepared in the commercial MRI device. So, we developed general purpose image data processing software that can be processed on the preexisting three-dimensional image data processing system.     

Usefulness of MRI for the pre-operative evaluation of the pulmonary arteries in Tetralogy of Fallot

Adequate pre-operative evaluation of patients with Tetralogy of Fallot (TF) includes cine-angiography to delineate the pulmonary vasculature and the coronary artery anatomy and to demonstrate the presence of multiple ventricular septal defects (VSDs). All other information is obtained from color-Doppler-echocardiography. Magnetic resonance imaging (MRI), using the spin-echo sequence and cine-angiography was employed on 18 patients with TF, four of whom had aorto-pulmonary shunts. Mean age at MRI was 12.9 m (SD 2.3 m) and 14.3 m (SD 2.8 m) at cine-angiography. To compare MRI and cine-angiography we measured the ascending aorta, the main, the left and right pulmonary arteries and each structure at three levels. Diagnostic agreement between the two imaging methods was found if, for each modality, one of the three measurements in one structure differed by more than 40% from the other two measured in case of a local stenosis, and the diameter of the main pulmonary artery was less than 60% of the aorta to diagnose hypoplasia of the main pulmonary artery. There was close agreement between cine-angiography and MRI. With regard to the intracardiac anatomy, MRI was superior to color-Doppler-echocardiography in the depiction of aortic override and of right ventricular hypertrophy. In three cases local stenoses in the pulmonary arteries were detected by MRI and cine-angiography. Hypoplasia of the main pulmonary artery was detected by MRI in six patients and by cine-angiography in five patients. Cine-angiography missed one case of hypoplasia. In the remaining 11 patients normal findings were found by MRI and cine-angiography. For the demonstration of shunts, gradient-recalled-echo MRI is expected to give better results than the spin-echo sequence which depicted two out of four shunts in this series. Cine-angiography can be substituted by MRI in delineating the pulmonary arteries. New developments in MRI indicate the feasibility of delineating the coronary arteries.