Spectrum Of Magnetic Resonance Imaging Findings Research Articles

A Spectrum of MRI Findings in Germinal Matrix Hemorrhages: A Case Series

The germinal matrix hemorrhage (GMH) can be diagnosed prenatally by ultrasound (US) and fetal magnetic resonance imaging (MRI). Prenatal imaging is essential for GMH grading and subsequent prognosis and clinical management. MRI benefits from higher specificity and sensitivity for GMH diagnosis then ultrasound. Fetal MRI advantages include high-resolution imaging, better visualization of the brain parenchyma with susceptibility to identify hemorrhage or blood breakdown products and non-invasiveness of the study. This article aims to present a series of cases with fetal GMH.

A Spectrum of MRI Findings in the Knee Joint: A Retrospective Study of Selected Population in South-South Nigeria

The knee is a very important joint and injuries affecting it may cause significant disability and discomfort to the patient. Despite a variety of methods available to assess injuries of the knee joint, Magnetic Resonance Imaging (MRI) continues to play a major role. This study evaluated the spectrum of MRI findings in a relatively low resource environment, with limited access to MRI modality. The outcome should justify further investment in MRI services in this locality. The study involves retrospective analysis of MRI reports of 198 clinically symptomatic patients referred for imaging in a Port-Harcourt. All examinations were performed using GE BRIVO MR 235 machine with 0.35 Tesla field strength in a well-coupled standard knee coil. All images were analyzed for normality or otherwise and radiological reports generated by competent radiologists. The most common findings are traumatic in origin, notably cruciate ligament tears (37.37%) and meniscal tears (33.3%) as well as quadriceps tendon tears (3.03%). The medial meniscus and anterior cruciate ligaments were more frequently involved. Furthermore, patients in the 3rd and 4th decade of life were more commonly involved, with a male preponderance. The less common findings of Synovial chondromatosis, cyst-like lesions, tumors and loose bodies, all buttress the importance of routine MRI in atraumatic cases. The spectrum of MRI findings in this study is a reflection of growing interest and confidence in MRI of the diseased knee joint in our environment. The outcome would be a justification for future investments in MRI. Keywords: Magnetic Resonance Imaging, knee injuries, tibial meniscal tears, incidental findings

English

BACKGROUND The sellar and juxtasellar region is a complex area where varied pathologies can occur. Differentiation among various pathologies may not always be easy, since many of these lesions mimic pituitary adenomas on clinical presentation, endocrinologic and radiologic examinations. The study intends to describe the imaging characteristics of the spectrum of pathological conditions affecting these regions using magnetic resonance imaging (MRI). METHODS The main source of data for the study were patients from hospitals attached to Bangalore Medical College and Research Institute, Bengaluru viz. Victoria Hospital, Bowring and Lady Curzon Hospital and Vani Vilas Hospital. Patients with suspected sellar and juxtasellar pathology on clinical examination referred to the Department of Radiodiagnosis from November 2017 to May 2019 underwent MRI study using Siemens 1.5-T Magnetom Avanto MR system. Magnetic resonance imaging was done in all patients according to the pituitary protocol. RESULTS Among the 50 patients, there were 16 males and 34 females. Most of the patients were in the third to fifth decade of life. The various abnormalities on MRI included neoplastic (68 %), malformative (8 %), vascular (6 %), granulomatous, infectious and inflammatory (18 %) lesions. Pituitary adenomas (46 %) were the most common lesions in sellar and juxtasellar regions, followed by tuberculosis (10 %), craniopharyngioma (8 %), Rathke's cleft cyst (6 %), meningioma (6 %), internal carotid artery (ICA) aneurysm (4 %), epidermoid (2 %) and miscellaneous lesions. CONCLUSIONS MR imaging characteristics were sufficiently distinct to allow various sellar and juxtasellar pathologies to be differentiated from each other. The spectrum of MRI findings were related to neoplastic, malformative, infectious, inflammatory, granulomatous and vascular causes. Our study observed that MRI with appropriate imaging protocols is the essential imaging modality in evaluation of sellar and juxtasellar lesions. KEYWORDS Pituitary, Sellar, Juxtasellar, Magnetic Resonance Imaging

Quadratus femoris muscle: spectrum of MR imaging findings in 51 patients presenting with painful hip

Purpose: To provide an overview of magnetic resonance (MR) imaging findings related to quadratus femoris muscle (QFm) pathologies in symptomatic patients. Material and Methods: MR imaging studies from 51 patients, who were retrospectively recruited within a 2-year period, in 5 health care centers were reviewed. Inclusion criteria included: (i) hip pain; (ii) QFm abnormal signal; (iii) identification of other pathology in the QFm anatomical area. Exclusion criteria included: (i) other symptomatic hip/pelvic pathology; (ii) incomplete MR examination. The presence/location of QFm oedema and configuration of QFm fibers were evaluated and classified. Hamstring tendons were assessed for tendinosis/tear. Ischiofemoral impingement syndrome (IFIs) was indicated by QFm oedema and restriction of ischiofemoral space (IFS)/quadratus femoris space (QFS). QFm tears were categorised as complete/partial/chronic. Fisher’s exact test was used for statistical analysis. Results: IFIs diagnosis, related to various aetiologies, was suggested in 39 patients. The absence of severe QFm oedema and crowded configuration of QFm fibers correlated with IFIs diagnosis (p<0.05). In 18/39 (46.2%) of patients, restriction of the IFS/QFS was due to an underlying pathology. QFm tears were diagnosed in 5 patients. QFm oedema, usually mild, located at the myotendinous junction, was revealed in 4/5 patients. In 7 patients various pathologies related to the QFm were disclosed, which broadly included neoplastic disorders, myositis and bursitis. Conclusions: MR imaging can depict and characterise various QFm pathologies including IFIs, traumatic lesions, myositis and neoplastic disorders. Detailed analysis of the oedema pattern and the configuration of muscular fibers matched with clinical findings can lead to precise diagnosis.

Spectrum of Magnetic Resonance Imaging Findings in Patients with Head Injury in a Nigerian Population

Head injury is a pressing public health concern the world over. Head injury and associated traumatic brain injury (TBI) usually result in neurocognitive impairments and psychological health issues especially when underlying chronic sequalae are not promptly diagnosed and managed. Magnetic resonance imaging (MRI) has been found to be the most sensitive imaging modality for the evaluation of lesions secondary to head injury. This study examined the spectrum of MRI findings in head injury cases in a population within South western Nigeria. A prospective study of MRI findings in 163 patients who presented to the radiology department of a foremost teaching hospital in South-western Nigeria with clinical history of head injury was undertaken for a period of 2 years (from January 2015 to December 2016). The following data were obtained and studied: demographic data, clinical history and MRI findings. The MR images were obtained with a 1.5Tesla Siemens MR Scanner. Both T1-weighted and T2-weighted MR imaging protocols were performed for all the patients. The MR images were acquired by the radiographers and interpreted by consultant radiologists. 121 (74.23%) of the subjects were males while 42 (26.76%) were females. Road traffic accident (RTA) (n = 87, 53.37%) was the major cause of head injury sustenance in more than half of the entire cases evaluated. The most common MRI findings are subdural haematoma (n = 41, 25.14%); cerebral contusion (n = 27, 16.56%); subarachnoid haemorrhage (n = 19, 11.65%); cerebral infarction (n = 12, 7.36%); skull fracture (n = 11, 6.74%); cerebral atrophy (n = 10, 6.13%) and multiple sclerosis (n = 7, 4.30%). The least common findings are leucoencephalopathy (n = 5, 3.06%) and retained bullet (n = 5, 3.06%). Magnetic resonance imaging is a paramount imaging modality in the diagnosis of lesions secondary to head injury. Thus the need to make MRI facilities more available in healthcare settings of developing countries, like Nigeria, is re-emphasised.

Magnetic Resonance Imaging Findings After Percutaneous Irreversible Electroporation of Liver Metastases: A Systematic Longitudinal Study.

ObjectiveThe aim of this study was to systematically investigate the course of magnetic resonance (MR) signal intensity (SI) changes that occur in noncirrhotic livers after irreversible electroporation (IRE) of liver metastases.MethodsThis study is an institutional review board–approved prospective longitudinal follow-up study on 27 patients with 37 liver metastases who underwent computed tomography–guided percutaneous IRE and a standardized follow-up protocol by serial hepatic MR imaging studies that consisted of a gadobutrol-enhanced dynamic series, axial T2-weighted (T2w) turbo spin echo, and diffusion-weighted imaging (b = 0/50/800), acquired before, within 2, and at 24 hours after IRE; at 1, 2, 4, 6, 8, and 12 weeks after IRE; and every 3 months thereafter for a follow-up of at least 12 months.ResultsThe ablated target lesion remained visible within the ablation zone in 23 (62%) of 37 of cases for a mean time of 21 ± 20 weeks (median, 12 weeks). The ablation zone appeared homogeneously hyperintense on T2w turbo spin echo images on the day of IRE in 37 of 37 cases. By 24 hours after IRE, the ablation zone inverted its SI in 35 of 37 cases to intermediately hypointense, with a rim of T2w bright SI that exhibited arterial phase enhancement; this persisted for 7 ± 5 weeks (median, 4 weeks). The rim resolved in 35 (95%) of 37 cases within 3 months. The ablation zone increased slightly over the first 48 hours, then shrank progressively. Complete healing of the ablation zone was observed in 57% (21/37) after an average of 14 ± 15 (median, 8 weeks).Average apparent diffusion coefficient values of the ablation zone decreased from 0.74 ± 0.36 × 10−3 mm2/s pre-IRE to 0.63 ± 0.27 × 10−3 mm2/s within the first 24 hours (P < 0.05), followed by a progressive normalization to 0.91 ± 0.30 × 10−3 mm2/s at 2 months.ConclusionsKnowledge of the broad spectrum of MR imaging findings after IRE is important to avoid diagnostic errors in the follow-up of patients after IRE.

The magnetic resonance imaging spectrum of Pelizaeus–Merzbacher disease: A multicenter study of 19 patients

PurposeWe retrospectively evaluated the imaging spectrum of Pelizaeus–Merzbacher disease (PMD) in correlation with the clinical course and genetic abnormality. MethodsWe collected the magnetic resonance imaging (MRI) findings of 19 genetically proven PMD patients (all males, aged 0–29years old) using our integrated web-based MRI data collection system from 14 hospitals. The patterns of hypomyelination were determined mainly by the signals of the cerebrum, corticospinal tract, and brainstem on T2-weighted images (T2WI). We assessed the degree of myelination age on T1-weighted images (T1WI) and T2WI independently, and we evaluated cerebellar and callosal atrophy. The clinical severity and genetic abnormalities (causal mutations of the proteolipid protein gene PLP1) were analyzed together with the imaging findings. ResultsThe clinical stage tended to be more severe when the whole brainstem, or corticospinal tract in the internal capsule showed abnormally high intensity on T2WI. Diffuse T2-high signal of brainstem was observed only in the patients with PLP1 point mutation. Myelination age “before birth” on T1WI is a second manifestation correlated with the clinically severe phenotypes. On the other hand, eight patients whose myelination ages were > 4months on T1WI were associated with mild clinical phenotypes. Four of them showed almost complete myelination on T1WI with a discrepancy in myelination age between T1WI and T2WI. A random and patchy pattern of myelination on T2WI was noted in one patient with PLP1 point mutation. Advanced myelination was observed in three of the seven followed-up patients. Four patients had atrophy of the cerebellum, and 17 patients had atrophy of the corpus callosum. ConclusionOur multicenter study has demonstrated a wide variety of imaging findings of PMD. Signal intensity of brainstem and corticospinal tract of internal capsule would be the points to presume clinical severity in PMD patients. The spectrum of MRI findings should be kept in mind to diagnose PMD and to differentiate from other demyelinating leukodystrophies.

MRI-imaging and clinical findings of eleven children with tick-borne encephalitisand review of the literature.

The incidence of tick-borne encephalitis (TBE) is increasing in many countries. Magnetic resonance imaging (MRI) in the course of TBE is not regularly performed in children. The aim of our study was evaluating MRI-findings of children and adolescents with TBE. Retrospective evaluation of the charts and MRIs of patients who had been treated for TBE in the four participating hospitals in the last twenty years. 11 patients (5 male; age at TBE 3 weeks-15 9/12 years; mean 104.9 months) were included. MRI (within the first week after admission) revealed symmetric or asymmetric T2-hyperintensities in both thalami in 7/11 patients with additional bilateral lesions in putamen and/or caudate nucleus in 3 patients, and additional cortical lesions in 2 patients. Our youngest patient presented with T2-hyperintensities affecting the whole left cerebral hemisphere including white and grey matter and both cerebellar hemispheres. One patient had a minimal reversible T2-hyperintensity in the splenium of the corpus callosum (RHSCC). 3/11 patients had a normal MRI. 4/11 patients showed complete neurological recovery (2/4 with a normal MRI, RHSCC patient). 6/11 children survived with significant sequelae: hemiparesis (n=4); cognitive deficits (n=4); pharmacoresistant epilepsy (n=2). One patient died of a malignant brain edema. A spectrum of MRI findings can be found in children with TBE, often showing involvement of the subcortical deep grey matter structures. In children presenting with a meningoencephalitis and bilateral thalamic involvement TBE should be included in the differential diagnosis.

The spectrum of MRI findings in subacute sclerosing panencephalitis with clinical and EEG correlates

Reports of magnetic resonance imaging (MRI) findings in subacute sclerosing panencephalitis (SSPE) with clinical and electroencephalography (EEG) correlation are few. To describe the MRI features of SSPE and correlate with its clinical features and EEG. Clinical, MRI and EEG data of 33 patients (male/female 19/14; age: 11.4 ± 5.3 yr) were reviewed. All patients had raised IgG anti-measles antibody (≥ 1:625) in cerebrospinal fluid. Their clinical features were myoclonus (100%), seizures (42%), visual disturbances (18%), pyramidal signs (30%), extrapyramidal symptoms (27%), and cognitive impairment (79%) and behavioral changes (21%). EEGs were universally abnormal: diffuse slowing of background activity-all; periodic complexes-27 (symmetrical): High voltage delta waves (55%) and sharp & slow wave discharges (45%). MRI findings included – normal (9%), cerebral atrophy (78%), white matter (76%) and basal ganglia (6%) changes. Restricted diffusion in periventricular/subcortical region was noted in 4/23 patients (stage 2). Magnetic resonance spectroscopy showed decreased N-acetyl aspartate peaks and elevated choline peaks in 75% and lactate peak in 25% (stage 3) of patients. Correlation of background delta activity among patients with MRI signal abnormalities and those without any signal change was noted (P=0.02). There was significant correlation between visual deficits and bilateral parieto-occipital white matter signal changes (P=0.03). There was no other EEG-MRI or clinical-MRI correlation. MRI abnormalities in SSPE are diverse and may or may not reflect underlying pathology. Visual deficits were observed in patients with parieto-occipital white matter signal change. Restricted diffusion of signal abnormalities and lactate peak in magnetic resonance spectroscopy were uncommon and it may add to better understanding.

Emphasis on the MR imaging findings of brown tumor: a report of five cases

Brown tumors are focal reactive osteolytic lesions that are encountered in patients with primary or secondary hyperparathyroidism, and these tumors have nonspecific magnetic resonance (MR) imaging findings. However, there are only a few reports on MR imaging of brown tumors. The purpose of this study is to describe the spectrum of MR imaging findings of brown tumors. The MR imaging features of five patients with clinical and pathological evidence of brown tumor were retrospectively reviewed by two radiologists. The patients had primary hyperparathyroidism, which was confirmed as parathyroid adenoma (n = 2) and parathyroid carcinoma (n = 3). The MR images were evaluated for the presence of solid or cystic portions, the signal intensity of the lesions, the contrast enhancement pattern and the presence of cortex destruction and fluid-fluid levels. Twelve bone lesions were detected on the MR images of five patients; three lesions in two patients, four lesions in one patient, and one lesion in two patients. The tumor was solid in three lesions, mixed solid and cystic in four, and cystic in five. All the solid lesions were accompanied by mixed lesions. Discontinuity of the cortex and adjacent soft-tissue enhancement were seen in all the solid lesions. Fluid-fluid levels were seen in two cases within the cystic component of the mixed lesions and cystic lesions. The five patients with brown tumor demonstrated a wide spectrum of MR imaging findings. There are few lesions that are osteolytic on the radiographs and that show a short T2 on MR imaging, such as brown tumor. Multiple cystic or mixed lesions are the expected findings of brown tumors.

Focal nodular hyperplasia: findings at state-of-the-art MR imaging, US, CT, and pathologic analysis.

Focal nodular hyperplasia (FNH) is the second most common benign liver tumor after hemangioma. FNH is classified into two types: classic (80% of cases) and nonclassic (20%). Distinction between FNH and other hypervascular liver lesions such as hepatocellular adenoma, hepatocellular carcinoma, and hypervascular metastases is critical to ensure proper treatment. An asymptomatic patient with FNH does not require biopsy or surgery. Magnetic resonance (MR) imaging has higher sensitivity and specificity for FNH than does ultrasonography or computed tomography. Typically, FNH is iso- or hypointense on T1-weighted images, is slightly hyper- or isointense on T2-weighted images, and has a hyperintense central scar on T2-weighted images. FNH demonstrates intense homogeneous enhancement during the arterial phase of gadolinium-enhanced imaging and enhancement of the central scar during later phases. Familiarity with the proper MR imaging technique and the spectrum of MR imaging findings is essential for correct diagnosis of FNH.

Unusual appearances of uterine leiomyomas: MR imaging findings and their histopathologic backgrounds.

Typical appearances of uterine leiomyoma at magnetic resonance (MR) imaging are well established, and diagnosis is usually easy. However, cases that, are extremely difficult to differentiate from other conditions are occasionally encountered. To understand the wide spectrum of MR imaging findings, such unusual appearances can be classified into three categories: degeneration and other histopathologic findings, specific types of unusual leiomyomas, and unusual growth patterns. The common types of degeneration are hyaline (>60% of cases), cystic (approximately 4%), myxoid, and red. Edema is not a phenomenon of degeneration but is a common histopathologic finding (approximately 50% of cases). Hemorrhage, necrosis, and calcification (approximately 4% of cases) may also be observed. Specific types of unusual leiomyomas include lipoleiomyoma and myxoid leiomyoma, which may have MR imaging features characteristic enough to allow differentiation from other gynecologic and nongynecologic diseases. Intravenous leiomyomatosis, metastasizing leiomyoma, diffuse leiomyomatosis, and peritoneal disseminated leiomyomatosis represent unusual growth patterns; other unusual growth patterns are retroperitoneal growth, parasitic growth, and the pattern that may occur in cervical leiomyoma. Because leiomyomas are the most common gynecologic tumors and are exclusively benign, it is important to be familiar with the variety of MR imaging appearances of uterine leiomyomas to distinguish them from other significant diseases.

The idiopathic inflammatory myopathies: spectrum of MR imaging findings.

Magnetic resonance (MR) imaging is useful for demonstrating the soft-tissue and musculature changes seen in patients with idiopathic inflammatory myopathies (IIMs). These changes include edema within and around muscle, subcutaneous reticulation, muscle calcification, and fatty infiltration of muscle. Muscle edema is visible as areas of hyperintensity on short inversion time inversion recovery (STIR) images. Abnormal reticulation of the subcutaneous tissue can be due to subcutaneous edema or an infiltrating process; edema from inflammation appears as areas of low signal intensity on T1-weighted images and as areas of high signal intensity on STIR images. Intramuscular calcium deposition appears as hypointense areas with all pulse sequences. On T1-weighted images, fatty infiltration appears as areas of high signal intensity within muscles. Because of the improved visualization of muscle inflammation provided by STIR imaging and because MR imaging is noninvasive, it has become a useful modality for evaluating patients with IIMs.