Magnetic Resonance Imaging Appearance Research Articles

Cervical MRI Rating Scale: Innovative Approach to Differentiate between Demyelinating and Disc Lesions.

The difficult differentiation between multiple sclerosis (MS) lesions and cervical spondylotic myelopathy (CSM) in the cervical spine is well known. The magnetic resonance imaging (MRI) appearance of both lesions is similar, and clinical parameters are usually used for diagnosis. The objective was to establish areliable radiologic paradigm for diagnosis of demyelinating lesions in the cervical spine. The MRI studies of 33patients with MS (42lesions) and 55patients with CSM (60lesions) were obtained. Lesions were evaluated for vertebral level, lesion location and size in the sagittal and axial planes, cord thickness, well-defined or ill-defined borders, presence of edema and enhancement with gadolinium. Significant differences were used to create aparadigm, which was used for the evaluation of adifferent group of 32MRIs with 42concomitant MS and CSM lesions. Significant differences were seen in the level, location within the cord in both planes, lesion size, cord thickness and lesion border. The MS lesions were well-defined lesions found in C1-3, posterior in the sagittal plane, central in the axial plane, with anormal or increased cord thickness. Good agreement was seen in the validation stage. The new CSM-MS lesion score allows accurate diagnosis of demyelinating lesions in the cervical spine vs. CSM lesions.

High field magnetic resonance imaging is comparable with gross anatomy for description of the normal appearance of soft tissues in the equine stifle.

High field magnetic resonance imaging (MRI) is increasingly used for horses with suspected stifle disease, however there is limited available information on normal imaging anatomy and potential incidental findings. The aim of this prospective, anatomic study was to develop an optimized high field MRI protocol for evaluation of the equine stifle and provide detailed descriptions of the normal MRI appearance of the stifle soft tissues, using ultrasound and gross pathological examination as comparison tests. Nine cadaver limbs were acquired from clinically normal horses. Stifles were evaluated ultrasonographically and then by an extensive 1.5T MRI protocol. Subsequently, all stifles were evaluated for gross pathologic change. Findings were compared between gross evaluation and MRI imaging and described. No soft tissue structure abnormalities were identified on any evaluation. Specific descriptive findings of the meniscotibial, meniscofemoral, collateral, patellar and cruciate ligaments, and the menisci were reported. The high field MRI protocol described in this study provided high spatial and contrast resolution of the soft tissue structures, and this in turn allowed visualization of detailed structural characteristics, such as striations and variations in signal intensity. Findings supported the use of high field MRI as a modality for the evaluation of the soft tissues of the equine stifle. As clinical availability of this modality increases in the future, authors anticipate that new stifle diseases will be detected that have not previously been identified with other imaging modalities.

High field magnetic resonance imaging anatomy of feline carpal ligaments is comparable to plastinated specimen anatomy

Feline carpal ligament injuries are often diagnosed indirectly using palpation and stress radiography to detect whether there is instability and widening of joint spaces. There are currently no reports describing normal feline carpal ligament anatomy and the magnetic resonance imaging (MRI) appearance of the carpal ligaments. The objective of this prospective, anatomic study was to describe normal feline carpal ligament anatomy using gross plastinated specimens and MRI. We hypothesized that MRI could be used to identify the carpal ligaments as previously described in the dog, and to identify species specific variations in the cat. The study was conducted using feline cadaver antebrachii that were radiographed prior to study inclusion. Three limbs were selected for MRI to confirm repeatability of anatomy between cats. The proton density weighted pulse sequence was used and images were acquired in transverse, dorsal, and sagittal planes. Following MRI, the limbs were plastinated and a collagen stain was used to aid in identification of carpal ligament anatomy. These limbs were sliced in sagittal section, and a further six paired limbs were included in the study and sliced in transverse and dorsal planes. Anatomic structures were initially described using MRI and then subjectively compared with gross plastinated specimens. Readers considered the transverse MRI plane to be most useful for visualizing the majority of the carpal ligaments. Findings indicated that MRI anatomy of the carpal ligaments was comparable to plastinated anatomy; therefore MRI appears to be a beneficial imaging modality for exploration of feline carpal pathology.

Graft use in the treatment of large and massive rotator cuff tears: an overview of techniques and modes of failure with MRI correlation

Despite technical advances, repair of large or massive rotator cuff tears continues to demonstrate a relatively high rate of failure. Rotator cuff repair or superior capsular reconstruction (SCR) using a variety of commercially available grafts provides a promising option in patients with tears that may be at high risk for failure or otherwise considered irreparable. There are three major graft constructs that exist when utilizing graft in rotator cuff repair or reconstruction: augmentation at the rotator cuff footprint, bridging, and SCR. Each construct has a unique appearance when evaluated using postoperative magnetic resonance imaging (MRI), and each construct has unique sites that are predisposed to failure. Understanding the basic principles of these constructs can help the radiologist better evaluate the postoperative MRI appearance of these increasingly utilized procedures.

3.0 Tesla magnetic resonance imaging anatomy of the central nervous system, eye, and inner ear in birds of prey.

Despite the increasing interest in the clinical neurology of birds, little is known about the magnetic resonance imaging (MRI) appearance of the avian central nervous system, eye, and inner ear. The objective of this cadaveric study was to document the MRI anatomic features of the aforementioned structures using a high-resolution 3.0 Tesla MRI system. The final study group consisted of 13 cadavers of the diurnal birds of prey belonging to six species. Images were acquired in sagittal, dorsal, and transverse planes using T1-weighted and T2-weighted turbo spin echo sequences. A necropsy with macroscopic analysis of the brain and spinal cord was performed on all cadavers. Microscopic examination of the brain was performed on one cadaver of each species; the spinal cord was examined in three subjects. Anatomic structures were identified on the magnetic resonance images based on histologic slices and available literature. Very good resolution of anatomic detail was obtained. The olfactory bulbs; cerebral hemispheres; diencephalon; optic lobe; cerebellum; pons; ventricular system; optic, trigeminal, and facial nerves; pineal and pituitary glands; as well as the semicircular canals of the inner ear were identified. Exquisite detail was achieved on the ocular structures. In the spinal cord, the gray and white matter differentiation and the glycogen body were identified. This study establishes normal MRI anatomy of the central nervous system, eye, and inner ear of the birds of prey; and may be used as a reference in the assessment of neurologic disorders or visual impairment in this group of birds.

Diagnosis and differential diagnosis between focal nodular hyperplasia with inflammatory hepatocellular adenoma on MRI

Objective To compare the MRI features of focal nodular hyperplasia (FNH) and inflammatory hepatocellular adenoma (I-HCA), with an aim to improve the diagnostic accuracy in the two lesions. Methods Patients who underwent dynamic-enhanced MRI with histopathologically confirmed FNHs (21 patients with 21 tumors) and I-HCAs (10 patients with 12 tumors) were included in this retrospective study. The clinical and the imaging features, including the T2-and T1-weighted, diffusion weighted images, and the dynamic enhanced imagings were analyzed. Results No significant difference was observed in the clinical data between the 2 groups of patients, except in the serum levels of C-reactive protein. The serum C-reactive protein levels were significantly elevated in I-HCA than in FNH. Significant differences between patients with FNHs and I-HCAs were also found in the morphologic findings and the signal intensities (including shape, centre scar, necrosis, signal intensity of T2WI and DWI, and lesion signal intensity compared to those of the liver in the portal venous phase and delayed phase). The differences in lesion to liver signal in FNH were significantly lower than those in I-HCA in the T2WI and the delayed phases. The area under the curve (AUC) for the 2 groups of patients were 0.843 and 0.743, respectively, with no significant difference between them. Conclusions The MRI appearances of atypical FNHs overlapped with I-HCA. MRI features of isointensity on T2WI and DWI, and isointensity to the liver in the delayed phase were valuable to differentiate FNHs from I-HCAs. Most I-HCAs showed moderate and marked high signal intensity on T2WI and DWI. These features, when combined with an elevated serum C-reaction protein, necrosis in the lesion and hyperintensity in the delayed phase, were valuable in differentiating I-HCAs from FNH. Key words: Focal nodular hyperplasia; Inflammatory hepatocellular adenoma; Magnetic resonance imaging (MRI); Comparative study

Post-Mortem Magnetic Resonance Imaging Appearances of Feticide in Perinatal Deaths

Objective: The aim of this study was to characterise the imaging features seen in fetuses having undergone feticide by intracardiac potassium chloride injection compared to those of non-terminated fetuses at post-mortem magnetic resonance imaging (PMMRI). Methods: A case-control study was performed comparing PMMRI findings between two groups of patients – those having undergone feticide were matched to a control group of miscarried/stillborn fetuses. The groups were matched according to gestational age, weight, and time since death. Two independent readers reviewed the PMMRI for thoracic, abdominal, and musculoskeletal imaging features. The Fishers exact test was conducted for differences between the patient groups. Results: Twenty-six cases of feticide (mean gestation 25 weeks [20–36]) and 75 non-terminated fetuses (mean gestation 26.7 weeks [19–36]) were compared. There was a higher proportion of feticide cases demonstrating pneumothorax (23.1 vs. 1.3%, p = 0.001), haemothorax (42.3 vs. 4%, p = 0.001), pneumopericardium (30.8 vs. 5.3%, p = 0.002), and haemopericardium (34.6 vs. 0%, p = 0.0001). Intracardiac gas and intra-abdominal findings were higher in the feticide group, but the differences were not statistically significant. Conclusion: Characteristic PMMRI features of feticide can help improve reporter confidence in differentiating iatrogenic from physiological/pathological processes.

Characterization of the murine orthotopic adamantinomatous craniopharyngioma PDX model by MRI in correlation with histology.

PurposeAdamantinomatous craniopharyngiomas (ACP) as benign sellar brain tumors are challenging to treat. In order to develop robust in vivo drug testing methodology, the murine orthotopic craniopharyngioma model (PDX) was characterized by magnetic resonance imaging (MRI) and histology in xenografts from three patients (ACP1-3).MethodsIn ACP PDX, multiparametric MRI was conducted to assess morphologic characteristics such as contrast-enhancing tumor volume (CETV) as well as functional parameters from dynamic contrast-enhanced MRI (DCE-MRI) and diffusion-weighted imaging (DWI) including area-under-the-curve (AUC), peak enhancement (PE), time-to-peak (TTP) and apparent diffusion coefficient (ADC). These MRI parameters evaluated in 27 ACP PDX were correlated to histological features and percentage of vital tumor cell content.ResultsQualitative analysis of MRI and histology from PDX revealed a similar phenotype as seen in patients, although the MRI appearance in mice resulted in a more solid tumor growth than in humans. CETV were significantly higher in ACP2 xenografts relative to ACP1 and ACP3 which correspond to respective average vitality of 41%, <10% and 26% determined histologically. Importantly, CETV prove tumor growth of ACP2 PDX as it significantly increases in longitudinal follow-up of 110 days. Furthermore, xenografts from ACP2 revealed a significantly higher AUC, PE and TTP in comparison to ACP3, and significantly increased ADC relative to ACP1 and ACP3 respectively. Overall, DCE-MRI and DWI can be used to distinguish vital from non-vital grafts, when using a cut off value of 15% for vital tumor cell content.ConclusionsMRI enables the assessment of craniopharyngioma PDX vitality in vivo as validated histologically.

The characters of computed tomography and magnetic resonance imaging in adrenal oncoctyoma patients

Objective To summerize computed tomography(CT) and magnetic resonance imaging(MRI) appearances of the adrenal oncoctyoma(AOC), and to improve the diagnostic accuracy. Methods The 11 cases imaging materials of AOC confirmed by pathology from March 2006 to August 2017 were analyzed retrospectively.There were 3 males and 8 females, aged from 24 to 65 years old(mean 46.8 years). There were 11 cases with CT unenhanced scan in which 9 cases performed enhancing scan, 8 cases underwent unenhanced and enhanced MRI scan. Results Of 11 cases (13 lesions), 10 cases were singular, 1 was unilaterally multiple(3 lesions). 5 cases were located in the right side, 6 in the left side. 10 lesions presented oval, 3 were round. The diameters of all lesions ranged from 1.4 to 9.9 cm, with a mean of 3.9 cm. All lesions were shown well-defined soft-tissue density on plain CT scan, 69.2%(9/13)of whom were homogeneous, 30.8% were heterogenous. The CT value ranged from 32.6 to 48.6 HU, with a mean of 37.9 HU. In 9 cases, 5 masses were markedly enhanced, 2 were slightly enhanced and 2 were moderately enhanced, and all of them depicted prolongedly enhanced on triple-phase scan. The masses of 8 cases appeared isointensity or slightly hypointensity on T1WI, hyperintesity on fat-suppressed T2WI. The signal did not change on opposed-phase imaging. The lesions demonstrated heterogeneously prolonged enhancement to some degree on enhanced T1WI images. There was no peritumoral adjacent invasion, enlarged lymph nodes and metastasis. Conclusions AOC usually presents soft-tissue density on unenhanced CT, no changing on MRI opposed-phase images. The tumors are characterized by markedly heterogeneously prolonged enhanced on enhanced CT and MRI. Key words: Oncocytoma; Adrenal; Magnetic resonance imaging(MRI); Computed tomography(CT)

Magnetic Resonance Imaging Characteristics of Pituitary Abscess: A Review of 51 Cases.

To investigate pituitary abscess (PA) magnetic resonance imaging (MRI) features to improve the neuroradiologic and diagnostic knowledge of this rare disease and guide follow-up treatments. Clinical data were collected for 51 patients with PA, and MRI data were quantitatively reviewed in a retrospective analysis. Clinical factors were analyzed to investigate their relevance. PA neuroimaging showed special radiologic features, including hypointensity or isointensity on T1-weighted imaging (30 patients, 58.8%), isointensity or hyperintensity on T2-weighted imaging (39 patients, 76.5%), and disappearance of the posterior pituitary bright spot in most patients (44 patients, 86.3%). After gadolinium injection, rim or rimlike enhancement was observed in 82.4% of patients (n= 42). Half of those patients showed typical rim enhancement (profound peripheral enhancement with internal hypointensity); others showed atypical rim enhancement with special signs, such as enhanced, thick abscess wall and hyperintense flocculent or cottonlike foci within the internal hypointense region. Almost all patients (96.1%) presented at least 1 sign of adjacent anatomic structure invasion, including peripheral meninges enhancement, pituitary stalk thickening, and paranasal sinus mucosa enhancement. Rank correlation analysis of the clinical time course and MRI characteristics of PA showed a Spearman correlation coefficient of 0.270, indicating borderline significance (P= 0.055). Classic MRI characteristics of PA show T1 signal hypointensity or isointensity, T2 signal isointensity or hyperintensity, and peripheral rim enhancement after gadolinium injection. The MRI appearance of PA may reflect the abscess liquefaction and formation. Despite its profound significance for differential diagnosis, adjacent structure invasion is generally ignored by clinicians.

Secondary central nervous system lymphoma: spectrum of morphological MRI appearances.

BackgroundSecondary central nervous system lymphoma (SCNSL) is a rare and aggressive disease, which is defined as secondary central nervous system (CNS) involvement in patients with systemic lymphoma. According to previous reports, SCNSL presents mostly with leptomeningeal spread; however, our experience differs. In the present study, we demonstrate the diversity of magnetic resonance imaging (MRI) patterns in SCNSL.Patients and methodsInitial morphological MRI findings in 21 patients (10 women and 11 men with mean age 62.3±16.2 years) with SCNSL were retrospectively evaluated. All patients suffered from neurological symptoms and underwent MRI, and all cases were histologically verified. Twelve patients were treated by corticosteroids at the time of the initial MRI.ResultsParenchymal lesions were present in 18 of 21 cases (85.7%), solitary meningeal infiltration was present in 1 patient (4.8%), leptomeningeal infiltration in combination with hypophyseal involvement in 1 patient (4.8%), and solitary involvement of the sixth cranial nerve (CN) was found in 1 patient (4.8%). Multiple lesions were present in 11 of 21 cases (52.4%). Diffusion restriction in all or part of the lesion was detected in 14 of 18 cases (77.8%). All parenchymal lesions had an infiltrative appearance and most enhanced homogenously (11 of 17 cases; 64.7%). A combination of parenchymal and meningeal involvement was found in 10 of 21 cases (47.6%). Infiltration of the CNs, basal ganglia, corpus callosum, and ependyma was present in 8 of 21 cases (38.1%) for each of the abovementioned structures; hypothalamic–hypophyseal axis was affected in 7 of 21 cases (33.3%).ConclusionIn contrast to previous reports, SCNSL presented as parenchymal disease. MRI is not sufficient for differentiation between primary and secondary CNS lymphoma.

CT and MR imaging features in phosphaturic mesenchymal tumor-mixed connective tissue: A case report.

Phosphaturic mesenchymal tumor-mixed connective tissue (PMT-MCT) is rare and usually benign and slow-growing. The majority of these tumors is associated with sporadic tumor-induced osteomalacia (TIO) or rickets, affect middle-aged individuals and are located in the extremities. Previous imaging studies often focused on seeking the causative tumors of TIO, not on the radiological features of these tumors, especially magnetic resonance imaging (MRI) features. PMT-MCT remains a largely misdiagnosed, ignored or unknown entity by most radiologists and clinicians. In the present case report, a review of the known literature of PMT-MCT was conducted and the CT and MRI findings from three patient cases were described for diagnosing the small subcutaneous tumor. Typical MRI appearances of PMT-MCT were isointense relative to the muscles on T1-weighted imaging, and markedly hyperintense on T2-weighted imaging containing variably flow voids, with markedly heterogeneous/homogenous enhancement on post contrast T1-weighted fat-suppression imaging. Short time inversion recovery was demonstrated to be the optimal sequence in localizing the tumor.

The MR Imaging Appearance of Endoscopic Endonasal Skull Base Defect Reconstruction Using Free Mucosal Grafts

The MR Imaging Appearance of Endoscopic Endonasal Skull Base Defect Reconstruction Using Free Mucosal Grafts

Patellofemoral Cartilage Lesions Treated With Particulated Juvenile Allograft Cartilage: A Prospective Study With Minimum 2-Year Clinical and Magnetic Resonance Imaging Outcomes

To analyze the functional outcomes of patients treated with particulated juvenile articular cartilage (PJAC) for symptomatic articular cartilage lesions in the patellofemoral joint, correlates clinical outcomes with magnetic resonance imaging (MRI) appearance of the repair tissue using cartilage-sensitive quantitative T2-mapping. All patients treated with PJAC for patellofemoral lesions were identified and prospectively followed with clinical outcome scores (International Knee Documentation Committee [IKDC], Knee Outcome Survey-Activities of Daily Living [KOS-ADL], and Marx Activity Scale [MAS]). Postoperative MRI scans using quantitative T2 mapping were obtained and interpreted by an independent musculoskeletal radiologist. Twenty-seven patients treated with PJAC for 30 full-thickness patellofemoral cartilage lesions were identified; mean postoperative follow-up was 3.84years. Improvements from pre- to postoperative mean IKDC (45.9 vs 71.2, P < .001) and KOS-ADL (60.7 vs 78.8, P < .001) scores were observed; no significant change in MAS was seen (7.04 vs 7.17, P= .97). Advanced age, history of previous surgery, lesion location (patella vs trochlea), or concomitant tibial tubercle osteotomy did not affect outcome scores. Greater body mass index was associated with less improvement in KOS-ADL score. No patients required reoperation for graft-related issues. Lesion fill exceeding 67% by MRI assessment was noted in 69.2% of lesions; depth of lesion fill did not correlate with clinical outcomes. Quantitative T2-mapping revealed prolonged relaxation time at the graft site compared with adjacent normal cartilage at both deep and superficial zones. This study found significantly improved pain and function in patients treated with PJAC for symptomatic patellofemoral articular cartilage defects. No patients required reoperation for graft-related issues. Postoperative MRI revealed majority lesion fill in more than 69% of patients, but persistent morphologic differences between graft site and normal adjacent cartilage remain. Though we support PJAC use in this setting to improve patient subjective outcomes, improved appearance on postoperative imaging was not found to provide additional clinical benefit. Level IV, case series.

Magnetic resonance perfusion for differentiating low-grade from high-grade gliomas at first presentation.

Magnetic resonance perfusion for differentiating low-grade from high-grade gliomas at first presentation.

MRI Evaluation of Repaired Versus Unrepaired Interportal Capsulotomy in Simultaneous Bilateral Hip Arthroscopy: A Double-Blind, Randomized Controlled Trial.

Techniques used in hip arthroscopy continue to evolve, and controversy surrounds the need for capsular repair following this surgical intervention. The purpose of this study was to evaluate the magnetic resonance imaging (MRI) appearance of the hip capsule in patients with femoroacetabular impingement (FAI) who underwent simultaneous bilateral hip arthroscopy through an interportal capsulotomy with each hip randomized to undergo capsular repair or not undergo such a repair. This double-blind, randomized controlled trial included 15 patients (30 hips), with a mean age of 29.2 years, who underwent simultaneous bilateral hip arthroscopy utilizing a small (<3-cm) interportal capsulotomy for the treatment of FAI. The first hip treated in each patient was intraoperatively randomized to undergo capsular repair or no capsular repair. The contralateral hip then received the opposite treatment. MRI was performed at 6 and 24 weeks postoperatively, and the scans were analyzed by 2 musculoskeletal radiologists. The patients and the radiologists were blinded to the treatment performed on each hip. Capsular dimensions were measured at the level of the healing capsulotomy site and, for hips with a persistent defect, at locations both proximal and distal to the defect. These values were then analyzed at both time points to assess the rate and extent of capsular healing. At 6 weeks postoperatively, a continuous hip capsule (with no apparent capsulotomy defect) was observed in 8 hips treated with capsular repair and 3 hips without such a repair. Of the 19 hips with a discontinuous capsule at 6 weeks, 17 were available for follow-up at 24 weeks postoperatively; all 17 demonstrated progression to healing, with a contiguous appearance without defects and no difference in capsular dimensions between treatment cohorts. Arthroscopic repair of a small interportal hip capsulotomy site yields an insignificant increase in the percentage of continuous hip capsules seen on MRI at 6 weeks postoperatively compared with no repair. Repaired and unrepaired capsulotomy sites progressed to healing with a contiguous appearance on MRI by 24 weeks postoperatively. Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Mapping the microscale origins of magnetic resonance image contrast with subcellular diamond magnetometry

Magnetic resonance imaging (MRI) is a widely used biomedical imaging modality that derives much of its contrast from microscale magnetic field patterns in tissues. However, the connection between these patterns and the appearance of macroscale MR images has not been the subject of direct experimental study due to a lack of methods to map microscopic fields in biological samples. Here, we optically probe magnetic fields in mammalian cells and tissues with submicron resolution and nanotesla sensitivity using nitrogen-vacancy diamond magnetometry, and combine these measurements with simulations of nuclear spin precession to predict the corresponding MRI contrast. We demonstrate the utility of this technology in an in vitro model of macrophage iron uptake and histological samples from a mouse model of hepatic iron overload. In addition, we follow magnetic particle endocytosis in live cells. This approach bridges a fundamental gap between an MRI voxel and its microscopic constituents.

Magnetic Resonance Imaging correlates of benign and malignant alterations of the spinal bone marrow.

Background and aim of the work: Bone marrow (BM) abnormalities in the spine are a common, sometimes unexpected, finding on Magnetic Resonance Imaging (MRI), which is the most sensitive imaging modality to evaluate the marrow, and their interpretation can be difficult for the unexperienced radiologist. In this review, the MRI appearance of normal age-related BM changes, as well as the imaging features of benign and malignant diseases, are presented. Discussion: A large variety of BM signal alterations has been identified and described, including normal variants, BM reconversion, degenerative changes, infections, spondyloarthritis and osteonecrosis, trauma, neoplastic lesions (both primary or metastatic), post-radiation and chemotherapy sequelae. Conclusions: Knowledge of normal age-related BM appearance, normal variants and patterns of involvement in focal and diffuse bone diseases is essential, together with clinical and laboratory data, to narrow the list of the possible differential diagnoses. The radiologist should be familiar with these signal changes, as they can sometimes be discovered incidentally. In this context, it is equally important not to attribute pathological significance to benign alterations and to promptly detect signs of malignant diseases. (www.actabiomedica.it)

Magnetic resonance imaging spectrum of intracranial tubercular lesions: one disease, many faces.

Tuberculosis is a devastating disease and has shown resurgence in recent years with the advent of acquired immunodeficiency syndrome. Central nervous system involvement is the most devastating form of the disease, comprising 10% of all tuberculosis cases. The causative organism, Mycobacterium tuberculosis, incites a granulomatous inflammatory response in the brain, the effects of which can be appreciated on magnetic resonance imaging (MRI), which can thus be used for diagnosis of the same. Neurotuberculosis can present in various patterns, which can be identified on MRI. The meningeal forms include leptomeningitis and pachymeningitis. Parenchymal forms of neurotuberculosis include tuberculoma in its various stages, tubercular cerebritis and abscess, tubercular rhombencephalitis, and tubercular encephalopathy. Each pattern has characteristic MRI appearances and differential diagnoses on imaging. Complications of neurotuberculosis, usually of tubercular meningitis, include hydrocephalus, vasculitis, and infarcts as well as cranial nerve palsies. Various MRI sequences besides the conventional ones can provide additional insight into the disease, help in quantifying the disease load, and help in differentiation of neurotuberculosis from conditions with similar imaging appearances and presentations. These can enable accurate and timely diagnosis by the radiologist and early institution of treatment in order to reduce the likelihood of permanent neurological sequelae.

Clinicoradiological aspects of pontine tegmental cap dysplasia: Case report of a rare hindbrain malformation.

Malformations involving the brainstem are very rare and present with a varied spectrum of clinical symptoms due to multiple cranial nerve palsies and pyramidal tract involvement. Of these, pontine tegmental cap dysplasia is a very unusual malformation, characterized by ventral pons hypoplasia and an ectopic dorsal band of tissue, projecting into the fourth ventricle, from dorsal pontine tegmentum. A 4-year-old male child, presenting with left facial nerve palsy, revealed hypoplastic ventral pons and an ectopic structure on magnetic resonance imaging (MRI). The ectopic structure was isointense to pons, arose from the left side of dorsal pontine tegmentum, at pontomedullary junction and protruded into the fourth ventricle, impinging upon the left seventh and eighth cranial nerves. Diffusion tensor imaging (DTI) depicted abnormal white matter tracts in ectopic tissue with absent transverse pontine fibres and abnormal middle and superior cerebellar peduncles. The typical MRI appearance, coupled with DTI, helped us reach an accurate diagnosis of pontine tegmental cap dysplasia, in a setting of neurological dysfunction.