Pathological Magnetic Resonance Imaging Findings Research Articles

A Practical Guide to Imaging of Cartilage Repair with Emphasis on Bone Marrow Changes

Orthopedic surgeons have multiple options available to treat articular cartilage lesions, including microfracture, osteochondral autografting, and autologous chondrocyte implantation. By having basic knowledge of these surgical procedures, radiologists can more accurately interpret imaging studies obtained after surgery. In this article, we briefly review the different types of cartilage repair procedures, their appearance on magnetic resonance imaging (MRI), and pathologic MRI findings associated with postoperative complications. We also briefly discuss advanced MRI techniques (T2 mapping, delayed gadolinium-enhanced MRI of cartilage, sodium MRI) that have been recently used to assess the biochemical composition of repair tissue matrix. MRI can accurately assess the status and health of cartilage repair tissue. By providing this information to orthopedic surgeons, radiologists can play a valuable role in the management of patients who undergo cartilage repair surgery.

Diagnostic accuracy of magnetic resonance imaging (MRI) in the assessment of tumor invasion depth in oral/oropharyngeal cancer

The purpose of the present study was to evaluate the diagnostic value of MRI for measuring invasion depth in oral/oropharyngeal carcinoma. We retrospectively reviewed pathologic specimens and MRI findings of 114 patients who were diagnosed with squamous cell carcinoma of the oral cavity and oropharynx. Invasion depths were evaluated in pathologic specimens and by MRI. The mean histologic and MRI invasion depths were 13.57 ± 8.476 and 15.24 ± 10.700 mm, respectively. The overall Pearson's correlation coefficient for histologic and MRI (T1W-MRI) invasion depths was 0.825, which was statistically significant (P<0.001). Pearson's correlation coefficients for histologic and MRI invasion depths in oral tongue, tongue base, and tonsil cancers were 0.949, 0.941, and 0.578, respectively. The MRI invasion depth was significantly different according to nodal status in cancers of the oral tongue (P=0.001(∗)) and tongue base (P=0.003(∗)). With MRI, the invasion depth cutoff values for determining positive nodes were 9.5 and 14.5mm in cancers of the oral tongue and tongue base, respectively. Preoperative MRI is an accurate method for measuring tumor invasion depth in oral tongue and tongue base cancers. Furthermore, it has predictive value for nodal metastasis in the oral tongue and tongue base.

Degenerative changes were common in brain magnetic resonance imaging in patients with newly diagnosed Parkinson’s disease in a population-based cohort

The aim of this study was to investigate newly diagnosed patients with Parkinson's disease (PD) with structural magnetic resonance imaging (MRI), to compare them with healthy controls, to relate the findings to clinical subtypes--tremor dominant (TD) or postural instability and gait difficulty (PIGD)--and to investigate the relationship between both the duration from onset of symptoms to diagnosis and the severity of symptoms and the MRI findings. Patients with a definite PD diagnosis were compared to patients with a probable PD diagnosis. We hypothesized that the PIGD subtype, the probable PD group, a greater symptom severity and a longer symptom duration would all be associated with more frequent pathological findings. Sixty-six PD patients were included and examined with MRI, 35 with the PIGD subtype and 23 with the TD subtype. Fifty-three had definite PD and 13 probable PD. Thirty healthy individuals, matched for age and sex, served as controls. Degenerative changes in the cerebellar cortex and the superior cerebellar peduncle were significantly more common in the probable PD group than in the controls, suggesting the possibility of an emerging atypical parkinsonian disorder. No significant MRI differences were found between definite PD and controls, between definite PD and probable PD, nor between PIGD and TD. No significant associations were found between duration to diagnosis and MRI results, nor between severity of symptoms and MRI results. Thus, although pathological MRI findings were common they can not be used to separate subgroups of PD in newly diagnosed patients.

Diffusion tensor imaging: the normal evolution of ADC, RA, FA, and eigenvalues studied in multiple anatomical regions of the brain

The aim of our work was to investigate the process of myelination in healthy patients using the diffusion parameters apparent diffusion coefficient (ADC), relative anisotropy (RA), fractional anisotropy (FA), and eigenvalues. Age-dependent changes were assessed using the slope m of the fit functions that best described the data. Seventy-two patients (3 weeks-19 years) without pathological magnetic resonance imaging findings were selected from all pediatric patients scanned with diffusion tensor imaging over a 5-year period at our institution. ADC, RA, FA, and eigenvalue maps were calculated and regions of interest were selected in anterior/posterior pons, genu/splenium of corpus callosum (CC), anterior/posterior limb of internal capsule (IC), and white matter (WM) regions (frontal, temporal, parietal, occipital WM). Statistical analysis was performed using Spearman correlation coefficient and regression analysis. Mean values ranged 71.6 x 10(-5) to 90.3 x 10(-5) mm(2)/s (pons/parietal WM) for ADC, 0.32-0.94 (frontal WM/CC) for RA, and 0.36-0.81 (frontal WM/splenium) for FA. Logarithmic fit functions best described the data. Strong age influences were observed for CC, pons, and parietal/frontal WM and changes were significant for all three eigenvalues, most pronounced for perpendicular eigenvalues. Changes in RA and FA differed depending on the structure anisotropy. Changes observed for ADC, RA, FA, and eigenvalues with age were consistent with previous findings. Changes detected for RA and FA varied due to the different scaling of both parameters. We found that the use of the largely linear scaled RA adds more valuable information for the assessment of age-dependent structural changes as compared to FA. Additionally, we report normative values for the diffusion parameters studied.

Disc pathology after whiplash injury. A prospective magnetic resonance imaging and clinical investigation.

This study was used to evaluate the relationship between magnetic resonance imaging findings and clinical findings after whiplash injury. To identify initial soft-tissue damage after whiplash injury, the development of disc pathology, and the relationship of disc pathology to clinical findings. Although a few studies have reported pathological magnetic resonance imaging findings after whiplash injuries, there is no prospective study published to our knowledge. Thirty-nine patients, 20 women and 19 men with a mean age of 32 years, were treated for whiplash injury. Magnetic resonance imaging and clinical examination were performed in a blinded manner at a mean of 11 days after trauma. The procedure was repeated at a 2-year follow-up visit. Two patients could not be examined with the second magnetic resonance imaging because of claustrophobia and pregnancy, respectively. The authors found 13 patients (33%) with disc herniations with medullary (six cases) or dura (seven cases) impingement over the 2-year follow-up period. At the follow-up examination all patients with medullary impingement had persistent or increased symptoms, and three of 27 patients (11%) with no or slight changes on magnetic resonance imaging had persistent symptoms. No ligament injuries were diagnosed. Although disc pathology seems to be one contributing factor in the development of chronic symptoms after whiplash injury, it may be unnecessary to examine these patients in the acute phase with magnetic resonance imaging; correlating initial symptoms and signs to magnetic resonance imaging findings is difficult because of the relatively high proportion of false-positive results. Magnetic resonance imaging is indicated later in the course of treatment in patients with persistent arm pain, neurologic deficits or clinical signs of nerve root compression to diagnose disc herniations requiring surgery.

Clinical and MRI Findings of the Temporomandibular Joint in Relation to Occlusion in Young Adults

Magnetic resonance imaging (MRI) is excellent for visualizing soft tissues of the temporomandibular joint (TMJ) . Because it has no harmful effects, it can be used in asymptomatic subjects. MRI and clinical findings relating to TMJs were correlated with findings relating to occlusion in 20 medical and dental students (13 women, 7 men) who volunteered to participate in our study. Subjects with clinically evident joint signs such as clicking, crepitation or tenderness on palpation also exhibited pathologic MRI findings, especially in regards to configuration, position and function of the disk, and, often, disturbances of occlusal relationships between the upper and lower teeth.

The Incidence of Occult Spinal Dysraphism and the Onset of Neurovesical Dysfunction in Children with Anorectal Anomalies

The urological malformations associated with anorectal anomalies (ARA) are not only anatomical, but also functional, the latter being related to congenital neurovesical dysfunction (NVD). The true incidence of spinal dysraphism (SD) in these children is still unclear and is probably underestimated. The concept of caudal regression could explain its association with the anorectal anomalies. Because of awareness of the late onset of neurovesical dysfunction and/or orthopaedic symptoms in some of our patients, in 1991 we started to screen with magnetic resonance imaging (MRI) the spinal cord of all patients with ARA. Eighteen (44%) out of 41 patients without neurological or orthopaedic symptoms and 7 (78%) of 9 children with neurological or orthopaedics symptoms screened by MRI showed pathological findings. The overall incidence of spinal dysraphism in ARA was 50%, without any great difference with respect to the type of the anomaly (high, low, cloacal). The pathological MRI findings encountered were: fibrolipoma (with or without a thickened filum terminale), tethering of the cord and syringomyelia, and sac anomalies. In order to check the onset of NVD in these children, we performed urodynamic studies with external sphincter electromyography in 24. Grouped by age: 14 were between 5 and 18 months and ten were 4 to 13 years old. Ten patients (71%) out of the first group and 3 (30%) out of the second had a normal urodynamic pattern. A total of 11 children had pathological findings; of these, 4 infants had a hyperreflexic bladder (one with detrusor-sphincter dyssynergia) suggesting upper motor neuron (UMN) lesion. Of the 7 older patients, two had UMN and 3 lower motor neuron (LMN) lesion.(ABSTRACT TRUNCATED AT 250 WORDS)

Role of nuclear magnetic resonance imaging in the diagnosis of monosymptomatic optic neuritis

34 patients with monosymptomatic optic neuritis were examined ophthalmologically and by magnetic resonance imaging (MRI). In 18 patients subclinical lesions with a high MRI signal intensity were found. The distribution of these lesions was similar to that seen in multiple sclerosis. Neither the severity of the visual impairment nor the course of remission correlated to the MRI findings. Pathologic MRI findings were more common in patients aged over 27 than in younger patients (57% vs. 42%).