Biomedical subjects

L M Teresi

Publications and source records attributed to L M Teresi.

22 records · Page 2Linked to original sources

PubMedDate not supplied

Magnetic resonance imaging of bioabsorbale polylactic acid interference screws during the first 2 years after anterior cruciate ligament reconstruction.

Bioabsorbable screws composed of poly(L-lactic acid) (PLA) were used for graft fixation and studied prospectively with serial magnetic resonance imaging (MRI) scans at 8, 16, and 24 months after autogenous patellar tendon anterior cruciate ligament (ACL) reconstruction in 10 patients. Conventional spin echo, proton density, and T2-weighted double echo sequences were obtained, as well as T2-weighted fat-saturated fast spin echo sequences. All but one of the screws (19 of 20) were evident in all serial scans. These showed minimal decrease in size over time. The one screw that had completely disappeared 8 months after reconstruction had cracked during insertion. None of the reconstructed ACL grafts showed clinical instability, persistent effusions, or detectable adverse reactions to the screws. Two patients developed abnormal signal in the tibial tunnel: one developed fluid anterior to the graft, and the other developed increased signal within the graft. The abnormal signal resolved with time in both patients. Other than the preceding changes, no abnormalities were detected on conventional sequences. Fat-saturated fast spin echo sequences showed a variable amount of increased signal around the tunnels, suggesting edema or fibrovascular marrow changes. The changes noted near the tunnels on the fat-suppressed scans most probably represent a general reaction to surgical insult rather than a reaction to the bioabsorbable screws, as similar changes were noted at the patellar harvest site.

Absorbable Implants↗

PubMedDate not supplied

Improving the diagnostic accuracy of MR in the detection of infraspinatus tendon injuries.

PURPOSE: Our goal was to determine the accuracy of MRI in the diagnosis of infraspinatus tendon injury and more specifically to determine if the antero-posterior extent of a rotator cuff tear is predictive of infraspinatus tearing. METHOD: The MR images of 41 shoulders with surgically proven supraspinatus tears at surgery were retrospectively reviewed. The following were assessed for each of the 41 studies: the number of oblique coronal images on which a tendon defect could be seen, the angle subtended by the tear on axial images (the rotator cuff "axial angle"), and the extent of signal abnormality on sagittal images. RESULTS: The rotator cuff axial angle was 75.6 degrees in patients with infraspinatus tendon tears (ITTs) versus 40 degrees in those without ITTs, and this difference was significant (p < 0.001, t = 3.06). The mean number of oblique coronal images (obtained with a 4 mm slice and 1 mm gap) showing signal abnormality was 5.4 in the ITT group versus 2.9 in those without ITTs, and this difference was also significant (p < 0.001, t = 4.45). The mean sagittal extent of the tendon abnormality was 24.6 mm in the ITT group and 11.6 mm in those without ITTs, but the difference was not significant (p > 0.05, t = 1.1364). CONCLUSION: The axial angle and the number of oblique coronal images in which signal abnormality was present were significantly related to a higher incidence of infraspinatus tears.

Adult↗

PubMedDate not supplied

Association of deep white matter infarction with chronic communicating hydrocephalus: implications regarding the possible origin of normal-pressure hydrocephalus.

The coexistence of cerebrovascular disease leading to deep white matter infarction and normal-pressure hydrocephalus has been noted previously in clinical studies, as both diseases can present with the triad of gait disturbance, dementia, and incontinence. The purpose of this MR study was to determine if the two diseases demonstrated a statistical association. Evidence of patchy periventricular hyperintensity representing presumed deep white matter infarction was sought in 20 patients shunted for normal-pressure hydrocephalus and in 35 additional consecutive patients with clinical symptoms and MR findings consistent with normal-pressure hydrocephalus. Deep white matter infarction was also sought in 62 consecutive age-matched control subjects. There was a statistically significant (p less than .001) higher association (58%) of marked infarction in the 55 patients with normal-pressure hydrocephalus than in the age-matched controls (24%). MR findings of communicating hydrocephalus (ventriculomegaly and increased aqueductal CSF flow void) were sought in 78 consecutive patients with presumed deep white matter infarction, and the degree of severity of the two diseases was also found to be statistically significant (p less than .05). In view of this association, the possibility that the two diseases are related was considered. A potential mechanism is discussed whereby deep white matter infarction leading to decreased periventricular tensile strength could result in communicating hydrocephalus. It is plausible that normal-pressure hydrocephalus may result from a number of different insults to the brain.

Aged↗

PubMedDate not supplied

The "notch" sign: meniscal contour deformities as indicators of tear in MR imaging of the knee.

Conventional magnetic resonance (MR) criteria for meniscal tearing emphasize intrameniscal signal and its communication with the articular surface. In this retrospective study, the value of a focal contour deformity of the meniscal articular surface, termed a "notch," as an additional MR sign of meniscal tearing was assessed. One hundred fifty-four menisci were evaluated. Twenty-three of 24 notches correlated with the site of tear at arthroscopy. Seven notches improved the reading confidence from possible to definite tear; in eight notches, the diagnosis of tear would otherwise not have been considered. Five tears occurred without intrameniscal signal, four following recent trauma. The notch sign improved the sensitivity from 79.8 to 87.8%. Notches are useful additional signs of meniscal tearing, increasing the confidence of a reading when occurring near grade 1 or 2 meniscal signal, and are the only MR sign present in some tears.

False Negative Reactions↗