PubMed Health⌕ Search

Biomedical subjects

M J Tuite

Publications and source records attributed to M J Tuite.

At least 19 recordsLinked to original sources
PubMed2001

Angled oblique sagittal MR imaging of rotator cuff tears: comparison with standard oblique sagittal images.

OBJECTIVE: To compare the accuracy for diagnosing rotator cuff tears of oblique coronal images supplemented with standard oblique sagittal images versus thinner-section angled oblique sagittal images. DESIGN AND PATIENTS: The study included 75 consecutive patients who had a shoulder MR scan followed by arthroscopy. MR images included oblique coronal, oblique sagittal (4 mm thick, 1 mm interslice gap), and angled oblique sagittal (3 mm/0.2 mm) images perpendicular to the lateral cuff. A musculoskeletal staff radiologist and fellow separately evaluated the cuff for tears on the oblique coronal images supplemented with either the oblique sagittal or the angled sagittal images. RESULTS: For distinguishing a cuff tear from no tear, the staff radiologist had an accuracy of 0.76 (95% confidence interval: 0.67, 0.85) with the standard sagittal set, and 0.88 (0.80, 0.95) with the angled set (P=0.04). There was a nonsignificant improvement in accuracy for the fellow, calculated as 0.73 (0.63, 0.83) on the standard sagittal set and 0.76 (0.67, 0.85) on the angled set. Both readers also improved their diagnostic accuracy for partial-thickness tears with the angled set, although the improvement was statistically significant only for the staff radiologist. CONCLUSION: There is a slight improvement in accuracy for diagnosing rotator cuff tears, particularly partial-thickness tears, for the more experienced radiologist using thinner-section angled oblique sagittal images. These images may be useful as a supplemental sequence in patients where it is important to identify partial-thickness tears accurately.

Adult↗
PubMed2000

Superior labrum anterior-posterior (SLAP) tears: evaluation of three MR signs on T2-weighted images.

PURPOSE: To compare the sensitivity and specificity of three magnetic resonance (MR) imaging signs for the diagnosis of superior labrum anterior-posterior (SLAP) tears. MATERIALS AND METHODS: The study involved 23 consecutive patients with a type 2, 3, or 4 SLAP tear at arthroscopy and 31 age-matched control patients with an arthroscopically normal or type 1 SLAP lesion. The superior labrum was evaluated on MR images for high signal intensity extending to the articular surface in the posterior third of the labrum, an irregular or laterally curved area of high signal intensity, or two high-signal-intensity lines. RESULTS: The sensitivity, specificity, and accuracy of posterior high signal intensity for a type 2, 3, or 4 SLAP tear were 48%, 94%, and 74%, respectively, for observer 1 and 61%, 81%, and 72%, respectively, for observer 2. For laterally curved area of high signal intensity, these values were 65%, 84%, and 76%, respectively, and 56%, 84%, and 72%, respectively. For two high-signal-intensity lines, these values were 17%, 94%, and 61%, respectively, and 13%, 94%, and 59%, respectively. For the presence of either posterior or laterally curved high signal intensity, the sensitivity was 65% for both observers, whereas the specificity was 84% for observer 1 and 74% for observer 2. The kappa values for interobserver agreement were 0.60 for posterior high signal intensity and 0.58 for laterally curved high signal intensity. CONCLUSION: Laterally curved and posterior high signal intensities are specific signs for distinguishing a SLAP tear from a normal-variant superior sublabral recess.

Adolescent↗
PubMed2000

"Dem bones": osteochondral injuries of the knee.

MR imaging plays a valuable role in the diagnosis and staging of osteochondral injuries of the femorotibial joint. Bone contusions may be the source of a patient's pain, and MR imaging characteristics of certain types may help to predict which contusions might progress to more serious osteochondral lesions. MR imaging also is vital in the diagnosis of occult osteochondral fractures and in accurately classifying displaced intra-articular fractures. Although osteochondral dissecans usually is diagnosed radiographically, MR imaging is the best noninvasive test for determining if an osteochondral fragment is unstable. Unstable lesions are a treatable cause of knee pain.

Fractures, Spontaneous↗
PubMed1999

Fat-suppressed fast spin-echo mid-TE (TE[effective]=34) MR images: comparison with fast spin-echo T2-weighted images for the diagnosis of tears and anatomic variants of the glenoid labrum.

OBJECTIVE: To compare the sensitivity, specificity, and accuracy of fat-suppressed fast spin-echo (FSE) mid-TE (TE[effective]=34) images with fat-suppressed FSE T2-weighted images for the diagnosis of labral abnormalities. DESIGN AND PATIENTS: The study included 27 consecutive patients who had axial fat-suppressed FSE T2-weighted and fat-suppressed FSE mid-TE MR images, and had labral abnormalities diagnosed at arthroscopy. The acquisition time was about 5 min for each sequence, but the mid-TE sequence allowed a higher spatial resolution than the T2-weighted images (256x256 versus 256x192). Twenty-eight age-matched patients with arthroscopically normal labra were included as a control group. The labrum was graded on the MR images as normal or abnormal separately by two musculoskeletal radiologists who were masked to the history and arthroscopic results. The surgical findings were used as the gold standard for calculating the sensitivity, specificity, and accuracy for interpreting the correct location of a labral abnormality. The sensitivity, specificity, and accuracy for the two sequences were compared with a McNemar test, and significance defined as P<0.05. RESULTS: For observer 1, the sensitivity for labral abnormalities was 0.59 on the T2-weighted images, and 0.78 on the mid-TE images (P=0.12). The specificity was 0.54 for the T2-weighted, and 0.64 for the mid-TE images (P=0.51). The accuracy was 0.56 for the T2-weighted, and 0.71 for the mid- TE images (P=0.08). For observer 2, the sensitivity/specificity/accuracy was 0.67/0.93/0.80 for the T2-weighted, and 0.70/0.86/0.78 for the mid-TE images (all P>0.5). CONCLUSION: In this small study there is no statistically significant difference for demonstrating labral abnormalities between FSE T2-weighted images, and higher-resolution fat-suppressed FSE mid-TE (TE[effective]=34) images obtained with a similar acquisition time. Although there was a general trend toward higher sensitivity and accuracy with the mid-TE sequence, particularly for one of the two observers, a larger study is needed to determine whether this is the preferred single axial pulse sequence for conventional MR imaging of the labrum.

Adolescent↗
PubMed1998

Anterior versus posterior, and rim-rent rotator cuff tears: prevalence and MR sensitivity.

PURPOSE: To determine the relative distribution of the locations of rotator cuff tears, and the sensitivity of anterior versus posterior tears on MR images. PATIENTS AND METHODS: We identified 110 consecutive patients who had a shoulder MR and either a partial-thickness or a small full-thickness rotator cuff tear diagnosed at arthroscopy. From the arthroscopy videotapes, we classified the tears as centered in the anterior or posterior half of the cuff, and as either in the critical zone or adjacent to the bony insertion. The original MR interpretation was compared with the arthroscopic findings. MR sensitivity and patient age were compared between patients with tears in the anterior and posterior halves of the cuff. In addition, in patients with partial tears less than 2 cm in diameter, an age comparison between those with tears in the critical zone and those with articular surface tears adjacent to the bony insertion (rim-rent tear) was performed. RESULTS: The tear was centered in the anterior half of the rotator cuff in 79% of the patients younger than 36 years old, and in 89% of the patients 36 years old and over. The average age of the patients with tears in the anterior half (44 years) was not significantly different from the average age of those with posterior tears (40 years) (P = 0.23). The sensitivity of MR for anterior tears was 0.69, and for posterior tears it was 0.56 (P = 0.17). The average age of the 9 patients with rim-rent tears was 31 years, while that of the 28 patients with similarly-sized partial tears not involving the insertion was 40 years old (P = 0.048). Five of the nine rim-rent tears (0.56) were interpreted correctly on the original MR report; two of the other tears were misinterpreted as intratendinous fluid but were diagnosable in retrospect. CONCLUSION: Even in patients less than 36 years old, most partial and small full-thickness rotator cuff tears are centered in the anterior half of the supraspinatus. Although our figure for MR sensitivity for these tears is lower than in recent articles, we found no significant difference between the sensitivity of MR for diagnosing posterior tears versus tears in the anterior half of the supraspinatus tendon. Rim-rent tears can be mistaken for intratendinous signal, and should be carefully looked for in younger patients with shoulder pain.

Adolescent↗
PubMed1997

Anteroinferior tears of the glenoid labrum: fat-suppressed fast spin-echo T2 versus gradient-recalled echo MR images.

OBJECTIVE: To compare fat-suppressed fast spin-echo (FSE) T2-weighted images with gradient-recalled echo (GRE) T2*-weighted images in the evaluation of anteroinferior labral tears. DESIGN: MR images were retrospectively reviewed by two radiologists masked to the history and arthroscopic findings. They separately interpreted the anteroinferior labrum as torn or intact, first on one pulse sequence and then, 4 weeks later, on the other sequence. The MR interpretations were correlated with the arthroscopic findings. PATIENTS: Nine patients with anteroinferior labral tears, and nine similarly-aged patients with normal, labra were studied. RESULTS AND CONCLUSIONS: Observer 1 had a sensitivity of 0.56 on the GRE images and 0.67 on the FSE images (P > 0.5), with a specificity of 1.0 for both sequences. Observer 2 had a sensitivity of 0.78 and a specificity of 0.89 for both sequences. In this small study there is no significant difference between GRE and fat-suppressed FSE images in their ability to diagnose anteroinferior labral tears. When evaluating the labrum with conventional MRI, axial fat-suppressed FSE T2-weighted images can be used in place of GRE images without a loss of accuracy.

Adolescent↗
PubMed1997

CNS lymphoma in an AIDS patient involving the posterior fornix case report.

We report an unusual presentation of CNS lymphoma involving the posterior fornix in a patient with AIDS. The patient's initial symptoms included progressive cognitive impairment, consistent with AIDS dementia, as well as impotence and urinary retention suggestive of myelopathy. An MR scan with gadolinium-DTPA enhancement demonstrated enhancing lesions in the cerebellum and in the posterior fornix. At autopsy, the later lesions proved to be lymphoma. This case demonstrates the unusual clinical features that may occur with lesions in the limbic system and importance of gadolinium-enhanced MRI in the evaluation of symptoms of cognitive impairment in patients with advanced HIV infection.

Acquired Immunodeficiency Syndrome↗
PubMed1996

Evaluation of post-exercise magnetic resonance images of the rotator cuff.

OBJECTIVE: To examine the effect of strenuous exercise on the magnetic resonance imaging (MRI) characteristics of the rotator cuff tendon. A second objective was to define an optimal time to image the rotator cuff and possibly eliminate exercise-induced false positives. DESIGN AND PATIENTS: Five male subjects from 24 to 38 years old with normal rotator cuffs by history, physical examination, and screening MRI underwent a rotator cuff exercise session on the Biodex System 2 (Biodex, Shirley, New York). The exercise sessions were followed by sequential MRI scans of the exercised shoulder. These were performed immediately and at 8 h and 24 h after exercise. RESULTS AND CONCLUSIONS: The rotator cuff tendon and subacromial-subdeltoid bursal signal remained unchanged from the pre-exercise through the 24-h post-exercise scans. The rotator cuff muscle signal was increased in five of five subjects on the immediate post-exercise fat-suppressed T2-weighted images. This signal returned to baseline by the 8-h scan. Positive findings of rotator cuff pathology on MRI after strenuous athletic activity should not be discounted as normal exercise-induced changes. Also, diagnostic MRI scanning may take place after a practice session without an increased risk of false positives.

Adult↗
PubMed1996

Anterosuperior labral variants of the shoulder: appearance on gradient-recalled-echo and fast spin-echo MR images.

PURPOSE: To characterize the magnetic resonance (MR) imaging appearance of two anterosuperior labral variants, the sublabral foramen (SLF) and the Buford complex. MATERIALS AND METHODS: The axial gradient-recalled-echo (GRE) MR images and the fat-suppressed, T2-weighted, fast spin-echo (SE) images were reviewed in 19 patients with arthroscopically proved SLF and 11 patients with a Buford complex. The anterosuperior labrum was graded as normal, detached, or absent on the images. RESULTS: For the patients with an SLF, the anterosuperior labrum was graded as detached in all patients who underwent fast SE imaging but in only 43% of patients who underwent GRE imaging. For the patients with a Buford complex, the anterosuperior labrum was graded as absent in only 30% of patients who underwent GRE imaging and in none of the patients who underwent fast SE imaging. CONCLUSION: Isolated MR abnormalities of the anterosuperior labrum may represent either of the two asymptomatic labral variants.

Adult↗
PubMed1996

Imaging barium-free bone cement.

Prior to 1972, polymethylmethacrylate, or PMMA, did not contain barium sulfate and was, therefore, radiolucent. We describe a technique using magnetic resonance imaging that is very useful in imaging barium-free PMMA.

Barium Sulfate↗
PubMed1996

MR of the postoperative knee.

There have been multiple recent refinements in the arthroscopic techniques of meniscal surgery and anterior cruciate ligament (ACL) reconstruction, and these are now allowing many postoperative patients to resume an active lifestyle. A result is an increasing number of postoperative patients who are referred for a magnetic resonance (MR) scan of the knee because of a recurrent injury. In this article, we will discuss some of the MR findings of retorn menisci and the role of MR arthrography. We will also review the changes that occur in the MR appearance of the ACL graft during the first year after surgery, and its effect on the accuracy of diagnosing graft tears. The MR findings after other less common knee procedures will also be described.

Anterior Cruciate Ligament↗
PubMed1995

Plain film evaluation of bone grafting for nonunited scaphoid fractures.

OBJECTIVE: To determine how the appearance of fracture line bridging and graft incorporation changed on sequential plain films obtained during the healing of successful grafts for scaphoid nonunion. DESIGN: We identified 50 patients who had healed Russe bone grafts for nonunited scaphoid fractures. These patients had 214 sets of wrist radiographs obtained 1-36 months after surgery. Each set of radiographs was reviewed in random order by two observers who were blinded as to the patient's name and the time interval since surgery. Closure of the fracture line and the presence of a linear lucency in each of six zones surrounding the graft were assessed using a three-point grading scale. PATIENTS: Forty-six men and four women were included in the study. Their mean age was 30 years with a range from 21-43 years. RESULTS AND CONCLUSIONS: With increasing time after surgery, there was progressive fracture line closing and disappearance of linear lucencies at the interfaces between the scaphoid and the graft. However, a 20% of the patients had a well-defined lucency in at least one of the six zones around the graft on their last film. Even 1 year after surgery, the fracture line showed no bridging on the radial side in 22% of patients and on the ulnar side in 11%. We conclude that after grafting, most scaphoid nonunions show progressive fracture line closure and graft incorporation. However, the fracture line may not completely close and lucencies may persist in several zones around the graft for more than 1 year. These radiographic appearances should be recognized as part of the normal spectrum of healing.

Adult↗
PubMed1995

Effect of field of view on MR diagnosis of rotator cuff tears.

PURPOSE: To determine the effect of decreasing the field of view (FOV) on the accuracy of MR for diagnosing rotator cuff tears. MATERIAL AND METHODS: One hundred shoulder MR scans with surgical correlation were evaluated for the presence or absence of a cuff tear. The sensitivity and specificity of MR relative to the surgical results were determined for the 59 patients scanned with a 24-cm FOV, and the 41 patients scanned with an 18-cm FOV. All other imaging parameters including acquisition time were identical. The sensitivity and specificity of the two groups were compared using a t-test. RESULTS: The specificity of MR for diagnosing a rotator cuff tear improved from 0.65 for the 24-cm FOV group to 0.89 for the 18-cm FOV group (P = 0.04). The sensitivity changed from 0.91 to 0.96 (P = 0.25). CONCLUSION: Reducing the FOV from 24 cm to 18 cm results in a statistically significant improvement in specificity of MR for diagnosing rotator cuff tears.

Adult↗
PubMed1995

MR imaging of a meniscal ossicle.

We report the MR appearance of a meniscal ossicle, which is an unusual etiology for knee pain. The role of MR in differentiating a meniscal ossicle from a loose body is presented. The MR images also demonstrated associated tibial cartilage thinning and a possible meniscal tear. These MR findings led to arthroscopic treatment rather than conservative management. A review of the literature on meniscal ossicles is also presented.

Adult↗
PubMed1995

MR diagnosis of labral tears of the shoulder: value of T2*-weighted gradient-recalled echo images made in external rotation.

OBJECTIVE: Because several studies have shown that conventional MR imaging can fail to diagnose a significant percentage of labral tears, some authors have proposed obtaining T2*-weighted gradient-recalled echo images with the humerus in external rotation. The purpose of our study was to determine whether the diagnostic accuracy of detecting anteroinferior labral tears by MR imaging would be improved by adding a T2*-weighted gradient-recalled echo sequence with the humerus in external rotation. MATERIALS AND METHODS: The study included 24 patients for whom axial MR images of the shoulder were obtained with the humerus in both the neutral position and external rotation. Two observers interpreted the images made in the neutral position and then noted any change in their interpretations after viewing findings on the external-rotation images. MR results were correlated with surgical findings. At surgery, 14 anteroinferior labra were found to be torn and 10 were found to be intact. RESULTS: Both observers identified one patient for whom a surgically proved labral tear was seen only on the external-rotation images. The sensitivity increased from 0.43 to 0.50 (p = .35) for observer 1 and from 0.36 to 0.43 (p = .35) for observer 2. The specificity of 0.90 for both observers remained unchanged. The accuracy improved from 0.62 to 0.67 for observer 1 and from 0.55 to 0.62 for observer 2. CONCLUSION: The addition of external-rotation T2*-weighted gradient-recalled echo images to the MR examination for tears of the anteroinferior labrum leads to a small but statistically insignificant increase in diagnostic sensitivity. We conclude that the small increase in sensitivity does not justify the routine use of this sequence.

Adolescent↗
PubMed1995

Acromial angle on radiographs of the shoulder: correlation with the impingement syndrome and rotator cuff tears.

OBJECTIVE: This study was undertaken to determine the reproducibility of measurements of an acromial angle on radiographs and to correlate those measurements with the presence of the impingement syndrome and rotator cuff tears. MATERIALS AND METHODS: Ninety-nine shoulders in 95 patients who had an arch radiograph and had undergone shoulder arthroscopy were included in this retrospective study. The acromial angle was measured on the arch view of the shoulder independently by three observers who were blinded to the name, history, and arthroscopic results. The angle was measured at the intersection of lines drawn along the inferior cortex of the anterior and posterior portions of the acromion. Interobserver variability was determined by the intercorrelation coefficient (a test of reproducibility of quantitative measurements). The average of the three measurements for each patient was correlated with the preoperative diagnosis and the arthroscopic findings. RESULTS: A correlation was found between increasing severity of cuff disease as determined on arthroscopy and increasing acromial angle (p < .01). In 67 patients (70 shoulders) with impingement, patients with a full-thickness tear (29%) accounted for 43% of those with an angle of 30 degrees or greater. The average acromial angle for patients with impingement was greater than that for either patients with instability or patients with trauma (p < .05 for both). An angle of 25 degrees or greater was measured in 63% of patients with impingement but in only 18% of those with instability. The average acromial angle in patients with impingement and an intact rotator cuff was also greater than the average angle in patients with instability (p = .001). The interobserver variability had an intercorrelation coefficient of 0.90. CONCLUSION: The acromial angle is an objective and fairly reproducible measure of anterior acromial shape. The angle is useful in identifying patients with a greater likelihood of having a rotator cuff tear and in distinguishing patients with primary impingement from those with instability.

Acromion↗
PubMed1994

Diagnosis of partial and complete rotator cuff tears using combined gradient echo and spin echo imaging.

Most magnetic resonance (MR) studies evaluating the rotator cuff for tears have used T2-weighted imaging in the coronal oblique and sagittal oblique planes. T2*-weighted gradient echo imaging, however, has advantages over spin echo imaging, including contiguous slices without cross-talk, high contrast around the cuff, and intrinsically shorter imaging times which can be used to increase the number of signals averaged and thus improve the signal-to-noise ratio. We reviewed the shoulder MR scans of 87 consecutive patients who underwent both a MR scan and a shoulder arthroscopy during which the size of tears, if present, was graded. The reviewers were blinded as to the history and arthroscopic results. The MR scans included oblique coronal T2*-weighted gradient echo and oblique sagittal T2-weighted spin echo images. MR cuff grades were correlated with arthroscopic findings. For complete tears, the sensitivity of MR was 0.91 and the specificity 0.95. For partial tears, the sensitivity was 0.74 and the specificity 0.87. This accuracy is similar to two-plane T2-weighted imaging as previously reported in the literature. There was a statistically significant correlation (p < 0.0005) between the cuff grade as determined by MR and the arthroscopic findings.

Adult↗