Interposition of the Posterior Cruciate Ligament into the Medial Compartment of the Knee Joint on Coronal Magnetic Resonance Imaging

Objective

The purpose of our study was to evaluate the overall prevalence and clinical significance of interposition of the posterior cruciate ligament (PCL) into the medial compartment of the knee joint in coronal magnetic resonance imaging (MRI).

Materials and Methods

We retrospectively reviewed 317 consecutive patients referred for knee MRI at our institution between October 2009 and December 2009. Interposition of the PCL into the medial compartment of the knee joint on proton coronal MRI was evaluated dichotomously (i.e., present or absent). We analyzed the interposition according to its prevalence as well as its relationship with right-left sidedness, gender, age, and disease categories (osteoarthritis, anterior cruciate ligament tear, and medial meniscus tear).

Results

Prevalence of interposition of PCL into the medial compartment of the knee joint was 47.0% (149/317). There was no right (50.0%, 83/166) to left (43.7%, 66/151) or male (50.3%, 87/173) to female (43.1%, 62/144) differences in the prevalence. There was no significant association between the prevalence and age, or the disease categories.

Conclusion

Interposition of the PCL into the medial compartment of the knee joint is observed in almost half of patients on proton coronal MRI of the knee. Its presence is not associated with any particular factors including knee pathology and may be regarded as a normal MR finding.     

Anterior Cruciate Ligament Tear: Reliability of MR Imaging to Predict Stability after Conservative Treatment

Objective

The aim of this study is to evaluate the reliability of MR imaging to predict the stability of the torn anterior cruciate ligament (ACL) after complete recovery of the ligament''s continuity.

Materials and Methods

Twenty patients with 20 knee injuries (13 males and 7 females; age range, 20-54) were enrolled in the study. The inclusion criteria were a positive history of acute trauma, diagnosis of the ACL tear by both the physical examination and the MR imaging at the initial presentation, conservative treatment, complete recovery of the continuity of the ligament on the follow up (FU) MR images and availability of the KT-2000 measurements. Two radiologists, who worked in consensus, graded the MR findings with using a 3-point system for the signal intensity, sharpness, straightness and the thickness of the healed ligament. The insufficiency of ACL was categorized into three groups according to the KT-2000 measurements. The statistic correlations between the grades of the MR findings and the degrees of ACL insufficiency were analyzed using the Cochran-Mantel-Haenszel test (p < 0.05).

Results

The p-values for each category of the MR findings according to the different groups of the KT-2000 measurements were 0.9180 for the MR signal intensity, 1.0000 for sharpness, 0.5038 for straightness and 0.2950 for thickness of the ACL. The MR findings were not significantly different between the different KT-2000 groups.

Conclusion

MR imaging itself is not a reliable examination to predict stability of the ACL rupture outcome, even when the MR images show an intact appearance of the ACL.     

Correlation of Histological Examination of Meniscus with MR Images: Focused on High Signal Intensity of the Meniscus Not Caused by Definite Meniscal Tear and Impact on MR Diagnosis of Tears

Objective

To document the causes of high signal intensity of the meniscus which is not caused by definite meniscal tears on MR imaging, through correlation with histological examination.

Materials and Methods

For the correlation between the MR image and histology, we obtained prospectively 31 meniscal specimens from 21 patients. Proton density-weighted turbo spin-echo MR images were used. Minimal tear, thinning of the lamellar layer, degeneration of the central layer, and radial tie fibers were detected upon histological examination, and were correlated with the corresponding MR images.

Results

Minimal tear of the lamellar layer was seen in 60 zones out of 100 slides. On MR images, 29 (48.3%) of these 60 zones had high signal intensity. Thinning of the lamellar layer was seen in 24 zones, with 7 (29.2%) having high signal intensity. 57 central zones showed degenerative change in the central layer and high signal intensity on all corresponding MR images. Radial tie fibers in the central layer appeared as high signal intensity areas.

Conclusion

Minimal tear and thinning of the lamellar layer, degeneration and radial tie fibers of the central layer of the meniscus cause high signal intensity on MR images.     

Optimization of the Contrast Mixture Ratio for Simultaneous Direct MR and CT Arthrography: an in Vitro Study

Objective

This study was designed to determine the optimal mixture ratio of gadolinium and iodinated contrast agent for simultaneous direct MR arthrography and CT arthrography.

Materials and Methods

An in vitro study was performed utilizing mixtures of gadolinium at six different concentrations (0.625, 1.25, 2.5, 5.0, 10 and 20 mmol/L) and iodinated contrast agent at seven different concentrations (0, 12.5, 25, 37.5, 50, 75 and 92-99.9%). These mixtures were placed in tissue culture plates, and were then imaged with CT and MR (with T1-weighted sequences, proton-density sequences and T2-weighted sequences). CT numbers and signal intensities were measured. Pearson''s correlation coefficients were used to assess the correlations between the gadolinium/iodinated contrast agent mixtures and the CT numbers/MR signal intensities. Scatter diagrams were plotted for all gadolinium/iodinated contrast agent combinations and two radiologists in consensus identified the mixtures that yielded the optimal CT numbers and MR signal intensities.

Results

The CT numbers showed significant correlation with iodinated contrast concentrations (r = 0.976, p < 0.001), whereas the signal intensities as measured on MR images showed a significant correlation with both gadolinium and iodinated contrast agent concentrations (r = -484 to -0.719, p < 0.001). A review of the CT and MR images, graphs, and scatter diagram of 42 combinations of the contrast agent showed that a concentration of 1.25 mmol/L gadolinium and 25% iodinated contrast agent was the best combination for simultaneous CT and MR imaging.

Conclusion

A mixture of 1.25 mmol/L gadolinium and 25% iodinated contrast agent was found to be optimal for simultaneous direct MR arthrography and CT arthrography.     

0.2-Tesla magnetic resonance imaging of internal lesions of the knee joint: a prospective arthroscopically controlled clinical study

The results of magnetic resonance imaging (MRI) were compared with those of arthroscopy in a prospective series of 244 patients. A dedicated system for MRI of limbs and peripheral joints – the 0,2-T Artoscan (Esaote, Italy) – was used for imaging knee joint lesions. T1-weighted spin-echo sagittal images, T2-weighted gradient-echo coronal images, and axial views for lesions of the femoropatellar joint were acquired. Paraxial sagittal and oblique coronal views were obtained for imaging of the cruciate ligaments. This protocol allowed excellent visualization of the cruciate ligaments and medial and lateral meniscus in almost all patients. Compared with arthroscopy performed within 48 h after imaging, the sensitivity, specificity, and accuracy were respectively 93%, 97%, and 95% for tears of the medial meniscus; 82%, 96%, and 93% for tears of the lateral meniscus; 100%, 100%, and 100% for tears of the posterior cruciate ligament; 98%, 98%, and 97% for tears of the anterior cruciate ligament; and 72%, 100%, and 92% for full-thickness articular cartilage lesions. The examination can be performed within 30–45 min at lower cost than diagnostic arthroscopy. MRI with a 0.2-T magnet is a safe and valuable adjunct to the clinical examination of the knee and an aid to efficient preoperative planning. Received: 13 October 1997 Accepted: 3 March 1998     

Comparison of 3.0-T MR vs 3.0-T MR arthrography of the hip for detection of acetabular labral tears and chondral defects in the same patient population

Objective:

We report our experience in diagnostic sensitivity of 3.0-T conventional MR vs 3.0-T MR arthrography of the hip for detection of acetabular labral tears and chondral defects in the same patient population.

Methods:

43 consecutive patients had both conventional hip MR and MR arthrography examinations performed. These examinations were reviewed retrospectively by independent reading of two musculoskeletal radiologists who read the MR and MR arthrogram examinations in a randomized fashion (i.e. MR and MR arthrogram examinations were read at separate sittings and in a randomized fashion so as not to bias reviewers). Scans were assessed for acetabular labral tears and chondral defects. All patients went on to arthroscopy.

Results:

Of these 43 patients, 40 had acetabular labral tears read by Reader 1 and 39 had acetabular labral tears read by Reader 2 on MR arthrogram, 39 had acetabular labral tears read by Reader 1 and 38 had acetabular labral tears read by Reader 2 on conventional MR examination. There were 42 labral tears in 43 patients at arthroscopy. There were four false-negative labral tears compared with arthroscopy on MR and three false negatives on MR arthrography for Reader 1 and five false negatives on MR and four false negatives on MR arthrography for Reader 2. Each reader had one false-positive labral tear compared with arthroscopy on both MR and MR arthrography. There were 32 acetabular chondral defects at arthroscopy. Reader 1 saw 21 acetabular chondral defects on conventional MR and 27 chondral defects at MR arthrography. Reader 2 saw 19 acetabular chondral defects at conventional MR and 25 acetabular chondral defects on MR arthrography. There were no false-positive readings of chondral defects compared with arthroscopy on MR and one false positive for Reader 1 and two false positives for Reader 2 on MR arthrography as compared with arthroscopy. On conventional MR examination, sensitivities and specificities as compared with arthroscopy were as follows: Reader 1 acetabular labral tear (90% sensitivity, 0% specificity) and Reader 2 acetabular labral tear (88% sensitivity, 0% sensitivity). On MR arthrogram, sensitivities and specificities as compared with arthroscopy for Reader 1 were 93%, 0% and for Reader 2 were 90%, 0%, respectively. Sensitivities and specificities for detection of acetabular chondral defects as compared with arthroscopy were Reader 1 conventional MR (65% sensitivity, 100% specificity), Reader 1 MR arthrography (81% sensitivity, 91% specificity), Reader 2 conventional MR (59% sensitivity, 100% specificity) and Reader 2 MR arthrography (71% sensitivity, 82% specificity).

Conclusion:

In this series, 3.0-T MR demonstrated sensitivity for detection of acetabular labral tears that rivals the sensitivity of 3.0-T MR arthrography of the hip. In this series, 3.0-T MR arthrography was more sensitive than conventional 3.0-T MR for detection of acetabular chondral defects.

Advances in knowledge:

3.0-T MR and MR arthrography are near equivalent in the diagnosis of acetabular labral tears. This information is useful for pre-operative planning.MR arthrography has been reported to be more sensitive and specific for detection of acetabular labral tears in the hip than conventional MRI.^1–10 MR arthrography has also been reported to be superior in detection of acetabular cartilage defects as compared with conventional MRI.¹¹ To our knowledge 3.0-T MR vs 3.0-T MR arthrography sensitivity for detection of acetabular labral tears and chondral defects has not been specifically assessed.To our knowledge, Petersilge et al¹ first reported the utility of hip MR arthrography in the diagnosis of acetabular labral tears. Toomayan et al² compared MR arthrography of the hip with conventional MRI of the hip in different patient populations. He found MR arthrography with a small field of view to be substantially more sensitive for detection of acetabular labral tears than conventional MRI. Sutter et al¹¹ found 1.5 T MR arthrography to be superior to conventional MRI for detecting labral tears and acetabular cartilage defects.Patients with acetabular labral tears present with symptoms of persistent pain, clicking, locking and decreased range of motion. With the availability of hip arthroscopy, labral tears can more easily be addressed with minimally invasive surgery. Accurate pre-operative identification of labral tears is needed.² Based on previous studies demonstrating the accuracy of MR arthrography in detection of acetabular labral tears, surgeons often request MR arthrography of the hip to characterize labral tears prior to surgery.^1–10 The purpose of this study is to assess 3.0-T MR vs MR arthrography diagnostic performance in detection of acetabular labral tears and chondral defects in the same patient population using arthroscopy as a reference standard.     

Grading Anterior Cruciate Ligament Graft Injury after Ligament Reconstruction Surgery: Diagnostic Efficacy of Oblique Coronal MR Imaging of the Knee

Objective

The purpose of this study was to evaluate the diagnostic efficacy of using additional oblique coronal MRI of the knee for grading anterior cruciate ligament (ACL) graft injury after ligament reconstruction surgery.

Materials and Methods

We retrospectively reviewed 51 consecutive MR knee examinations of 48 patients who underwent both ACL reconstruction and follow-up arthroscopy. The MR examinations included the orthogonal axial, sagittal, coronal images and the oblique coronal T2-weighted images, which were oriented in parallel with the course of the femoral intercondylar roof. Two radiologists independently evaluated the status of the ACL grafts with using the routine knee MRI and then with adding the oblique coronal imaging. The severity of ACL graft injury was graded using a 3-point system from MR images as intact, partial tear or complete tear, and the results were compared with the arthroscopic results. Weighted kappa statistics were used to analyze the diagnostic accuracies of the knee MRI with and without the additional oblique coronal imaging. For each evaluation, the observers reported a confidence level for grading the ACL graft injuries in the two imaging groups.

Results

The weighted kappa values according to the routine knee MRI were 0.555 (reader 1) and 0.515 (reader 2). The inclusion of additional oblique coronal imaging increased the weighted kappa values to 0.666 (reader 1) and 0.611 (reader 2). The mean confidence levels by each reader were significantly higher (p < 0.01, paired t-test) with the additional oblique coronal imaging than by using the routine knee MRI alone.

Conclusion

The additional use of oblique coronal MRI of the knee improves both the diagnostic accuracy and confidence for grading ACL graft injury.     

Thin-Section CT Findings of Arc-Welders' Pneumoconiosis

Objective

To describe the thin-section CT findings of arc-welders'' pneumoconiosis.

Materials and Methods

Eighty-five arc-welders with a three to 30 (mean, 15)-year history of exposure underwent thin-section CT scanning. The extent of abnormalities detected was correlated with the severity of dyspnea and pulmonary function tests. For comparison, images of 43 smoking males (mean 25 pack-year) who underwent thin-section CT for other reasons (smokers'' group) were also analyzed.

Results

Fifty-four welders (63.5%) and six smokers (14.0%) showed positive findings. Predominant thin-section CT findings were poorly-defined centrilobular micronodules (30/54, 55.6%), branching linear structure (18/54, 33.3%), and ground-glass attenuation (6/54, 11.1%). In the smokers'' group, poorly-defined micronodules were found in four patients, branching linear structures in one, and ground-glass attenuation in one. In welders, the extent of abnormalities seen on thin-section CT showed no significant correlation with the severity of dyspnea or the results of pulmonary funotion test.

Conclusion

Poorly-defined centrilobular micronodules and branching linear structures were the thin-section CT findings most frequently seen in patients with arc-welders'' pneumoconiosis. Less commonly, extensive ground-glass attenuation was also seen.     

Cherubism: panoramic and CT features in adults

Objectives:

To describe the panoramic radiographic and CT features of cherubism in an unselected series of 15 adults.

Methods:

In this cross-sectional study, 15 individuals aged 29–84 years with familial non-syndromal molecularly confirmed cherubism were examined with panoramic radiography and CT. Bone abnormalities were analysed and described.

Results:

11 (73%) of the 15 adults had mandibular abnormalities. These abnormalities ranged from subtly detectable to severe, and were less prevalent and expansive but could be rather similar to the characteristic image features in children. Unilocular radiolucencies were more common than multilocular radiolucencies, and a specific feature of these abnormalities was that they were exclusively found in the anterior mandible.

Conclusions:

The radiographic and CT abnormalities of cherubism in adults were frequent and extremely heterogeneous, with some distinct features.     

Comparison between Conventional MR Arthrograhphy and Abduction and External Rotation MR Arthrography in Revealing Tears of the Antero-Inferior Glenoid Labrum

Objective

To compare, in terms of their demonstration of tears of the anterior glenoid labrum, oblique axial MR arthrography obtained with the patient''s shoulder in the abduction and external rotation (ABER) position, with conventional axial MR arthrography obtained with the patient''s arm in the neutral position.

Materials and Methods

MR arthrography of the shoulder, including additional oblique axial sequences with the patient in the ABER position, was performed in 30 patients with a clinical history of recurrent anterior shoulder dislocation. The degree of anterior glenoid labral tear or defect was evaluated in both the conventional axial and the ABER position by two radiologists. Decisions were reached by consensus, and a three-point scale was used: grade 1=normal; grade 2=probable tear, diagnosed when subtle increased signal intensity in the labrum was apparent; grade 3=definite tear/defect, when a contrast material-filled gap between the labrum and the glenoid rim or deficient labrum was present. The scores for each imaging sequence were averaged and to compare conventional axial and ABER position scans, Student''s t test was performed.

Results

In 21 (70%) of 30 patients, the same degree of anterior instability was revealed by both imaging sequences. Eight (27%) had a lower grade in the axial position than in the ABER position, while one (3%) had a higher grade in the axial position. Three whose axial scan was grade 1 showed only equivocal evidence of tearing, but their ABER-position scan, in which a contrast material-filled gap between the labrum and the glenoid rim was present, was grade 3. The average grade was 2.5 (SD=0.73) for axial scans and 2.8 (SD=0.46) for the ABER position. The difference between axial and ABER-position scans was statistically significant (p<0.05).

Conclusion

MR arthrography with the patient''s shoulder in the ABER position is more efficient than conventional axial scanning in revealing the degree of tear or defect of the anterior glenoid labrum. When equivocal features are seen at conventional axial MR arthrography, oblique axial imaging in the ABER position is helpful.     

MR- arthrography: anatomic variant from link between lateral meniscus and anterior and posterior cruciate ligaments. A case report and review of the literature

Menisci congenital anomalies are rare morphologic abnormalities including accessory meniscus, discoid meniscus, double-layered meniscus, hypoplastic meniscus and ring-shaped meniscus (RSM). In a 35 year-old male patient, MR arthrography showed a bridging accessory bundle connecting the anterior cruciate ligament and posterior cruciate ligament with the posterior horn of the lateral meniscus. Arthroscopic examination showed a fan-like obstacle embracing the posterior horn of the lateral meniscus. It would be important to correctly identify this anatomical variant, because the bundle connecting the external meniscus to the ligaments of the central pivot can be misinterpreted as a meniscal fragment.     

Mucoid degeneration of the anterior cruciate ligament: frequently under-diagnosed entity in MRI

Objective

The purpose of our study was to describe the MR appearance of mucoid degeneration of the anterior cruciate ligament and to address its clinical significance.

Patients and methods

A database search of 2000 knee MRI examinations revealed 32 examinations (Chart 1) with reported mucoid degeneration of the anterior cruciate ligament.

Results

Of 32 examinations that met imaging criteria, all patients (100%) had different degrees of mucoid degeneration. Associated ganglia were seen in eight patients; located in the proximal ligament in four examinations (12.5%) and the distal ligament in two (6%) and involved the mid-portion of the ligament in two (6%).Intra-osseous cysts were noted distally in 15 examinations (47%), proximally in four (12.5%) and on both sides in six (19%). All our patients had accessible medical records; no clinical evidence of instability was reported.Four patients who underwent arthroscopy had an intact anterior cruciate ligament at that time.

Conclusion

Anterior cruciate ligament mucoid degeneration has specific MRI features and should not be misdiagnosed as partial or total tear, and typically not associated with ligament instability.     

Detectability of Various Sizes of Honeycombing Cysts in an Inflated and Fixed Lung Specimen: the Effect of CT Section Thickness

Objective

We wanted to clarify the relationship between the visibility of air cysts on CT images, the CT slice thickness and the size of the air cysts, with contact radiographs as the gold standard, for the accurate evaluation of honeycomb cysts.

Materials and Methods

An inflated and fixed autopsied lung having idiopathic interstitial pneumonia was evaluated. The corresponding air cysts were identified on the contact radiographs of a 0.5 mm-thick-section specimen and also on the CT images of three different kinds of section thickness: 0.5, 1.0 and 2.5 mm. The maximal diameters of the air cysts were measured under a stereomicroscope.

Results

A total of 341 air cysts were identified on the contact radiograph, and they were then evaluated. Sixty-six percent of air cysts 1 to 2 mm in diameter were detected by 0.5 mm slice thickness CT, while only 34% and 8% were detected by 1.0 and 2.5 mm slice thickness CT, respectively. Only 28% and 22% of air cysts less than 1 mm in diameter were detected by 0.5 and 1.0 mm slice thickness CT, respectively. CT with a 2.5 mm slice thickness could not demonstrate air cysts less than 1 mm in diameter.

Conclusion

The CT detection rate of honeycombing is significantly influenced both by the slice thickness and the size of the air cysts.     

Deltoid Ligament and Tibiofibular Syndesmosis Injury in Chronic Lateral Ankle Instability: Magnetic Resonance Imaging Evaluation at 3T and Comparison with Arthroscopy

Objective

To evaluate the prevalence of deltoid ligament and distal tibiofibular syndesmosis injury on 3T magnetic resonance imaging (MRI) in patients with chronic lateral ankle instability (CLAI).

Materials and Methods

Fifty patients (mean age, 35 years) who had undergone preoperative 3T MRI and surgical treatment for CLAI were enrolled. The prevalence of deltoid ligament and syndesmosis injury were assessed. The complexity of lateral collateral ligament complex (LCLC) injury was correlated with prevalence of deltoid or syndesmosis injuries. The diagnostic accuracy of ankle ligament imaging at 3T MRI was analyzed using arthroscopy as a reference standard.

Results

On MRI, deltoid ligament injury was identified in 18 (36%) patients as follows: superficial ligament alone, 9 (50%); deep ligament alone 2 (11%); and both ligaments 7 (39%). Syndesmosis abnormality was found in 21 (42%) patients as follows: anterior inferior tibiofibular ligament (AITFL) alone, 19 (90%); and AITFL and interosseous ligament, 2 (10%). There was no correlation between LCLC injury complexity and the prevalence of an accompanying deltoid or syndesmosis injury on both MRI and arthroscopic findings. MRI sensitivity and specificity for detection of deltoid ligament injury were 84% and 93.5%, and those for detection of syndesmosis injury were 91% and 100%, respectively.

Conclusion

Deltoid ligament or syndesmosis injuries were common in patients undergoing surgery for CLAI, regardless of the LCLC injury complexity. 3T MRI is helpful for the detection of all types of ankle ligament injury. Therefore, careful interpretation of pre-operative MRI is essential.     

Comparison of Image Quality of Shoulder CT Arthrography Conducted Using 120 kVp and 140 kVp Protocols

Objective

To compare the image quality of shoulder CT arthrography performed using 120 kVp and 140 kVp protocols.

Materials and Methods

Fifty-four CT examinations were prospectively included. CT scans were performed on each patient at 120 kVp and 140 kVp; other scanning parameters were kept constant. Image qualities were qualitatively and quantitatively compared with respect to noise, contrast, and diagnostic acceptability. Diagnostic acceptabilities were graded using a one to five scale as follows: 1, suboptimal; 2, below average; 3, acceptable; 4, above average; and 5, superior. Radiation doses were also compared.

Results

Contrast was better at 120 kVp, but noise was greater. No significant differences were observed between the 120 kVp and 140 kVp protocols in terms of diagnostic acceptability, signal-to-noise ratio, or contrast-to-noise ratio. Lowering tube voltage from 140 kVp to 120 kVp reduced the radiation dose by 33%.

Conclusion

The use of 120 kVp during shoulder CT arthrography reduces radiation dose versus 140 kVp without significant loss of image quality.     

Meniscal bucket handle tears: a retrospective study of arthroscopy and the relation to MRI

In this study, we aim to evaluate the arthroscopic findings of meniscal bucket handle tears and to correlate them with the proposed MR imaging signs of meniscal bucket handle tears suggested in the literature. Thirty-six patients who had a diagnosis of bucket handle tear in arthroscopy, in either medial or lateral meniscus, were included in our study (32 males and 4 females). Meniscal tears were evaluated in arthroscopy according to Dandys classification. The MRIs were retrospectively analyzed regarding the following findings: absence of bow tie sign, presence of double posterior cruciate ligament (PCL) sign, double anterior horn sign, flipped meniscus sign, disproportional posterior horn sign, and fragment within the intercondylar region. Locked types I and II fragment of medial meniscus and half-length, whole-width and whole length–half-width fragment of lateral meniscus in arthroscopy were basically correlated with fragment within the intercondylar notch and absent bow tie signs in MRI. We did not find the double PCL sign in any of the patients with a lateral meniscal bucket handle tear. The most common signs in MR images of meniscal bucket handle tears were the fragment in the notch sign and the absent bow tie sign. They were observed with equal frequency of 88.8%. The presence of double PCL sign, double anterior horn sign, flipped meniscus sign, disproportional posterior horn sign were less common (41.66, 33, 25, and 27.7%, respectively). We conclude that the presence of at least two of the six MRI signs should be regarded as highly suggestive for bucket handle tears of menisci.     

An anatomical study of normal meniscal roots with isotropic 3D MRI at 3T

Objectives

To clarify the morphological features of normal meniscal roots on magnetic resonance (MR) imaging with an isotropic 3D proton density-weighted (PDW) sequence.

Materials

3D PDW MR was performed in sixty-two patients at 3 T before knee arthroscopy. MR images of 34 normal medial menisci and 33 intact lateral menisci confirmed by arthroscopy were retrospectively evaluated. MR signals, insertion sites, dimensions and courses of four meniscal roots were recorded.

Results

The anterior root of medial meniscus (ARMM) was typically hypointense, while the posterior root of medial meniscus (PRMM) and the anterior root of lateral meniscus (ARLM) were prone to be hyperintense or showing a comblike signal, and the posterior root of lateral meniscus (PRLM) was usually hypointense or comblike on PDW MR images. ARMM and PRLM had more complex and diverse insertion patterns than ARLM and PRMM. There were significant statistical differences of the lengths, widths, heights and course angles among four meniscal roots (all P < 0.001).

Conclusions

The signal intensity of each meniscal root can be hypointense, hyperintense, or comblike on 3D PDW MR images. ARMM and PRLM have more complex and diverse insertion patterns than ARLM and PRMM. The dimensions and courses of four meniscal roots all differ.     

The importance of arthroscopy in sports injuries in children and adolescents

Within a 3-year period (1985–1988), 60 children and adolescents with knee injuries sustained mainly while skiing or playing football (soccer) underwent clinical examination, X-radiography and arthroscopy. Nearly all the patients still had open epiphyseal plates in the knee region. Arthroscopy revealed more severe intra-articular trauma than had been suspected on the basis of clinical findings. The skiing injuries most commonly involved anterior cruciate ligament tears, whereas injuries of the patellar retinaculum and medial meniscus lesions predominated in soccer injuries. On comparison with arthroscopic diagnosis, clinical diagnosis was erroneous in about 45%. The sost common mistaken clinical diagnosis was medial meniscus tear. Of the 60 knee joints subjected to arthroscopy, 40 were severely enough injured to warrant surgery. Only one had normal intra-articular findings. The study demonstrates that children and adolescents can suffer knee trauma requiring surgery, despite open growth plates. Downhill skiing and soccer are particularly risky sports in this respect. Therefore, sports injuries involving haemarthrosis are clearly an indication for arthroscopy, even in childhood and adolescence. Arthroscopy enables early identification of the type and extent of intra-articular trauma and subsequent early initiation of appropriate therapy.     

Superficial Endobronchial Lung Cancer: Radiologic-Pathologic Correlation

Objective

To analyze the plain chest radiographic and CT findings of superficial endobronchial lung cancer and to correlate these with the findings of histopathology.

Materials and Methods

This study involved 19 consecutive patients with pathologically proven lung cancer confined to the bronchial wall. Chest radiographs and CT scans were reviewed for the presence of parenchymal abnormalities, endobronchial nodules, bronchial obstruction, and bronchial wall thickening and stenosis. The CT and histopathologic findings were compared.

Results

Sixteen of the 19 patients had abnormal chest radiographic findings, while in 15 (79%), CT revealed bronchial abnormalities: an endobronchial nodule in seven, bronchial obstruction in five, and bronchial wall thickening and stenosis in three. Histopathologically, the lesions appeared as endobronchial nodules in 11 patients, irregular thickening of the bronchial wall in six, elevated mucosa in one, and carcinoma in situ in one.

Conclusion

CT helps detect superficial endobronchial lung cancer in 79% of these patients, though there is some disagreement between the CT findings and the pathologic pattern of bronchial lesions. Although nonspecific, findings of bronchial obstruction or bronchial wall thickening and stenosis should not be overlooked, and if clinically necessary, bronchoscopy should be performed.     

Hepatic Sinusoidal Obstruction Syndrome Caused by Herbal Medicine: CT and MRI Features

Objective

To describe the CT and MRI features of hepatic sinusoidal obstruction syndrome (HSOS) caused by herbal medicine Gynura segetum.

Materials and Methods

The CT and MRI features of 16 consecutive Gynura segetum induced HSOS cases (12 men, 4 women) were analyzed. Eight patients had CT; three patients had MRI, and the remaining five patients had both CT and MRI examinations. Based on their clinical presentations and outcomes, the patients were classified into three categories: mild, moderate, and severe. The severity of the disease was also evaluated radiologically based on the abnormal hepatic patchy enhancement in post-contrast CT or MRI images.

Results

Ascites, patchy liver enhancement, and main right hepatic vein narrowing or occlusion were present in all 16 cases. Hepatomegaly and gallbladder wall thickening were present in 14 cases (87.5%, 14/16). Periportal high intensity on T2-weighted images was present in 6 cases (75%, 6/8). Normal liver parenchymal enhancement surrounding the main hepatic vein forming a clover-like sign was observed in 4 cases (25%, 4/16). The extent of patchy liver enhancement was statistically associated with clinical severity classification (kappa = 0.565).

Conclusion

Ascites, patchy liver enhancement, and the main hepatic veins narrowing were the most frequent signs of herbal medicine induced HSOS. The grade of abnormal patchy liver enhancement was associated with the clinical severity.