Imaging features of ischial bursitis with an emphasis on ultrasonography

OBJECTIVE: The aim of this study was to evaluate the imaging features of ischial bursitis with an emphasis on ultrasonography (US). DESIGN AND PATIENTS: Our study included 31 patients with a painful mass or tenderness in their buttock who underwent US (n=27), CT (n=1), or MR imaging (n=4). A needle aspiration (n=6) or a bursal excision (n=5) was performed in those patients who had no clinical improvement in spite of the conservative treatment. Evaluation included lesion location, size, wall of the bursae, and intrinsic characteristics on US, CT and MR imaging. RESULTS: Ischial bursitis was superficial to the ischial tuberosity in all patients (n=31). The lesion ranged from 1.5 cm to 7 cm (average 3.8 cm) in diameter. The bursal wall was identifiable in 25 cases (81%). Internal septa and mural nodules were seen in 12 (39%) and 17 cases (55%), respectively. Sonography showed that fluid within the bursa was hypoechoic (59%), hyperechoic (26%), or of mixed echogenicity (15%). The bursae were compressible by the transducer. Power Doppler examination (n=7) showed hypervascularity of the bursal wall. All lesions imaged with contrast-enhanced CT and MR imaging had an enhancing thin wall and mural nodule. CONCLUSIONS: Ischial bursitis, superficial to the ischial tuberosity, can be clearly demonstrated on sonography and appears as a thin-walled cystic lesion, with or without internal septa and mural nodules.     

Contrast-enhanced MRI of the subdeltoid,subacromial bursa in painful and painless rotator cuff tears

Objective

Although shoulder pain is often associated with rotator cuff tears, many tears are asymptomatic and are not the cause of the patient''s pain. This may explain the persistence of symptoms in some patients despite technically successful rotator cuff repair. It has been proposed that rotator cuff tears cause pain through subdeltoid/subacromial bursal inflammation. The aim of this study was to determine whether bursal inflammation seen on MRI is associated with pain in patients with rotator cuff tears of the shoulder.

Methods

The shoulders of 255 patients were screened with ultrasound. 33 full-thickness rotator cuff tears (18 with shoulder pain and 15 without pain) were identified and subsequently studied using contrast-enhanced MRI of the shoulder. Enhancement of the subacromial bursa was scored independently by two musculoskeletal radiologists. Logistic regression was used to determine whether bursal enhancement was independently associated with pain.

Results

There was a significant association between pain and age, with greater likelihood of pain in younger patients. Bursal enhancement was common in both painful and painless tears. No statistically significant link between pain and bursal enhancement was seen, even after accounting for age.

Conclusion

Although enhancement of the subdeltoid/subacromial bursa was common, no evidence was found to support the hypothesis that bursal enhancement is associated with pain in rotator cuff tears. It is therefore unlikely to determine reliably which patients would benefit from rotator cuff repair.

Advances in knowledge

Bursal enhancement and thickening does not reliably correlate with symptoms or presence of rotator cuff tear.Rotator cuff tears are a common cause of pain in the shoulder. Surgical repair is an effective treatment, but a significant proportion of patients (5–12.5%) fail to achieve a satisfactory outcome [1-4]. Long-term outcome of surgery correlates poorly with the integrity of the cuff repair [5-7] and persistence of pain is a major factor [1]. In some cases, this may be because the shoulder pain is not due to rotator cuff damage at all [8]. Other painful shoulder pathologies are common, particularly in the elderly, including glenohumeral and acromioclavicular arthritis [9], and bone marrow oedema [10]. Asymptomatic rotator cuff tears are common, with increasing incidence with age and a reported prevalence of up to 80% in subjects aged over 80 years [11]. A significant proportion of these are full-thickness tears with one study reporting full-thickness tears in 28% of people over the age of 60 [12]. Rotator cuff tears may remain asymptomatic despite their large size [13] and, although the size of tears often increases, symptoms may develop or resolve with conservative treatment [14-16]. As yet there is no clear consensus regarding the indications for rotator cuff surgery [17,18]. A technique to determine whether a known rotator cuff tear is responsible for an individual patient''s pain would therefore be of great clinical value in developing patient management plans. While MRI has been shown to be accurate for detecting rotator cuff tears [19,20], there is no convincing evidence to date that it can be used to determine whether a full-thickness tear is symptomatic [12,21].The mechanism by which rotator cuff tears cause pain is poorly understood. Tears are associated with histological inflammation of the subdeltoid/subacromial bursa and this has recently been proposed as a cause of pain [22]. Synovial inflammation in the bursa in symptomatic rotator cuff tears could potentially be detected by the associated enhancement in the inflamed bursa seen on MRI after the administration of intravenous contrast agent, in the same way that synovial volume in joints in inflammatory arthritis has been shown to correlate with histological measures of inflammation [23]. The aim of this study was to use contrast-enhanced MRI to assess subacromial bursitis in patients with painful and painless rotator cuff tears in order to test the hypothesis that synovial enhancement at the subacromial bursa is greater in patients with shoulder pain.     

Imaging features of iliopsoas bursitis

The aim of this study was firstly to describe the spectrum of imaging findings seen in iliopsoas bursitis, and secondly to compare cross-sectional imaging techniques in the demonstration of the extent, size and appearance of the iliopsoas bursitis as referenced by surgery. Imaging studies of 18 patients (13 women, 5 men; mean age 53 years) with surgically proven iliopsoas bursitis were reviewed. All patients received conventional radiographs of the pelvis and hip, US and MR imaging of the hip. The CT was performed in 5 of the 18 patients. Ultrasound, CT and MR all demonstrated enlarged iliopsoas bursae. The bursal wall was thin and well defined in 83% and thickened in 17% of all cases. The two cases with septations on US were not seen by CT and MRI. A communication between the bursa and the hip joint was seen, and surgically verified, in all 18 patients by MR imaging, whereas US and CT failed to demonstrate it in 44 and 40% of the cases, respectively. Hip joint effusion was seen and verified by surgery in 16 patients by MRI, whereas CT (4 of 5) and US ( n=12) underestimated the number. The overall size of the bursa corresponded best between MRI and surgery, whereas CT and US tended to underestimate the size. Contrast enhancement of the bursal wall was seen in all cases. The imaging characteristics of iliopsoas bursitis are a well-defined, thin-walled cystic mass with a communication to the hip joint and peripheral contrast enhancement. The most accurate way to assess iliopsoas bursitis is with MR imaging; thus, it should be used for accurate therapy planning and follow-up studies. In order to initially prove an iliopsoas bursitis, US is the most cost-effective, easy-to-perform and fast alternative.     

"Crazy-Paving" Patterns on High-Resolution CT Scans in Patients with Pulmonary Complications after Hematopoietic Stem Cell Transplantation

Objective

To describe the pulmonary complications following hematopoietic stem cell transplantation (HSCT) that can present with a "crazy-paving" pattern in high-resolution CT scans.

Materials and Methods

Retrospective review of medical records from 2,537 patients who underwent HSCT. The "crazy-paving" pattern consists of interlobular and intralobular septal thickening superimposed on an area of ground-glass attenuation on high-resolution CT scans. The CT scans were retrospectively reviewed by two radiologists, who reached final decisions by consensus.

Results

We identified 10 cases (2.02%), seven male and three female, with pulmonary complications following HSCT that presented with the "crazy-paving" pattern. Seven (70%) patients had infectious pneumonia (adenovirus, herpes simplex, influenza virus, cytomegalovirus, respiratory syncytial virus, and toxoplasmosis), and three patients presented with non-infectious complications (idiopathic pneumonia syndrome and acute pulmonary edema). The "crazy-paving" pattern was bilateral in all cases, with diffuse distribution in nine patients (90%), predominantly in the middle and inferior lung regions in seven patients (70%), and involving the anterior and posterior regions of the lungs in nine patients (90%).

Conclusion

The "crazy-paving" pattern is rare in HSCT recipients with pulmonary complications and is associated with infectious complications more commonly than non-infectious conditions.     

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.     

Concordance of US and MRI for diagnosis of ligamentous and tendinous injuries around the ankle

Purpose

To estimate the accuracy of ultrasonography in detection of tendinous and ligamentous injuries around the ankle in comparison to MRI.

Blood supply of the subacromial bursa and rotator cuff tendons on the bursal side

Purpose

Vascularity of the subacromial bursa and rotator cuff tendons is key factors in the pathogenesis of subacromial bursitis and impingement syndrome, rotator cuff tendinitis, and rotator cuff tears. The purpose of this study was to investigate and describe blood supply to the cranial and caudal parts of the subacromial bursa and the vascularity of the rotator cuff tendons on the bursal side.

Methods

Fourteen fresh cadaveric shoulders from six females and eight males with a mean age of 71.7 (±10.8) years were studied. Before dissection, an arterial injection of 10% aqueous dispersion of latex was administered. Post-injection, the shoulders were fixed in an alcohol–formalin–glycerol solution.

Results

The cranial and caudal bursa of all specimens was mainly supplied by the thoracoacromial, suprascapular, and anterior and posterior circumflex humeral arteries. The cranial part of the bursa was supplied anteriorly by the thoracoacromial artery, and posteriorly and medially by the posterior circumflex humeral artery as far as the medial third. The caudal part received arterial blood anteriorly from the anterior circumflex humeral artery, and posteriorly and medially by the posterior circumflex humeral artery as far as the medial third of the caudal bursa. In addition, the suprascapular artery branched at the upper surface of the coracohumeral ligament, and the subcoracoid artery branched at the under surface of the same ligament.

Conclusion

The subacromial bursa appears well vascularized. The results of the present investigation showed that blood supply to the subacromial bursa at the caudal part and rotator cuff tendons on the bursal side was linked to the same arteries. The subcoracoid artery supplied interval rotator structures close to the caudal bursa. It is the wish of the authors that this meticulous anatomical work will help surgeons in their day-to-day clinical work, e.g. to minimize the risk of complications such as perioperative bleeding.

     

Computed Tomography and Magnetic Resonance Imaging Findings of Nasal Cavity Hemangiomas According to Histological Type

Objective

To compare computed tomography (CT) and magnetic resonance imaging (MRI) findings between two histological types of nasal hemangiomas (cavernous hemangioma and capillary or lobular capillary hemangioma).

Materials and Methods

CT (n = 20; six pre-contrast; 20 post-enhancement) and MRI (n = 7) images from 23 patients (16 men and seven women; mean age, 43 years; range, 13-73 years) with a pathologically diagnosed nasal cavity hemangioma (17 capillary and lobular capillary hemangiomas and six cavernous hemangiomas) were reviewed, focusing on lesion location, size, origin, contour, enhancement pattern, attenuation or signal intensity (SI), and bony changes.

Results

The 17 capillary and lobular hemangiomas averaged 13 mm (range, 4-37 mm) in size, and most (n = 13) were round. Fourteen capillary hemangiomas had marked or moderate early phase enhancement on CT, which dissipated during the delayed phase. Four capillary hemangiomas on MRI showed marked enhancement. Bony changes were usually not seen on CT or MRI (seen on five cases, 29.4%). Half of the lesions (2/4) had low SI on T1-weighted MRI images and heterogeneously high SI with signal voids on T2-weighted images. The six cavernous hemangiomas were larger than the capillary type (mean, 20.5 mm; range, 10-39 mm) and most had lobulating contours (n = 4), with characteristic enhancement patterns (three centripetal and three multifocal nodular), bony remodeling (n = 4, 66.7%), and mild to moderate heterogeneous enhancement during the early and delayed phases.

Conclusion

CT and MRI findings are different between the two histological types of nasal hemangiomas, particularly in the enhancement pattern and size, which can assist in preoperative diagnosis and planning of surgical tumor excision.     

Application of MRI of the wrist for age determination in international U-17 soccer competitions

Background

To guarantee equal chances for different age groups, age‐related tournaments for male and female players have been established in soccer. However, as registration at birth is not compulsory in some countries, other methods of age determination are needed to prevent participation in the incorrect age group.

Objectives

To evaluate the age of soccer players of international U‐17 competitions from the degree of fusion of the distal radius and to compare the findings with an age‐related normative population.

Methods

MRI scans of the wrist of a representative sample of 189 players from four U‐17 competitions (FIFA U‐17 World Cups 2003 and 2005, and Asian (AFC) U‐17 championships 2004 and 2006) were analysed using a previously published grading system.

Results

Because of different regulations, all players in the AFC U‐17 championships were younger than 17 years, whereas 71% of the players in the FIFA U‐17 World Cup competitions were 17 years old. The distal radius of 15% of players from the AFC U‐17 tournaments and 27% of the players from the FIFA U‐17 tournaments were graded as completely fused on the MRI scans, which is a substantially higher percentage than in the respective age groups of a previously published normative population of soccer players. Furthermore, in contrast with the normative population, no significant correlation between the age category and the fusion grading (r  =  0.13) was observed in U‐17 players.

Conclusion

From the MRI results, U‐17 soccer players seem to be more mature than a normative population of the same age category. However, the lack of correlation between age category and degree of fusion in U‐17 players supports the suspicion that the age stated in the official documents of the U‐17 players examined might not be correct in all cases.     

Gadoxetic Acid (Gd-EOB-DTPA)-Enhanced MRI versus Gadobenate Dimeglumine (Gd-BOPTA)-Enhanced MRI for Preoperatively Detecting Hepatocellular Carcinoma: an Initial Experience

Objective

This study was designed to compare the diagnostic performance of gadoxetic acid-enhanced magnetic resonance imaging (MRI) with gadobenate dimeglumine-enhanced MRI for preoperatively detecting hepatocellular carcinoma (HCC).

Materials and Methods

Eighteen consecutive patients (17 men and one woman, age range: 31-73 years) with 22 HCCs underwent examinations with gadoxetic acid enhanced MRI and gadobenate dimeglumine-enhanced MRI on a 3.0-Tesla unit. The diagnosis of HCC was established after surgical resection and pathological conformation. Three observers independently reviewed each MR image in a random order on a tumor-by-tumor basis. The diagnostic accuracy of these techniques for the detection of HCC was assessed by performing an alternative free-response receiver operating characteristic (ROC) analysis. The sensitivity and positive predictive values were evaluated.

Results

The average value of the area under the ROC curve (Az) for gadoxetic acid enhanced MRI (0.887) was not significantly different from the Az (0.899) for gadobenate dimeglumine-enhanced MRI (p > 0.05). The overall sensitivities of gadoxetic acid enhanced MRI and gadobenate dimeglumine-enhanced MRI were 80% and 83%, respectively, with no significant difference (p > 0.05). The differences of the positive predictive values for the two contrast agents for each observer were not statistically significant (p > 0.05).

Conclusion

The diagnostic performance of gadoxetic acid-enhanced MRI and gadobenate dimeglumine-enhanced MRI for preoperatively detecting HCC is quite similar.     

Multiparametric MRI of the prostate with three functional techniques in patients with PSA elevation before initial TRUS-guided biopsy

Objective:

Multiparametric MRI (mp-MRI) of the prostate is increasingly being used for local staging and detection of recurrence of prostate cancer (PCA). In patients with elevated prostate-specific antigen (PSA), mp-MRI could provide information on the position of the cancer, allowing adjustments to be made to the needle depth and direction before repeat transrectal ultrasound (TRUS)-guided biopsy to ensure accurate sampling of lesions. The purpose of the prospective study was to evaluate mp-MRI of the prostate in patients with PSA elevation before initial TRUS-guided biopsy.

Methods:

mp-MRI was performed in 94 patients using a 1.5-T scanner (MAGNETOM Aera^®; Siemens Healthcare, Erlangen, Germany) and 16-channel phased-array body coil (Siemens Healthcare). T₂ weighted images (T2WI), diffusion-weighted imaging (DWI), dynamic contrast-enhanced (DCE) MRI and MR spectroscopy were obtained. TRUS-guided random biopsies and additional targeted biopsies of suspicious MRI areas were performed.

Results:

Additional targeted biopsies were obtained in 17 of 43 (40%) patients with PCA. 11 of 17 targeted biopsies contained PCA. 5 of 11 PCAs were diagnosed only by additional targeted biopsies. Sensitivity of mp-MRI in patients was 97.7% and specificity was 11.8%. mp-MRI was false negative in one patient. Sensitivity of mp-MRI in 207 lesions was 80.9% and specificity was 44.7%. In a logistic regression model, the apparent diffusion coefficient value was the only significant parameter to differentiate malignant and benign lesions.

Conclusion:

mp-MRI should be performed in patients with PSA elevation before initial TRUS-guided biopsy to allow additional targeted biopsies from suspicious areas of MRI. We recommend mp-MRI with T2WI, DWI, DCE MRI and MR spectroscopy. DWI as the most reliable technique should be used in every mp-MRI.

Advances in knowledge:

DWI is the most reliable technique in mp-MRI of the prostate.     

Morton Neuroma: Evaluated with Ultrasonography and MR Imaging

Objective

The purpose of this study was to compare the diagnostic accuracy of both ultrasonography (US) and magnetic resonance imaging (MRI) for the assessment of Morton neuroma.

Materials and Methods

Our study group was comprised of 20 neuromas from 17 patients, and the neuromas were confirmed on surgery following evaluation with US, MRI, or both US and MRI. The diagnostic criterion for Morton neuroma, as examined by US, was the presence of a round or ovoid, well-defined, hypoechoic mass. The diagnostic criterion, based on MR imaging, was a well defined mass with intermediate to low signal intensity on both the T1- and T2-weighted images. The retrospective comparison between the sonographic and MR images was done by two experienced radiologists working in consensus with the surgical and pathologic correlations.

Results

The detection rate of Morton neuroma was 79% for 14 neuromas from 11 patients who had undergone US followed by an operation. The detection rate was 76% for 17 neuromas from 15 patients who had undergone MRI and a subsequent operation. The mean size of the examined neuromas was 4.9 mm on the US images and it was 5.1 mm on the MRI studies. Ten neuromas (71%) were 5 mm or less as measured by US, and three neuromas were not detected, whereas on the MRI analysis, 10 neuromas (59%) were 5 mm or less and four neuromas were not visualized. Among the patients examined during postoperative follow-up, symptoms were completely relieved in 85% and the symptoms were partially relieved in 15%.

Conclusion

US and MR imaging are comparable modalities with high detection rate for the evaluation of Morton neuroma.     

Pseudobursae: a useful finding in patients with painful hip arthroplasty

A retrospective review of 178 consecutive subtraction hip arthrograms (175 patients) was performed to evaluate the significance of cavities or bursal communications (or both) with the pseudocapsule in patients with painful hip arthroplasty. Bursae and/or communicating cavities were shown in 75 (43%) of the 175 patients. Communicating irregular cavities were noted in 12 patients (nine infected), and smooth bursae or bursalike structures were noted in 63 patients. The most frequent bursal locations were the greater trochanteric region (32/63), supraacetabular region (18/63), and iliopsoas (12/63). Three patients had multiple bursae. Six of the 18 acetabular bursae were associated with previous dislocations. Twenty-seven patients with bursae had no radiographic findings of loosening or infection. Of these 27, 12 (44%) responded to local injection of anesthetic into the bursa and were judged clinically to have bursitis. Arthrography, with aspiration from the bursae or cavities and injection of anesthetic, provides additional information regarding painful hip arthroplasty and may prevent unnecessary surgery.     

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.     

The value of magnetic resonance arthrography of the temporomandibular joint in imaging disc adhesions and perforations

Objectives

This study attempted to validate MR arthrography (MRAr) of the temporomandibular joint (TMJ) in detecting the position, integrity and relations of the articular disc and retrodiscal tissue.

Methods

A total of 20 TMJs from 10 patients with severe TMJ dysfunction underwent MRI and MRAr. A paramagnetic contrast medium was injected into the upper joint compartment to observe possible adhesions and/or leakage into the lower compartment. 15 TMJs were surgically or arthroscopically explored and restored.

Results

MRAr was approximately in the same diagnostic value as MRI when locating position, but superior in detecting disc perforations (eight TMJs) and adhesions (seven TMJs) appearing together in four cases. Surgery confirmed radiological findings in all but one case, where arthroscopy and surgery failed to confirm a disc perforation indicated by MRAr.

Conclusions

TMJ MRAr may simultaneously reveal adhesions and perforations. Sensitivity and the probability of false-positive results require further study.     

MRI-Guided Intervention for Breast Lesions Using the Freehand Technique in a 3.0-T Closed-Bore MRI Scanner: Feasibility and Initial Results

Objective

To report the feasibility of magnetic resonance imaging (MRI)-guided intervention for diagnosing suspicious breast lesions detectable by MRI only, using the freehand technique with a 3.0-T closed-bore MRI scanner.

Materials and Methods

Five women with 5 consecutive MRI-only breast lesions underwent MRI-guided intervention: 3 underwent MRI-guided needle localization and 2, MRI-guided vacuum-assisted biopsy. The interventions were performed in a 3.0-T closed-bore MRI system using a dedicated phased-array breast coil with the patients in the prone position; the freehand technique was used. Technical success and histopathologic outcome were analyzed.

Results

MRI showed that four lesions were masses (mean size, 11.5 mm; range, 7-18 mm); and 1, a nonmass-like enhancement (maximum diameter, 21 mm). The locations of the lesions with respect to the breast with index cancer were as follows: different quadrant, same breast - 3 cases; same quadrant, same breast - 1 case; and contralateral breast - 1 case. Histopathologic evaluation of the lesions treated with needle localization disclosed perilobular hemangioma, fibrocystic change, and fibroadenomatous change. The lesions treated with vacuum-assisted biopsy demonstrated a radial scar and atypical apocrine hyperplasia. Follow-up MRI after 2-7 months (mean, 4.6 months) confirmed complete lesion removal in all cases.

Conclusion

MRI-guided intervention for breast lesions using the freehand technique with a 3.0-T closed-bore MRI scanner is feasible and accurate for diagnosing MRI-only lesions.     

Anatomy of the Sinoatrial Nodal Branch in Korean Population: Imaging with MDCT

Objective

To evaluate, on a retrospective basis, the anatomic characteristics of the arterial supply to the sinoatrial node (SAN) in the Korean population using an ECG-gated multi-detector CT (MDCT).

Materials and Methods

The electrocardiographic-gated MDCTs of 500 patients (258 men and 242 women; age range, 17-83 years; mean age, 58.6 ± 12.04 years) were analyzed retrospectively. In each case, the SAN artery (arteries) was named according to a special nomenclature with regard to origin, course, and termination.

Results

A total of 516 SAN arteries were visualized in 496 patients. The SAN was supplied by a single artery in 476 (96.4%) cases and by 2 arteries in 18 (3.6%) cases. The SAN originated from the right coronary artery in 265 (53.4%) cases and from the left circumflex in 213 (43%) cases.

Conclusion

This study can provide basic data on variations of the SAN artery in the Korean population.     

Web-based calibration of observers using MRI of the temporomandibular joint

Objectives

Research diagnostic criteria for temporomandibular disorders (RDC/TMDs) were proposed in 1992 with the aim of standardizing and testing methods for diagnosing TMDs. RDC/TMDs have so far been lacking standardized methods for imaging and criteria for imaging diagnosis of disorders of the temporomandibular joint (TMJ). Criteria for disorders of the TMJ have recently been proposed for MRI. The aim of this study was to publish MR images of the TMJ on the web and to test the agreement of five observers using the criteria.

Methods

20 cases of MRI of the TMJ were published on the web together with the criteria. The MR images were taken in closed and open mouth positions, and sagittal and coronal views. Five observers diagnosed disc position, disc shape, joint effusion and loose calcified bodies in the TMJ.

Results

In all cases except one, three or more observers agreed upon the diagnosis. All agreed on whether a loose calcified body was present or not. The second best agreement was obtained for disc position in the sagittal view, where all observers agreed in 16 of the 20 cases. For disc position in the coronal view and the evaluation of the disc shape, observer agreement was lower.

Conclusion

Criteria were useful in order to standardize and simplify evaluation and thereby probably increase the diagnostic outcome among different observers for MRI of the TMJ. We recommend that the criteria be used internationally to facilitate comparisons between different studies.