MR and CT arthrography of the hip

CT arthrography (CTa) and MR arthrography (MRa) are useful tools for the investigation of intra-articular hip disease. They are minimally invasive techniques with a very low rate of complications and can be performed safely. CTa or MRa can be performed after an intra-articular injection of diluted contrast, but both techniques can also be performed after a single injection. As radiologists we should be able to address the surgeon's questions and work together to standardize terminology and classifications systems for accurate reporting. This update emphasizes radiological findings with a clinical perspective. CTa and MRa allow the precise diagnosis of labral tears, loose bodies, and intra-articular ligaments (capsular and ligamentum teres). The use of careful technique and a tailored protocol has improved our ability to detect and describe cartilage lesions. This is essential because knowledge of the status of the cartilage may dictate a specific surgical approach, and when cartilage lesions are extensive, they are a negative prognostic indicator for arthroscopic treatment.     

MR arthrography of the hip: normal intra-articular structures and common disorders

This pictorial review illustrates the anatomical features of normal intra-articular components of the hip and their common disorders on MR arthrography. On T1-weighted MR arthrograms, the normal contrast-filled joint cavity shows a homogeneous high signal intensity. Normal acetabular labrum appears as a well-delineated triangle showing a low signal intensity, surrounded by contrast material in the perilabral recess. Intra-articular paramagnetic contrast outlines labral tears, loose bodies, communicating labral cysts and cartilage lesions (traumatic tears, focal defects, degenerative fissures and thinning), and improves their detection. Overall, MR arthrography enables accurate detection and staging of hip intra-articular structure abnormalities. Received: 6 June 1998; Revision received: 2 January 1999; Accepted: 2 April 1999     

Indirect magnetic resonance arthrography of the shoulder; a reliable diagnostic tool for investigation of suspected labral pathology

Purpose

Indirect magnetic resonance arthrography (I-MRA) confers significant logistical advantages over direct MRA and does not require articular injection. In this study, we determined the diagnostic performance of I-MRA in relation to conventional MRI and arthroscopy or surgery in detecting tears of the glenoid labrum, including Bankart lesions and superior labral antero-posterior (SLAP) tears in a standard clinical setting.

Patients and methods

Ninety-one symptomatic patients underwent conventional MRI and I-MRA of the affected shoulder, followed by either arthroscopy or open surgery. The scans were interpreted independently by two experienced radiology consultants with a special interest in musculoskeletal radiology. Using the surgical findings as the standard of reference, sensitivity, specificity, and diagnostic accuracy of conventional non-contrast MRI and I-MRA in the detection of labral tears were calculated.

Results

The sensitivity of I-MRA was 95 and 97 %, respectively, for two radiologists as opposed to 79 and 83 % for conventional MRI. For both radiologists, the specificity of I-MRA, as well as MRI, was 91 % for detection of labral tears of all types. Accuracy of diagnosis was 93 and 95 %, respectively, for two radiologists with indirect MRA, compared to 84 and 86 % with non-contrast MRI.

Conclusions

This retrospective study shows that I-MRA is a highly accurate and sensitive method for the detection of labral tears. The data obtained supports the use of I-MRA as standard practice in patients with shoulder instability due to suspected labral pathology where further investigative imaging is indicated.     

评价肩袖肌腱撕裂:多层螺旋CT关节成像与1.5TMR关节成像的比较

摘要目的比较多层螺旋CT关节成像与1.5T MR关节成像对于肩袖损伤的诊断价值。材料与方法本研究已获得伦理委员会批准,且所有受试者均签署知情同意书。对56例病人分别行CT及MR关节成像,并由2名放射科医师独立评估     

Low-dose unenhanced multidetector CT of patients with suspected renal colic

OBJECTIVE: This study is designed to assess the intraobserver and interobserver agreements and the diagnostic performances of low-dose unenhanced multidetector CT (MDCT) in patients with suspected renal colic. SUBJECTS AND METHODS: The study included 106 patients who underwent unenhanced MDCT with 4 x 2.5 mm collimation, 120 kVp, 30 mAs, and, if necessary, additional focused acquisitions at 60 or 120 mAs on areas with an equivocal ureteral stone or with significant image noise. The effective radiation dose was computer-simulated with software based on the Monte Carlo model and International Commission on Radiological Protection recommendations. CT scans were archived and independently reviewed by three radiologists during two interpretation sessions on a workstation with three dimensions functions. Intraobserver and interobserver agreements were calculated with the kappa statistics. Accuracy for detection of ureteral stone on low-dose MDCT was calculated by comparison with combined clinical (stone passage), surgical (stone retrieval, extracorporeal shock wave lithotripsy), biologic (urinalysis, urine culture), and other imaging (excretory urography, standard-dose MDCT, follow-up sonography, and abdominal radiography) findings or by evidence for an alternative diagnosis. RESULTS: Ureteral stones were present in 38 (36%) of 106 patients. Thirty-six of 38 ureteral stones were detected by low-dose MDCT. From reviewer to reviewer, the number of true-positive, false-positive, true-negative, and false-negative findings ranged, respectively, from 34 to 36, 1 to 4, 64 to 68, and 2 to 4. The corresponding sensitivity, specificity, and accuracy ranged from 89.5% to 94.7%, from 94.1% to 100%, and from 93.4% to 98.1%, respectively. The intraobserver and interobserver agreements were excellent, with kappa values ranging from 0.87 to 0.98. In 13 patients, an alternative diagnosis explaining the patient's symptoms was proposed by all reviewers using images obtained at 30 mAs. No additional or alternative diagnosis was found at standard dose. At 30 mAs, the mean effective dose was 1.2 mSv in men and 1.9 mSv in women. Additional acquisitions at 60 mAs, all focused on the lower pelvis, were acquired in 20 patients, but the corresponding images were needed by the reviewers for only six of them. The acquisitions at 60 mAs were responsible for an additional mean effective dose of 0.5 in men and 0.8 mSv in women. CONCLUSION: Our study shows that low-dose unenhanced MDCT is appropriate for the diagnosis of ureteral stones, and that it provides excellent intraobserver and interobserver agreements and does not obscure alternative diagnoses.     

A comparative study to evaluate the role of intra-articular adrenaline in double-contrast knee arthrography

The addition of adrenaline to meglumine iothalamate (Conray 280) in double-contrast knee arthrography significantly improves meniscal coating, in both immediate and delayed films, when compared with iothalamate alone. The quality of coating is comparable to that with sodium meglumine ioxaglate (Hexabrix 320) without adrenaline. The addition of adrenaline to ioxaglate produces no significant improvement in arthrographic quality in either immediate or delayed films. The use of iothalamate with adrenaline is less expensive than ioxaglate alone, but this financial advantage has to be balanced against the significantly greater pain associated with the use of intra-articular adrenaline.     

Comparison of MR arthrography with arthroscopy of the hip for the assessment of intra-articular loose bodies

Objective To assess the specificity and sensitivity of MR arthrography of the hip in comparison with arthroscopy for the evaluation of intra-articular loose bodies. Design Over a 3-year period, 81 consecutive patients underwent a total of 82 hip arthroscopies by a single orthopedic surgeon for intractable hip pain. Of the 82 arthroscopies, 70 had pre-operative MR arthrograms. Of these, 57 were available for retrospective review, after which they were compared with the operative notes of the subsequent arthroscopies. Results Of 82 arthroscopies 16 (20%) demonstrated intra-articular loose bodies, while, in the study group, nine of 57 had loose bodies (16%). There was a total of seven discordant cases (five false negatives and two false positives). The sensitivity of MR arthrography for detection of intra-articular loose bodies was 44%, while the specificity was 96%. Conclusion While the specificity of MR arthrography for the detection of intra-articular loose bodies was high (96%), the sensitivity was not nearly as good (44%). Presented at the Special Scientific Section of the ISS in Vancouver, Canada, September 2006.     

Low-tube-current multidetector CT for children with suspected extrinsic airway compression

OBJECTIVE: The purpose of our study was to review the technical success achieved using low-tube-current multidetector CT for the evaluation of children with suspected extrinsic airway compression and to evaluate the need for sedation during this procedure. MATERIALS AND METHODS: We reviewed all CT examinations performed for the evaluation of extrinsic airway compression during the first year after installation of a multidetector CT scanner at a pediatric hospital. We recorded the technical parameters including tube current, kilovoltage, slice thickness, mode of study, sedation technique, and amount of contrast material and noted which postprocessing techniques were applied. Studies were evaluated for timing of contrast bolus, image quality, motion artifact, need for sedation, and the diagnoses made. RESULTS: Fifty-four studies were performed in 50 patients (30 boys, 20 girls; age range, 15 days to 17 years; mean age, 2.4 years). The mean tube current was 52.2 mA (range, 30-140 mA). Thirty-four studies (63%) were performed without sedation: 12 with sedation administered under supervision of the radiologist, six with general anesthesia supervised by an anesthesiologist, and two in patients who arrived in the radiology department already intubated. Imaging quality was excellent in 35 studies (65%), diagnostic in 19 studies (35%), and poor in none. Motion artifact was present on several slices in two examinations (4%). Contrast medium administration was well-timed in 49 studies (91%), early in three studies (5%), and late in two studies (4%). Airway abnormalities were detected in 26 (48%) of the studies and included extrinsic compression by vascular anomalies (n = 14) or nonvascular masses (n = 5) and intrinsic airway disease without extrinsic compression (n = 7). CONCLUSION: Evaluation for extrinsic compression of the airway in children can be accomplished using a low-tube-current multidetector CT protocol; in most pediatric patients, the examination can be performed without sedation.     

Gynecologic pathology on multidetector CT: a pictorial review

The purpose of this pictorial essay is to review the imaging appearance of the spectrum of gynecologic pathology that may be visualized by multidetector computed tomography (CT). Although ultrasound and magnetic resonance imaging remain the primary imaging modalities for evaluating female patients with suspected obstetric and gynecologic pathology, CT is frequently performed as the initial imaging modality in the evaluation of abdominal and pelvic pain of unknown etiology. Pelvic pain in women due to a gynecologic condition may also mimic numerous other conditions such as appendicitis and diverticulitis, resulting in initial evaluation by CT—particularly in the emergency setting. The radiologist should, therefore, be familiar with the spectrum of gynecologic and obstetric pathology that may be present on a CT evaluation of the abdomen and pelvis regardless of the study indication, particularly because CT is often the most readily available imaging modality in the emergency setting on a 24/7 basis.     

The role of spiral multidetector dynamic CT in the study of Williams-Campbell syndrome

Williams-Campbell syndrome is a cystic bronchiectatic disease secondary to deficiency or defect of cartilaginous plates in the wall of the airways. In the literature, two main forms are suggested: congenital and acquired (post-infectious). The most frequent symptoms are represented by recurrent pulmonary infections from childhood. Multislice spiral dynamic CT has a major role in the study of cystic pulmonary disease and in differentiating Williams-Campbell syndrome from the other causes of cystic bronchiectasis, in which even lung function tests can give deceptive results.     

The role of multidetector CT virtual hysterosalpingography in the evaluation of female infertility

Purpose

To assess the role of 64-row multidetector computed tomography virtual hysterosalpingography (MDCT VHSG) in the evaluation of the female reproductive tract in infertile patients and compare it with conventional X-ray hysterosalpingography (HSG).

Methods and material

The studied group included 25 patients with infertility. All patients were evaluated with 64-row MDCT VHSG and X-ray HSG. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of both examinations for uterine pathology, fallopian tube pathology and per lesion pathology were calculated. The duration for both examinations, patient discomfort and patient effective dose were documented.

Results

The mean duration for MDCT VHSG and X-ray HSG was 6.5 ± 1.9 and 26.9 ± 2.9 min respectively, MDCT VHSG has a significantly less median patient discomfort and mean patient effective dose. Sensitivity, specificity, PPV and NPV for uterine pathology were 100%, 100%, 100% and 100% respectively for MDCT VHSG and 90%, 93.3%, 90% and 93.3% respectively for X-ray HSG, the inter-method agreement for uterine pathology was k = 0.83. Sensitivity, specificity, PPV and NPV for the detection of fallopian tube pathology were 100%, 93%, 91 and 100% respectively for MDCT VHSG and 100%, 86%, 85% and 100% respectively for X-ray HSG and k = 0.76. Sensitivity, specificity, PPV and NPV for per patient pathology were 100%, 91%, 93% and 100% respectively for MDCT VHSG and 87%, 80%, 87% and 80% respectively for X-ray HSG and k = 0.75.

Conclusion

MDCT VHSG could be an excellent new alternative diagnostic procedure in the infertility assessment workup.     

The lateral approach for hip arthrography

Despite advances in imaging techniques, hip arthrography is still a useful diagnostic tool. We have found that the lateral approach to the hip joint, with the needle inserted superior to the greater trochanter and parallel to the table top under fluoroscopic control, allows easy advancement of the needle into the lateral hip joint space.     

Feasibility and preliminary results of SPECT/CT arthrography of the wrist in comparison with MR arthrography in patients with suspected ulnocarpal impaction

Purpose

To evaluate the feasibility and performance of SPECT/CT arthrography of the wrist in comparison with MR arthrography in patients with suspected ulnocarpal impaction.

Methods

This prospective study included 28 wrists of 27 patients evaluated with SPECT/CT arthrography and MR arthrography. Iodine contrast medium and gadolinium were injected into the distal radioulnar and midcarpal joints. Late-phase SPECT/CT was performed 3.5 h after intravenous injection of approximately 650 MBq ^99mTc-DPD. MR and SPECT/CT images were separately reviewed in relation to bone marrow oedema, radionuclide uptake, and tears in the scapholunate (SL) and lunotriquetral (LT) ligaments and triangular fibrocartilage complex (TFCC), and an overall diagnosis of ulnar impaction. MR, CT and SPECT/CT imaging findings were compared with each other, with the surgical findings in 12 patients and with clinical follow-up.

Results

The quality of MR arthrography and SPECT/CT arthrography images was fully diagnostic in 23 of 28 wrists (82 %) and 25 of 28 wrists (89 %), respectively. SPECT/CT arthrography was not diagnostic for ligament lesions due to insufficient intraarticular contrast in one wrist. MR and SPECT/CT images showed concordant findings regarding TFCC lesions in 22 of 27 wrists (81 %), SL ligament in 22 of 27 wrists (81 %) and LT ligament in 23 of 27 wrists (85 %). Bone marrow oedema on MR images and scintigraphic uptake were concordant in 21 of 28 wrists (75 %). MR images showed partial TFCC defects in four patients with normal SPECT/CT images. MR images showed bone marrow oedema in 4 of 28 wrists (14 %) without scintigraphic uptake, and scintigraphic uptake was present without MR bone marrow oedema in three wrists (11 %). Regarding diagnosis of ulnar impaction the concordance rate between CT and SPECT/CT was 100 % and reached 96 % (27 of 28) between MR and SPECT/CT arthrography. The sensitivity and specificity of MR, CT and SPECT/CT arthrography were 93 %, 100 % and 100 %, and 93 %, 93 % and 93 %, respectively.

Conclusion

SPECT/CT arthrography of the wrist is feasible. Regarding diagnosis of ulnar impaction we found a high concordance with MR arthrography. SPECT/CT arthrography of the wrist is an alternative to MR arthrography in patients with contraindications to MR imaging.     

Comparison between low-dose and standard-dose multidetector CT in patients with suspected chronic sinusitis

OBJECTIVE: This study was designed to compare low- and standard-dose multidetector CT (MDCT) findings in patients with suspected chronic sinusitis. SUBJECTS AND METHODS. Fifty patients underwent MDCT at 10 and 150 effective mAs. The low-dose MDCT protocol delivered a radiation dose of 0.047 mSv in men and 0.051 mSv in women, whereas the standard-dose MDCT protocol delivered a radiation dose of 0.70 mSv in men and 0.76 mSv in women. Scans of the right and left sides of sinonasal cavities were reviewed by three radiologists, with each physician reviewing a scan twice over an interval of more than 2 weeks. The reviewers were asked to evaluate the scans for eight mucosal and two bone abnormalities. We calculated the number of discrepancies in observed abnormalities between pairs of reviewers, among all three reviewers, and between findings on scans acquired with the two radiation doses. RESULTS: The mean number of discrepancies in observed abnormalities on scans acquired with different radiation doses ranged from 0 to 5.2. Discrepancies between pairs of reviewers ranged from 1.0 to 12.8 for low-dose scans and from 1.0 to 13.0 for standard-dose scans. Discrepancies among all reviewers ranged from 1.0 to 10.3 for low-dose scans and from 1.0 to 8.7 for standard-dose scans. In analyzing cases of significant discrepancies in observations, we found greater variation between pairs of reviewers and among all three reviewers than between findings obtained with different dose levels. CONCLUSION: Dose reduction played a far less important role in discrepancies of detected abnormalities than did the human element of reviewer observation. Given this finding and the fact that low-dose MDCT delivers a radiation dose that is no higher than that delivered by a four-view radiographic examination, low-dose MDCT should be considered the imaging method of choice in patients with suspected chronic sinusitis.     

Chest pain in the emergency department: role of multidetector CT

The development of newer generations of multidetector computed tomographic (CT) scanners capable of enabling accurate assessment of the coronary arteries in conjunction with the increasing placement of CT scanners near the emergency department has raised interest in using CT to provide a comprehensive imaging evaluation of patients presenting with acute chest pain. In this article, the authors review the challenges surrounding the current clinical and imaging work-up of chest pain in the emergency room and provide a framework for understanding the potential role of CT.     

上盂唇前后撕裂:多层CT关节成像诊断的准确度及阅片者间可信度

目的评估多层CT关节成像对上盂唇前后(SLAP)损伤的诊断及分类的准确性与阅片者间的可信度。材料与方法本研究经机构审查委员会批准并获得知情同意。回顾性