Pre-operative Assessment of Shoulder Pathologies on MRI by a Radiologist and an Orthopaedic Surgeon

Introduction

Pathologies of the shoulder, i.e. rotator cuff tears and labral injuries are very common. Most patients receive MRI examination prior to surgery. A correct assessment of pathologies is significant for a detailed patient education and planning of surgery.

Materials and methods

Sixty-nine patients were identified, who underwent both, a standardised shoulder MRI and following arthroscopic shoulder surgery in our hospital. For this retrospective comparative study, the MRIs were pseudonymised and evaluated separately by an orthopaedic surgeon and a radiologist. A third rater evaluated images and reports of shoulder surgery, which served as positive control. Results of all raters were then compared. The aim was an analysis of agreement rates of diagnostic accuracy of preoperative MRI by a radiologist and an orthopaedic surgeon.

Results

The overall agreement with positive control of detecting transmural cuff tears was high (84% and 89%) and lower for partial tears (70-80%). Subscapularis tears were assessed with moderate rates of agreement (60 - 70%) compared to intra-operative findings. Labral pathologies were detected mostly correctly. SLAP lesions and pulley lesions of the LHB were identified with only moderate agreement (66.4% and 57.2%) and had a high inter-rater disagreement.

Conclusion

This study demonstrated that tears of the rotator cuff (supraspinatus, infraspinatus) and labral pathologies can be assessed in non-contrast pre-operative shoulder MRI images with a high accuracy. This allows a detailed planning of surgery and aftercare. Pathologies of the subscapularis tendon, SLAP lesions and biceps instabilities are more challenging to detect correctly. There were only small differences between a radiologic and orthopaedic interpretation of the images.

Magnetic resonance imaging of the sacroiliac joints in patients with suspected spondyloarthritis--comparison of turbo spin-echo and gradient-echo sequences for the detection of structural alterations

PURPOSE

Magnetic resonance imaging (MRI) is the method of choice for the evaluation of spondyloarthritis (SpA). According to the guidelines of the Assessment of Spondyloarthritis International Society (ASAS) and Outcome Measures in Rheumatology (OMERACT), MRI findings in SpA of the spine and the sacroiliac joints (SIJ) are classified as inflammatory and structural alterations. Modern gradient-echo sequences (GRE) are recommended for optimized detection of structural alterations of the SIJ. We assess the benefit of GRE in the detection of structural alterations of the SIJ in comparison to conventional turbo spin-echo sequences (TSE).

MATERIAL AND METHODS

Retrospective study of 114 patients who received MRI of the SIJ for the evaluation of SpA. Structural alterations of the SIJ were assessed by two blinded readers separately for T1 TSE and T2* GRE. The findings were classified according to a previously published chronicity score separately for both sides and sequences. Interobserver reliability was calculated with Cohen's Kappa, and the significance of findings was assessed with the Wilcoxon test. P-values <0.05 were required for statistical significance.

RESULTS

68 of 114 (60%) patients showed SpA-typical findings of the SIJ. The average chronicity score for GRE (score 3.3) was significantly higher than for TSE (score 2.6), p=0.001. The Kappa-values for the interobserver reliability were 0.86-0.90 without any statistically significant differences between both sides and sequences.

CONCLUSION

Both T1 TSE and T2* GRE showed a high interobserver reliability in the detection of structural alterations in patients with SpA. However, T2* GRE detected significantly more structural alterations than T1 TSE and should be an integral part of a modern MRI protocol for the diagnostic workup of patients with suspected SpA.

KEY POINTS

T2* gradient-echo sequences are superior to T1 turbo spin-echo sequences in the detection of structural SI-joint alterations.

[Detection of intrinsic ligament and TFCC lesions of the wrist. Direct versus indirect MRI arthrography]

BACKGROUND

The purpose of this study was to validate the diagnostic value of direct magnetic resonance imaging (dMRI) arthrography and indirect MRI (iMRI) arthrography concerning intrinsic ligament injuries and tears of the triangular fibrocartilage complex (TFCC).

PATIENTS AND METHODS

A randomized prospective trial was conducted with patients who presented with wrist pain potentially due to carpal lesions and 10 patients aged 19-60 years (3 female and 7 male) were included. Between the clinical examination and the diagnostic and therapeutic arthroscopy, dMRI and iMRI arthrography were performed for the diagnostics of injuries of the intrinsic ligaments or the TFCC. The results of dMRI and iMRI arthrography were evaluated by two radiologists blinded to the injuries of the patients and a consensus was reached. The results were compared with the findings obtained by arthroscopy.

RESULTS

In the arthroscopy five lesions of the scapholunate ligament (SL), one of the lunotriquetral ligament (LT) and seven of the TFCC were identified. The sensitivity of iMRI and dMRI for carpal ligament lesions (SL and LT) was low (50 %) whereas the specificity was high (93 %). For injuries of the TFCC the sensitivity (up to 100 %) and the specificity (100 %) were both excellent. The area under the curve (AUC) in the receiver operating characteristics (ROC) analysis was high for TFCC lesions in both dMRI and iMRI arthrography.

CONCLUSION

Indirect MRI arthrography is a suitable method for detection of injuries of the TFCC and intrinsic ligaments of the wrist with good sensitivity and specificity. Despite the low number of patients the results of this study showed that there were no essential differences between dMRI and iMRI arthrography with respect to the diagnostic value for carpal injuries of the wrist.

[As time goes by--is it worth intensifying patient care during the waiting period for radiological examinations?]

PURPOSE

Service characteristics in hospital care in general have a high influence on patients' contentment. One of the key features of good service is waiting time. The aim of this study was to analyze the influence of ambience and individual care while waiting for a radiological examination on patient satisfaction.

MATERIALS AND METHODS

The study was conducted prospectively and included and total of 100 patients at a tertiary care center. All patients waiting for contrast-enhanced computed tomography (CT) and were randomly divided into two groups. 50 patients waited under regular circumstances, i.e. the normal waiting ara of our radiological department, whilst the remaining 50 patients spent their waiting time in a separate small waiting area with intensified care and service. Both subjective and objective waiting time and the patients' contentment were raised with a standardized questionnaire. Quality criteria mentioned by the patients were then ranked according to their importance.

RESULTS

Of all included patients 76 % were ambulant with an average age of 60 years (range 22 - 83 years) and 69 % female. These characteristics were identical in both groups. With a mean waiting time of 90 minutes (Group intensified care 100 minutes, group regular care 81 minutes) most patients evaluated the overall service during waiting time as "good" to "ideal", only 2 % as of "low quality". No significant differences between the two study arms concerning the patient satisfaction could be detected. Patients with intensified care estimated their delay time significantly shorter by an average of 24 minutes (p < 0.02). For 40 % a detailed consent discussion was the main quality criterion, while a short waiting time only for 24 %.

CONCLUSION

An optimized, i.e. intensified care during the waiting time for a radiological examination results in a significant reduction of the subjective waiting time, but does not lead to a significantly higher patient contentment. The subjective judgement of examination quality seems to influence the acceptance of prolonged latency to a high degree.

[Clinical significance of conventional follow-through examinations of the gastrointestinal passage in a university hospital]

PURPOSE

The follow-through examination (FTE) is still a widely used radiological method. Modern sectional imaging techniques (CT, MRI, sonography) are established routine examinations offering a wider range of information. In this context the study tries to answer the question of the current significance of FTE of the gastrointestinal tract.

MATERIALS AND METHODS

We retrospectively analyzed data of 300 patients, who had undergone FTE between 2001 and 2009 in a university hospital. The medical history, current anamnesis and the therapeutic consequences of the examination for each patient were evaluated based on radiological reports and electronic medical files.

RESULTS

The most frequent indication to perform the examination was an uncertain gastrointestinal passage or/and the exclusion of stenosis (70%). In 10% of all FTEs there were complications which led to examination abortion in 2% of cases. In patients who underwent surgery of the abdomen, the examination was performed 8 days (median) after surgery. In 35% of these patients, FTE was done within the first 6 days after surgery. 87% of the patients received further diagnostics before getting pharmacotherapy or surgery. None of the analyzed patients had been operated on after an FTE of the abdomen without being investigated by another diagnostic method. The average radiation exposure was 7 mSv.

CONCLUSION

Considering the wide availability of modern sectional imaging methods that are usually necessary for taking significant therapeutic steps, the indication for FTE examinations of the gastrointestinal tract should be very restrictive. The relatively high radiation exposure supports this suggestion.

Real-time elastography of hepatic thermal lesions in vitro: histopathological correlation

PURPOSE

To evaluate the reliability of elastography, a new ultrasonographic method, for delineating thermal lesion boundaries in porcine liver tissue by comparing lesion dimensions determined by real-time elastography with the findings at gross pathology.

MATERIALS AND METHODS

A total of 15 thermal lesions with diameters ranging from 17 to 60 mm were created using radiofrequency ablation (RFA). Color-coded elastography was performed by one experienced examiner, using a 6 - 15 MHz high frequency linear transducer (LOGIQ E9, GE). Lesions were examined using B-mode and real-time elastography (RTE). Lesion detection, delineation and size were assessed using B-mode and RTE immediately after each thermal ablation ( < 5 min). Measurements of the sections representing the same image plane used for elastography were taken during pathologic examination and compared to the measurements obtained from the elastograms.

RESULTS

In our sample a statistically significant correlation in vitro between RTE and pathological measurements with respect to the lesion's principal axis and area (r2 = 0.9338 long axis, r2 = 0.8998 short axis and r2 = 0.9676 area) was found. Overall, elastography slightly underestimated the lesion size, as judged by the digitalized pathologic images.

CONCLUSION

These results support that RTE outperforms conventional B-mode ultrasound and could potentially be used for the routine assessment of thermal therapies.

[Plain abdominal radiograph - is there any additional clinical value based on the supine projection?]

BACKGROUND

To assess the diagnostic value of an additionally acquired plain abdominal radiograph in supine position.

MATERIALS AND METHODS

Two experienced radiologists evaluated retrospectively 2148 consecutive patients having plain abdominal radiographs acquired in a tertiary care center. There were 1385 patients having an erect view and 763 patients with a left lateral decubitus view. All patients had a second examination in supine position. First the radiographs in erect or decubitus view were evaluated regarding the presence and details of pathological changes. After 4 weeks all radiographs including the supine view were evaluated again. Next to pathological changes the additional value of the supine projection was assessed. The results were compared and the additional diagnostic value using the supine view was noted.

RESULTS

We evaluated 2148 patients having a plain abdominal radiograph (1325 men, 823 women, mean 58.9 years, range 15-96 years). The average age within the group acquired with left decubitus view was 61.1 years, while patients having an erect view had a mean age of 57.0 years. For the first evaluation we found pathological changes in 10.5% (decubitus view: 13.1%, erect view 9.5%; p = 0.01). The most frequent diagnosis was ileus (7.7%) followed by abdominal free air (2.4%). The results were confirmed during the second reading in 99.2%. In 3.5% (decubitus view 5.8%, erect view 2.2%) more anatomical structures were depicted considering the supine projection and the decubitus/erect projections. The anatomical information was in no case relevant for the diagnosis.

CONCLUSION

Having the information of an supine view additionally to an decubitus/erect view increases the depiction of anatomical structures up to 5.8%. Nevertheless there was no additional diagnostic relevant information based on the supine view.

Image fusion with volume navigation of contrast enhanced ultrasound (CEUS) with computed tomography (CT) or magnetic resonance imaging (MRI) for post-interventional follow-up after transcatheter arterial chemoembolization (TACE) of hepatocellular carcinomas (HCC): Preliminary results

AIM

The assessment of the immediate post-interventional microcirculation and perfusion following transcatheter arterial chemoembolization (TACE) with new real time imaging fusion technique (VNav) of computed tomography (CT) or magnetic resonance imaging (MRI) with contrast enhanced ultrasound (CEUS) compared to follow-up.

MATERIAL

Following TACE an image fusion of CEUS with CT or MRI of the liver was performed in 20 patients (18 men, 2 women; age 29-75 years) with confirmed hepatocelluar carcinoma (HCC) to evaluate the post-interventional tumor vascularization and perfusion of HCC tumor lesions. Image fusion with CEUS performed immediately was compared with the result at the end of TACE (DSA), with post TACE CT (non-enhanced CT within 24 hours) and with follow up CT (enhanced CT after 6 weeks) after embolization. Ultrasound was performed using a 1-5 MHz multifrequency SonoVue transducer (LOGIQ 9/GE) after a bolus injection of 2-4ml SonoVue® with contrast harmonic imaging (CHI). Thirteen examinations were fused with a contrast enhanced CT, 7 with a MRI performed before TACE.

RESULTS

The post-interventional volume navigation image fusion of CT or MRI with CEUS showed differences regarding the residual tumor perfusion compared to other modalities. The correlation (Spearman-test) between the perfusion result at the end of TACE, non-enhanced CT after TACE and image fusion with CEUS was 0.42 and 0.50. The difference between the result at the end of TACE and the fusion with CEUS was significant (p < 0.05, Wilcoxon-test). The correlation between fusion of CEUS with CT/MRI and follow-up CT (after 6 weeks) was 0.64, the difference was not significant (p > 0.05). The differences between native CT within 24 hours after TACE and follow up CT after 6 weeks or fusion of CEUS and CT/MRI were significant (p < 0.05). The inter-observer variability was 0.61 at the end of TACE, 0.58 at non-enhanced CT (within 24 hours), 0.87 at fusion CEUS with CT/MRI and 0.74 at follow up CT after 6 weeks (Cohens Kappa test).

CONCLUSION

Image fusion with volume navigation (VNav) of CEUS with CT or MRI allows an accurate localisation of foci in patients with HCC. This exact mapping permits an easier control and evaluation of the results after TACE. The fusion of CEUS and CT or MRI allows a better evaluation of the microcirculation and the residual tumor perfusion at an earlier point of time than usual modalities of therapy control like non-enhanced CT. This might lead to a more differentiated monitoring of therapy.

Detection and characterization of endoleaks following endovascular treatment of abdominal aortic aneurysms using contrast harmonic imaging (CHI) with quantitative perfusion analysis (TIC) compared to CT angiography (CTA)

PURPOSE

To show the feasibility of the detection of endoleaks following endovascular treatment of aortic aneurysms using contrast harmonic imaging (CHI) in comparison to computed tomography angiography (CTA).

MATERIALS AND METHODS

51 patients with suspected endoleaks, who underwent previous endovascular treatment for abdominal aortic aneurysm, were examined using CTA and vascular ultrasound. Biphasic CTA in all cases and digital subtraction angiography (DSA) in 8 patients were evaluated by two radiologists in consensus and served as the standard of reference. Ultrasound was performed by an experienced examiner with a multi-frequency linear transducer (2 - 4 MHz) using CHI following bolus injection of 2.4 ml of SonoVue® IV (maximum 5 ml). All images were evaluated by two observers in consensus regarding the reperfusion of the abdominal aneurysm using time intensity curve (TIC) analysis.

RESULTS

In 30 of 51 patients, endoleaks were detected concordantly in CHI and CTA. In 20 of 51 patients, no endoleak was found in CHI and CTA/DSA. In one patient, a type II endoleak could initially only be detected in CHI and was later confirmed in follow-up examinations by CTA (sens. 99%, spec. 93%, NPV 99 %, PPV 95%). TIC analysis allowed evaluation of the perfusion dynamics of endoleaks in all patients. Significant differences were found (p < 0.05, Mann Whitney U Test) regarding the perfusion within the aneurysm when an endoleak was present (10.39 ± 4.29 dB) or not present (6.42 ± 2.86 dB).

CONCLUSION

CHI with perfusion analysis allows definite detection of endoleaks, especially if contraindications for CTA are present. CHI presents an alternative for follow-up monitoring.

Transmural penetration of intravenously applied microbubbles during contrast-enhanced ultrasound as a new diagnostic feature in patients with GVHD of the bowel

GVHD is a common complication in patients after allo-SCT. Early detection is important because early therapy may improve the outcome. We evaluated contrast-enhanced ultrasound (CEUS) in patients with GVHD to assess typical imaging features. CEUS was performed in nine patients with histologically proven GVHD. As a control four healthy volunteers and six patients with Crohn's disease (CD) were examined. We employed a high-resolution multi-frequency transducer (6-9 MHz) with contrast harmonic imaging. After the injection of 2.4 mL SonoVue (Bracco, Milan, Italy) intravenously data were acquired and stored digitally. Regions of interest were manually placed over the surrounding mesenteric fat, bowel wall and bowel lumen. Maximum signal increase of each compartment was calculated. Patients with CD and GVHD showed significant contrast uptake in the bowel wall. In contrast to CD patients and healthy volunteers, patients with GVHD showed transmural penetration of microbubbles into the bowel lumen. We assume that the damaged gut mucosal barrier in GVHD enables the microbubbles to penetrate through the bowel wall into the bowel lumen. The penetration of microbubbles into the bowel lumen may serve as a novel diagnostic feature for GVHD if confirmed in controlled clinical trials.

[Cost analysis of contrast-enhanced cranial MRI at a German university hospital]

PURPOSE

Detailed evaluation and cost analysis of a cranial contrast-enhanced MRI (c-ceMRI) in outpatients, inpatients, patients in an intensive care unit and children under anesthesia.

MATERIALS AND METHODS

Based on a detailed process-oriented model, we calculated the cost of a cranial MRI for the four situations mentioned above. A comprehensive evaluation of the overhead and personnel costs was performed.

RESULTS

We performed 5108 MRI examinations on 2 scanners in the year 2008. 2150 examinations (42 %) were identified as c-ceMRI. For inpatients we calculated a total cost of € 242.46 per examination with a personnel cost of € 81.71 for the radiological department. In outpatients we calculated total costs of € 181.97 with radiological personnel costs of € 68.67. Patients coming from an intensive care unit were treated by an intensive care team, which resulted in total costs of € 416.58 with € 283 in costs for radiological personnel (32.8 %). MRI examinations of children under anesthesia resulted in costs of € 616.79 for the hospital, of which € 285.78 were radiological personnel costs (34.5 %).

CONCLUSION

In this study we evaluated for the first time different radiological scenarios of a c-ceMRI at a university hospital. Considering the present reimbursement situation, all outpatients covered by statutory health insurance resulted in a deficit for the hospital. Particularly high costs for patients in intensive care units as well as for children under anesthesia have to be taken into account and are currently not adequately covered by care providers.

New perfusion imaging of tissue transplants with Contrast Harmonic Ultrasound Imaging (CHI) and Magnetic Resonance Imaging (MRI) in comparison with laser-induced Indocyanine Green (ICG) fluorescence angiography

PURPOSE

Evaluation of post-surgery tissue perfusion of free flaps of the lower leg with contrast enhanced harmonic imaging (CHI), laser-induced indocyanine green (ICG) fluorescence angiography and magnetic resonance imaging (MRI).

MATERIALS AND METHODS

10 patients with free flaps of the lower limb were evaluated with CHI, ICG-fluorescence angiography and perfusion weighted MRI. Perfusion weighted MRI was performed after intravenous bolus injection of 25 ml Gd-DTPA. The ICG fluorescence was detected by a near-infrared-laser device (lambda em = 780 nm). Ultrasound was carried out by an experienced examiner with a linear probe after intravenous bolus injection of 2.4 ml SonoVue. For MRI time intensity curves as well as color-coded blood volume maps of the whole free flap were qualitatively evaluated. For CHI and ICG time intensity curves in selected regions of interest were analyzed. A score from 1-5 (1 = low, 5 = excellent) was used for analysis of perfusion images by three independent readers.

RESULTS

In 3 cases (radialis, parascapular and lateral thigh flap) CHI, MRI and ICG perfusion imaging showed an excellent (score 4-5) contrast enhancement of the cutaneous and subcutaneous part of the free flaps. In 2 cases of osteocutaneous flaps perfusion in central and distal parts of the free flaps was reduced (score 2). Correlation between CHI, MRI and ICG was 0.69-0.83 for the distal parts of the free flaps and 0.74-0.87 for the center of the flaps (Spearman test). Perfusion in the center of the free flaps was significantly different for MRI and ICG and also for MRI and CHI (p<0.05, Wilcoxon test).

CONCLUSION

These first results introduce CHI and MRI perfusion imaging as a promising post-surgery monitoring in patients with free flaps.

Multidetector CT (MD-CT) in the diagnosis of uncertain open globe injuries

PURPOSE

To evaluate the significance of multislice CT for the diagnosis of uncertain penetrating globe injuries.

MATERIALS AND METHODS

Based on a retrospective chart review between 2002 and 2007, we identified 59 patients presenting with severe ocular trauma with uncertain rupture of the globe due to massive subconjunctival and/or anterior chamber hemorrhage. The IOP (intraocular pressure) was within normal range in all patients. High resolution multidetector CT (MD-CT) scans (16 slice scans) with axial and coronar reconstructions were performed in all patients. The affected eye was examined for signs of penetrating injury such as abnormal eye shape, scleral irregularities, lens dislocation or intravitreal hemorrhages. Four experienced radiologists read the CT scans independently. Beside the diagnosis, the relevant morphological criteria and the optimal plane orientation (axial or coronar) were specified. The sensitivity, specificity, and negative and positive predictive value were calculated. Additionally the interobserver variability was determined by applying the Cohen's kappa test. Surgical sclera inspections were performed in all cases as a standard of reference. The evaluations of the CT examination were compared with the surgery reports.

RESULTS

59 patients were evaluated (42 men, 17 women). The mean age was 29 years (range 7 - 91). In 17 patients a rupture of the globe was diagnosed during surgery. 12 of these 17 penetrating injuries (70.6 %) were classified correctly by MDCT, 5 of the 17 (29.4 %) were not detectable. 42 patients did not have an open globe injury. 41 of these patients were diagnosed correctly negative by MDCT, and one patient was classified false positive. This results in a sensitivity of 70 % with a specificity of 98 %. There was high inter-rater agreement with kappa values between 0.89 - 0.96. Most discrepancies were caused by wrong negative findings. The most frequent morphologic criteria for open globe injury were the deformation (n = 10) and the volume reduction (n = 7) of the globe. These changes were most certain and visible in the axial orientation.

CONCLUSION

In about one third of all unclear cases with rupture of the globe due to severe trauma, CT evaluation failed to correctly diagnose the open globe injury, which might lead to a delay in necessary surgical intervention. Thus, surgical sclera inspection is always mandatory in such unclear trauma cases regardless of the MD-CT results.