Internal Impingement of the Shoulder: A Risk of False Positive Test Outcomes in External Impingement Tests?

BACKGROUND: External impingement tests are considered as being particularly reliable for identifying subacromial and coracoid shoulder impingement mechanisms. The purpose of the present study was to evaluate if these tests are likely to provoke an internal shoulder impingement mechanism which, in cases of a pathologic condition, can lead to a positive test result. METHOD: In 37 subjects, the mechanical contact between the glenoid rim and the rotator cuff (RC) was measured quantitatively and qualitatively in external impingement test positions using an open MRI system. RESULTS: Mechanical contact of the supraspinatus with the posterosuperior glenoid was present in 30 subjects in the Neer test. In the Hawkins test, the subscapularis was in contact with the anterosuperior glenoid in 33 subjects and the supraspinatus in 18. In the horizontal impingement test, anterosuperior contact of the supraspinatus with the glenoid was identified in 35 subjects. CONCLUSION: The Neer, Hawkins, and horizontal impingement tests are likely to provoke the mechanism of an internal shoulder impingement. A posterosuperior internal impingement mechanism is being provoked predominately in the Neer test. The Hawkins test narrows the distance between the insertions of the subscapularis and supraspinatus and the anterosuperior labrum, which leads to an anterosuperior impingement mechanism.

In vivo analysis of coracoid and subacromial shoulder impingement mechanism during clinical examination.

BACKGROUND: Understanding the mechanisms of shoulder impingement created by clinical tests is crucial to accurately evaluate the condition. The objective of this study was to relate mechanisms of subacromial and coracoid impingement occurring in positions of the shoulder during clinical examination, in quantitative and qualitative terms. METHODS: A 1.0T open magnetic resonance imaging system was used in 18 female and 19 male subjects, to determine the distances between the humeral head and the acromion or coracoid, and contact with the rotator cuff (RC). Measurements were taken with the shoulder in neutral, "Hawkins", "Neer", and 90° abduction/15° internal rotation (horizontal impingement test) positions. Additionally, impingement was classified based on the grade of RC contact with the acromion or coracoid. RESULTS: In the Hawkins position, distance between the supraspinatus and the coracoid was closest (14.5 ± 4.5 mm), while the coracohumeral distance (CHD) narrowed (p < 0.001). In the horizontal impingement test position, the minimum distance between the subscapularis and coracoid was found, whereas the CHD increased (27.4 ± 5.7 mm). In the Neer and Hawkins positions, the space between the greater tuberosity and acromion was significantly narrowed, which was also the case in the horizontal impingement test position compared to neutral position (p < 0.001). CONCLUSION: Shoulder movements of forward flexion and internal rotation (Hawkins test) and abduction and internal rotation (horizontal impingement test) can lead to different coracoid impingement mechanisms during clinical examination. The Hawkins, Neer, and horizontal impingement tests lead to comparable narrowed acromiohumeral distances and subacromial contact of the RC. LEVEL OF EVIDENCE: Therapeutic level III.

Radiologic examinations in human temporal bone specimens using digital volume tomography and high-resolution computed tomography after implantation of middle ear prosthesis and cochlear implant electrode array.

INTRODUCTION: Adequate imaging of the middle ear and its surrounding structures is an essential preoperative part in ear surgery. In the past, the main disadvantage of computed tomography (CT) scanners was the decreased diagnostic quality due to metallic artifacts. Furthermore, these scanners showed mostly an inferior image quality compared to digital volume tomography (DVT) in the temporal bone. It was the aim of this experimental study to compare the image quality of a state-of-the-art dual-source 2 × 128-slice CT scanner to DVT in temporal bone specimen. MATERIALS AND METHODS: Metallic prosthesis (PORP, TORP, stapes piston, cochlear implant electrode array) and an autologous incus were implanted in temporal bone specimen to analyze the diagnostic quality concerning the characterization of anatomic structures. Three further temporal bones were scanned without any preparation. Independently, 2 otologists and 2 radiologists scored the image quality of defined anatomic structures, using a range from 4 (excellent) to 0 (no diagnostic value). RESULTS: The general score for DVT was 2.67, whereas CT reached a score of 2.76. The diagnostic value for hard contrast objects was 3.0 for DVT and 2.9 for CT, whereas the score for soft tissue was 1.1 for DVT and 2.3 for CT. Almost no quality reduction of the display of anatomic structures caused by metallic artifacts could be detected in both diagnostic modalities. DISCUSSION: Both DVT and high-resolution CT allow good overall image quality in temporal bones, with discrete advantages for digital volume tomographic scans in terms of the image quality of hard contrast objects like bony structures or metallic implants.

Noninvasive in vivo tracking of mesenchymal stem cells and evaluation of cell therapeutic effects in a murine model using a clinical 3.0 T MRI.

Cardiac cell therapy with mesenchymal stem cells (MSCs) represents a promising treatment approach for end-stage heart failure. However, little is known about the underlying mechanisms and the fate of the transplanted cells. The objective of the presented work is to determine the feasibility of magnetic resonance imaging (MRI) and in vivo monitoring after transplantation into infarcted mouse hearts using a clinical 3.0 T MRI device. The labeling procedure of bone marrow-derived MSCs with micron-sized paramagnetic iron oxide particles (MPIOs) did not affect the viability of the cells and their cell type-defining properties when compared to unlabeled cells. Using a clinical 3.0 T MRI scanner equipped with a dedicated small animal solenoid coil, 10(5) labeled MSCs could be detected and localized in the mouse hearts for up to 4 weeks after intramyocardial transplantation. Weekly ECG-gated scans using T1-weighted sequences were performed, and left ventricular function was assessed. Histological analysis of hearts confirmed the survival of labeled MSCs in the target area up to 4 weeks after transplantation. In conclusion, in vivo tracking of labeled MSCs using a clinical 3.0 T MRI scanner is feasible. In combination with assessment of heart function, this technology allows the monitoring of the therapeutic efficacy of regenerative therapies in a small animal model.

Bronchogenic cyst mimicking ischemic heart disease.

Bronchogenic cysts are generally asymptomatic and are detected incidentally by radiographic imaging as a smooth homogeneous mediastinal/pulmonary lesion. We present a case of a large bronchogenic cyst in the posterior mediastinum mimicking ischemic heart disease in a 70-year-old man with unknown heart disease. In patients with chest pain the rare case of a bronchogenic cyst has to be considered for management of atypical angina pectoris.

MRI in patients with pacemakers: overview and procedural management.

BACKGROUND: Magnetic resonance imaging (MRI) is generally contraindicated for patients with a pacemaker (PM) or implantable cardiac defibrillator (ICD), because of the risk of life-threatening interference with the device. Nevertheless, the question whether to perform MRI despite the presence of these devices can still arise when MRI is vitally indicated. In some hospitals, special precautionary measures are taken so that MRI can be performed in such cases. METHODS: This review is based on the authors' experience in 42 patients who underwent MRI at our university hospital, on the pertinent literature, and on the recommendations of medical societies. RESULTS: Because of its excellent image quality, MRI is often an indispensable diagnostic tool. Structured multidisciplinary management enables it to be performed safely even in patients with a PM or ICD. Pre- and post-MRI checks of the device are recommended, as well as extensive monitoring and the availability of the necessary personnel to deal with an emergency. In general, the pacing and defibrillator functions should be deactivated; for pacemaker-dependent patients, the asynchronous pacing mode should be activated. No serious incidents have occurred when these precautions have been observed, either among our own patients or in the literature. Newer PM systems have been approved for MRI scanning under certain conditions. CONCLUSION: In patients with a PM or ICD, the benefit of MRI may far outweigh its risks if the indication has been established for the particular patient as an interdisciplinary decision and if the appropriate precautions are observed during scanning. Now that newer PM systems have been approved for MRI scanning, the problem seems close to being solved.

Transmurality of scar influences the effect of a hybrid-intervention with autologous bone marrow cell injection and aortocoronary bypass surgery (MNC/CABG) in patients after myocardial infarction.

BACKGROUND: Cell therapy (CTx) is a strategy to support cardiac regeneration after myocardial infarction (MI). Thus far, clinical studies provided mixed results. Here, we investigated whether transmurality of the infarct may play a relevant role. METHODS: 18 patients (63 ± 3 years, 15 male) undergoing elective coronary artery bypass graft (CABG) surgery 2.2 ± 0.7 months post MI participated. 10 had transmural and 8 non-transmural infarct scars assessed by Tc-99m-MIBI Single-Photon Emission Computed Tomography (SPECT) and F18-FDG-Positron-Emission-Tomography (PET). During surgery, 10 ml of sternal bone marrow were obtained, mononuclear cells (MNC) were isolated. At the end of surgery MNC were injected into the infarctions' center and border zones (10 injections, 2 ml total, 6.6 ± 1.3 × 10(7) MNC). RESULTS: No major complications attributable to cell therapy were observed. The sizes of non-transmural scars were reduced at 3 and 24 months after treatment (7.7 ± 1.1% and 5.5 ± 1.8 vs. 17.5 ± 4.9%, P=0.05 and P=0.04), while transmural scars remained unchanged (23.5 ± 2.6% and 23.8±3.2 vs. 23.5 ± 2.6%, P>0.99 and P=0.95). A trend towards improved LVEF was seen in patients with non-transmural scars (MRI: 48.8 ± 5.1% vs. 30.6 ± 8.7%, P=0.3; SPECT: 54.1 ± 3.1 vs. 41.0 ± 4.0, P=0.086), but not in patients with transmural scars (MRI: 36.7 ± 3.9 vs. 34.3 ± 5.0, P=0.63, SPECT: 37.8 ± 3.1 vs. 37.9 ± 2.3%, P=0.96). CONCLUSIONS: A single hybrid intervention of MNC recovery, purification and injection with CABG-surgery (MNC/CABG) may be an attractive modality for cell therapy. However, no regeneration of avital transmural scar tissue seems to occur, while the contribution of MNC to improved perfusion in non-transmural myocardial infarct scars remains to be determined.

In vitro measurements of flow using multislice computed tomography (MSCT).

To examine in vitro whether an assessment of flow in normal and obstructed vessels is essentially possible using modern multislice CT-scanners. An experimental model allowed known stenoses to be perfused at defined flow rates. Aorta and coronary arteries were simulated by silicone tubes. A pulsatile pump was used to perfuse water through the system with intermittent injection of a bolus of radio-opaque contrast agent. CT-measurements were carried out with slice orientation perpendicular to the tubes. 50-90% concentric stenoses were examined 5 times at 4 different stenosis slice distances. A mathematical algorithm calculated the temporal density changes within a ROI in the tube cross-sections. Quantitative assessment of the data simultaneously acquired with the 16-slice system for the "coronary" and "aortal" time-density curves showed that the model allowed for exclusion of a ≥ 80% stenosis grade with a 99% probability when the slopes of the density increase quotient was > 0.79; a stenosis grade of ≥ 90% could be excluded when the slopes of the density increase quotient was > 0.52. A Quotient > 0.94 for "peak density" was associated with a 99% probability of a stenosis grade ≥ 70%. The 64-slice system allowed stenosis grades of ≥ 80% to be discriminated from lower grades. The general feasibility of the in vitro approach was verified in an in vivo model. The spatial, contrast and temporal resolution of CT scanners with at least 16 detector rows enables qualitative and semiquantitative assessment of stenotic changes in flow.

Image quality of digital direct flat-panel mammography versus an indirect small-field CCD technique using a high-contrast phantom.

OBJECTIVE: To compare the detection of microcalcifications on mammograms of an anthropomorphic breast phantom acquired by a direct digital flat-panel detector mammography system (FPM) versus a stereotactic breast biopsy system utilizing CCD (charge-coupled device) technology with either a 1024 or 512 acquisition matrix (1024 CCD and 512 CCD). MATERIALS AND METHODS: Randomly distributed silica beads (diameter 100-1400 µm) and anthropomorphic scatter bodies were applied to 48 transparent films. The test specimens were radiographed on a direct digital FPM and by the indirect 1024 CCD and 512 CCD techniques. Four radiologists rated the monitor-displayed images independently of each other in random order. RESULTS: The rate of correct positive readings for the "number of detectable microcalcifications" for silica beads of 100-199 µm in diameter was 54.2%, 50.0% and 45.8% by FPM, 1024 CCD and 512 CCD, respectively. The inter-rater variability was most pronounced for silica beads of 100-199 µm in diameter. The greatest agreement with the gold standard was observed for beads >400 µm in diameter across all methods. CONCLUSION: Stereotactic spot images taken by 1024 matrix CCD technique are diagnostically equivalent to direct digital flat-panel mammograms for visualizing simulated microcalcifications >400 µm in diameter.

MDCT evaluation of injuries after tram accidents in pedestrians.

Multidetector computed tomography (MDCT) is especially suited for emergency diagnostics in multiple trauma patients. The objectives of this study were to investigate the types and frequencies of injuries associated with tram accidents in pedestrians. Eighteen consecutive pedestrian patients with multiple traumas after tram accidents were evaluated with MDCT in our Level I Trauma Center. The mean age in our patient cohort was 36.9 years with a range from 14-92 years. There was a trend for accident events occurring more commonly during the winter months in middle-aged men, often under the influence of alcohol. Patients were divided into two groups with unilateral or complex injury patterns. In both groups, leading diagnoses were head (83.3%) and thorax injuries (66.6%). Abdominal injuries (44.4%) were less common and mainly found in the complex injuries group. The most serious injuries occurred in the complex injuries group when the victim was caught under or between tramcars. A wide range of injuries is associated with tram accidents in pedestrians, which can be classified into two main injury patterns, unilateral and complex. The life-limiting injuries in this setting involved the head with a mortality rate of 22.2% (four patients) in our cohort.

Percutaneous fluoroscopically guided salvage of misplaced perirectal (125)I prostate seeds-easy way out.

Permanent prostate implants are widely used as therapy for localized prostate cancer. Transperineal placement of (125)I seeds can be directed safely by transrectal ultrasound imaging. Misplaced seeds can produce serious damage in various organs, especially in the rectal mucosa. The rescue of misplaced seeds can be performed with open surgery or with minimally invasive percutaneous intervention. We report a case of percutaneous fluoroscopically guided salvage of misplaced perirectal (125)I prostate customized stranded seeds using an interventional angiographic catheter.

Hybrid contrast-enhanced MR angiography of pelvic and lower extremity vasculature at 3.0 T: initial experience.

PURPOSE: The objective of this study was to describe contrast-enhanced magnetic resonance angiography (MRA) of the lower extremities at 3.0 T system for assessment of high resolution images in patients with peripheral arterial occlusive disease (PAOD). MATERIAL AND METHODS: 21 Patients with suspected PAOD were examined with four-station MRA at a 3.0 T MR system. The MRA protocol consisted of a hybrid technique with two contrast media injections, the first one for visualization of the calf and foot vasculature (non-moving-table technique), the second one for imaging the aortoiliacal and femoral arteries (moving-table technique). For the femoropopliteal and calf station a randomly segmented central k-space ordering (contrast-enhanced timing-robust angiography [CENTRA]) was used. MR-images were analyzed independently by two radiologists with regard to image quality, venous overlap and grade of stenosis. In 6 patients digital subtraction angiography was performed within the following 7 days and evaluated by two radiologists in consensus with regard to the grade of stenosis. The vasculature-tree of each leg was divided in 12 segments, and 3 anatomical regions (iliacal, femoropopliteal, calf/foot). RESULTS: 490 and 488 of 495 arterial segments were visualized with diagnostic image quality by observer 1 and observer 2, respectively. Image quality was excellent in 470 and 457 arterial segments, respectively. Only 4 segments were rendered as non-diagnostic due to venous overlap. Relevant arterial stenoses (50-99%) were detected in 43 and 47 segments by observer 1 and observer 2, 66 and 65 arterial segments, respectively, were interpreted as occluded. CONCLUSION: The hybrid MRA protocol at 3.0 T offers high diagnostic quality for the whole peripheral arterial tree without venous contamination at high spatial resolution.

What determines the efficacy of forced-air warming systems? A manikin evaluation with upper body blankets.

BACKGROUND: Forced-air warming has gained acceptance as an effective means to prevent perioperative hypothermia. However, little is known about the influence of air flow and air temperature at the nozzle and the influence of heat distribution in the blankets on the efficacy of these systems. METHODS: We conducted a manikin study with heat flux transducers using five forced-air warming systems to determine the factors that are responsible for heat transfer from the blanket to the manikin. RESULTS: There was no relation between air temperature at the nozzle of the power unit and the resulting heat transfer. There was also no relation between the air flow at the nozzle of the power unit and the resulting heat transfer. However, all blankets performed best at high air flows above 19 L/s. The heat exchange coefficient, the mean temperature gradient between the blanket and the manikin correlated positively with the resulting heat transfer and the difference between the minimal and maximal blanket temperature correlated negatively with the resulting heat transfer. CONCLUSIONS: The efficacy of forced-air warming systems is primarily determined by the blanket. Modern power units provide sufficient heat energy to maximize the ability of the blanket to warm the patient. Optimizing blanket design by optimizing the mean temperature gradient between the blanket and the manikin (or any other surface) with a very homogeneous temperature distribution in the blanket will enable the manufacturers to develop better forced-air warming systems.

Complete remission in a colon cancer patient with a large, irresectable liver metastasis after XELOX/cetuximab/bevacizumab treatment.

BACKGROUND: Stage IV colorectal cancer is usually an incurable disease. However, patients with resectable metastases have 5-year disease-free survival rates of up to 30%. Even with primarily irresectable disease, cure can be achieved in patients who become operable after neoadjuvant treatment. To improve the prognosis of these patients, highly effective neoadjuvant regimens need to be developed. CASE REPORT: Here, we report the case of a 62-year-old male patient who had been diagnosed with International Union against Cancer (UICC) stage III colon cancer 7 years previously and now presented with a large, irresectable liver metastasis and enlarged perihepatic lymph nodes. After neoadjuvant treatment with cetuximab, bevacizumab and XELOX, the patient showed a complete remission and underwent surgery. Histopathologically, the resected tissue and lymph nodes were free of residual tumor. CONCLUSION: To our knowledge, this is the first report of a complete pathological response in a patient with irresectable colorectal cancer after intensive chemotherapy/anti-EGFR/ VEGF antibody therapy. This combination regimen may help to improve the survival rates for patients with irresectable disease.

Feasibility of peripheral contrast-enhanced magnetic resonance angiography at 3.0 Tesla with a hybrid technique: comparison with digital subtraction angiography.

PURPOSE: To prospectively determine feasibility and diagnostic accuracy of 3D contrast-enhanced MR-angiography (CE-MRA) at 3.0 tesla (T) in patients with peripheral arterial occlusive disease. Digital subtraction angiography (DSA) was used as reference standard. MATERIAL AND METHODS: Thirty consecutive patients with suspected peripheral arterial occlusive disease were examined on a 3.0 T MR system by using the integrated whole body coil. A 4-station examination protocol in hybrid technique was chosen, containing 2 gadodiamide injections, the first one for imaging the calf and foot arteries (single-step technique) and the second injection for the visualization of the aortoiliacal and femoral arteries (bolus-chase MRA). All patients underwent DSA within the following 48 hours. The arterial tree of each leg was divided in 15 segments and 4 anatomic regions (iliacal, femoral, popliteal/proximal calf, distal calf/foot). Two radiologists analyzed the MR-images with regard to image quality, grade of stenosis, and venous overlap. DSA-images were analyzed by 2 radiologists in consensus with regard to the stenosis grade. RESULTS: Eight hundred eighty-five and 884 of 889 arterial segments at CE-MRA were rated with excellent or good diagnostic image quality by observer 1 and observer 2, respectively. In only 3 segments image quality was affected by venous contamination. Sensitivity of CE-MRA for determination of relevant arterial stenoses (50%-99%) and occlusions--as compared with DSA--was 95.3% (both observer) and specificity was 98.5% and 97.8% for observer 1 and observer 2, respectively. CONCLUSION: Peripheral hybrid CE-MRA at 3.0 T is feasible and proved to be reliable at depiction of stenoses and occlusions of the whole pelvic and lower leg arterial system.