MR microscopy of the human fetal upper extremity - a proof-of-principle study.

BACKGROUND: Current knowledge of the human fetal and embryonic development relies on early descriptive studies of humans and from experimental studies of laboratory animals and embryos. Taking the upper extremity as an example, this study explores the potential of magnetic resonance microscopy (MRM) for the assessment of the development of the fetal upper extremity and discusses its correlation with histological findings. METHODS: Ex vivo MRM at 7.1 T (Clin Scan, Bruker Biospin, Germany) was performed in 10 human specimens at 8 to 12 weeks of gestational age (GA). In-plane resolution was 20 µm with a slice thickness of 70 µm. MRM was followed by histological work-up of the specimens. MRM images were then correlated with conventional histology with a focus on the presence of chondrification and ossification. RESULTS: Ossification of the upper human extremity is detectable at 8 weeks GA in the humerus and the long bones of the forearm. There is excellent correlation for location and size of ossification between MRM and conventional histology. MRM imaging is in accordance with historical studies. CONCLUSION: Ex vivo MRM for the non-invasive assessment of the embryonic and fetal development of the upper human extremity is feasible. It may provide an accurate complementary tool for the evaluation of embryological development.

Results of Mannerfelt wrist arthrodesis for rheumatoid arthritis in relation to the position of the fused wrist.

PURPOSE: The wrist is involved early in rheumatoid arthritis and is often severely affected. A stable wrist is crucial to good hand function, which often necessitates a fusion. One of the most commonly used techniques in rheumatoid patients is the Mannerfelt arthrodesis. In this retrospective study the outcome and the patient's subjective satisfaction are presented and compared to other techniques. Also the influence of the position of the wrist following a fusion procedure is analysed. METHODS: Thirty-four wrists were retrospectively analysed using radiological measurements, functional scores such as the Disabilities of the Arm, Shoulder and Hand (DASH) and a pain assessment. The objective function of the hand with the fused wrist was assessed. RESULTS: In 92.6% of wrists the patients rated their satisfaction as good or excellent. The mean DASH score post-operatively was 63.3. Of the wrists, 17 were fixed in a median flexed position of 13° and 17 wrists in a median extended position of 8°. There was no statistically significant correlation between the position of the wrist and the satisfaction or objective function. The rate of fusion was 94.1%. CONCLUSIONS: The Mannerfelt arthrodesis achieves good results and provides a high rate of satisfaction and pain relief in our study. It has major advantages compared to other wrist fusion techniques in the rheumatoid patient. We could not show clear statistical evidence for better results in either a flexed or an extended position, but the ratings of the patients indicated better subjective results with a slightly extended position of the arthrodesis.

MR microscopy of the developing upper extremity of the chicken in ovo using 7 Tesla MRI.

MR microscopy (MRM) is known as ultra-high-field (UHF) magnetic resonance imaging with an in-plane spatial resolution of <100 µm, yields highly resolved non-invasive anatomical imaging and allows longitudinal assessment of embryonic avian development. The aim of the present study was to evaluate the feasibility of in vivo anatomical MRI assessment of the developing upper extremity of the chicken. Thirty-eight fertilized chicken eggs were examined at 7 Tesla acquiring high-resolution T2-weighted images with an in-plane resolution of 74 × 74 µm. To reduce motion artefacts, the eggs were moderately cooled before and during MRI. Development of the upper extremity was anatomically and quantitatively assessed. Chondrification and ossification on MRI were correlated with histological examination. MRM allowed the identification of the embryo from stage D5 onwards. First chondrification of the upper extremity was visible at stage D7, and the differentiation of the forearm was possible from stage D9 throughout the developmental period with excellent correlation to histology. MRM also allowed the differentiation between cortical and medullary bone as well as the detection of chondrified areas. UHF MRM allows the in vivo and in ovo evaluation of the upper limb during embryonic development and provides non-invasive longitudinal anatomical information. This technique allows longitudinal studies of the same embryo during the developmental period and may therefore provide further insights into the development of the upper extremity. With improved coil technique and increasing availability of UHF MR systems, there is great potential regarding several research topics in experimental musculoskeletal radiology.

Effects of prenatal Doppler ultrasound on the retina of the chick embryo in ovo.

Currently, the effect of prenatal ultrasound on foetal development is intensively discussed and the guidelines for prenatal diagnostics have been changed. However, data supporting these concerns are scarce. Therefore, we used an established in ovo model of the chicken embryo to investigate cell proliferation and apoptosis within the retina. A total of 21 chicken eggs were fenestrated on Day 5 and allocated to either the control (n = 8) or exposition group (n = 13). The exposition group was treated with pulsed-wave Doppler ultrasound (PWD) for 10 min while controls remained without treatment. After subsequent incubation (6-48 h), the eggs were sacrificed, and chicken embryos were examined morphologically (HE-staining) and immunohistochemically. Counting of apoptotic and proliferating cells per retina was performed using antibodies specific for phospho-histone-H3 and active caspase-3 in combination with a biotin-labelled secondary antibody and peroxidase conjugated avidin-biotin complex for chromogenic detection. Due to a rather low number of specimens at each time point after ultrasound exposition, we neglected the effects of incubation time and focused on treatment effects. This approach revealed that the median number of proliferating cells is reduced after 10 min of exposure to PWD (569 vs. 766), while the number of apoptotic cells is fairly comparable between groups (5 vs. 6). Our data contribute to a better understanding of prenatal US on foetal development by suggesting that PWD could have an impact on the number of proliferating cells in the developing chicken retina and therefore justify further investigations.

Acute inversion injury of the ankle without radiological abnormalities: assessment with high-field MR imaging and correlation of findings with clinical outcome.

BACKGROUND: Acute inversion injuries of the ankle are the most common sports accidents, accounting for approximately 10% of emergency room admissions. In up to 85%, an injury of the lateral collateral ligaments is observed. Classically, the assessment of these injuries has relied on clinical examination and radiographs, including stress views. The aim of our study was to correlate prospectively the findings of high-field 3 T MRI in acute ankle distortion with clinical outcome. METHODS: During a 6-month period, 38 patients were prospectively included. MRI was performed within 48 h of trauma and clinical examination using a protocol consisting of axial T2-weighted and coronal and sagittal T1-weighted images and a sagittal proton density (PDw) sequence. Each ligament injury was graded on a three-point scale. Functional outcome was evaluated using the AOFAS ankle-hindfoot scale. RESULTS: In 24/38 patients (63.12%), ligament injury was observed. In 22/24 cases, this was an injury of the lateral ligaments and in 2/24 cases of the medial ligaments. Injury of the syndesmosis occurred in three patients, a bone bruise in four, and an osteochondral lesion in three cases. Patients with an injury of two or more ligaments or a bone bruise had a lower AOFAS score and returned to sports activities and full weight-bearing later (P < 0.01). CONCLUSION: MR imaging at 3 Tesla is an independent predictor for clinical outcome. Therefore MRI may be beneficial in those cases where the findings influence further treatment.

Rectal intussusception due to re-recurrent ovarian fibrosarcoma.

BACKGROUND: Primary ovarian fibrosarcomas are very rare tumours associated with an extremely poor prognosis. Most patients relapse or die within 2 years. Because of the low incidence, it is difficult to identify prognostic factors or to establish treatment guidelines. CASE REPORT: In this report, we present a patient with the second relapse of an ovarian fibrosarcoma localised in the rectosigmoid. The tumour caused intussusception into the rectum, leading to large bowel obstruction. After complete resection of the tumour, the patient completely recovered. 28 months after primary diagnosis, follow-up did not show any signs of recurrent tumour disease. CONCLUSIONS: Reviewing the literature, it is recommended that all patients should primarily be operated on and generally be followed up closely. In patients with incomplete resection, palliative chemo- and/or radiotherapy is recommended. In our opinion, in patients with complete resection, adjuvant chemo- and/or radiotherapy should be considered. Only in patients with high-grade fibrosarcomas, adjuvant intra- or postoperative radiotherapy should be applied.

Differences in Neuronal Representation of Mental Rotation in Patients With Complex Regional Pain Syndrome and Healthy Controls.

Spatial integration of parts of the body is impaired in patients with complex regional pain syndrome (CRPS). Because the training of mental rotation (MR) has been shown to be among the effective therapy strategies for CRPS, impairment of MR is also important for the pathophysiological understanding of CRPS. The aim of this study was to evaluate whether differences in the neural representation of MR occur between patients with CRPS and healthy controls (HC). Therefore, we included 15 patients with chronic CRPS and 15 age- and gender-matched HC. We assessed behavioral (accuracy and reaction time for MR of both hands), clinical (Disabilities of Arm, Shoulder and Hand questionnaire) and magnetic resonance imaging (T1-weighted, function magnetic resonance imaging during MR) data. Reaction times in the patient group were delayed compared with HC without a lateralization effect for the affected hand side. Although both groups showed an activation pattern typical for MR, only HC showed a highly significant contrast for the rotated versus unrotated hands in the right intraparietal sulcus. Patients with CRPS showed a reduction of functional magnetic resonance imaging activation in areas including the subthalamic nucleus, nucleus accumbens, and putamen. Regression analysis for the CRPS group emphasized the importance of putamen and nucleus accumbens activation for MR performance. This study highlights the reduced access of patients with CRPS for mental resources modulating arousal, emotional response, and subcortical sensorimotor integration. PERSPECTIVE: This study localized the underlying neural responses for impaired mental rotation in patients with complex regional pain syndrome as a decrease in basal ganglia (putamen) and nucleus accumbens activation.

[Hyperspectral imaging demonstrates microcirculatory effects of postoperative exercise therapy in Dupuytren's disease]. / Hyperspektralimaging demonstriert mikrozirkulatorische Effekte postoperativer Ergotherapie bei Patienten mit Morbus Dupuytren.

BACKGROUND: Dupuytren's disease (DD) is a common connective tissue disorder of the hand. To prevent recurrence of contractures, patients usually receive early postoperative ergotherapy (ET). However, it is yet unknown how this measure impacts on local blood flow and hence on the occurrence or prevention of postoperative complications. Hyperspectral imaging (HSI) allows for a quantitative evaluation of tissue perfusion by measuring oxygen saturation and tissue water content. OBJECTIVE: The aim of this work was to evaluate the microcirculatory effects of early ET after partial fasciectomy in DD using HSI for optimised treatment and prevention. PATIENTS AND METHODS: In five patients, the oxygen saturation and tissue water content of the hand were measured before and 20 min after exercise therapy on the first two postoperative days using HSI. RESULTS: HSI demonstrated improved tissue perfusion in terms of quantity and quality following ET in all patients. After ET, all patients showed a relative increase in oxygen saturation of up to 20 % and a reduction in tissue water of up to 17 %. CONCLUSION: HIS allows for a fast and non-invasive evaluation of increased oxygen supply and decreased tissue water content in the surgical site after partial fasciectomy in DD following postoperative exercise therapy. This may improve wound healing and decrease the rate of recurrence in DD.

Ultrahigh-Field Quantitative MR Microscopy of the Chicken Eye In Vivo Throughout the In Ovo Period.

PURPOSE: Ultrahigh-field MRI (UHF-MRI) with an in-plane spatial resolution of less than 100 µm is known as MR microscopy (MRM). MRM provides highly resolved anatomical images and allows quantitative assessment of different tissue types using diffusion-weighted imaging (DWI). The aim of the present study was to evaluate the feasibility of combined in vivo anatomical and quantitative assessment of the developing chicken eye in ovo. PROCEDURES: Thirty-eight fertilized chicken eggs were examined at 7.1 T (ClinScan, Bruker Biospin, Germany) acquiring a dataset comprising T2-weighted anatomical images, DWI, and diffusion tensor imaging. To reduce motion artifacts, the eggs were moderately cooled before and during MR imaging. Two eggs were imaged daily for the entire developmental period, and 36 eggs were examined pairwise at only one time point of the embryonic period. Development of the eye was anatomically and quantitatively assessed. RESULTS: From the D5 embryonic stage (116-124 h), MRM allowed differentiation between lens and vitreous body. The lens core and periphery were first identified at D9. DWI allowed quantification of lens maturation based on a significant decrease in apparent diffusion coefficient values and course of fractional anisotropy. Repeated moderate cooling had no influence on the development of the chicken embryo. CONCLUSIONS: MRM allows in vivo assessment of embryonic development of the chicken eye in ovo without affecting normal development. The method provides anatomical information supplemented by quantitative evaluation of lens development using DWI. With increasing availability of ultrahigh-field MR systems, this technique may provide a noninvasive complementary tool in the field of experimental ophthalmology.

Hyperspectral imaging as a novel diagnostic tool in microcirculation of wounds.

Monitoring of perfusion is a cornerstone in surgery, phlebology and basic science to proof wound healing by interventions. In chronic wound management it is of utmost importance to realize and parametrize wound bed perfusion to verify actual, and plan further treatment by noninvasive diagnostics. Up to now monitoring is based on visual inspection of wounds as conventionally practiced over more than decades. The main problems of visual inspection are the lack of standardization and comparability because of interindividual variations. Therefore technical performance with contact free probes based on standardized perfusion measuring is strongly needed. Hyperspectral imaging (HSI) was investigated to overcome manual and visual wound inspection in monitoring of wound healing. HSI works noninvasive, and imaging of relevant perfusion parameters is possible without the need of contrast enhancing drugs. METHODS: HSI technology uses imaging spectroscopic analysis in visual and near infrared spectrum to get information on imaged tissue in less than 10 s. Tissue is radiated by broad spectrum light and the following parameters are calculated from remitted spectra: the grade of oxygenation and the volume proportion of hemoglobin (in superficial and also deeper (8 mm) tissues. The calculated data comprise the "Tissue hemoglobin oxygen saturation" (StO2) as percental oxygenation index to assess superficial perfusion (VIS-spectrum), the "Near infrared perfusion" (NIR) to assess deeper perfusion (near infrared spectrum) and the "Tissue hemoglobin index" (THI) to measure the percental volume of hemoglobin of surface perfusion (VIS-spectrum). The measurements of these parameters are calculated as false color-coded perfusion results on screen.We investigated different kind of wounds (combustion, infection, ulcer wounds, wounds in immune disorders, trauma wounds) determining superficial and deeper oxygen saturation, hemoglobin distribution and water content using hyperspectral imaging with TIVITA™ Tissue system. RESULTS: Hyperspectral Imaging allowed easy real time determination and visualization of hemodynamically relevant parameters- superficial and deeper oxygen saturation, total hemoglobin and tissue water content. In the patient with scleroderma, acral lesions with decreased perfusion correlated well with necrotic skin aspects.HSI clearly revealed macroscopic conspicuous suture wounds after Dupuytren surgery, infected soft tissue wounds with strong inflammatory hyperemia, edema in burn injuries, spatial geometry of abscess formation and chronic ulcer wounds. All measurements influenced further surveillance decisions. Hyperspectral imaging seems suitable for routine diagnostics and monitoring of skin and soft tissue lesions like acute and chronic wounds. It allows surveillance of postoperative suture wounds and burn wounds. Special indications may be transplant surveillance and monitoring of therapeutical interventions.

3-Tesla Kinematic MRI of the Cervical Spine for Evaluation of Adjacent Level Disease After Monosegmental Anterior Cervical Discectomy and Arthroplasty: Results of 2-Year Follow-Up.

STUDY DESIGN: We prospectively evaluated adjacent disc levels after anterior cervical discectomy and arthroplasty (ACDA) using kinematic magnetic resonance imaging (MRI) and plain functional radiographs. OBJECTIVE: ACDA is an established treatment for degenerative cervical disc disease. The objective of this study was to evaluate the use of kinematic MRI for assessing the range of motion (ROM) before and after ACDA compared with plain functional radiographs and to evaluate adjacent degenerative disc disease (aDDD) at mid-term follow-up. SUMMARY OF BACKGROUND DATA: Twenty patients (12 females, 8 males; median age 45.6 ±â€Š6.9 yrs) treated by ACDA (BryanDisc; Medtronic, MN) underwent plain functional radiography and kinematic MRI of the cervical spine at 3 T before and 6 and 24 months after surgery. METHODS: A sagittal T2-weighted (T2w) 2D turbo spin echo (TSE) sequence and a 3D T2w dataset with secondary axial reconstruction were acquired. Signal intensity of all nonoperated discs was measured in regions of interest (ROI). Disc heights adjacent to the operated segment were measured. ROM was evaluated and compared with plain functional radiographs. Clinical outcome was evaluated using the visual analog scale (VAS) for head, neck and radicular pain, and the neck disability index (NDI). RESULTS: Mean ROM of the cervical spine on functional plain radiographs was 21.25 ±â€Š8.19°, 22.29 ±â€Š4.82°, and 26.0 ±â€Š6.9° preoperatively and at 6-month and 24-month follow-up, respectively. Mean ROM at MRI was 27.1 ±â€Š6.78°, 29.45 ±â€Š9.51°, and 31.95 ±â€Š9.58°, respectively. There was a good correlation between both techniques. Follow-up examinations demonstrated no signs of progressive degenerative disc disease of adjacent levels. All patients had clinical improvement up to 24 months after surgery. CONCLUSION: After ACDA, kinematic MRI allows evaluation of the ROM with excellent correlation to plain functional radiographs. Mid-term follow-up after ACDA is without evidence of progressive DDD of adjacent segments. LEVEL OF EVIDENCE: 3.

Comparison of clinical results after pisiformectomy in patients with rheumatic versus posttraumatic osteoarthritis.

Pisotriquetral osteoarthritis is important to consider in the differential diagnosis of chronic ulnar-sided wrist pain. It can develop following traumatic injury to the pisiform or in rheumatic diseases, such as rheumatoid arthritis or psoriatic arthritis. It has been shown that pisiformectomy can relieve symptoms in cases that have not responded to nonoperative treatment, and the excision does not compromise the function or strength of the wrist. Most studies focus on posttraumatic causes of pisotriquetral osteoarthritis. In the current study, rheumatic causes are also considered and the outcomes are compared. This retrospective study included 35 patients who underwent pisiformectomy for pisotriquetral osteoarthritis. All patients underwent a thorough diagnostic evaluation to exclude other etiologies for ulnar-sided wrist pain. Radiological examinations including posteroanterior and lateral views of the wrist and a tangential view of the pisotriquetral joint were analyzed. All patients had excellent or very good results after pisiformectomy, with a significant reduction in pain. No significant difference was found in the outcomes for patients with rheumatic vs posttraumatic osteoarthritis. Patients with rheumatic causes of pisotriquetral osteoarthritis can be successfully treated with pisiformectomy. With respect to idiopathic causes, these patients need a longer postoperative period to gain full pain relief. It is important to consider the possibility of pisotriquetral osteoarthritis after excluding other diagnoses in patients with rheumatic osteoarthritis.

Incidence of microperforation for surgical gloves depends on duration of wear.

BACKGROUND: The use of sterile gloves is part of general aseptic procedure, which aims to prevent surgical team members from transmitting infectious agents to patients during procedures performed in an operating room. In addition, surgical gloves also protect team members against patient-transmitted infectious agents. Adequate protection, however, requires that the glove material remain intact. The risk of perforations in surgical gloves is thought to correlate with the duration of wear, yet very few prospective studies have addressed this issue. METHODS: We prospectively collected 898 consecutive pairs of used surgical gloves over a 9-month period in a single institution. After surgical team members wore the gloves during surgical procedures, the gloves were examined for microperforations using the watertight test described in European Norm 455, part 1. The gloves were analyzed as a pair; if 1 glove had a perforation, the pair was considered to be perforated. In addition, we evaluated the use of a hand cream that contained a suspension of cornstarch and ethanol to determine its potential influence on the rate of microperforation. RESULTS: Wearing gloves for 90 minutes or less resulted in microperforations in 46 (15.4%) of 299 pairs of gloves, whereas wearing gloves for 91-150 minutes resulted in perforation of 54 (18.1%) of 299 pairs, and 71 of (23.7%) of 300 pairs were perforated when the duration of wear was longer than 150 minutes (P = .05). Subgroup analysis revealed no significant difference in the rates of microperforation for surgeons (56 [23.0%] of 244 pairs of gloves perforated), first assistants (43 [19.0%] of 226 pairs perforated), and surgical nurses (53 [20.5%] of 259 pairs perforated). Of 171 microperforations, 114 (66.7%) were found on the left hand glove (ie, the glove on subjects' nondominant hand), predominantly on the left index finger (55 [32.3%]). The use of the hand cream had no influence on the rate of microperforation. CONCLUSION: Because of the increase in the rate of microperforation over time, it is recommended that surgeons, first assistants, and surgical nurses directly assisting in the operating field change gloves after 90 minutes of surgery.