Improved Detectability of Brain Stem Ischemia by Combining Axial and Coronal Diffusion-Weighted Imaging.

BACKGROUND AND PURPOSE: To evaluate the benefit of a coronal diffusion-weighted imaging (DWI) in addition to standard axial DWI for the detection of brain stem infarctions. METHODS: A retrospective analysis of patients with symptoms consistent with acute and subacute brain stem infarction who received magnetic resonance imaging, including axial and coronal DWI. Diffusion restrictions were identified by 2 independent raters blinded for the final clinical diagnosis in 3 separate reading steps: axial DWI, coronal DWI, and combined axial and coronal DWI. Lesion location and certainty level were both documented for each reading step. In cases of reader disagreement, an additional consensus reading was performed. RESULTS: Two hundred thirty-nine patients were included. Of these, 124 patients (51.9%) were clinically diagnosed with brain stem infarction. Sensitivity, specificity, positive, and negative predictive values were best for combined DWI assessment (90.3%, 99.1%, 99.1%, and 90.5%) compared with axial (85.5%, 94.9%, 94.6%, and 85.8%) and coronal DWI alone (87.9%, 96.5%, 96.5%, and 88.1%). Diffusion restriction on combined DWI was diagnosed in 112/124 patients compared with 106/124 on axial DWI and 109/124 on coronal DWI. Interobserver agreement for the detection of brain stem lesions was the highest in the combined rating step (Cohen κ coefficient=0.94). CONCLUSIONS: Coronal DWI sequences might improve the detection rate of brain stem infarction compared with standard axial DWI. The combined coronal and axial DWI provides the best detection rate while minimally increasing scan times.

Diffusion-weighted imaging of the kidneys in haemolytic uraemic syndrome.

OBJECTIVES: To evaluate the kidneys of patients with haemolytic uraemic syndrome (HUS) using diffusion-weighted imaging (DWI) and Doppler ultrasound (US) compared with healthy controls. MATERIALS AND METHODS: Fifteen patients (mean age 33.3 years; three male; 12 female) with diarrhoea-positive HUS and 15 healthy volunteers were prospectively evaluated with DWI and Doppler US. A total apparent diffusion coefficient (ADCTOT), and ADCs predominantly reflecting microperfusion (ADCLOW) and diffusion (ADCHIGH) were calculated. Doppler US evaluated renal vascularity and flow. RESULTS: When compared with controls, kidneys affected by HUS showed reduced cortical ADC values (ADCTOT 1.79±0.22 vs. 2.04±0.1x10-3 mm2/s, P 0.001), resulting in either low corticomedullary differences (11/15 patients) or an inverted corticomedullary pattern (4/15 patients). Reduction of cortical ADC values was associated with a decrease of cortical vascularity on Doppler US (ADCTOT, P<0.001; ADCLOW, P 0.047). Kidneys with complete absence of the cortical vasculature on Doppler US (four patients) also demonstrated limited diffusion (ADCHIGH, P 0.002). Low glomerular filtration rate, requirement for haemodialysis during hospitalization, and longer duration of haemodialysis were associated with decreased cortical diffusivity (ADCTOT: P 0.04, 0.007, and <0.001, respectively). CONCLUSION: DWI shows qualitative and quantitative abnormalities in kidneys affected by HUS, thereby extending the non-invasive assessment of renal parenchymal damage. KEY POINTS: • In HUS, DWI is feasible for functional characterization of kidney involvement. • Kidneys affected by HUS showed reduced cortical diffusivity. • Decreased cortical diffusivity was associated with lower kidney function. • Requirement and duration of haemodialysis was linked to degree of cortical alterations.

Diffusion-weighted imaging of the healthy pancreas: ADC values are age and gender dependent.

PURPOSE: To investigate the healthy pancreas with diffusion-weighted imaging (DWI) for characterization of age and gender-related differences in apparent diffusion coefficient (ADC) values. MATERIALS AND METHODS: Sixty six volunteers were prospectively enrolled (33 male, 33 female; range 1.4 to 83.7 years of age) and echo-planar DWI of the pancreas was performed. ADC values were measured in the pancreas head, body, and tail using a pixel-by-pixel approach. Effects of age and gender on ADC values were analyzed using a two-factorial multivariate analysis of variance (MANOVA). RESULTS: ADC values correlated inversely with the age of the volunteers. The mean global pancreatic ADC values (× 10(-3) mm(2)/s) in the age groups 0-20 years, 21-40 years, and > 40 years were 1.18 ± 0.19, 1.07 ± 0.13, and 0.99 ± 0.18, respectively. Female individuals had higher mean global ADC values than male (1.13 ± 0.14 versus 1.02 ± 0.18 × 10(-3) mm(2)/s). MANOVA showed significant effects of age (P value 0.022, eta(2) = 0.13) and gender (P value 0.001, eta(2) = 0.28) on ADC values. CONCLUSION: Pancreatic ADC values decline with ageing and show significant gender differences with higher mean values in females. The awareness of baseline values adjusted to age and gender will be important for correct interpretation of individual cases and design of future studies.

Comparative diagnostic performance of ¹8F-FDG PET/CT versus whole-body MRI for determination of remission status in multiple myeloma after stem cell transplantation.

OBJECTIVES: To compare the diagnostic performance of whole-body magnetic resonance imaging (WBMRI) versus (18)F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography/computed tomography (PET/CT) for determination of remission status in patients with multiple myeloma (MM) after stem cell transplantation (SCT). METHODS: Thirty-one patients were examined by both WBMRI and PET/CT after SCT. Imaging results and clinical remission status as determined by the clinical gold standard (Uniform Response Criteria) were compared. RESULTS: One hundred four lesions were detected in 21 patients. PET/CT had a sensitivity of 50.0 %, a specificity of 85.7 %, a positive predictive value of 62.5 %, a negative predictive value of 78.3 %, and an overall accuracy of 74.2 % for determination of remission status. MRI had a sensitivity of 80.0 %, a specificity of 38.1 %, a positive predictive value of 38.1 %, a negative predictive value of 80 %, and an overall accuracy of 51.6 %. Concordant results were observed in only 12 (11.5 %) of the 104 lesions. CONCLUSIONS: In the post-treatment setting, both FDG PET/CT and WBMRI provide information about the extent of disease, allowing for a more comprehensive evaluation of persisting or recurrent myeloma. MRI may often be false positive because of persistent non-viable lesions. Therefore, PET/CT might be more suitable than MRI for determination of remission status.

18F-FDG PET/CT for detection and localization of residual or recurrent disease in patients with multiple myeloma after stem cell transplantation.

PURPOSE: The aim of the study was to determine the diagnostic performance of (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT for the detection and localization of residual or recurrent disease in patients with multiple myeloma (MM) after stem cell transplantation. METHODS: A total of 197 whole-body (18)F-FDG PET/CT scans were performed in 99 patients with MM at different time points in the course of disease after autologous or allogeneic stem cell transplantation. Post-transplant PET/CT scans and clinical remission status as determined by the clinical gold standard (Uniform Response Criteria) were analysed and compared. RESULTS: A total of 576 focal osseous and extramedullary lesions were detected in 79 scans. Additional diffuse bone marrow involvement was detected in 17 patients. (18)F-FDG PET/CT had a sensitivity of 54.6%, a specificity of 82.1%, a positive predictive value of 82.3%, a negative predictive value of 54.2% and an overall accuracy of 65.5%. The sensitivity of (18)F-FDG PET/CT was shown to depend on the disease category according to the Uniform Response Criteria for myeloma. CONCLUSION: In patients with MM in the post-transplant setting, (18)F-FDG PET/CT may (1) contribute to the detection and localization of disease, (2) provide information about the extent of distinct myeloma manifestations and the total disease burden and (3) add information about the metabolic activity of disease, but (4) has substantially lower sensitivity for this purpose compared to the pretreatment setting.

Follow-up of radiologically totally implanted central venous access ports of the upper arm: long-term complications in 127,750 catheter-days.

OBJECTIVE: The purpose of this article is to retrospectively evaluate radiologically totally implanted central venous access ports (VAPs) of the upper arm in terms of safety, technical feasibility, and device-related complications. MATERIALS AND METHODS: Five hundred seven consecutive patients (mean [± SD] age, 59.2 ± 11.4 years) who received a totally implanted central VAP between January 2005 and July 2010 were included. The insertion procedure was performed in an interventional radiology suite using the Seldinger technique. Neither antibiotic prophylaxis nor long-term anticoagulation was administered. RESULTS: In 507 patients, a total of 523 devices were implanted. Of these 523 procedures, 512 complete datasets were available during follow-up. The primary technical success rate was 99.04%. All procedures were completed without major complications. During follow-up and with a total number of 127,750 days of totally implanted central VAP implantation (248 ± 279 days/patient; range, 1-1687 days/patient), 50 devices had to be revised because of complications (9.8%). Complications occurred at a mean of 114 ± 183 days (range, 1-1113 days) after placement. Early complications were noted in 21 of 512 cases (4.1%), and late complications were noted in 29 of 512 cases (5.7%). Complications were as follows: local infections, 4.9% (25/512); systemic infections, 0.4% (2/512); venous thrombosis, 1.6% (8/512); paralysis of the median nerve, 0.6% (3/512); skin dehiscence at the port site, 0.2% (1/512); and mechanical problems including catheter line displacement, port hub rotation, and catheter fracture, 2.1% (11/512). CONCLUSION: Radiologic placement of a totally implanted central VAP is a safe procedure with a low rate of both early and late device-related complications. The method is effective for delivery of chemotherapy, parenteral nutrition, and frequent IV medication.

Single-Center Retrospective Comparative Study Evaluating the Benefit of Computed Tomography Angiography Prior to Prostatic Artery Embolization.

PURPOSE: To explore whether a computed tomography angiography (CTA) of the pelvis prior to prostatic artery embolization (PAE) is a beneficial preprocedural planning tool regarding the technical success. MATERIALS AND METHODS: Eighty patients with lower urinary tract symptoms treated with PAE were analyzed retrospectively. Forty of these patients received a CTA of the pelvis prior to the procedure (Group A) and were compared to 40 patients who were treated with PAE without prior CT imaging (Group B). Technical success rate, rate of complications, fluoroscopy time (FT), and mean dose area product (DAP) were assessed and compared. All operators performed at least 50 PAE prior to this study. When needed, cone-beam CT (CBCT) was available during intervention. RESULTS: Mean age was 68.43 ± 8.30 years in Group A and 70.42 ± 7.11 years in Group B (p = 0.252). Mean body mass index was 26.78 ± 3.73 in Group A and 26.85 ± 3.5 in Group B (p = 0.319). Overall technical success was 96.3%. Bilateral PAE was achieved in 60 patients (75.0%) while unilateral PAE was performed in 17 patients (21.3%). Technical failure (no embolization) occurred in two patients of Group A and one patient of Group B. No statistical significance was seen between groups for technical success rate (p = 1.0). Mean DAP was 10,164 × cm2 ± 3944 cGy × cm2 in Group A and 10,039 × cm2 ± 3761 cGy × cm2 in Group B (p = 0.885). Mean FT was 49.27 ± 22.97 min in Group A and 44.32 ± 17.82 min in Group B (p = 0.285). No intervention-related complications during PAE were reported. CONCLUSION: With experienced interventionalists and CBCT available during PAE, preprocedural CTA has no additional benefit for technical outcome.

Diffusion-weighted imaging of the healthy pancreas: apparent diffusion coefficient values of the normal head, body, and tail calculated from different sets of b-values.

PURPOSE: To evaluate differences in apparent diffusion coefficient (ADC) values between head, body, and tail regions and the impact of sets of b-values used in diffusion weighted imaging (DWI) of the normal pancreas. MATERIALS AND METHODS: In 51 healthy volunteers echo-planar DWI of the pancreas was prospectively performed with b-values of 50, 400, and 800 s/mm(2) . All four possible combinations of b-values were used to calculate ADC values in a total of 587 regions in the pancreas head, body, and tail regions. Dependency of ADC values on the anatomical regions and on the applied sets of b-values was calculated using multivariate analysis of variance (ANOVA). RESULTS: Mean ADC values differed significantly between the anatomical regions with the lowest values measured in the pancreatic tail (head 1.13 ± 0.20, body 1.05 ± 0.20, and tail 0.94 ± 0.18 × 10(-3) mm(2) /s; P < 0.05). ANOVA showed no dependency of ADC values on the sets of b-values used. CONCLUSION: ADC values differed significantly between the pancreatic head, body, and tail region, with decreasing ADC values toward the tail. Cautious interpretation of DWI results with adjusted, normalized values adapted to the anatomical region seems advisable. The knowledge of such differences may enhance the method's capability to differentiate between different pancreatic pathologies.

Osteochondral Lesions of the Talus: A Review on Talus Osteochondral Injuries, Including Osteochondritis Dissecans.

This is a review on talus osteochondritis dissecans and talus osteochondral lesions. A majority of the osteochondral lesions are associated with trauma while the cause of pure osteochondritis dissecans is still much discussed with a possible cause being repetitive microtraumas associated with vascular disturbances causing subchondral bone necrosis and disability. Symptomatic nondisplaced osteochondral lesions can often be treated conservatively in children and adolescents while such treatment is less successful in adults. Surgical treatment is indicated when there is an unstable cartilage fragment. There are a large number of different operative technique options with no number one technique to be recommended. Most techniques have been presented in level II to IV studies with a low number of patients with short follow ups and few randomized comparisons exist. The actual situation in treating osteochondral lesions in the ankle is presented and discussed.

Osteochondritis Dissecans of Smaller Joints: The Elbow.

This review presents the current understanding of the etiology, pathogenesis, and how to diagnose and treat osteochondritis dissecans (OCD) at the elbow joint followed by an analysis of particular characteristics and outcomes of the treatment. OCD is seen in patients with open growth plates (juvenile OCD [JOCD] and in adults [AOCD] with closed growth plates [adult OCD). The etiology at smaller joints remains as unclear as for the knee. Mechanical factors (throwing activities [capitulum] seem to play an important role. Clinical symptoms are unspecific. Thus, imaging techniques are most important for the diagnosis. In low-grade and stable lesions, treatment involves rest and different degrees of immobilization until healing. When surgery is necessary, the procedure depends on the OCD stage and on the state of the cartilage. With intact cartilage, retrograde procedures are favorable while with damaged cartilage, several techniques are used. Techniques such as drilling and microfracturing produce a reparative cartilage while other techniques reconstruct the defect with osteochondral grafts or cell-based procedures such as chondrocyte implantation. There is a tendency toward better results when reconstructive procedures for both the bone and cartilage are used. In addition, comorbidities at the joint have to be treated. Severe grades of osteoarthritis are rare.

Position Paper of the German Society for Interventional Radiology (DeGIR) on Prostatic Artery Embolization. / Positionspapier der Deutschen Gesellschaft für Interventionsradiologie (DeGIR) zur Prostataarterienembolisation.

BACKGROUND: In recent years prostate artery embolization (PAE) evolved into a clinically established minimally invasive endovascular treatment option for lower urinary tract symptoms caused by benign prostate syndrome (BPS). METHODS: In this interdisciplinary position paper, initiated by the steering group for research of the German Society for Interventional Radiology (IR), the method of PAE is presented and discussed in the context of current evidence. RESULTS: PAE is a safe IR procedure for the treatment of BPS. In terms of symptom relief, measured with the IPSS (International Prostate Symptom Score), the PAE has comparable effect, similar to the historic gold standard, transurethral resection (TUR) of the prostate. With regard to reducing subvesical obstruction PAE is inferior to TUR, but does not limit subsequent surgery. Based on current evidence, PAE is recommended by the British National Institute for Health and Care Excellence as an alternative therapy. The feasibility under local anaesthesia and the preservation of sexual function are important arguments for patients in favour of interventional therapy. Patient selection and therapy concepts require close interdisciplinary collaboration between urologists and radiologists. CONCLUSION: Effectiveness and safety of PAE for the treatment of BPS are proven. Further randomized trials should focus on long term outcome and help to identify most suitable indications for PAE. KEY POINTS: · PAE, an endovascular procedure, is a patient-friendly, minimally invasive, alternative therapy option of the BPS. · PAE can reduce the symptoms of the lower urinary tract (LUTS), comparable to transurethral resection (TUR). The deobstructive and volume-reducing potential of the PAE is inferior to that of the TUR. · The main advantages of PAE are use of local anesthesia (no general anesthesia required), short patient recovery and maintenance of sexual function, including antegrade ejaculation.. · Based on current evidence PAE should be considered after conservative drug therapy and before TUR.. · The role of PAE in the context of other minimally invasive procedures (MIST) requires further evaluation with an open minded approach towards PAE.. · PAE is carried out by interventional radiologists, usually on a referral basis from urologists, and requires close interdisciplinary cooperation.. CITATION FORMAT: · Kovacs A, Bücker A, Grimm M et al. Position Paper of the German Society for Interventional Radiology (DeGIR) on Prostatic Artery Embolization. Fortschr Röntgenstr 2020; 192: 835 - 846.

Intraoperative cone-beam computed tomography in oral and maxillofacial surgery using a C-arm prototype: first clinical experiences after treatment of zygomaticomaxillary complex fractures.

PURPOSE: To describe the first clinical applications of intraoperative cone-beam computed tomography with an integrated flat-panel detector in oral and maxillofacial surgery after surgical treatment of zygomaticomaxillary complex fractures PATIENTS AND METHODS: Nine cone-beam computed tomography datasets of patients with zygomaticomaxillary complex fractures were intraoperatively acquired using a mobile isocentric C-arm (PowerMobil; Siemens Medical Solutions, Erlangen, Germany), including a flat-panel detector. Datasets based on 400, 200, and 100 fluoroscopic images were performed with different tube currents (4.6 mA, 3.3 mA, 2.3 mA, 1.2 mA, and 0.5 mA) and a current tube voltage of 100 kV. Postprocessing resulted in 15 different datasets available for comparison with corresponding preoperative computed tomography datasets. Four oral and maxillofacial surgeons and 2 experienced radiologists evaluated each dataset regarding noise, transition, and the delimitation of landmarks. RESULTS: All examinations were successfully performed. Reconstructed datasets showed high-resolution images of all midfacial osseous structures in near-computed tomography quality. Regarding high-contrast structures, detailed analyses of datasets acquired in this study suggest that the parameters 400 projections, 1.2 mA, and 100 kV are sufficient. In terms of soft-tissue visualization, a higher level of mA seems preferable. CONCLUSIONS: The tested prototype predicts a new era in cone-beam computed tomography imaging. The integration of a flat-panel detector will overcome the limitations of current available systems. The size of the field of view is increased allowing regularly the visualization of the whole facial skeleton. Particularly in cases of open reduction of unilateral fractures, the assessment of symmetry is of clinical value.

Computed tomography findings in patients with primarily unknown causes of severe or recurrent epistaxis.

OBJECTIVE: In addition to rhinoscopy, computed tomography of paranasal sinuses (CT) may be performed on patients with primary unknown cause of severe epistaxis (SE) or recurrent epistaxis (RE) to further assess the potential cause of bleeding. The aim of this study was to evaluate CT findings during the work-up of intractable epistaxis patients. METHODS: 6937 patients were treated in our emergency department with acute epistaxis between 2009-2018. 304/6937 patients underwent CT and rhinoscopy due to intractable SE or RE. 33 patients presented with head trauma prior to epistaxis and were excluded from the final analysis. In 271 cases the primary causes of SE (n = 252) or RE (n = 19) remained unknown. Two observers retrospectively evaluated CT scans for potential sources of epistaxis. Disagreement was settled by consensus. CT and rhinoscopy findings were compared. RESULTS: In 247/271 (91.1%) SE patients no related pathology was found on CT. A possible cause for epistaxis was found in all RE patients, but only in 5/252 (1.9%) patients with SE. Most tumours (10/11) and inflammatory conditions (9/10) were found in patients with RE. In three SE cases, a tumour was suspected on CT, from which two suspicions were refuted during rhinoscopy. CT revealed 10 cases of inflammatory conditions of the sinus and anatomical variant as potential cause of bleeding. CONCLUSION: For patients with unknown causes of epistaxis, supplementary CT imaging may be a useful diagnostic add-on to rhinoscopy in the event of RE, tumour suspicion or inflammation of the paranasal sinuses. However, in most cases of first-time SE, CT does not necessarily add to the diagnosis. In these cases, the marginal benefit of CT needs to be weighed carefully against its risks.

The spectrum of syndromes and manifestations in individuals screened for suspected Marfan syndrome.

The diagnosis of Marfan syndrome (MFS) is based on evaluating a large number of clinical criteria. We have observed that many persons presenting in specialized centers for "Marfan-like" features do not have MFS, but exhibit a large spectrum of other syndromes. The spectrum of these syndromes and the distribution of "Marfan-like" features remain to be characterized. Thus, we prospectively evaluated 279 consecutive patients with suspected MFS (144 men and 135 women at a mean age of 34+/-13 years) for presence of 27 clinical criteria considered characteristic of MFS. The most frequent reasons to refer individuals for suspected MFS were skeletal features (31%), a family history of MFS, or aortic complications (29%), aortic dissection or aneurysm (19%), and eye manifestations (9%). Using established criteria, we confirmed MFS in 138 individuals (group 1) and diagnosed other connective tissue diseases, both with vascular involvement in 30 (group 2) and without vascular involvement in 39 (group 3), and excluded any distinct disease in 72 individuals (group 4). Clinical manifestations of MFS were present in all four patient groups and there was no single clinical criterion that exhibited positive and negative likelihood ratios that were per se sufficient to confirm or rule out MFS. We conclude that "Marfan-like" features are not exclusively indicative of MFS but also of numerous, alternative inherited diseases with many of them carrying a hitherto poorly defined cardiovascular risk. These alternative diseases require future study to characterize their responses to therapy and long-term prognosis.

A pilot study of docetaxel and trofosfamide as second-line 'metronomic' chemotherapy in the treatment of metastatic non-small cell lung cancer (NSCLC).

BACKGROUND: The aim of this pilot study was to evaluate the efficacy and safety of a chemotherapy containing docetaxel and oral trofosfamide as a 'metronomic' secondline treatment of patients with metastatic non-small cell lung cancer (NSCLC). PATIENTS AND METHODS: 21 patients with stage IV disease NSCLC who had progressed under first-line chemotherapy were enrolled. Previous chemotherapy was platinum-based in 15 patients (71.4%), whereas 6 patients (28.6%) had received platinum-free combination chemotherapy. Patients received docetaxel 25 mg/m(2) on days 1, 8, and 15 every 4 weeks plus trofosfamide 50 mg per day. RESULTS: A total of 62 chemotherapy cycles were administered. The median number of cycles per patient was 3. The overall response rate to chemotherapy was 19%, median overall survival was 6.9 months, the median progression-free survival 2.9 months, the 1-year survival rate 28.6%, and the 2-year survival rate 7.1%. No grade IV toxicity was observed. CONCLUSIONS: Our results suggest that the combination of docetaxel and trofosfamide in a metronomic schedule is active and well tolerable as second-line therapy in patients with metastatic NSCLC. The concept of metronomic chemotherapy promises to be a valuable addition to the existing treatment options in NSCLC and warrants further investigation in phase III studies.

Osteochondritis Dissecans: Etiology, Pathology, and Imaging with a Special Focus on the Knee Joint.

This article is a review of the current understanding of the etiology, pathogenesis, and how to diagnose and treat knee osteochondritis dissecans (OCD) followed by an analysis of and outcomes of the treatments available. OCD is seen in children and adolescents with open growth plates (juvenile OCD) and adults with closed growth plates (adult OCD). The etiology of OCD lesions remains unclear and is characterized by an aseptic necrosis in the subchondral bone area. Mechanical factors seem to play an important role. Clinical symptoms are unspecific. Thus, imaging techniques are most important. Regarding treatment, a tremendous number of publications exist. Spontaneous healing is expected unless there is an unstable fragment, and treatment involves rest and different degrees of immobilization until healing. Patients with open physes and low-grade lesions have good results with conservative therapy. When surgery is necessary, the procedure depends on the stage and on the state of the cartilage. With intact cartilage, retrograde procedures are favorable. When the cartilage is damaged, several techniques can be used. While techniques such as drilling and microfracturing produce reparative cartilage, other techniques reconstruct the defect with additional osteochondral grafts or cell-based procedures such as chondrocyte transplantation. There is a tendency toward better results when using procedures that reconstruct the bone and the cartilage and there is also a trend toward better long-term results when comorbidities are treated. Severe grades of osteoarthrosis are rare.

Early detection of pulp necrosis and dental vitality after traumatic dental injuries in children and adolescents by 3-Tesla magnetic resonance imaging.

OBJECTIVES: More than 50% of all children suffer a traumatic dental injury (TDI) during childhood. In many cases, dentists apply root canal treatment (RCT), which is performed on an average of 7-10 days after replantation. Our aim was to evaluate whether RCT is necessary in many cases, and whether revitalization of affected teeth is possible and measurable by visualization using 3T magnetic resonance imaging (MRI). MATERIAL AND METHODS: Seven healthy children with TDI were treated by repositioning of the affected teeth and reduction of alveolar process fractures followed by splinting. Two weeks after initial treatment, splints were removed. After 6 weeks, all children received 3-Tesla (3T), three-dimensional, high-resolution MRI with a 20-channel standard head and neck coil. The mean age of the children (male/female = 5:2) was 10.8 years (range, 8-17 years). In addition, all children received conventional dental examination for tooth vitality and dental sensitivity to cold and tenderness on percussion. RESULTS: 3T MRI provided excellent images that allowed fine discrimination between dental pulp and adjacent tooth. Using four in-house optimized, non-contrast-enhanced sequences, including panoramic reconstruction, the assessment and analysis of the dental pulp was sufficiently feasible. We could demonstrate reperfusion and thus vitality of the affected teeth in 11 sites. In one child, MRI was able to detect nonreperfusion after TDI of the affected tooth. MRI results were confirmed by clinical examination in all cases. As a consequence of this expectant management and proof of reperfusion and tooth vitality by 3T MRI, only one child had to be treated by RCT. CONCLUSION: 3T MRI is a very promising tool for visualization and detection in the field of dental and oromaxillofacial diseases. By using new 3T MRI sequences in children with TDI, we could demonstrate that RCT are not necessary in every case, and thus could prevent unnecessary treatment of children in the future. Larger studies should follow to confirm the potential benefit in clinical practice.

Bile resistance of coated transjugular intrahepatic portosystemic shunt stents in a flow-model.

PURPOSE: We sought to test the bile resistance of transjugular intrahepatic portosystemic shunt (TIPS) stents with 3 different coatings. MATERIALS AND METHODS: Three stents with different coating materials (monolayer polyethylene terephthalate [PETP], monolayer polytetrafluoroethylene [PTFE], and double layer [PTFE]) were tested in a flow model. After testing the sealing of the system with isotonic saline solution, fresh human bile was circulated. Constant pressure was 50 cm H2O. Bile resistance of the stent membranes was analyzed. RESULTS: Two of the 3 stents proved completely resistant to water. Only the PETP stent was resistant to bile. The PTFE-coated stents were not bile resistant. CONCLUSION: The bile resistance of coated TIPS stents and, thus, the dependency of TIPS shunt patency is called into question. The stent with the reported superior patency rates does not show experimental bile resistance.

Evaluation of four different optimized magnetic-resonance-imaging sequences for visualization of dental and maxillo-mandibular structures at 3 T.

OBJECTIVES: The purpose of this study was to evaluate four in-house optimized, non-contrast enhanced sequences for MRI-investigation of maxillo-mandibular and dental structures by use of 3 T. METHODS: 12 volunteers with different dental status were examined by using a 3 T MRI with a 20-channel standard head-and-neck coil. All images performed were evaluated by using 3D-techniques, with different slice-thicknesses, in 3D T1- and T2-weighted sequences, as well as by using new techniques of image depictions. In addition phantom measurements were performed to estimate the extent of image artefacts caused by retainers and metal implants. RESULTS: Mean age of the participants was 33 years (range, 25.5-62.75 years), and the sex ratio was 5 females to 7 males. We identified different techniques to improve osseous and dental structures, despite problems caused by dental implants, tooth crowns or braces. CONCLUSION: The sequences evaluated offered excellent visualization in 2D and 3D of osseous and dental structures. Anatomical, osseous and dental structures were described at their ROI, in relation to patients with dental and head and neck pathologies. The ability to detect and distinguish pathological processes as soon as possible in 3D with excellent image quality avoiding ionizing radiation remains a challenging domain.

99mTc-MDP SPECT/CT for assessment of condylar hyperplasia.

We report a case of condylar hyperplasia diagnosed with 99mTc-MDP SPECT/CT. A 21-year-old woman with facial asymmetry was referred for assessment of condylar growth activity. SPECT/CT confirmed condylar hyperactivity, and simultaneous low-dose CT contributed to the diagnosis of hemimandibular hyperplasia. SPECT/CT may become a valuable tool for the diagnosis and comprehensive assessment of condylar hyperplasia, providing both functional and morphological information.