Institute of Radiology and Nuclear Medicine

Baselland, Switzerland

Institute of Radiology and Nuclear Medicine

Baselland, Switzerland
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Hirschmann M.T.,Kantonsspital Bruderholz | Mathis D.,Kantonsspital Bruderholz | Afifi F.K.,Kantonsspital Bruderholz | Rasch H.,Institute of Radiology and Nuclear Medicine | And 5 more authors.
Knee Surgery, Sports Traumatology, Arthroscopy | Year: 2013

Purpose: The purpose of this study was to introduce a novel standardized algorithm using SPECT/CT, which promises the potential combined assessment of the biology of the joint in particular the bone-graft-fixation complex and the 3D tunnel placement in patients after ACL reconstruction. Its clinical application and inter- and intra-observer reliability should be critically evaluated. Methods: A novel SPECT/CT localization scheme consisting of 13 tibial, 9 femoral and 4 patellar regions on standardized axial, coronal and sagittal slices is proposed. The tracer activity on SPECT/CT was localized and recorded in 25 consecutive patients using a 3D volumetric and quantitative analysis software. The inter- and intra-observer reliability was assessed for localization and tracer activity. The tunnel position was assessed in 3D-CT using standardized frames of reference. The inter- and intra-observer reliability (OR) of the measured distances were calculated (ICC). Results: The localization scheme for tracer uptake analysis was useful and easily applicable in all 25 knees. It showed very high inter-OR and intra-ORs for all regions (ICC > 0. 80). Tibial and femoral tunnel position measurements showed strong agreement between the readings of the two observers; the ICCs for the position, angulation, length and entry point of the femoral tunnel were >0. 88 (intra-OR) and >0. 86 (inter-OR). The ICC for the position of the tibial tunnel (angulation, length and entry point) was >0. 79 (intra-OR) and >0. 74 (inter-OR). Conclusions: The SPECT/CT algorithm presented is highly reliable and clinically feasible. Combining the 3D-mechanical information on tunnel placement and attachment areas and the 3D metabolic data will be helpful in evaluating patients with pain after ACL reconstruction. © 2012 Springer-Verlag.


Tausch C.,Brust Zentrum Zurich | Baege A.,Brust Zentrum Zurich | Baege A.,University of Zürich | Dietrich D.,Statistical Unit | And 5 more authors.
European Journal of Surgical Oncology | Year: 2013

Background Tracing lymphatic drainage of the ipsilateral arm of node positive breast cancer patients, termed "axillary reverse mapping" (ARM), has recently been described in several reports. We analyzed our experience with this new technique in patients scheduled for axillary lymph node dissection (ALND) and evaluated its usefulness for reducing the incidence of lymphedema. Methods Blue dye was injected subcutaneously along the intermuscular groove of the upper inner arm; radioisotope was injected subcutaneously in the interdigital webspace of the hand. All blue and radioactive lymph vessels and lymph nodes were recorded. Only unsuspicious "ARM lymph nodes" located in the lateral part of the axillary basin were preserved. All other level I and II axillary lymph nodes were removed. Resected ARM nodes were immediately separated from all other lymph nodes. Results ARM was performed in 143 patients subsequently undergoing ALND. ARM lymph nodes were successfully identified in 112 cases (78%). In 55 patients at least one ARM lymph node had to be removed. In 14 of these, tumor involvement was confirmed. In 71 patients one or more ARM nodes were preserved. During a median follow-up time of 19 months no axillary recurrence was noted. 35 of 114 evaluated patients developed lymphedema. Preservation of ARM lymph nodes did not significantly decrease the incidence of lymphedema. Conclusion ARM is feasible for patients with node positive breast cancer. However, we found no evidence that it reduces the incidence of lymphedema. © 2013 Elsevier Ltd. All rights reserved.


Hoffmann R.-T.,Ludwig Maximilians University of Munich | Jakobs T.F.,Ludwig Maximilians University of Munich | Kubisch C.H.,Ludwig Maximilians University of Munich | Trumm C.,Ludwig Maximilians University of Munich | And 4 more authors.
European Journal of Radiology | Year: 2010

This retrospective study aimed to evaluate the feasibility and effectiveness of radiofrequency ablation (RFA) in patients with solitary kidney for the treatment of renal cell carcinoma (RCC). Within 2 years 10 patients (seven males, three females; age 65 ± 8 years) were treated. All patients had a history of nephrectomy of the contralateral kidney. The indications for RFA were inoperability or high probability of complete renal failure after surgical enucleation of the tumor. 13 tumors with a size between 1.9 and 4.2 cm (average 2.7 cm) were treated. In patients with a tumor diameter larger than 2.5 cm a transarterial embolization was performed prior to RFA to reduce heat sink effect and risk of bleeding. Therapeutical success was defined as a lack of contrast enhancement in follow up examinations and shrinking of the treated area. Furthermore all patients' renal function was monitored. RFA of renal tumors under CT-fluoroscopy was feasible in all patients. Within the follow up (3 and 24 months) no tumor recurrence or major complication was detected. One patient developed another RCC and was successfully treated with a second RF-ablation. None of the patients developed renal failure with the need of hemodialysis. In one of the patients a hemorrhage into the surrounding tissue was noticed, which stopped spontaneously. RFA is a valuable and effective therapeutical option in patients with solitary kidney suffering from inoperable renal cell carcinoma. The complication rate is small and an excellent tumor control can be achieved without deterioration of the renal function. © 2008 Elsevier Ireland Ltd. All rights reserved.


Gerhard P.,Kantonsspital Bruderholz | Bolt R.,Institute of Radiology and Nuclear Medicine | Duck K.,Center Hospitalier Of Luxembourg | Mayer R.,Praxisklinik2000 | And 2 more authors.
Knee Surgery, Sports Traumatology, Arthroscopy | Year: 2013

Purpose: The primary purpose of our study was to analyse the long-term outcome of patients treated for anterior cruciate ligament (ACL) tears by anatomical single-bundle ACL reconstruction with patellar tendon autograft. The secondary purpose was to identify predictive factors for good outcome and occurrence of osteoarthritis. Methods: Sixty-three patients (m:f = 54:9; mean age at surgery, 27 ± 7 years) treated by ACL reconstruction were evaluated with a mean follow-up of 16 ± 1 years using IKDC2000, the SF36, Lysholm and Tegner score, Knee Society score, visual analogue scale for pain and satisfaction and KOOS. The femoral tunnel position was evaluated according to Sommer. It was also assessed in percentage of the Blumensaat line and the tibial tunnel position in percentage of the total anterior-posterior plateau length. The extent of osteoarthritis was graded according to the Kellgren-Lawrence score. Results: The total IKDC2000 was normal in 20 (32 %), nearly normal in 29 (46 %), abnormal in 12 (19 %) and severely abnormal in 3 (5 %) of patients. The mean total SF-36 was 89 ± 13, the Lysholm score 95 ± 12, the Knee Society score 191 ± 16 and the total KOOS 84 ± 19. The Tegner score decreased from pre-injury 7(4-10) to 6 (2-10) at follow-up. The Kellgren-Lawrence score was normal in 17 (27 %), suspected osteoarthritis in 25 (40 %), minimal osteoarthritis in 5 (8 %), moderate osteoarthritis in 9 (14 %) and severe osteoarthritis in 3 patients (5 %). The femoral tunnel was in zone A in 43 patients (68 %), in zone B in 16 (25 %) and in zone C in 4 patients (7 %). The femoral tunnel position in percentage of the Blumensaat line was 49 ± 3 (range, 44-57), and the tibial tunnel position in percentage of the total anterior-posterior plateau length was 32 ± 6 (range, 21-46). Patients with meniscal lesion at the time of ACL tear showed significantly less favourable outcomes than those without. Conclusions: Patients treated by the proposed ACL reconstruction technique showed on average good to excellent long-term results. A meniscal lesion at the time of ACL tear was highly predictive for less favourable outcome. Level of evidence: IV. © 2012 Springer-Verlag.


Hirschmann M.T.,Kantonsspital Baselland Bruderholz | Amsler F.,Amsler Consulting | Rasch H.,Institute of Radiology and Nuclear Medicine
European Journal of Nuclear Medicine and Molecular Imaging | Year: 2015

Purpose: Bone single photon emission computed tomography (SPECT)/CT is considered as beneficial in unhappy patients with pain, stiffness or swelling after total knee arthroplasty (TKA). The purpose of this study was to identify typical patterns of bone tracer uptake (BTU), distribution and intensity values in patients after TKA. The above findings were correlated with the type and fixation of TKA, the time from TKA and intraoperative findings at revision surgery. Methods: A total of 100 knees of 84 consecutive patients (mean age ± SD 70 ± 11 years) after TKA with persistent knee pain were prospectively included. All patients underwent clinical examination, standardized radiographs and 99mTc-hydroxymethane diphosphonate (HDP) SPECT/CT as part of a routine diagnostic algorithm. The diagnosis before and after SPECT/CT and final treatment were recorded. TKA component position was determined on 3-D reconstructed images. Intensity and anatomical distribution of BTU was determined. Maximum intensity values were recorded as well as ratios in relation to the proximal midshaft of the femur. Univariate analyses (chi-square test, Pearson’s correlation and t test for independent samples) were performed (p < 0.05). Results: SPECT/CT changed the clinical diagnosis and final treatment in 85/100 (85 %) knees. Intraoperative findings confirmed the preoperative SPECT/CT diagnosis in 32/33 knees (97 %). TKA loosening as well as progression of patellofemoral osteoarthritis (OA) was correctly diagnosed in 100 % of knees. Typical patterns of BTU for specific pathologies were identified. Loose femoral TKA components significantly correlated with increased BTU at the lateral femoral regions (p < 0.05). Loose tibial TKA components significantly correlated with increased BTU at all tibial regions (p < 0.05) and around the tibial peg (p > 0.01). Conclusion: The diagnostic benefits of SPECT/CT in patients after TKA have been proven. Typical pathology-related BTU patterns were identified, which will improve reporting quality. Due to the benefits in establishing the correct diagnosis, SPECT/CT should be part of the routine diagnostic algorithm for patients with pain after TKA. © 2015, Springer-Verlag Berlin Heidelberg.


Awengen R.,Kantonsspital Baselland Bruderholz | Rasch H.,Institute of Radiology and Nuclear Medicine | Amsler F.,Amsler Consulting | Hirschmann M.T.,Kantonsspital Baselland Bruderholz
European Journal of Nuclear Medicine and Molecular Imaging | Year: 2016

Purpose: The primary purpose of this retrospective study was to evaluate the differences of bone tracer uptake (BTU) in symptomatic and asymptomatic knees after bilateral total knee arthroplasty (TKA) and identify typical BTU patterns with regards to TKA component position and alignment. Methods: A consecutive number of 37 patients after bilateral TKA were retrospectively included. The knees were grouped into symptomatic (group A) and asymptomatic (group B) knees. All patients underwent 99m-Tc-HDP-SPECT/CT. Coronal, rotational, and sagittal TKA component position was analysed in 3D reconstructed CT. BTU was anatomically localised and quantified using a validated standardized localization scheme. Maximum BTU values for each area were recorded and normalized values calculated. Signed log-rank test, chi-square test, paired t-tests, and Pearson correlations were used (p <0.05). Results: Symptomatic TKAs were significantly more flexed and had a tendency to be more internally rotated when compared to asymptomatic ones (p < 0.05). In all regions, the mean BTU in asymptomatic knees was lower than in symptomatic knees. In both groups the highest mean BTU was found around the tibial stem (symptomatic 7.30; asymptomatic 6.30, p = 0.061) and at the tip of the tibial stem (symptomatic 5.49; asymptomatic 4.74, p = 0.062). Superior patellar regions showed higher BTU than inferior regions. The highest patellar BTU was found in the superior medial patella (symptomatic 4.99; asymptomatic 3.98, p = 0.048). The lowest BTU was found in the posterior femoral regions (flatsp, flatip, fmedsp, fmedip) (Table 3). Tibial and patellar areas showed twice as high mean BTUs than femoral areas (Fig. 3). A significant correlation of TKA component position and BTU was demonstrated. Conclusions: Distribution and intensity of BTU in SPECT/CT depends on TKA component position and alignment. In addition, typical BTU patterns in symptomatic and asymptomatic knees were identified. A profound knowledge of BTU pattern, TKA component position, and alignment helps to identify pathologies in patients after TKA. Clinical evidence: Diagnostic study, level II © 2015, Springer-Verlag Berlin Heidelberg.


Hirschmann M.T.,Kantonsspital Bruderholz | Mathis D.,Kantonsspital Bruderholz | Rasch H.,Institute of Radiology and Nuclear Medicine | Amsler F.,Amsler Consulting | And 2 more authors.
International Orthopaedics | Year: 2013

Purpose: SPECT/CT is a hybrid imaging modality, which combines a 3D scintigraphy (SPECT) and a conventional computerised tomography (CT). SPECT/CT allows accurate anatomical localisation of metabolic tracer activity. It allows the correlation of surgical factors such as tunnel position and orientation with mechanical alignment, clinical outcome and biological factors. The purpose of this study was to investigate whether the SPECT/CT tracer uptake (intensity and distribution) correlates with the stability and laxity of the knee joint and the position and orientation of the tibial and femoral tunnels in patients after anterior cruciate ligament (ACL) reconstruction. Methods: A consecutive series of knees (n = 66), with symptoms of pain and/or instability after ACL reconstruction were prospectively evaluated using clinical examination and 99mTc-HDP-SPECT/CT. Clinical laxity testing was performed using the Rolimeter (Ormed, Freiburg, Germany) including Lachman testing (0-2 mm, 3-5 mm, 6-10 mm, >10 mm), anterior drawer test (0-2 mm, 3-5 mm, 6-10 mm, >10 mm), pivot shift test (positive versus negative) and patient-based subjective instability (yes versus no). For analysis of SPECT/CT tracer uptake a previously validated SPECT/CT localisation scheme consisting of 17 tibial, nine femoral and four patellar regions on standardised axial, coronal, and sagittal slices was used. The tracer activity on SPECT/CT was localised and recorded using a 3D volumetric and quantitative analysis software. Mean, standard deviation, minimum and maximum of grading for each area of the localisation scheme were recorded. The position and orientation of the tibial and femoral tunnel was assessed using a previously published method on 3D-CT. Results: Correlation of instability, pivot shift as well as clinical laxity testing with 99mTc-HDP-SPECT/CT tracer uptake intensity and distribution showed no significant correlation. 99mTc-HDP-SPECT/CT tracer uptake correlated significantly with the position and orientation of the ACL graft. A more horizontal femoral graft position showed significantly increased tracer uptake within the superior and posterior femoral regions. A more posteriorly-placed femoral insertion site showed significantly more tracer uptake within the femoral and tibial tunnel regions. A more vertical or a less medial tibial tunnel orientation showed significant increased uptake within the tibial and femoral tunnel regions. A more anterior tibial tunnel position showed significantly more tracer uptake in the femoral and tibial tunnel regions as well as the entire tibiofemoral joint. Conclusions: SPECT/CT tracer uptake intensity and distribution showed a significant correlation with the femoral and tibial tunnel position and orientation in patients with symptomatic knees after ACL reconstruction. No correlation was found with stability or clinical laxity. SPECT/CT tracer uptake distribution has the potential to give us important information on joint homeostasis and remodelling after ACL reconstruction. It might help to predict ACL graft failure and improve our surgical ACL reconstruction technique in finding the optimal tunnel and graft position and orientation. © 2012 Springer-Verlag Berlin Heidelberg.


Hirschmann M.T.,Kantonsspital Bruderholz | Konala P.,Imperial College London | Iranpour F.,Imperial College London | Kerner A.,Institute of Radiology and Nuclear Medicine | And 2 more authors.
BMC Musculoskeletal Disorders | Year: 2011

Background: The purpose of our study was to evaluate the clinical value of hybrid SPECT/CT for the assessment of patients with painful total knee arthroplasty (TKA). Methods. Twenty-three painful knees in patients following primary TKA were assessed using Tc-99m-HDP-SPECT/CT. Rotational, sagittal and coronal position of the TKA was assessed on 3D-CT reconstructions. The level of the SPECT-tracer uptake (0-10) and its anatomical distribution was mapped using a validated localization scheme. Univariate analysis (Wilcoxon-Mann-Whitney, Spearmean's-rho test, p < 0.05) was performed to identify any correlations between component position, tracer uptake and diagnosis. Results: SPECT/CT imaging changed the suspected diagnosis and the proposed treatment in 19/23 (83%) knees. Progression of patellofemoral OA (n = 11), loosening of the tibial (n = 3) and loosening of the femoral component (n = 2) were identified as the leading causes of pain after TKA. Patients with externally rotated tibial trays showed higher tracer uptake in the medial patellar facet (p = 0.049) and in the femur (p = 0.051). Patients with knee pain due to patellofemoral OA showed significantly higher tracer uptake in the patella than others (p < 0.001). Conclusions: SPECT/CT was very helpful in establishing the diagnosis and guiding subsequent management in patients with painful knees after TKA, particularly in patients with patellofemoral problems and malpositioned or loose TKA. © 2011 Hirschmann et al; licensee BioMed Central Ltd.


Kraljevic M.,University of Basel | Zumstein V.,University of Basel | Wirz D.,University of Basel | Hugli R.,Institute of Radiology and Nuclear Medicine | Muller-Gerbl M.,University of Basel
International Orthopaedics | Year: 2011

Purpose: Failures in total shoulder replacements are often due to aseptic loosening of the glenoid component; the subchondral bone plate is an important factor governing primary fixation of implant materials. Therefore, we investigated characteristic mineralisation patterns of the subchondral bone plate, which demonstrate long-term stress on articular surfaces, age-related changes, postsurgical biomechanical situations and regions of fixation. Using computed tomography osteo-absorptiometry (CT-OAM), these distribution patterns can be demonstrated in vivo. The aim of this study was to investigate the relationship between subchondral bone-plate mineralisation measured with CT-OAM and the mechanical strength measured by indentation. Methods: A total of 32 cadaverous glenoid cavities were evaluated by CT-OAM and indentation testing. Linear regression was used to compare mineralisation and strength of the subchondral bone plate. Results: Results showed two patterns of mineralisation distribution. Twenty-eight cavities were related to bicentric distribution pattern and four showed a single maximum. The correlation coefficient between CT-OAM density and subchondral bone-plate strength was determined to be between 0.62 and 0.96 (P < 0.02). Conclusions: Long-term stress affects not only the subchondral but also the underlying cancellous bone. It therefore can be assumed that mineralisation patterns of the subchondral bone plate continue in cancellous bone. Areas of high density could serve as anchoring locations for orthopaedic implants in resurfacing the glenoid cavity. © 2011 Springer-Verlag.


Kraljevic M.,University of Basel | Zumstein V.,University of Basel | Hugli R.,Institute of Radiology and Nuclear Medicine | Muller-Gerbl M.,University of Basel
Surgical and Radiologic Anatomy | Year: 2013

Purpose: Mineralization distribution of the subchondral bone plate can be used as a marker for long-term stress distribution in diarthrodial joints. Severe injuries or pathological changes of the glenohumeral joint often end in osteoarthritis, where shoulder arthroplasty has become the treatment of choice. The computed tomography osteoabsorptiometry (CT-OAM) is a non-invasive method to determine the distribution of the mineralization of the subchondral bone plate in vivo, which is an important factor concerning the implantation of orthopedic endoprostheses. The aim of this study was to investigate the mineralization of both joint partners of the glenohumeral joint and to compare them with each other. Methods: The distribution of the mineralization of the subchondral bone plate of 57 shoulder specimens was determined by means of CT-OAM. To evaluate a correlation between age and localization of subchondral mineralization maxima, the Chi-square test correlation test was applied. Results: Forty-nine glenoid cavities (86 %) showed a bicentric mineralization distribution pattern with anterior and posterior maxima, only 8 glenoid cavities (14 %) revealed a monocentric mineralization pattern with anterior maxima. Forty-five humeral heads (79 %) showed a bicentric distribution pattern with anterior and posterior maxima, 12 humeral heads (21 %) could be classified as monocentric with a centro-posterior pronounced maximum. Conclusions: We could demonstrate that stress distribution in both joint partners of the glenohumeral joint is inhomogeneous and characteristically bicentric due to the physiological incongruity. Monocentric mineralization patterns can result as a cause of age-related loss of incongruity. © 2012 Springer-Verlag France.

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