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- Al-Amiry, Bariq, 1976-
(författare)
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Radiological measurements in total hip arthroplasty
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Every year, about 1 million patients worldwide and 20000 patients in Sweden undergo total hip arthroplasty (THA). This type of operation is considered a successful, safe and cost-effective procedure to regain mobility and restore hip joint function in patients suffering from severe hip joint disease or trauma. The main goals of the operation are to relief the pain, improve quality of life (QoL) and to restore the biomechanical forces around the hip with appropriate femoral offset (FO), leg length and proper component position and orientation. The radiographic preoperative planning and postoperative evaluation of these parameters require good validity, interobserver reliability and intraobserver reproducibility. Most patients are satisfied after THA, although this treatment still has its complications. About 10 % of THA patients report persistent pain and suboptimal functional outcome and QoL at long-term follow-up. The absolute number of dissatisfied patients is expected to rise given the increase in the annual number of THA performed. Therefore, every effort should be made to investigate factors that possibly influence THA outcome. The data available about the influence of preoperative radiological severity and symptom duration of OA on the outcome of THA are scarce and contradictory. Further studies even needed to evaluate the effect of obesity on post-operative THA radiological measurements
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| 2. |
- Alshamari, Muhammed, 1975-
(författare)
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Low-dose computed tomography of the abdomen and lumbar spine
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Radiography is a common radiologic investigation despite abundant evidence of its limited diagnostic value. On the other hand, computed tomography (CT) has a high diagnostic value and is widely considered to be among the most important advances in medicine. However, CT exposes patients to a higher radiation dose and it might therefore not be acceptable simply to replace radiography with CT, despite the powerful diagnostic value of this technique. At the expense of reduced CT image quality, which could be adjusted to the diagnostic needs, low-dose CT of abdomen and lumbar spine can be performed at similar dose to radiography. The aim of the current thesis project was to evaluate low-dose CT of the abdomen and lumbar spine and to compare it with radiography. The hypothesis was that CT would give better image quality and diagnostic information compared to radiography at similar dose levels. Firstly, the diagnostic accuracy of low-dose CT of the abdomen was evaluated. Results showed that low-dose CT of abdomen has a high sensitivity and specificity compared to radiography, i.e., it has higher diagnostic accuracy. Similar results were obtained from our systematic review. Secondly, in a phantom study, an ovine phantom was scanned at various CT settings. The image quality was evaluated to obtain a protocol for the optimal settings for low-dose CT of lumbar spine at 1 mSv. This new protocol was then used in a clinical study to assess the image quality of low-dose CT of the lumbar spine and compare it to radiography. Results showed that low-dose CT has significantly better image quality than radiography. Finally, the impact of Iterative reconstruction (IR) on image quality of lumbar spine CT was tested. Iterative reconstruction is a recent CT technique aimed to reduce radiation dose and/or improve image quality. The results showed that the use of medium strength IR levels in the reconstruction of CT image improves image quality compared to filtered back projection. In conclusion, low-dose CT of the abdomen and lumbar spine, at about 1 mSv, has better image quality and gives diagnostic information compared to radiography at similar dose levels and it could therefore replace radiography.
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| 3. |
- Söderman, Tomas
(författare)
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Radiological methods in rheumatoid arthritis and osteoarthritis
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The dissertation's theme is the critical role of radiology when evaluating two different groups of patients. Firstly, patients with rheumatoid arthritis (RA) of the cervical spine were studied to evaluate upper spine instability with dynamic computed tomography (CT). Secondly, after anterior cruciate ligament (ACL) reconstruction, patients with a long-term follow-up were studied to evaluate osteoarthritis (OA). In paper I, 21 consecutive patients with atlantoaxial subluxation due to RA planned for atlantoaxial fusion were included. Radiographs were obtained in neutral and flexed positions, CT and Magnetic Resonance Imaging (MRI) was performed with the neck in the neutral position and CT also in flexion. Radiographs and CT measurements of atlantoaxial subluxation correlated but were larger using radiographs than CT in flexion. The spinal cord compression was significantly worse at CT obtained in flexed position than MRI in the neutral position. In papers II and III, the cohort consisted of 60 patients, and in paper IV, 73 patients. Mean follow-up was 31 years after ACL reconstruction. MRI, radiographs, International Knee Documentation Committee (IKDC) clinical assessment, Knee injury Osteoarthritis Outcome Score (KOOS), Short Form-36 (SF-36), Tegner Activity Scale, and KT-1000 arthrometer were used in order to evaluate the patients. Thirty-three patients showed an intact ACL graft, and 40 a ruptured ACL graft. Forty-nine patients had tibiofemoral OA, and 28 patients had patellofemoral OA. Patients with ruptured ACL grafts had more OA in the medial tibiofemoral compartment than those with an intact ACL graft. Sport and Recreation Function and Quality of life scores were higher in patients with an intact ACL graft than those with a ruptured ACL graft. All subscales of KOOS were higher in the group without OA. KOOS Quality of life score was lower than for a control group of men. The IKDC overall clinical assessment was worse in patients with a ruptured ACL graft. This thesis suggests that radiographs remain the primary imaging method for evaluating atlantoaxial instability. However, CT in flexed position is useful in the preoperative imaging workup. Patients with a ruptured ACL graft presented with more OA of the medial tibiofemoral compartment than those with an intact graft. Patients with an intact ACL graft and those without OA reported higher sports activity and recreation and better knee-related Quality of life. Knee-related Quality of life in the study group was reduced compared to a reference group.
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