Treatment response of colorectal cancer liver metastases to neoadjuvant or conversion therapy: a prospective multicentre follow-up study using MRI, diffusion-weighted imaging and 1H-MR spectroscopy compared with histology (subgroup in the RAXO trial).

BACKGROUND: Colorectal cancer liver metastases respond to chemotherapy and targeted agents not only by shrinking, but also by morphologic and metabolic changes. The aim of this study was to evaluate the value of advanced magnetic resonance imaging (MRI) methods in predicting treatment response and survival. PATIENTS AND METHODS: We investigated contrast-enhanced MRI, apparent diffusion coefficient (ADC) in diffusion-weighted imaging and 1H-magnetic resonance spectroscopy (1H-MRS) in detecting early morphologic and metabolic changes in borderline or resectable liver metastases, as a response to first-line neoadjuvant or conversion therapy in a prospective substudy of the RAXO trial (NCT01531621, EudraCT2011-003158-24). MRI findings were compared with histology of resected liver metastases and Kaplan-Meier estimates of overall survival (OS). RESULTS: In 2012-2018, 52 patients at four Finnish university hospitals were recruited. Forty-seven patients received neoadjuvant or conversion chemotherapy and 40 liver resections were carried out. Low ADC values (below median) of the representative liver metastases, at baseline and after systemic therapy, were associated with partial response according to RECIST criteria, but not with morphologic MRI changes or histology. Decreasing ADC values following systemic therapy were associated with improved OS compared to unchanged or increasing ADC, both in the liver resected subgroup (5-year OS rate 100% and 34%, respectively, P = 0.022) and systemic therapy subgroup (5-year OS rate 62% and 23%, P = 0.049). 1H-MRS revealed steatohepatosis induced by systemic therapy. CONCLUSIONS: Low ADC values at baseline or during systemic therapy were associated with treatment response by RECIST but not with histology, morphologic or detectable metabolic changes. A decreasing ADC during systemic therapy is associated with improved OS both in all patients receiving systemic therapy and in the resected subgroup.

Pediatric primary synovial chondromatosis of the shoulder, biceps tendon sheath and subcoracoid bursa.

A child with shoulder pain and great palpable mass without any injury history is an emergent case until the diagnosis is confirmed. We report the clinical findings, imaging features, surgery and histological analyses of primary synovial chondromatosis in glenohumeral joint, biceps tendon sheath and subcoracoid bursa in a child, aged 14. Primary synovial chondromatosis is characterised by multiple calcified nodules in joints, tendons or bursa areas. The condition is more usual in large joints, in particular in lower extremities. It may be symptomless until the volume of chondromatosis has increased to such an extent that it results in pain, locking symptom or palpable mass. The treatment is removal of the loose bodies and potentially synovectomy, in means of open or arthroscope-assisted surgery. Postoperative follow-up is recommended due to the risk of recidivism and potential malignant transformation. The disease is more common in older patients and there are only isolated cases in pediatric population.

Association between adolescent sport activities and lumbar disk degeneration among young adults.

The relationship between different sport activities and lumbar intervertebral disk degeneration (DD) is largely unknown. We evaluated whether adolescent participation in different sports is associated with lumbar DD in a population-based birth cohort of young adults. A total of 558 young adults (325 females and 233 males) underwent magnetic resonance imaging (MRI, 1.5-T scanner). A DD sum score, based on the Pfirrmann grading, was calculated for all lumbar levels. The sum score was categorized into no DD, 1, 2, or at least 3. Participation in different sport activities was self-reported by postal surveys at 16, 18, and 19 years, and three groups were formed based on participation frequency in 11 sports: (a) highly active (at least twice a week), (b) moderately active (2-4 times a month), and (c) inactive (maximum once a month). Cumulative odds ratios (COR) and their 95% confidence intervals (CI) were obtained for each sport by ordinal logistic regression, adjusting for gender, body mass index, age, socioeconomic status, smoking, and other sports. Highly active participation in jogging/running and swimming was associated with a higher DD sum score (COR: 3.0; 95% CI: 1.4-6.3 and 5.0; 1.7-15.2, respectively) compared to inactive participation, whereas highly active participation in skating showed low COR. In conclusion, running and swimming at least twice a week in early adulthood are potentially associated with lumbar DD. Follow-up studies with MRI are needed to show whether frequent exposure to running or swimming has further effect on the integrity of lumbar intervertebral disks.

Large bowel obstruction in a young woman simulating a malignant neoplasm: a case report of actinomyces infection.

Pelvic and intra-abdominal Actinomycosis can be difficult to diagnose preoperatively and it may also mimic many other diseases, including malignancies. We present a patient with pelvic Actinomycosis probably caused by a long-standing intrauterine device (IUD). We emphasize the challenges in diagnostic process and stress that though a rare disease, intra-abdominal Actinomycosis should be suspected in cases with intra-abdominal mass of uncertain etiology. The early recognition may spare the patient from extensive surgical operation.

Justification of CT examinations in young adults and children can be improved by education, guideline implementation and increased MRI capacity.

OBJECTIVE: To determine whether the justification of CT examinations performed on young patients can be improved by various interventions and whether these have an effect on the total number of CTs performed. METHODS: Specific interventions-education, guideline implementation and increased MRI capacity-were introduced at the Oulu University Hospital, Oulu, Finland, following a previous study demonstrating unjustified use of CT examination in young patients. In the present study, the justification of 177 CT examinations of the lumbar and cervical spine, head, abdomen, nasal sinuses and trauma performed on patients aged under 35 years in 2009 was analysed retrospectively by looking at requests and corresponding patient files. The indications of the examinations were compared with the referral guidelines recommended by the European Commission. Results from our previously published similar study carried out before the interventions were used as a reference. RESULTS: The proportion of justified CT examinations increased from 71% (141/200) in 2005 to 87% (154/177) in 2009 (p<0.001), and in the lumbar spine group from 23% (7/30) to 81% (22/27) (p<0.001). In the case of most of the unjustified examinations, MRI could have been performed instead. The total number of CT examinations carried out on young patients decreased by 7% (p=0.012) and in the lumbar spine group by 79% (p<0.001). CONCLUSION: The implemented interventions decreased the number of CT examinations performed on young patients, and the justification of the examinations improved significantly. ADVANCES IN KNOWLEDGE: This study demonstrates that it is possible to reduce the number of various CT examinations and to improve their justification in young patients by regular education, guideline implementation and increased MRI capacity.

Magnetic resonance-guided growth plate bone bridge resection at 0.23 Tesla: report of a novel technique.

BACKGROUND: Growth plate or physeal cartilage trauma may result in delayed or immediate failure of growth due to bone bridge formation at the insult site. With computed tomography (CT) and magnetic resonance imaging (MRI), the role of imaging has expanded from diagnosis to treatment planning and therapy guidance. PURPOSE: To describe a technique for MR-guided growth plate bone bridge resection and to evaluate feasibility of the procedure. MATERIAL AND METHODS: Three consecutive patients with growth plate bone bridges were treated surgically under MR guidance. All bridges were detected with prior MRI and radiographs. All patients were referred to procedure due to growth plate bridge associated growth anomaly and pertaining clinical symptoms. The effect of the treatment was evaluated after 48 months with a clinical follow-up. RESULTS: All bridges were successfully detected, marked, and removed under MRI guidance. All patients had relief from their symptoms. Two patients had lasting results from the operation with no further operative treatment needed or scheduled at 48 months from primary treatment. There was one clinical failure, with the patient requiring repeated osteotomies. CONCLUSION: We have successfully implemented a novel therapy for growth plate bridge resection.

Cost comparison of low-field (0.23 T) MRI-guided laser ablation and surgery in the treatment of osteoid osteoma.

The purpose of this study was to analyze the costs of magnetic resonance imaging (MRI)-guided laser ablation and to compare them with the costs of surgery in the treatment of osteoid osteoma. Seven patients with osteoid osteoma were treated with MRI-guided interstitial laser ablation during 1 year. The reference material consisted of six patients whose osteoid osteoma was treated surgically by either superficial or deep excision with metallic fixation. The costs were analyzed by using activity-based cost accounting. The mean cost of the MRI-guided laser ablation was 2,392 euros and of the excision of superficially located osteoid osteoma 1,807 euros. The cost of excision of deeply located osteoma with metallic fixation was considerably higher (4,996 euros). This was due to the higher material, personnel, and ward costs. The cost of MRI-guided laser ablation of osteoid osteoma was higher than the cost of surgical excision of a superficial osteoma but considerably lower than the cost of excision of a deeply located osteoma where metallic fixation was needed. When the number and mean cost of sick days or days of restricted weight bearing were also included, the cost of MRI-guided laser ablation was lower than the costs of either superficial or deep excision.

MRI-guided abdominal biopsy in a 0.23-T open-configuration MRI system.

The purpose of this study was to test the hypothesis that when ultrasound (US) guidance is not feasible, abdominal biopsies can be performed safely and accurately under magnetic resonance imaging (MRI) guidance in a low-field environment. MRI-guided abdominal biopsy was performed on 31 consecutive patients, in whom US-guided abdominal biopsy was not possible because the lesion was not visualized in US (n=27) or an US-guided procedure was not considered safe (n=4). The locations of the lesions were liver (n=14), pancreas (n=6), lymph node (n=4), retroperitoneal mass (n=3), adrenal gland (n=3) and spleen (n=1). The average size of the lesion was 2.2 cm (range 1-4 cm) in maximum diameter. All procedures were done by using a 0.23-T open-configuration C-arm-shaped MRI scanner with interventional optical tracking equipment and software. Fine-needle aspiration (FNA) biopsy was performed on all 31 patients; 18 patients underwent both FNA biopsy and cutting needle core biopsy. Procedures were evaluated for diagnostic sensitivity, specificity and accuracy as well as procedure time and complications. The FNA biopsy specimens were adequate for interpretation in 27 (87%) of 31 cases. Two of these proved to be false-negative findings during follow-up or subsequent biopsy. The final diagnosis was malignant in 15 and benign in 16 patients. The sensitivity, specificity and accuracy of FNA biopsy were 71, 100 and 81%, respectively. Of the 18 core-needle biopsies, one was determined false-negative owing to nonrepresentativeness. The sensitivity, specificity and accuracy of histological samples were 90, 100 and 94%, respectively. The needle time was 19 min on average and the mean room time was 1 h 48 min. No immediate or late complications occurred. MRI-guided abdominal biopsy can be performed safely and accurately in a low-field environment in patients for whom an US-guided procedure is not feasible.

Cost comparison analysis of low-field (0.23 T) MRI- and CT-guided bone biopsies.

The aim of this study was to analyze and compare the costs of low-field (0.23 T) MRI- and CT-guided bone biopsies. The cost comparison consisted of 18 MRI-guided and 12 CT-guided bone biopsies performed during a 1-year period. The costs and activities of these two methods were analyzed by using activity-based cost accounting (ABC). The costs of MRI-guided bone biopsy (1205 Euro) were 2.55-fold compared with those of the CT-guided bone biopsy (472 Euro). The higher costs of the biopsy procedure in MRI were due to the higher material (5.57-fold) and personnel (2.73-fold) costs. The MRI-guided bone biopsies proved to be considerably more expensive than CT-guided bone biopsies. This was due to the higher material costs, especially the highly priced MRI compatible instrumentation and the longer procedure time. The MRI guidance in performing bone biopsies should be justified on the basis of the better accuracy and the lack of radiation. Evaluations of cost-effectiveness concerning MRI-guided bone biopsy are needed.

Nerve root infiltration of the first sacral root with MRI guidance.

The purpose of this clinical trial was to describe the methodology and evaluate the accuracy of optical tracking-based magnetic resonance (MR)-guided infiltration of the first sacral (S1) root. Thirty-five infiltrations were performed on 34 patients with a 0. 23-T open C-arm magnet installed in a fully equipped operation room with large-screen (36 inches) display and optical navigator utilizing infrared passive tracking. T1 and T2 fast spin-echo (FSE) images were used for localizing the target and fast field echo for monitoring the procedure. Saline as contrast agent in single-shot (SS)FSE images gave sufficient contrast-to-noise ratio. Twenty-four patients had unoperated L5/S1 disc herniation, and 10 had S1 root irritation after failed back surgery. Needle placement was successful in 97% of the cases, and no complications occurred. Outcome was evaluated 1-6 months (mean 2.2 months) after the procedure and was comparable to that of other studies using fluoroscopy or computed tomography guidance. MR-guided placement of the needle is an accurate technique for first sacral root infiltration.