Pitfalls and value of organ specific approach in evaluating indeterminate lesions detected on CT in colorectal cancer by [F18] FDG PET/CT.

OBJECTIVE: The objective of this study is to evaluate the value of FDG PET/CT for different involved organs showing Indeterminate/ equivocal / suspicious lesions detected on IV contrasted CT during surveillance follow up for colorectal cancer. MATERIALS AND METHODS: A total of 67 patients with colorectal cancer how are on regular surveillance follow up by IV contrasted CT scans revealing indeterminate lesions were studied. Subsequent FDG PET/CT evaluation was performed as a problem solving modality. PET/CT results were statistically characterized when compared to biopsy results or to follow/up results. Also Statistical parameters were calculated for each organ involved. The evaluation of all CT indeterminate lesions by FDG PET/CT showed overall sensitivity of 93%, Specificity of 81%, Negative predictive value of 94%, Positive predictive value 80% and accuracy of 87%. However in an organ specific approach the highest accuracy was for lymph nodes with results showing a 100% accuracy and the lowest accuracy was for local disease at a value of 80%. Probable explanations for the falsely characterized lesions resulting in the pitfalls seen and in the imperfect accuracy were provided. CONCLUSION: Study shows that FDG PET/CT is an excellent tool in characterizing CT indeterminate lesions during surveillance of colorectal cancer, However different organs showed variable accuracy results with the highest accuracy for our study was for lymph node status (100%) and the lowest accuracy being for local disease at the original site of primary tumor (80%).

Vesico-Adnexal Fistula Treated with Transurethral Embolization Under Fluoroscopic Guidance.

BACKGROUND Vesico-adnexal fistulae are rare. Potential causes of such fistulae include infection, endometriosis, and iatrogenic causes following pelvic surgeries. To the best of our knowledge, only 3 cases of vesico-adnexal fistulae have been reported, and all these patients were treated surgically by removing the involved adnexa, excising the fistulous duct, and suturing the bladder. We describe the first case of vesico-adnexal fistula that developed after pelvic surgery, and it was successfully treated by transurethral embolization under fluoroscopic guidance. CASE REPORT Our patient was a 27-year-old woman with a history of hysterectomy. She presented to our institution with urethral discharge and a recurrent urinary tract infection. The cystogram showed a fistula tract connecting the urinary bladder and left adnexal cystic cavity. She was treated conservatively with antibiotics and prolonged Foley catheterization to allow for spontaneous closure of the fistula; however, conservative management failed. The patient was successfully treated with transurethral embolization of the tract under fluoroscopic guidance. CONCLUSIONS In such a rare scenario with limited treatment options, interventional radiology offers an alternative minimally invasive treatment strategy.

Branching patterns of the aortic arch: a computed tomography angiography-based study.

PURPOSE: This study aimed to investigate the anatomical variations in direct branches of the aortic arch in Jordanians using the contrast Computed Tomography (CT) imaging techniques and to determine their prevalence according to sex. METHODS: This analytical, retrospective study included 500 patients (209 females, 291 males), who were referred to the Radio-Diagnostic Department at King Abdullah University Hospital for CT angiography of the aortic arch from 2010 to 2014. Patients were selected using a random sampling method. RESULTS: Six patterns of arrangement of arteries according to their origin from the aortic arch were identified in Jordanians. The most common pattern was the normal classical one and accounted for 61.2 % of cases. All other patterns were considered variations and accounted for 38.8 % of cases. Variation patterns were classified into six different types. There was no significant correlation (p > 0.05) between sex and the occurrence of different types of variations. CONCLUSION: This study provides new information regarding the prevalence of aortic arch branching variations in Jordanians. A wide range of anatomical variations in the branching pattern of the aortic arch was observed. This should be taken into consideration during angiography, aortic instrumentation, and supra-aortic thoracic, head, and neck surgery.

Clinical relevance of 18F-FDG-negative osteoblastic metastatic bone lesions noted on PET/CT in breast cancer patients.

PURPOSE: Our study aims to assess the clinical relevance of fluorine-18 fluorodeoxyglucose (F-FDG) negative osteoblastic metastatic bone lesions noted on PET/computed tomography (CT) in breast cancer patients. PATIENTS AND METHODS: The medical records of breast cancer patients were reviewed retrospectively from January 2012 until April 2015. We included the patients who had metastatic bone disease evaluated by F-FDG-PET/CT. Group 1 included patients with newly diagnosed metastatic bone disease at the time of imaging and group 2 included patients with a history of treated metastatic bone disease at the time of imaging. Functional and structural bone abnormality was monitored on F-FDG-PET/CT scans. RESULTS: Fifty-three patients, median age 47.1 years (range 27-80 years), were included. Group 1 included 35 patients. Of those, 88% had predominantly F-FDG-avid osteolytic and mixed lesions (destructive pattern). Complete response was noted in 65% of the patients after treatment, evidenced by disappearance of bony focal activity with partial or total ossification of most osteolytic lesions converting into mixed and 'secondary' osteoblastic lesions. In addition, more ossified lesions were noted in some patients whose lesions were left untreated for long time (aged lesions). The remaining 12% of group 1 patients had pure 'primary' osteoblastic lesions (nondestructive pattern), which started small and expanded with time and tend to be F-FDG-negative. Group 2 included 18 patients who had predominantly mixed and 'secondary' osteoblastic lesions. CONCLUSION: We described two types of osteoblastic metastatic bone lesions in breast cancer patients: 'primary' and 'secondary'. 'Secondary' lesions (88%) are totally ossified (healed) osteolytic lesions and are almost always F-FDG-negative on PET/CT. These lesions are of no clinical importance. Healing is potentially seen after treatment or if the lesions are left untreated for a long time (aged lesions). 'Primary' lesions (12%) are seen without previous bone destruction and tend to be F-FDG-negative, although they contain tumor cells. Hence, sequential CT is more helpful than sequential FDG-PET in following 'primary' lesions.

Osteoblastoma is a metabolically active benign bone tumor on 18F-FDG PET imaging.

We describe a case of a 9-y-old girl who on (18)F-FDG PET imaging was found to have a highly metabolically active sacral tumor with an average standarized uptake value of 6.2. The tumor was proven to be osteoblastoma by pathologic examination. Osteoblastoma is a relatively rare benign primary bone tumor and occurs predominantly in patients younger than 20 y. The most common area of involvement is the spine. Osteoblastoma has been reported to be metabolically active on (18)F-FDG PET imaging, with an average standarized uptake value of 3.2, which renders (18)F-FDG PET imaging unable to differentiate benign from malignant primary bone tumors. To our knowledge, only 5 cases of osteoblastoma evaluated by (18)F-FDG PET imaging have been reported in the literature; all were metabolically active on (18)F-FDG PET imaging. The objective of this case report is to show that a metabolically active primary bone tumor on (18)F-FDG PET imaging might be benign and not necessarily malignant.

Radiofrequency ablation of osteoid osteoma using tissue impedance as a parameter of osteonecrosis.

INTRODUCTION: The aim of this study is to assess the safety and the efficacy of radiofrequency ablation (RFA) of osteoid osteoma with Soloist monopolar electrode using tissue impedance, rather than temperature, as an indicator of osteonecrosis. METHODS: The medical records and imaging studies of 30 patients (males 18, females 12) who underwent RFA of osteoid osteoma at our institution were reviewed. The mean age of the patients was 15.3 years (range 5-34 years) and the mean duration of follow up was 26.9 months (range 3-52 months). The lesions were located in the femur (n=6, 53%), tibia (n = 8, 27%), hand (n = 3, 10%), foot (n = 2, 6%) and humerus (n = 1, 3%). The procedure was performed with general anaesthesia under CT guidance. The nidus was accessed with 11-gauge bone biopsy needle and then the stylet was removed and replaced by monopolar 16.5G radiofrequency probe with a 9-mm active tip through the coaxial axis. Power delivery via the radiofrequency generator was started at 2 W and increased gradually until the end point of 450-500 Ω reached and 'Roll-Off' achieved indicating coagulation necrosis of the target lesion. RESULTS: The procedure was technically successful in all patients. The mean procedure time was 72 min and the mean RFA time was 12.7 min. The clinical success rate was 93%. In one patient, the procedure was abandoned due to immature Roll-Off despite all measures. In one patient (3%), recurrence occurred 39 months after the procedure. No major complications were encountered. Two minor skin burns occurred that were resolved with conservative measures. CONCLUSION: RFA of osteoid osteoma using Soloist monopolar electrode is a safe and effective treatment. Tissue impedance could be used as an alternative to temperature to indicate osteonecrosis of osteoid osteoma during RFA.

Isolated lipoma of filum terminale in adults: MRI findings and clinical correlation.

INTRODUCTION: Fat within the filum terminale is frequently seen on routine magnetic resonance imaging (MRI) of the lumbosacral spine (LSS), with prevalence of 1-5%. The objective of this study was to determine the prevalence and MRI features of isolated lipoma of filum terminale (LFT) in adult population and its correlation with the patient clinical presentations. METHODS: Prospective analysis of all lumbosacral MRI performed at King Abdullah University Hospital during a 21-month period. A total of 37 patients with LFT were included. Patients were divided into two groups. Group A patients have neurological deficit manifested by either motor, sensory or sphincter abnormality. Group B patients have normal neurological examination. Clinical findings were correlated with: A: thickness of LFT, B: length of LFT, C: distance of LFT from conus medullaris (CM), D: age of the patient. RESULTS: The prevalence of isolated LFT in our study was 3.2%. There was no significant correlation between the thickness or length of LFT and the presence of neurological deficit. The distance of LFT from CM was also not correlated with the patient clinical presentation. No significant difference in the age between the two groups. CONCLUSION: LFT in adult likely represent an incidental finding on routine lumbosacral MRI. Special attention for LFT in children is mandatory as it may indicate clinical tethering in otherwise normal appearing LSS.

Reproducibility of gallbladder ejection fraction measured by Fatty meal cholescintigraphy.

PURPOSE: There are conflicting data in the literature regarding the reproducibility of the gallbladder ejection fraction (GBEF) measured by fatty meal cholescintigraphy (CS). We aimed to test the reproducibility of GBEF measured by fatty meal CS. METHODS: Thirty-five subjects (25 healthy volunteers and 10 patients with chronic abdominal pain) underwent fatty meal CS twice in order to measure GBEF1 and GBEF2. The healthy volunteers underwent a repeat scan within 1-13 months from the first scan. The patients underwent a repeat scan within 1-4 years from the first scan and were not found to have chronic acalculous cholecystitis (CAC). Our standard fatty meal was composed of a 60-g Snickers chocolate bar and 200 ml full-fat yogurt. RESULTS: The mean ± SD values for GBEF1 and GBEF2 were 52 ± 17% and 52 ± 16%, respectively. There was a direct linear correlation between the values of GBEF1 and GBEF2 for the subjects, with a correlation coefficient of 0.509 (p = 0.002). Subgroup data analysis of the volunteer group showed that there was significant linear correlation between volunteer values of GBEF1 and GBEF2, with a correlation coefficient of 0.473 (p = 0.017). Subgroup data analysis of the non-CAC patient group showed no significant correlation between patient values of GBEF1 and GBEF2, likely due to limited sample size. CONCLUSIONS: This study showed that fatty meal CS is a reliable test in gallbladder motility evaluation and that GBEF measured by fatty meal CS is reproducible.