Postoperative Diagnostic Imaging Research Articles

Imaging in Hip Arthroplasty Management Part 2: Postoperative Diagnostic Imaging Strategy.

Hip arthroplasty (HA) is a frequently used procedure with high success rates, but 7% to 27% of the patients complain of persistent postsurgical pain 1 to 4 years post-operation. HA complications depend on the post-operative delay, the type of material used, the patient’s characteristics, and the surgical approach. Radiographs are still the first imaging modality used for routine follow-up, in asymptomatic and painful cases. CT and MRI used to suffer from metallic artifacts but are nowadays central in HA complications diagnosis, both having their advantages and drawbacks. Additionally, there is no consensus on the optimal imaging workup for HA complication diagnosis, which may have an impact on patient management. After a brief reminder about the different types of prostheses, this article reviews their normal and pathologic appearance, according to each imaging modality, keeping in mind that few abnormalities might be present, not anyone requiring treatment, depending on the clinical scenario. A diagnostic imaging workup is also discussed, to aid the therapist in his imaging studies prescription and the radiologist in their practical aspects.

Resorbable self-locking device for canine lung lobectomy: A clinical and experimental study.

To test the feasibility of a resorbable self-locking device for sealing of lung tissue in lung lobectomy in experimental dogs and dogs with pulmonary mass, and to study its resorption with CT. Experimental study and clinical case series. Five beagles in the experimental group; six canine patients with a pulmonary mass in the clinical group. In both groups, an intercostal incision into thorax was performed. A resorbable self-locking device, LigaTie, was applied at the hilum of left cranial lobe in the experimental group and the affected lobe in the clinical group. Each lobe was removed by cutting the tissue just distal to the device. Video-assisted thoracic surgery was used in the experimental group; postoperative diagnostic imaging was repeated monthly until the device was not apparent on CT. Application of LigaTie was feasible for lung lobectomy in all dogs. The device enabled en bloc ligation of the hilum of the affected lobe including the pulmonary arteries and veins and lobular bronchus. No air leakage from the resection stump was observed in any dog. Trace of the device on CT images gradually decreased and was undetectable at 4months postoperatively in experimental dogs. This study suggested that the resorbable self-locking device may be used for sealing of airways in complete lung lobectomy. The resorbable self-locking device is suggested to be useful for canine lung lobectomy and may facilitate thoracoscopic lung lobectomy. Further investigations on its clinical application in small animal surgery are warranted.

Multimodal imaging of composite carbon fiber-based implants for orthopedic spinal fixation.

As cancer treatments continue to improve, the incidence of spinal metastases and the need for surgical management of these with fixation procedures are growing rapidly. Traditionally metallic implants, composed of titanium alloy, have been used in surgical fixation of unstable or symptomatic vertebral metastases or traumatic injuries. Metallic implants, however, cause significant artifact on post-operative imaging, degrading image quality and limiting interpretation, and can also impair the planning and delivery of radiotherapy. Composite carbon fiber-based materials, such as carbon fiber-reinforced polyetheretherketone (PEEK), have been developed to overcome these issues and are now available for spinal fixation procedures. We aimed to review the multimodal imaging features of these new implants. Current literature and a case example from our institution were used to describe the multimodal imaging characteristics and considerations of new carbon fiber-based spinal fixation implants. New carbon fiber-based spinal implants allow far greater visualization of surrounding structures on post-operative cross-sectional imaging, significantly improving diagnostic accuracy and precision of radiotherapy planning, and do not significantly absorb or scatter X-ray photons during radiotherapy delivery. There are, however, important surgical and radiologic considerations associated with the use of carbon fiber-based implants which radiologists must be aware of, such as implications for surgical planning and intra-operative fluoroscopic and post-operative plain radiographic imaging. The use of carbon fiber-based implants, rather than traditional metallic implants, for spinal fixation offers significant advantages for post-operative diagnostic imaging and radiotherapy planning and delivery.

Frequency and predictors of detecting early locoregional recurrence/disease progression of oral squamous cell carcinoma with high-risk factors on imaging tests before postoperative adjuvant radiotherapy.

To clarify the frequency and predictors of detecting early locoregional recurrence/disease progression (LR/DP) during the interval between surgery and postoperative adjuvant radiotherapy with/without chemotherapy in patients with oral squamous cell carcinoma. Data on 65 patients who had undergone the initial radical surgery for previously untreated oral squamous cell carcinoma which were scheduled to receive adjuvant radiotherapy with/without chemotherapy were reviewed. Of the 65 patients, 63 (97%) were margin-positive/close and/or extracapsular extension-positive (hereinafter, high-risk factors). Eighteen (28%) patients had abnormal findings suggestive of LR/DP on postoperative imaging. Fifteen (23%) patients were diagnosed with LR/DP and treatment policy was changed. Univariate and multivariate analyses revealed higher frequencies of abnormal findings suggestive of LR/DP (univariate/multivariate analysis, p = 0.020/0.036), diagnosing of LR/DP, and changing the treatment policy (univariate/multivariate analysis, p = 0.042/0.046), among the patients who underwent postoperative diagnostic imaging tests or radiotherapy-planning contrast-enhanced (CE) CT without diagnostic imaging tests as compared with those who underwent radiotherapy-planning non-CECT without such tests. The frequency of detecting of early LR/DP before postoperative adjuvant treatment in oral squamous cell carcinoma patients with high-risk factors was high. Furthermore, postoperative diagnostic imaging tests and radiotherapy-planning CECT may be useful to detect early LR/DP in oral squamous cell carcinoma patients before postoperative adjuvant therapy.

Incidence Rates of Postoperative Pulmonary Embolisms in Symptomatic and Asymptomatic Patients, Detected by Diagnostic Images - A Single-Center Retrospective Study.

Pulmonary embolism (PE) is a serious complication during the perioperative period. However, because most previous studies on the incidence of postoperative PE are based on symptoms, asymptomatic occurrences of PE have been overlooked, and the absolute incidence of postoperative PE remains unknown. The aim of this study was to investigate the incidence of perioperative PE, regardless of its symptoms, by reviewing the clinical interpretations of the diagnostic images obtained during the postoperative period. Methods and Results: This study included all patients aged at least 18 years who underwent operations under general and/or neuraxial anesthesia in our institution from 2013 to 2016. We reviewed all interpretations of the diagnostic imaging performed in the postoperative period. We analyzed the 90-day cumulative incidence of postoperative PE and the characteristics, risk factors, and symptoms of patients with and without postoperative PE. Among 21,763 operations, postoperative diagnostic imaging was performed in 1,168 patients, which found PE in 217 patients. Symptoms appeared in 11.1% (24/217) of the PE patients, and 66.7% of these symptoms were decreased levels of SpO2alone. Mortality from PE was 0.5% (1/217). Diagnostic imaging found a number of postoperative PE cases, regardless of the presence of symptoms. Although symptomatic PE was not a frequent occurrence, these findings suggest that clinicians should be aware of postoperative PE even under current prophylaxis.

Predictors of outcome in dogs treated with adjuvant carboplatin for appendicular osteosarcoma: 65 cases (1996–2006)

To determine outcomes and prognostic factors for those outcomes in dogs with appendicular osteosarcoma treated with curative-intent surgery and adjuvant carboplatin. Retrospective case series. 65 client-owned dogs with appendicular osteosarcoma and no evidence of gross metastatic disease at the time of diagnosis. Medical records of dogs that underwent limb amputation or distal ulnectomy and adjuvant carboplatin treatment for appendicular osteosarcoma were reviewed. Adverse effects of chemotherapy and findings regarding preoperative biopsy specimens and postoperative diagnostic imaging were recorded. Signalment, clinical history, and chemotherapy variables were evaluated for associations with outcome. Histologic grade and other variables were evaluated for association with outcome for 38 tumors that were retrospectively graded. The median disease-free interval was 137 days (95% confidence interval [CI], 112 to 177 days). Median survival time was 277 days (95% CI, 203 to 355 days). The 1-, 2-, and 3-year survival rates were 36%, 22%, and 19%, respectively. None of the chemotherapy variables were associated with outcome. Preoperative proteinuria was the only clinical variable associated with poor outcome. Histologic features of tumors associated with a poor outcome were intravascular invasion, mitotic index > 5 in 3 microscopic hpfs, and grade III classification. Carboplatin administration was well tolerated and resulted in a disease-free interval and median survival time similar to those of other published protocols.

'The intraabdominal bleeding with an inguinal defect that mimicking a femoral vein aneurysm'. A case report

Inguinal hernia repair is commonly performed operation in surgical practice. Thirty-five years old female patient was operated with the diagnosis of inguinal hernia. The inguinal defect was misdiagnosed as femoral vein aneurysm in surgical exploration. The postoperative diagnostic imaging revealed that the inguinal defect had been confused as femoral vein aneurysm due to intra-abdominal hemorrhogical fluid after an ovarian cyst rupture.

Diagnostic Medical Radiation Dose in Patients After Laparoscopic Bariatric Surgery

The purpose of this study was to estimate the cumulative radiation dose from computed tomography (CT) scans and upper gastrointestinal fluoroscopic exams in the post-bariatric-surgery population and correlate these values with current concepts of potential radiation-induced cancer risk. A retrospective study of 100 roux-en-y gastric bypass (RYGB) patients and 100 gastric band patients was performed. The cumulative estimated radiation doses from CT scans and fluoroscopic studies received by these patients over a 2.5-year postoperative interval were calculated. The rate of positive radiological studies was determined. Nonlinear regression analyses were used to identify potential independent predictors of higher radiation dose. Mean cumulative dose was 20 +/- 20 mSv for RYGB patients and 11 +/- 11 mSv for gastric band patients. The RYGB procedure and a higher preoperative body mass index were each significant predictors of higher cumulative radiation doses. Dose in the RYGB group ranged from 4 to 156 mSv. Dose in the gastric banding group ranged from 4 to 46 mSv. In the RYGB cohort, positive findings were present in 35% and 16% of CT and fluoroscopic studies, respectively, and 24% and 22% in the gastric band group. None of the fluoroscopic exams performed after the routine 24-h postoperative studies were positive. Allowing for uncertainties of cancer risk at doses less than 50 mSv, patients undergoing laparoscopic bariatric surgery may receive radiation doses from postoperative diagnostic imaging tests that increase their lifetime cancer risk.

Spine imaging after lumbar disc replacement: pitfalls and current recommendations

BackgroundMost lumbar artificial discs are still composed of stainless steel alloys, which prevents adequate postoperative diagnostic imaging of the operated region when using magnetic resonance imaging (MRI). Thus patients with postoperative radicular symptoms or claudication after stainless steel implants often require alternative diagnostic procedures.MethodsPossible complications of lumbar total disc replacement (TDR) are reviewed from the available literature and imaging recommendations given with regard to implant type. Two illustrative cases are presented in figures.ResultsAccess-related complications, infections, implant wear, loosening or fracture, polyethylene inlay dislodgement, facet joint hypertrophy, central stenosis, and ankylosis of the operated segment can be visualised both in titanium and stainless steel implants, but require different imaging modalities due to magnetic artifacts in MRI.ConclusionAlternative radiographic procedures should be considered when evaluating patients following TDR. Postoperative complications following lumbar TDR including spinal stenosis causing radiculopathy and implant loosening can be visualised by myelography and radionucleotide techniques as an adjunct to plain film radiographs. Even in the presence of massive stainless steel TDR implants lumbar radicular stenosis and implant loosening can be visualised if myelography and radionuclide techniques are applied.

WE‐C‐T‐6E‐03: Superparamagnetic Nanoparticles for Brain Tumor Diagnosis and Therapeutics

Gliomas are currently the most common and lethal type of primary brain tumor. Treating malignant gliomas remains a formidable challenge due to the difficulty in differentiating between tumor and healthy brain tissue, the rapid growth rate of invasive gliomas, intrinsic cellular resistance of gliomas to drugs, and the blood brain barrier (BBB) preventing the passage of drugs and contrast agents. My talk will describe our recent work in the development of a multifunctional nanoprobe for targeting glioma tumors by conjugating iron oxide nanoparticles with a glioma tumor targeting molecule and a near infrared fluorescing (NIRF) molecule. The nanoprobe is detectable by both magnetic resonance imaging and fluorescence microscopy, and exhibits significant targeting capability to glioma cells and effective inhibition to glioma cell migration. Our results demonstrate a cellular‐level resolution that may promise accurate delineation of otherwise poorly defined glioma interfaces resulting from their highly invasive morphology. The application of the nanoprobe for preoperative and postoperative diagnostic imaging with MRI and the real‐time intraoperative visualization of tumor margins with optical devices is a novel approach to improve the effectiveness of diagnostic and therapeutic modalities available for brain tumor patients.

Postoperative Diagnostic Imaging for Dental Implants Through use of Cross-sectional Tomography by Panoramic Machine

Postoperative Diagnostic Imaging for Dental Implants Through use of Cross-sectional Tomography by Panoramic Machine

Pediatric liver transplantation. Part II. Diagnostic imaging in postoperative management.

The postoperative diagnostic imaging examinations of 44 children who underwent 59 orthotopic liver transplantations were reviewed. The imaging modalities used for the evaluation of suspected complications include plain roentgenography, ultrasonography (US), computed tomography (CT), nuclear scintigraphy, arteriography, percutaneous and operative cholangiography, and endoscopic retrograde cholangiopancreatography. The main postoperative complications included ischemia, thrombosis (hepatic artery and portal vein), infarction, obstruction or leakage of the biliary anastomosis, hepatic and perihepatic infection, and allograft rejection. US, the most frequently used abdominal imaging modality, was best suited for detection of biliary duct dilatation, fluid collections in or around the transplanted liver, and hepatic arterial, inferior vena caval, and portal vein thrombosis. CT was especially helpful in corroborating findings of infection and in locating abscesses. Technetium 99m sulfur colloid (early- and late-phase imaging) provided a sensitive, although nonspecific, means of assessing allograft vascularization and morphology. Angiography showed vascularity most clearly, and cholangiography was the most useful in the assessment of bile duct patency. A diagnostic imaging algorithm is proposed for evaluation of suspected complications.