Beyond the Radiograph: Radiological Advances in Surgery

ABSTRACT

Advancements in imaging techniques and the development of new radiological modalities have opened exciting venues for furthering surgical specialties. From the initial and innovative discovery of the radiograph by Röentgen, radiology has found an important and central role in the expansion of surgical possibilities. In this historical review, the innovation and discoveries behind the development of the radiograph, fluoroscopy, angiography and ultrasound are examined. Additionally, the use of these imaging modalities in surgery is discussed. Learning from the discoveries of history's giants, we hope to advance our own knowledge and create new possibilities, a future that will hold great promise for the radiologists and surgeons of tomorrow.     

Practical use of imaging technique for management of bone and soft tissue tumors

Imaging modalities including radiography, computed tomography (CT), and magnetic resonance imaging (MRI) are necessary for the diagnosis of bone and soft tissue tumors. The history of imaging began with the discovery of X-rays in the 19th century. The development of CT, MRI, ultrasonography, and positron emission tomography (PET) have improved the management of bone and soft tissue tumors. X-ray imaging and CT scans enable the evaluation of bone destruction, periosteal reaction, sclerotic changes in lesions, condition of cortical bone, and ossification. MRI enables the assessment of tissue characteristics, tumor extent, and the reactive areas. Functional imaging modalities including ²⁰¹thallium (²⁰¹Tl) scintigraphy can be used to differentiate benign lesions from malignant lesions and to assess chemotherapeutic effects. Real-time assessment of soft tissue tumors by ultrasonography enables accurate and safe performance of surgery and biopsy. This article describes useful imaging modalities and characteristic findings in the management of bone and soft tissue tumors.     

对比不同影像学方法对胰腺神经内分泌肿瘤的检出率

目的探讨不同影像学检查方法对检出胰腺神经内分泌肿瘤(P-NEN)的价值。方法回顾性分析40例(共43个病灶)经手术后病理证实的P-NEN患者的影像学资料,包括CT、MRI、超声内镜(EUS)、PET/CT,与手术结果相对照,分析各种影像学方法对P-NEN的检出率。结果 CT、MRI、EUS及PET/CT对P-NEN病灶的检出率分别为76.74%(33/43)、94.87%(37/39)、94.59%(35/37)和51.52%(17/33)。MRI与EUS病灶检出率差异无统计学意义(P均0.05),余两两比较差异均有统计学意义(P均0.05)。结论 MRI可作为P-NEN的首选影像学检查方法。     

Projected lifetime cancer risk for patients undergoing spine surgery for isthmic spondylolisthesis

BACKGROUND CONTEXTRadiographs, fluoroscopy, and computed tomography (CT) are increasingly utilized in the diagnosis and management of various spine pathologies. Such modalities utilize ionizing radiation, a known cause of carcinogenesis. While the radiation doses such studies confer has been investigated previously, it is less clear how such doses translate to projected cancer risks, which may be a more interpretable metric.PURPOSE(1) Calculate the lifetime cancer risk and the relative contributions of preference-sensitive selection of imaging modalities associated with the surgical management of a common spine pathology, isthmic spondylolisthesis (IS); (2) Investigate whether the use of intraoperative CT, which is being more pervasively adopted, increases the risk of cancer.STUDY DESIGN/SETTINGRetrospective cross-sectional study carried out within a large integrated health care network.PATIENT SAMPLEAdult patients who underwent surgical treatment of IS via lumbar fusion from January 2016 through December 2021.OUTCOME MEASURES(1) Effective radiation dose and lifetime cancer risk associated with each exposure to ionizing radiation; (2) Difference in effective radiation dose (and lifetime cancer risk) among patients who received intraoperative CT compared to other intraoperative imaging techniques.METHODSBaseline demographics and differences in surgical techniques were characterized. Radiation exposure data were collected from the 2-year period centered on the operative date. Projected risk of cancer from this radiation was calculated utilizing each patient's effective radiation dose in combination with age and sex. Generalized linear modeling was used to adjust for covariates when determining the comparative risk of intraoperative CT as compared to alternative imaging modalities.RESULTSWe included 151 patients in this cohort. The range in calculated cancer risk exclusively from IS management was 1.3-13 cases of cancer per 1,000 patients. During the intraoperative period, CT imaging was found to significantly increase radiation exposure as compared to alternate imaging modalities (adjusted risk difference (ARD) 12.33mSv; IQR 10.04, 14.63mSv; p<.001). For a standardized 40 to 49-year-old female, this projects to an additional 0.72 cases of cancer per 1,000. For the entire 2-year perioperative care episode, intraoperative CT as compared to other intraoperative imaging techniques was not found to increase total ionizing radiation exposure (ARD 9.49mSv; IQR -0.83, 19.81mSv; p=.072). The effect of intraoperative imaging choice was mitigated in part due to preoperative (ARD 13.1mSv, p<.001) and postoperative CTs (ARD 22.7mSv, p<.001).CONCLUSIONSPreference-sensitive imaging decisions in the treatment of IS impart substantial cancer risk. Important drivers of radiation exposure exist in each phase of care, including intraoperative CT and/or CT scans during the perioperative period. Knowledge of these data warrant re-evaluation of current imaging protocols and suggest a need for the development of radiation-sensitive approaches to perioperative imaging.     

The use of MRI,PET/CT,and nuclear scintigraphy in the imaging of pyogenic native vertebral osteomyelitis: a systematic review and meta-analysis

Background ContextNative vertebral osteomyelitis (NVO) is a severe infection with an increasing incidence globally. Although there is no widely agreed upon reference standard for diagnosis of the disease, imaging plays a crucial role. Magnetic resonance imaging (MRI) is currently the imaging modality of choice. In recent years, advances in imaging have allowed for a larger role for alternative imaging techniques in the setting of NVO.PurposeOur aim was to evaluate the diagnostic accuracy of MRI, PET/CT, and nuclear imaging, namely ⁶⁷Gallium and ^99mTechnetium scintigraphy, in the diagnosis of pyogenic NVO.Study Design/SettingWe conducted a systematic review of five medical databases and included all studies from 1970 to September 2021 that compared imaging techniques and provided sufficient data for diagnostic test accuracy meta-analysis.MethodsAbstract screening, full text review, and data extraction were done by a pair of independent reviewers. Nonnative and nonpyogenic patients were excluded. A bivariate random effect model was used for meta-analysis.ResultsTwenty studies were included in the meta-analysis, encompassing a total of 1,123 imaging studies. The meta-analysis sensitivity and specificity of MRI were 90% and 72% respectively; those of PET/CT were 93% and 80%; those of ⁶⁷Ga were 95% and 88%; those of ^99mTc were 86% and 39%; and the sensitivity and specificity of combined Ga and Tc were 91% and 92% respectively in the setting of suspected NVO.Conclusions⁶⁷Ga has the highest sensitivity for NVO, and its specificity is augmented when combined with ^99mTc. MRI and PET/CT are both highly sensitive modalities, although the specificity of PET/CT is slightly better. MRI remains an appropriate initial test depending on the availability of other modalities.     

Técnicas de imagen molecular en el cáncer de próstata: revisión de radiofármacos,modalidades y evidencia actual

IntroductionThe clinical course of Prostate cancer (PCa) are markedly diverse, ranging from indolent to highly aggressive disseminated disease. Molecular imaging techniques are playing an increasing role in early PCa detection, staging and disease recurrence. There are some molecular imaging modalities, radiotracers agents and its performance are important in current clinical practice PCa.ObjectiveThis review summarizes the latest information regarding molecular imaging of PCa and is designed to assist urologists with ordering and interpreting these modalities and different radiotracers for different patients.Evidence acquisitionA PubMed-based literature search was conducted up to September 2019. We selected the most recent and relevant original articles, metanalysis and reviews that have provided relevant information to guide molecular imaging modalities and radiotracers use.Evidence synthesisIn this review, we discuss 3 main molecular imaging modalities and 7 radiotracer technologies available.ConclusionsThe use molecular imaging modalities and radiotracers has a unique role in biochemical recurrence and diagnosis of ganglionar and bone progression of PCa. In the present time, no one of these molecular imaging modalities can be recommended over the classical work-up of abdominopelvic CT scan and bone scan, and large-scale and multi-institutional studies are required to validate the efficacy and cost utility of these new technologies.     

Intraobserver and interobserver reliabilty of measures of kyphosis in thoracolumbar fractures

Background contextConsensus documents have recently been developed enumerating the radiographic parameters thought to be most valid in the clinical evaluation of patients with thoracolumbar fractures.PurposeThe objective of this study was to assess the measurement reliability of plain X-rays, computed tomography (CT), and magnetic resonance imaging (MRI) and their inter-modality agreement, as the three imaging modalities are often clinically interchangeable. This process is an essential reliability evaluation of the measurement parameters being proposed.Study designThis study evaluated the interobserver and intraobserver reliability of plain radiographs, CT, and MRI measurements of sagittal kyphosis in thoracolumbar fractures.Patient sampleSuitable plain X-ray, CT, and MRI radiographic imaging of ten cases of thoracolumbar fracture were examined.MethodsSuitable plain X-ray, CT, and MRI radiographic imaging of ten cases of thoracolumbar fracture were examined by ten independent spine surgery fellowship-trained observers.Outcome measuresCobb angle measurement, Gardner segmental deformity angle, and anterior body compression percentage were measured.ResultsRegardless of the imaging modality or the parameter being measured, the intraobserver reliability is always better than the interobserver. Plain radiography has better overall, interobserver and intraobserver reliability, followed by CT and then MRI. Reliability is very high in general, with the highest reliability for intraobserver reliability of the linear measures on plain radiographs. The inter-modality agreement is highest for plain X-ray and CT.ConclusionsThis study demonstrates that Cobb angle measurement, Gardner segmental deformity angle, and anterior body compression percentage are reliable measures of thoracolumbar fracture kyphosis with very high interobserver and intraobserver reliability and very high inter-modality agreement of plain X-ray with CT.     

Future imaging modalities for the assessment of pancreas allografts a scan of the horizon

Pancreas transplantation (PT) allows improved glycaemic control for patients with complicated type 1 diabetes mellitus and is most commonly performed simultaneously with a renal transplant. Imaging modalities are critical for the assessment of pancreatic graft dysfunction, as clinical assessment and hyperglycaemia lack robust sensitivity for the transplant clinician. Biopsy represents the most conclusive standard of PT graft assessment but is challenging due to its invasive nature and the potential morbidity associated with the procedure. Innovative imaging technologies offer the opportunity to apply these modalities to improve PT outcomes while using non-invasive technologies to provide a diagnostic sensitivity that traditionally only biopsies can provide. Early graft dysfunction has traditionally been investigated with Computed tomography (CT) and ultrasound (US) scans. We explore adjuncts to these modalities including the application of contrast enhanced ultrasound (CEUS) for routine post-operative graft assessment to inform post-operative treatment strategies. There is currently a dearth of imaging modalities to reliably monitor long term graft function, but the use of innovative functional imaging techniques and how they can be applied to PT is discussed. Perfusion CT and glucose stimulated magnetic resonance imaging (MRI) to detect whole organ function are examined. In addition, early phase developments in beta-cell specific imaging methods to quantify beta-cell mass longitudinally are described. The clinical applications of such tools including Mn²⁺-enhanced MR and GLP-1R targeted PET/CT are reviewed and may demonstrate opportunities to provide the transplant clinician with greater information to support improved patient care.     

Final analysis of a prospective trial on functional imaging for nodal staging in patients with prostate cancer at high risk for lymph node involvement

PurposeAccurate staging modalities to diagnose lymph node involvement in patients with prostate cancer (PCa) are lacking. We wanted to prospectively assess sensitivity, specificity, and positive predictive value (PPV) and negative predictive value of ¹¹C-choline positron emission tomography (PET)-computed tomography (CT) and diffusion-weighted (DW) magnetic resonance imaging (MRI) for nodal staging in patients with PCa at high risk for lymph node involvement.Material and methodsIn total, 75 patients with a risk≥10% but<35% for lymph node (LN) metastases (Partin tables) who had N0 lesions based on the findings of contrast-enhanced CT scans were included. Patients underwent ¹¹C-choline PET-CT and DW MRI before surgery, which consisted of a superextended lymph node dissection followed by radical prostatectomy. LNs were serially sectioned and histopathologically examined after pankeratin staining. These results were used as the gold standard to compare with the imaging results.ResultsOf 1,665 resected LNs (median = 21, range: 7–49), 106 affected LNs (median = 2, range: 1–10) were found in 37 of 75 patients (49%). On a region-based analysis, we found a low sensitivity of 8.2% and 9.5% and a PPV of 50.0% and 40.0% for ¹¹C-choline PET-CT and DW MRI, respectively. The patient-based analysis showed a sensitivity of 18.9% and 36.1% for and a PPV of 63.6% and 86.7% ¹¹C-choline PET-CT and DW MRI, respectively. Even when both imaging modalities were combined, sensitivity values remained too low to be clinically useful.ConclusionsBecause of the low sensitivity, there is no indication for routine clinical use of either ¹¹C-choline PET-CT or DW MRI for LN staging in patients with PCa, in whom CT scan findings were normal.     

Measurement of PSA density by 3 imaging modalities and its correlation with the PSA density of radical prostatectomy specimen

ObjectiveTo evaluate the difference between the PSA density (PSAD) calculated with 3 imaging modalities and the PSAD of the radical prostatectomy specimen.Materials and methodsThe PSAD of 60 men with clinically localized prostate cancer was calculated with transabdominal ultrasound (TAUS), transrectal ultrasound (TRUS), and computed tomography (CT) before radical retropubic prostatectomy, and was compared with the PSAD of the surgical specimen using the paired t-test. The relationship of the real prostate volume and the difference between the PSAD calculated with the 3 imaging modalities and that of the PSAD of the specimen was analyzed using Pearson's correlation coefficient. Finally, the sensitivity of PSAD calculated with the examined imaging modalities and the specimen was also studied.ResultsThe mean difference between the PSAD calculated by each one of the 3 imaging modalities and the PSAD of the specimen was ?0.01 ng/ml/cm³ (P = 0.28) for TAUS, 0.01 ng/ml/cm³ (P = 0.37) for TRUS, and ?0.03 ng/ml/cm³ (P = 0.001) for CT. This difference has not been shown to depend on the real prostate volume according to Pearson's correlation coefficient, which was 0.056 (P = 0.673) for TAUS, ?0.014 (P = 0.917) for TRUS, and 0.184 (P = 0.159) for CT. The sensitivity of PSAD calculated with TAUS, TRUS, and CT was 58.3%, 65%, and 45%, respectively, while that of the specimen was 70%.ConclusionsAlthough PSAD showed a moderate sensitivity, TRUS and TAUS are the imaging modalities that calculate it closer to the real PSAD of the specimen.     

Justifying CT prior to MRI in cases of suspected occult hip fracture. A proposed diagnostic protocol

IntroductionPatients with clinical suspicion of hip fracture, but negative radiographs are suspected of having an occult hip fracture (OHF). Different diagnostic modalities are available for investigating OHF and various protocols have been suggested. MRI has the highest sensitivity and specificity, however availability is limited in many institutes. CT is readily accessible in the large majority of hospitals throughout the world but has lower sensitivity and may miss some fractures. In this article we investigate a protocol that balances these issues providing a practical and cost-effective solution.MethodsDuring a four-year period between 2012 and 2016 a strict diagnostic protocol was followed at our Medical Center for patients suspected of OHF. This MRI selective protocol consisted of CT initially being performed and only when negative for fracture, followed by an MRI. Retrospective analysis of all patients who followed the protocol was performed. The patients were divided into two groups: those diagnosed by CT alone and those diagnosed by MRI after having a negative CT scan. Diagnostic performance, time to diagnosis and the cost of this protocol were evaluated.Results103 patients were treated under the protocol. In 50 patients (49%) hip fracture was diagnosed by CT alone. In the remaining 53 patients (51%) no definitive diagnosis was reached by CT and MRI was subsequently performed. 12 of these 53 patients (23%) were diagnosed with hip fracture necessitating surgery. In the CT only group mean time from admission to diagnosis was 3 hours, in the CT + MRI group this rose to 40 hours. Cost analysis showed that this protocol was more cost-effective than performing MRI in all patients, saving an estimated 66,805 Euro during the study period.ConclusionThe clinical challenge of diagnosing OHF can be minimised by implementing a diagnostic protocol. The protocol should take into consideration the diagnostic sensitivity, availability and cost of different imaging modalities. An MRI selective strategy with initial CT scanning is recommended, as it reduces time to diagnosis and lowers overall costs.     

Glenoid Bone Loss in Shoulder Instability: Superiority of Three-Dimensional Computed Tomography over Two-Dimensional Magnetic Resonance Imaging Using Established Methodology

BackgroudRecent literature suggests that three-dimensional magnetic resonance imaging (3D MRI) can replace 3D computed tomography (3D CT) when evaluating glenoid bone loss in patients with shoulder instability. We aimed to examine if 2D MRI in conjunction with a validated predictive formula for assessment of glenoid height is equivalent to the gold standard 3D CT scans for patients with recurrent glenohumeral instability.MethodsPatients with recurrent shoulder instability and available imaging were retrospectively reviewed. Glenoid height on 3D CT and 2D MRI was measured by two blinded raters. Difference and equivalence testing were performed using a paired t-test and two one-sided tests, respectively. The interclass correlation coefficient (ICC) was used to test for interrater reliability, and percent agreement between the measurements of one reviewer was used to assess intrarater reliability.ResultsUsing an equivalence margin of 1 mm, 3D CT and 2D MRI were found to be different (p = 0.123). The mean glenoid height was significantly different when measured on 2D MRI (39.09 ± 2.93 mm) compared to 3D CT (38.71 ± 2.89 mm) (p = 0.032). The mean glenoid width was significantly different between 3D CT (30.13 ± 2.43 mm) and 2D MRI (27.45 ± 1.72 mm) (p < 0.001). The 3D CT measurements had better interrater agreement (ICC, 0.91) than 2D MRI measurements (ICC, 0.8). intrarater agreement was also higher on CT.ConclusionsMeasurements of glenoid height using 3D CT and 2D MRI with subsequent calculation of the glenoid width using a validated methodology were not equivalent, and 3D CT was superior. Based on the validated methods for the measurement of glenoid bone loss on advanced imaging studies, 3D CT study must be preferred over 2D MRI in order to estimate the amount of glenoid bone loss in candidates for shoulder stabilization surgery and to assist in surgical decision-making.     

Characterization of tumor thrombus in renal cell carcinoma with prostate specific membrane antigen (PSMA) positron emission tomography (PET)/computed tomography (CT)

IntroductionVenous tumor thrombus (TT) occurs as part of the natural history of renal cell carcinoma (RCC) local progression in a small minority of cases. MRI is currently the most accurate imaging modality for determining TT extent. PSMA PET/CT may improve RCC staging and IVC TT characterization. The objective of this study was to investigate the role of PSMA PET/CT in defining superior extent of TT in RCC and TT IVC tributary vessel spread, with comparative accuracy vs. MRI, to assess suitability for resection and inform preoperative surgical planning.MethodsPatients who underwent PSMA PET/CT for assessment of renal malignancy with TT from 2015 to 2020 at 3 tertiary hospitals in Brisbane, Australia, were retrospectively identified. TT extent was classified using Mayo Clinic levels and compared according to imaging modality.ResultsFourteen patients were included, all of which were clear cell RCC. Ten patients also underwent MRI, 6 of which were concordant in extent according to MRI and PSMA PET. Discordant extent occurred in 4 patients, of which 2 patients had non-PSMA avid thrombus (Mayo level 0 and level 3 on MRI). Further discordance was seen in a patient with adrenal vein and lumbar vein TT only seen on MRI and PSMA PET/CT, respectively. Finally, discordant extent was seen in another patient with Mayo level 4 TT without lumbar vein involvement on MRI vs. level 3 on PSMA PET/CT with lumbar vein involvement.ConclusionsPSMA PET/CT can provide additional information about TT extent in RCC which may not be seen on MRI. Additional information from PSMA PET/CT in this setting may assist surgical planning, in addition to detection of metastatic disease.     

Prostate cancer: to scan or not to scan for lymph node involvement?

OBJECTIVE: When diagnosing lymph node involvement in prostate cancer (PC), the available imaging techniques are considered to be of doubtful value but are still in common use in many institutions because of a lack of better alternatives. To help us choose between methods while we wait for improvements in technologies, we evaluated the performance of ultrasonography (US), CT and MRI. MATERIAL AND METHODS: We reviewed the records of all PC patients who were potential candidates for a surgical staging procedure prior to treatment with intent to cure at Skejby Sygehus, Denmark between 1996 and 2004. In total, 227 patients met our inclusion criteria and 149 were examined with US, 80 with MRI and 71 with CT. The performance of the three modalities was analysed. RESULTS: A total of 50 patients (22%) had lymph node metastases (pN1) and only 12 of these cases (24%) were detected by imaging. US identified all 12 pN1 patients, MRI five and CT did not identify any. Moreover, US missed 28 patients with pN1 metastases, MRI 18 and CT 13. Consequently, US, MRI and CT had sensitivities of 0.3, 0.22 and 0, respectively, while all three modalities had a specificity of 1. The 12 patients identified by imaging had clinically advanced and pathologically aggressive cancers. CONCLUSIONS: Available imaging techniques showed moderate to very low sensitivity. US proved superior to MRI and CT, but should only be applied in high-risk patients. In particular, CT can be considered unsuitable for diagnosing pelvic lymph node metastases in PC.     

Three artificial intelligence data challenges based on CT and MRI

PurposeThe second edition of the artificial intelligence (AI) data challenge was organized by the French Society of Radiology with the aim to: (i), work on relevant public health issues; (ii), build large, multicentre, high quality databases; and (iii), include three-dimensional (3D) information and prognostic questions.Materials and methodsRelevant clinical questions were proposed by French subspecialty colleges of radiology. Their feasibility was assessed by experts in the field of AI. A dedicated platform was set up for inclusion centers to safely upload their anonymized examinations in compliance with general data protection regulation. The quality of the database was checked by experts weekly with annotations performed by radiologists. Multidisciplinary teams competed between September 11^th and October 13^th 2019.ResultsThree questions were selected using different imaging and evaluation modalities, including: pulmonary nodule detection and classification from 3D computed tomography (CT), prediction of expanded disability status scale in multiple sclerosis using 3D magnetic resonance imaging (MRI) and segmentation of muscular surface for sarcopenia estimation from two-dimensional CT. A total of 4347 examinations were gathered of which only 6% were excluded. Three independent databases from 24 individual centers were created. A total of 143 participants were split into 20 multidisciplinary teams.ConclusionThree data challenges with over 1200 general data protection regulation compliant CT or MRI examinations each were organized. Future challenges should be made with more complex situations combining histopathological or genetic information to resemble real life situations faced by radiologists in routine practice.     

The added value of SPECT/CT in the painful foot and ankle: A review of the literature

IntroductionFoot and ankle injuries are common. Radiographic assessment is difficult because of the complex anatomy. In the past decade SPECT/CT made its introduction in assessing bone pathology, it combines both morphologic and pathologic imaging in one image aiming to increase sensitivity and specificity when compared with MRI or CT alone. The purpose of this review was to provide a literature overview on the diagnostic value of SPECT/CT in foot and ankle pathology.MethodsA literature search was conducted in the databases of PubMed and EMBASE between January 2004 and September 2019 for articles describing the diagnostic value of SPECT/CT in foot and ankle pathology. For assessment of methodological quality of each study included in the analysis, QUADAS-2 checklist was used. Main outcomes were change of management, improved diagnosis and symptomatic improvement.ResultsA total of eight studies were identified describing the diagnostic value of SPECT/CT in foot and ankle pathology based on patient data. The combined analysis shows that change of management and improved diagnosis occurred in 48–62% and 40–79% of the patients when compared with other imaging modalities and/or clinical assessment. Symptomatic improvement due to treatment based on SPECT/CT findings occurred in 92% of the patients.ConclusionSPECT/CT is useful when diagnosis based on other imaging modalities is inconclusive or when treatment based on these modalities does not lead to the desired symptomatic improvement.     

Correlation and comparison of syndesmosis dimension on CT and MRI

IntroductionVarious methods using CT scan have been described to diagnose distal tibiofibular syndesmotic injuries. However, CT scan does not take into account the amount of cartilage within the distal tibiofibular joint and could therefore lead to false positive results. We present the first study correlating the findings of the distal tibiofibular syndesmosis on CT and MRI scans.MethodsCT and MRI scan of consecutive patients over a period of 18 months, and of a time lapsed less than 12 months between the two imaging modalities, were reviewed. Measurements of the distal tibiofibular syndesmosis were taken according to a previously published study at the level of the distal tibial physeal scar.ResultsTwenty-six ankles from 25 patients were included in this study for analysis. Significant difference between CT and MRI assessments in the overall distal tibiofibular dimensions and in the posterior distal tibiofibular distance for those ankles with evidence of osteoarthritis was found. Interclass correlation coefficients suggest that such methodology was reproducible and reliable.ConclusionWhen the widening found on a CT scan is minor or the diagnosis is equivocal, a contralateral comparative CT or an ipsilateral MRI scan is recommended to prevent misdiagnosis.Level of evidenceLevel IV.     

Use of preoperative advanced imaging for reverse total shoulder arthroplasty

BackgroundIn order to avoid implant related complications related to glenosphere malposition, there has been an increased interest in the use of advanced imaging, including computed tomography (CT) and magnetic resonance imaging (MRI) for preoperative planning and patient-specific instrumentation for reverse shoulder arthroplasty (RSA). While recent literature has demonstrated improved component position when this technology is applied, the clinical benefits remain largely hypothetical and unproven. Thus, the goals of the current study were to utilize a national database to describe current trends in the use of preoperative advanced imaging and investigate the relationship between such imaging and postoperative complications compared to matched controls without any preoperative imaging.MethodsPatients undergoing RSA for non-fracture indications were identified within the Mariner dataset within the PearlDiver database from 2010 to 2018Q2. Patients who underwent preoperative advanced imaging (MRI and/or CT) within a year prior to surgery were then identified as study cohorts. A matched cohort undergoing RSA without preoperative advanced imaging was created for comparison purposes. The incidence of imaging over time and rates of loosening/osteolysis, periprosthetic fracture, prosthetic dislocation, and revision shoulder arthroplasty of all groups were compared using a regression analysis.ResultsThe percentage of patients who underwent preoperative CT (141% increase, P < .0001), and either MRI or CT (107% increase, P = .002) increased significantly during the study period, while there was no significant increase in MRI utilization (P = .122). Patients who underwent preoperative CT experienced significantly lower rates of revision shoulder arthroplasty (2.4% vs. 3.3%, OR = 0.72, P = .004) and periprosthetic dislocation (2.8% vs. 3.3%, OR 0.80, P = .039) within 2 years of RSA compared to patients who did not undergo preoperative CT, while preoperative MRI was associated with significantly lower rates of periprosthetic fracture (0.2% vs. 0.4%, OR 0.44, P = .005), revision shoulder arthroplasty (2.1% vs. 2.6%, OR = 0.75, P = .006), and periprosthetic dislocation (2.5% vs. 3.2%, OR 0.78, P = .003) within 2 years of RSA compared to patients without an MRI.ConclusionThere has been a significant increase in the utilization of preoperative CT as compared to MRI for RSA during the time period studied. The utilization of preoperative advanced imaging may be associated with a statistically significant reduction in multiple implant related complications following RSA for non-fracture indications, although these findings are of unclear clinical significance given limitations of the database and low percentage difference in complication rates.Level of Evidence: Level III     

Novel navigation surgery using image fusion of PET/CT and sonography for axillary neoplasm: First experience

INTRODUCTIONUltrasound sonography (US)-guided navigation systems are widely used in various organs, including the breast and liver, to locate precisely lesions that are difficult to palpate or isolate after being identified by other imaging techniques. A recent new method, “volume navigation” (Vnav), delivers real-time image fusion of US with other modalities such as MRI, CT, and PET/CT to facilitate identification and excision of suspected pathology.PRESENTATION OF CASEThe present report describes a novel navigation technique using Vnav-PET/CT, which delivers image fusion of US with PET/CT. To identify the axillary targets using Vnav-PET/CT, we set at least two landmarks then injected 0.2 ml viscous blue dye in and around the capsule, which resulted in precise resection. Case 1: A 53-year-old woman with 2 PET/CT-positive lymph nodes in the right axilla underwent easy identification of the targets using the navigation technique followed by lymph node dissection. Among 32 lymph nodes dissected, only the two lymph nodes stained by blue dye were shown histologically to be malignant. Case 2: A 68-year-old woman had a PET/CT-positive lymph node in the left axilla. Vnav-PET/CT easily identified the target, which was successfully dissected under local anaesthesia.DISCUSSIONThis navigation and marking using Vnav-PET/CT helped us easily approach the target, resulted in less surgical time, and avoided unsatisfactory axillary complications. These advances of the navigation system enable us to perform precise minimally invasive surgery.CONCLUSIONThis is the first report of navigation surgery using Vnav-PET/CT, which may assist minimally invasive procedures, especially in the axilla.     

Comparison of differences and random errors in pedicle diameter measurements between MRI and CT: observational study of 315 pedicles in Lenke type 1 adolescent idiopathic scoliosis patients

BACKGROUND CONTEXTPosterior spinal fusion with pedicle screws is commonly used for the treatment of adolescent idiopathic scoliosis (AIS). To reduce radiation exposure, methods other than computed tomography (CT) are desirable for preoperative determination of pedicle diameter.PURPOSEInvestigate the differences between magnetic resonance imaging (MRI) and CT measurements of pedicle diameter.STUDY DESIGNCross-sectional research.PATIENT SAMPLETwenty-one AIS Lenke type 1 patients (19 female and 2 males, mean age at surgery: 15.4 years) who underwent posterior spinal fusion between April 2009 and October 2019.OUTCOME MEASURESGap between CT and MRI pedicle diameters.METHODSThe inner and outer diameters of the right and left pedicles from T1 to L3 were measured separately by two spine surgeons for statistical comparisons.RESULTSThe respective minimum and maximum CT-MRI values were -3.7 mm and 4.7 mm for inner diameter and -4.6 mm and 5.3 mm for outer diameter. Regarding inter-examiner error, the probability of a 2 mm difference in measurement was less than 5% for both modalities. The probability of a 1 mm difference was also less than 5%, and that of a 3 mm or more difference was 2.1% for the inner diameter and 2.9% for the outer diameter. Whereas low body weight was significantly associated with measurement differences, pedicle laterality was not.CONCLUSIONSMRI does not have the reliability to measure pedicle size in AIS patients at present. However, with advancements in image processing technology, the accuracy of pedicle size measurement by MRI may soon improve.