Radiomics in the evaluation of lung nodules: Intrapatient concordance between full-dose and ultra-low-dose chest computed tomography

PurposeThe purpose of this study was to retrospectively evaluate the quantitative and qualitative intrapatient concordance of pulmonary nodule risk assessment by commercially available radiomics software between full-dose (FD) chest-CT and ultra-low-dose (ULD) chest CT.Materials and methodsBetween July 2013 and September 2015, 68 patients (52 men and16 women; mean age, 65.5 ± 10.6 [SD] years; range: 35–87 years) with lung nodules ≥ 5 mm and < 30 mm who underwent the same day FD chest CT (helical acquisition; 120 kV; automated tube current modulation) and ULD chest CT (helical acquisition; 135 kV; 10 mA fixed) were retrospectively included. Each nodule on each acquisition was assessed by a commercial radiomics software providing a similarity malignancy index (mSI), classifying it as “benign-like” (mSI < 0.1); “malignant-like” (mSI > 0.9) or “undetermined” (0.1 ≤ mSI ≤ 0.9). Intrapatient qualitative agreement was evaluated with weighted Cohen–Kappa test and quantitative agreement with intraclass correlation coefficient (ICC).ResultsNinety-nine lung nodules with a mean size of 9.14 ± 4.3 (SD) mm (range: 5–25 mm) in 68 patients (mean 1.46 nodule per patient; range: 1–5) were assessed; mean mSI was 0.429 ± 0.331 (SD) (range: 0.001–1) with FD chest CT (22/99 [22%] “benign-like”, 67/99 [68%] “undetermined” and 10/99 [10%] “malignant-like”) and mean mSI was 0.487 ± 0.344 (SD) (range: 0.002–1) with ULD chest CT (20/99 [20%] “benign-like”, 59/99 [60%] “undetermined” and 20/99 [20%] “malignant-like”). Qualitative and quantitative agreement of FD chest CT with ULD chest CT were “good” with Kappa value of 0.60 (95% CI: 0.46–0.74) and ICC of 0.82 (95% CI: 0.73–0.87), respectively.ConclusionA good agreement in malignancy similarity index can be obtained between ULD chest CT and FD chest CT using radiomics software. However, further studies must be done with more case material to confirm our results and elucidate the diagnostic capabilities of radiomics software using ULD chest CT for lung nodule characterization by comparison with FD chest CT.     

CT-guided infiltration of greater occipital nerve for refractory craniofacial pain syndromes other than occipital neuralgia

PurposeThe purpose of this study was to evaluate the effectiveness of computed tomography (CT)-guided infiltration of greater occipital nerve (GON) for the treatment of refractory craniofacial pain syndromes other than occipital neuralgia.Materials and methodsFifty-six patients suffering from refractory craniofacial pain syndromes were included between 2011 and 2017. There were 33 women and 23 men with a mean age of 50.7 years ± 13.1 (SD) (range: 27–74 years). CT-guided infiltration was performed at the intermediate site of the GON with local anesthetics and cortivazol. Twenty-six (26/56; 46%) patients suffered from chronic migraine, 14 (14/56; 25%) from trigeminal neuralgia and 16 (16/56; 29%) from cluster headaches. Clinical success at 1, 3, and 6 months was defined by a decrease of at least 50% of pain as assessed using visual analog scale (VAS).ResultsMean overall VAS score before infiltration was 8.7 ± 1.3 (SD) (range: 6 - 10). Mean overall VAS scores after infiltration were 2.3 ± 3 (SD) (range: 0 - 10) (P < 0.01) at one month, 3.5 ± 3.3 (SD) (range: 0 - 10) (P < 0.01) at three months and 7.6 ± 1.3 (SD) (range: 1–10) (P < 0.01) at six months. After infiltration, clinical success was achieved in 44 patients (44/56; 78.5%) at 1 month, 37 patients (37/56; 66%) at 3 months and 13 patients (13/56; 23%) at 6 months. Clinical success according to the clinical presentation were as follows: 88% (23/26) at one month, 73% (19/26) at 3 months, and 23% (6/26) at 6 months in patients with chronic migraine, 81% (13/16), 69% (11/16) and 31% (5/16) in those with cluster headaches and 57% (8/14), 50% (7/14) and 14% (2/14) in those with trigeminal neuralgia. No major complications due to CT-guided GON infiltration were reported in any patient.ConclusionCT-guided infiltration at the intermediate site of the GON appears as an effective treatment of craniofacial pain syndromes especially in patients with chronic migraine and those with cluster headaches.     

CT features of lung metastases from pancreatic adenocarcinoma: Correlation with histopathologic findings

PurposeThe purpose of this study was to evaluate the prevalence of an atypical, alveolar presentation of pulmonary metastases from pancreatic adenocarcinoma (PDAC) on computed tomography (CT) and to correlate CT features with those obtained at histopathologic analysis.Material and methodsA total of 76 patients with lung metastases from PDAC over a 10-year period (2009–2019) in a French university hospital were retrospectively included. There were 34 men and 42 women with a mean age of 67.6 ± 11.3 (SD) years (range: 38–89 years). CT features of PDAC were classified according to their presentations as usual metastatic pattern or atypical alveolar pattern; the atypical alveolar pattern corresponding to either ground glass nodules or opacities, solid nodules with a halo sign, “air-space” nodules with air bronchogram, or parenchymal consolidation. Imaging-histopathologic correlation was performed when tissue samples were available.ResultsPulmonary metastases were synchronous in 36 patients (36/76; 47%) and metachronous in 40 patients (40/76; 53%). A predominant alveolar presentation on CT was observed in 17 patients (17/76, 22%). Nodules with halo sign were the predominant alveolar pattern in 7 patients (7/17; 41%), air-space nodules were predominant in 4 patients (4/17; 24%) whereas pure ground glass nodules and consolidations were observed as predominant features in 3 patients (3/17; 18%) each. For 5 patients who had histopathological confirmation, alveolar metastases of PDAC were characterized by columnar tumor cells lining the alveolar wall, which was not seen in other radiological presentations, whereas there were no differences regarding mucin secretion between pulmonary metastases with alveolar presentation and those with typical pattern.ConclusionsLung metastases from PDAC may present with a so-called “alveolar” pattern on CT. This misleading CT features is found in 22% of patients with lung metastases from PDAC and is due to lepidic growth of the metastatic cells.     

Image-guided core biopsy of 2-cm or smaller renal tumors

PurposeThe purpose of this study was to retrospectively evaluate diagnostic yield, risk factors for diagnostic failure, and safety of image-guided core biopsy of renal tumors ≤ 2 cm.Materials and methodsEighty-four biopsies of 84 renal tumors (mean size, 1.5 ± 0.4 [SD] cm; range, 0.6–2.0 cm) from 84 patients (53 men, 31 women; mean age, 61.7 ± 12.7 [SD] years; age range, 34–87 years) were included. All adverse events (AEs) were evaluated based on the CIRSE classification. The 84 procedures were classified as diagnostic or nondiagnostic. Multiple variables related to the patients, tumors, and procedures were assessed to identify variables associated with diagnostic failure.ResultsAll 84 biopsies (100%) were technically successful, defined as penetration of the target and acquisition of some specimens. Eighty (80/84; 95.2%) biopsy procedures were diagnostic and four (4/84; 4.8%) procedures were nondiagnostic. Among 80 diagnosed renal tumors, 71/80 (88.8%) tumors were malignant (49 clear cell renal cell carcinomas [RCCs], 14 papillary RCCs, 3 chromophobe RCCs, 3 metastatic renal cancers, 1 lymphoma, and 1 unclassified RCC) and 9/80 (11.2%) lesions were benign (5 angiomyolipomas, 3 oncocytomas, and 1 inflammatory lesion). No significant differences existed in any variables between the two groups. A total of 57 (57/84; 67.9%) procedures resulted in 56 Grade 1, 2 Grade 2, and 1 Grade 3 AEs.ConclusionImage-guided biopsy of renal tumors ≤ 2 cm is safe and has a high diagnostic yield.     

Effectiveness of CT-guided epidural infiltration of steroids and local anesthetics for acute and chronic herpes zoster neuralgia

PurposeThe purpose of this study was to evaluate the effectiveness and complication rate of computed tomography (CT)-guided epidural injection of steroids and local anesthetics for pain relief in patients with neuralgia due to acute or chronic herpes zoster (HZ).Materials and methodsA prospective study was conducted from April 2017 to February 2019 including patients with HZ neuralgia (HZN) at any stage (acute or chronic, the latter being defined as pain lasting more than 3 months and also called post herpetic neuralgia [PHN]). The sensory ganglion of the affected dermatome and/or the affected sensory nerve was targeted under CT-guidance and local injection of a mixture of two vials of methylprednisolone 40 mg/mL and 2 mL of Lidocaine 1% was performed. Using a visual analogue scale (VAS, 0 to 10), pain was assessed prior to the procedure, and at day 7, 1 month, 3 months and 6 months. Adverse effects were graded according to the Society of Interventional Radiology classification.ResultsTwenty patients were included. There were 9 men and 11 women with a mean age of 67 ± 13.9 (SD) years (range: 27–83 years). Of these, 14 patients had acute HZN and 6 had PHN. Mean VAS at baseline was 8.1 ± 1.2 (SD) (range: 6–10) with significant decrease (P < 0.0001) at day 7 (3.4 ± 3.2 [SD]; range: 0–10), day 30 (3.4 ± 3.2 [SD]; range: 0–9), day 90 (2.9 ± 3.2 [SD]; range: 0–9), and day 180 (2.5 ± 3.1 [SD]; range: 0–9). Infiltrations were significantly more effective on acute HZN than on PHN (P < 0.001) and required significantly fewer infiltrations for pain relef (P = 0.002). Only one grade A adverse event was reported.ConclusionEpidural injection of a mixture of steroids and local anesthetics under CT-guidance is effective on HZN with a persisting effect over 6 months.     

Artificial intelligence solution to classify pulmonary nodules on CT

PurposeThe purpose of this study was to create an algorithm to detect and classify pulmonary nodules in two categories based on their volume greater than 100 mm³ or not, using machine learning and deep learning techniques.Materials and methodThe dataset used to train the model was provided by the organization team of the SFR (French Radiological Society) Data Challenge 2019. An asynchronous and parallel 3-stages pipeline was developed to process all the data (a data “pre-processing” stage; a “nodule detection” stage; a “classifier” stage). Lung segmentation was achieved using 3D U-NET algorithm; nodule detection was done using 3D Retina-UNET and classifier stage with a support vector machine algorithm on selected features. Performances were assessed using area under receiver operating characteristics curve (AUROC).ResultsThe pipeline showed good performance for pathological nodule detection and patient diagnosis. With the preparation dataset, an AUROC of 0.9058 (95% confidence interval [CI]: 0.8746–0.9362) was obtained, 87% yielding accuracy (95% CI: 84.83%–91.03%) for the “nodule detection” stage, corresponding to 86% specificity (95% CI: 82%–92%) and 89% sensitivity (95% CI: 84.83%–91.03%).ConclusionA fully functional pipeline using 3D U-NET, 3D Retina-UNET and classifier stage with a support vector machine algorithm was developed, resulting in high capabilities for pulmonary nodule classification.     

Spinal Arachnoid Web: A didactic report of two cases with clinical,radiological, surgical and pathological correlations

BackgroundArachnoid web (AW) is a rare but probably underestimated cause of spinal cord injury that is complex to diagnose due to subtle MRI findings and similarities to other better-known diseases such as arachnoid cyst (AC) or transdural spinal cord herniation (TSCH). Increased recognition of AW is mandatory since delay in diagnosis can lead to potentially serious neurological sequelae.Case presentationsWe report two additional cases of AW for didactic purposes, with special emphasis on the distinctive MRI and intraoperative findings. Both patients presented with progressively worsening neurological symptoms, including proprioceptive ataxia, motor weakness, numbness and neuropathic pain. The diagnosis of AW was suspected on the basis of specific MRI criteria, especially the so-called “scalpel sign”. Formal confirmation of the diagnosis was obtained in two patients that were managed surgically. Postoperative follow-up demonstrated significant functional recovery.DiscussionThere is a need for better recognition of AW by the medical community. Careful analysis of MRI semiology is crucial for the distinction between AW, AC and TSCH. Prompt and accurate diagnosis is mandatory to conserve functional prognosis, since appropriate surgical treatment with AW resection is curative, halting or even resolving the neurological symptoms.     

Feasibility of lung imaging with a large field-of-view spectral photon-counting CT system

PurposeThe purpose of this study was to characterize the technical capabilities and feasibility of a large field-of-view clinical spectral photon-counting computed tomography (SPCCT) prototype for high-resolution (HR) lung imaging.Materials and methodsMeasurement of modulation transfer function (MTF) and acquisition of a line pairs phantom were performed. An anthropomorphic lung nodule phantom was scanned with standard (120 kVp, 62 mAs), low (120 kVp, 11 mAs), and ultra-low (80 kVp, 3 mAs) radiation doses. A human volunteer underwent standard (120 kVp, 63 mAs) and low (120 kVp, 11 mAs) dose scans after approval by the ethics committee. HR images were reconstructed with 1024 matrix, 300 mm field of view and 0.25 mm slice thickness using a filtered-back projection (FBP) and two levels of iterative reconstruction (iDose 5 and 9). The conspicuity and sharpness of various lung structures (distal airways, vessels, fissures and proximal bronchial wall), image noise, and overall image quality were independently analyzed by three radiologists and compared to a previous HR lung CT examination of the same volunteer performed with a conventional CT equipped with energy integrating detectors (120 kVp, 10 mAs, FBP).ResultsTen percent MTF was measured at 22.3 lp/cm with a cut-off at 31 lp/cm. Up to 28 lp/cm were depicted. While mixed and solid nodules were easily depicted on standard and low-dose phantom images, higher iDose levels and slice thicknesses (1 mm) were needed to visualize ground-glass components on ultra-low-dose images. Standard dose SPCCT images of in vivo lung structures were of greater conspicuity and sharpness, with greater overall image quality, and similar image noise (despite a flux reduction of 23%) to conventional CT images. Low-dose SPCCT images were of greater or similar conspicuity and sharpness, similar overall image quality, and lower but acceptable image noise (despite a flux reduction of 89%).ConclusionsA large field-of-view SPCCT prototype demonstrates HR technical capabilities and high image quality for high resolution lung CT in human.     

Interstitial lung diseases in children

Interstitial lung disease (ILD) in children (chILD) is a heterogeneous group of rare respiratory disorders that are mostly chronic and associated with high morbidity and mortality. The pathogenesis of the various chILD is complex and the diseases share common features of inflammatory and fibrotic changes of the lung parenchyma that impair gas exchanges. The etiologies of chILD are numerous. In this review, we chose to classify them as ILD related to exposure/environment insults, ILD related to systemic and immunological diseases, ILD related to primary lung parenchyma dysfunctions and ILD specific to infancy. A growing part of the etiologic spectrum of chILD is being attributed to molecular defects. Currently, the main genetic mutations associated with chILD are identified in the surfactant genes SFTPA1, SFTPA2, SFTPB, SFTPC, ABCA3 and NKX2-1. Other genetic contributors include mutations in MARS, CSF2RA and CSF2RB in pulmonary alveolar proteinosis, and mutations in TMEM173 and COPA in specific auto-inflammatory forms of chILD. However, only few genotype-phenotype correlations could be identified so far. Herein, information is provided about the clinical presentation and the diagnosis approach of chILD. Despite improvements in patient management, the therapeutic strategies are still relying mostly on corticosteroids although specific therapies are emerging. Larger longitudinal cohorts of patients are being gathered through ongoing international collaborations to improve disease knowledge and targeted therapies. Thus, it is expected that children with ILD will be able to reach the adulthood transition in a better condition.     

Comparison of video-assisted thoracoscopic surgery with thoracotomy in bronchial sleeve lobectomy for centrally located non–small cell lung cancer

ObjectivesThe aim of this study was to investigate the adequacy of bronchial sleeve lobectomy by video-assisted thoracoscopic surgery in perioperative outcomes and its oncological efficacy by comparing with thoracotomy in a balanced population.MethodsA total of 363 patients who received bronchial sleeve lobectomy for non–small cell lung cancer from January 2013 to December 2017 were included and placed in the thoracotomy (n = 251) and video-assisted thoracoscopic surgery (n = 112) groups. Statistical analyses were performed to compare patients' demographics, perioperative outcomes, and survival between the 2 groups.ResultsA total of 116 thoracotomy cases were matched with 72 video-assisted thoracoscopic surgery cases by propensity score. Compared with thoracotomy, patients in the video-assisted thoracoscopic surgery group after matching had less intraoperative blood loss (P < .01) and length of postoperative hospital stay (P < .01), duration of chest tube drainage (P < .01), and intensive care unit stay (P = .03) despite comparable operative time, complication rate, and 30- to 90-day mortality rate. The overall survival and recurrence-free survival were similar in patients who received sleeve lobectomy by thoracotomy and video-assisted thoracoscopic surgery (log-rank, P = .24 and .20, respectively) at 3 years. Although advanced TNM stage was independently associated with worse overall survival and recurrence-free survival in multivariable analysis, older age was only predictive for worse overall survival (hazard ratio, 1.04; 95% confidence interval, 1.01-1.07; P = .02). Body mass index was also found be a predictive factor (overall survival: hazard ratio, 0.93; 95% confidence interval, 0.86-0.99, P = .03; recurrence-free survival: hazard ratio, 0.93; 95% confidence interval, 0.87-0.99, P = .02).ConclusionsWith appropriate patient selection and continued experience, video-assisted thoracoscopic surgery appears to be safe in the short-term perioperative period and does not appear to comprise oncologic outcomes in performing sleeve lobectomy.     

Discriminating between bronchiolar adenoma,adenocarcinoma in situ and minimally invasive adenocarcinoma of the lung with CT

PurposeTo identify computed tomography (CT) features that may help distinguish bronchiolar adenoma (BA) from lung adenocarcinomas in situ (AIS) and minimally invasive adenocarcinomas (MIA) among lung lesions presenting as ground-glass nodules (GGNs).Materials and methodsA total of 140 patients with GGNs confirmed by surgery and pathology, were reviewed retrospectively. There were 68 men and 72 women with a mean age of 64.3 ± 8.9 (SD) years (range: 31 – 85 years). The CT features of BA, AIS, and MIA were analyzed and compared. CT features, including percentage of solid component, maximum diameter of solid component, lesion density, location, margin, shape, pseudo-cavitation, calcification, ill-defined peripheral opacity, and air bronchogram, were analyzed using multivariate logistic regression and receiver operating characteristic curves.ResultsThere were 11/140 (7.9%) patients with BA (mean age, 67.7 ± 7.5 [SD]; range 45 – 77 years), 63/140 (45.0%) patients with AIS (mean age, 62.5 ± 8.6 [SD]; range 36 – 69 years) and 66/140 (47.1%) patients with MIA (mean age, 63.5 ± 7.9 [SD]; range 35 – 72 years). By comparison with AIS and MIA, significantly different CT features of BA included tumor size, solid component diameters, low CT attenuation of the ground-glass component, irregular shape, ill-defined peripheral opacity, pseudo-cavitation, and abnormal pulmonary vein. Ill-defined peripheral opacity (odds ratio, 1.060; 95% confidence interval [CI]: 1.020 – 1.380) and pseudo-cavitation (odds ratio, 1.236; 95% CI: 1.070 – 1.565) were variables independently associated with the diagnosis of BA.ConclusionCT provides morphological features that allow differentiating between BA and AIS-MIA among lung lesions presenting as GGNs.     

Comparison of conventional magnetic resonance imaging and diffusion-weighted imaging in the differentiation of bone plasmacytoma from bone metastasis in the extremities

PurposeTo compare conventional magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI) in the differentiation of bone plasmacytoma from bone metastasis in the extremities.Materials and methodsA total of 65 patients with 27 bone plasmacytomas (11 men; mean age, 63.6 ± 8.2 [SD] years) and 38 patients with bone metastases (20 men; mean age, 64.1 ± 11.5 [SD] years) were retrospectively included. Plasmacytomas and metastases were compared for size, peritumoral edema, signal intensity (SI), SI pattern, apparent diffusion coefficient (ADC) values and standard deviation (SD) of ADC. Receiver operating characteristic analysis with area under the curve (AUC) was used to calculate sensitivity, specificity, and accuracy of MRI and DWI for the diagnosis of plasmacytoma according to a defined cut-off value.ResultsOn conventional MRI, plasmacytomas showed less peritumoral edema (22% vs. 71%; P < 0.001), were more often hyperintense on T1-weighted image (48% vs. 18%; P = 0.022) and more homogeneous on T2-weighted image (78% vs. 26%; P < 0.001) and contrast-enhanced T1-weighted images (70% vs. 25%; P = 0.001) than bone metastases. Mean ADC value and SD of ADC were significantly lower in bone plasmacytomas (760.1 ± 196.9 [SD] μm²/s and 161.5 ± 62.7 [SD], respectively) than in bone metastases (1214.2 ± 382.6 [SD] μm²/s and 277.0 ± 110.3 [SD], respectively) (P < 0.001). Using an ADC value ≤ 908.3 μm²/s, DWI yielded 88% sensitivity and 78% specificity for the diagnosis of plasmacytoma. ADC value yielded best area under the curve (AUC = 0.913), followed by SD of ADC (AUC = 0.814) and homogeneity on T2-weighted images (AUC = 0.757). The combination of conventional MRI and DWI (AUC = 0.894) showed improved diagnostic performance over conventional MRI alone (AUC= 0.843) for discriminating between plasmacytoma and metastasis.ConclusionConventional MRI in combination with DWI can be useful to discriminate between bone plasmacytoma and bone metastasis in the extremities.     

Preoperative assessment of patient comorbidities before left colectomy: Comparison between ASA performance status scale and a new computed tomography physical status score

PurposeTo compare a newly developed preoperative computed tomography physical status (CT-PS) score with the American Society of Anesthesiology performance status (ASA-PS) scale in the assessment of patient preoperative health status and stratification of perioperative risk before left colectomy.Materials and methodsPreoperative chest-abdomen-pelvis CT examinations of patients who were scheduled to undergo elective laparoscopic left colonic resection for cancer in two centers were reviewed by two radiologists blinded to clinical data for the presence of several key imaging features in order to assess general, cardiac, pulmonary, abdominal, renal, vascular and musculoskeletal status. CT examinations of patients from center 1 were used to build a CT-PS score to predict ASA-PS ≥ III. CT-PS score was further validated using an external cohort of patients from center 2.ResultsDuring a 2-year period, 117 consecutive patients (63 men, 54 women; mean age, 65 ± 13 [SD] years; age range: 53–90 years) who underwent laparoscopic left colectomy for cancer in center 1 (66 patients, building cohort) and center 2 (51 patients, validation cohort) were retrospectively included. Ninety-one percent of patients were ASA-PS 1–2. Overall postoperative morbidity was 23% and severe morbidity 12%. The area under the receiver operating characteristic curve of CT-PS score was 0.968 (95% CI: 0.901–1.000) in the building cohort and 0.828 (95% CI: 0.693–0.963) in the validation cohort. The optimal thresholds yielded 87% (95% CI: 83–91%) sensitivity and 100% (95% CI: 91–100%) specificity in the building cohort and 75% (95% CI: 69–81%) sensitivity and 83% (95% CI: 77–88%) specificity in the validation cohort for the prediction of ASA-PS.ConclusionPreoperative chest-abdomen-pelvis CT thoroughly and wisely read is highly accurate to differentiate patients with ASA-PS I/II from those with ASA-PS III/IV before left colectomy.     

Head-to-head comparison of lung perfusion with dual-energy CT and SPECT-CT

PurposeTo compare the quantitative and qualitative lung perfusion data acquired with dual energy CT (DECT) to that acquired with a large field-of-view cadmium-zinc-telluride camera single-photon emission CT coupled to a CT system (SPECT-CT).Materials and methodsA total of 53 patients who underwent both dual-layer DECT angiography and perfusion SPECT-CT for pulmonary hypertension or pre-operative lobar resection surgery were retrospectively included. There were 30 men and 23 women with a mean age of 65.4 ± 17.5 (SD) years (range: 18–88 years). Relative lobar perfusion was calculated by dividing the amount (of radiotracer or iodinated contrast agent) per lobe by the total amount in both lungs. Linear regression, Bland-Altman analysis, and Pearson's correlation coefficient were also calculated. Kappa test was used to test agreements in morphology and severity of perfusion defects assessed on SPECT-CT and on DECT iodine maps with a one-month interval. Wilcoxon rank sum test was used to compare the sharpness of perfusion defects and radiation dose among modalities.ResultsStrong correlations for relative lobar perfusion using linear regression analysis and Pearson's correlation coefficient (r = 0.93) were found. Bland-Altman analysis revealed a −0.10 bias, with limits of agreement between [−6.01; 5.81]. With respect to SPECT- CT as standard of reference, the sensitivity, specificity, PPV, NPV, accuracy for lobar perfusion defects were 89.4% (95% CI: 82.6−93.4%), 96.5% (95% CI: 92.1−98.5%), 95.6% (95% CI: 90.9−97.8%), 91.4% (95% CI: 85.6−94.9%) and 93.0% (95% CI: 87.6−96.1%) respectively. High level of agreement was found for morphology and severity of perfusion defects between modalities (Kappa = 0.84 and 0.86 respectively) and on DECT images among readers (Kappa = 0.94 and 0.89 respectively). A significantly sharper delineation of perfusion defects was found on DECT images (P < 0.0001) using a significantly lower equivalent dose of 4.1 ± 2.3 (SD) mSv (range: 1.9–11.85 mSv) compared to an equivalent dose of 5.3 ± 1.1 (SD) mSv (range: 2.8–7.3 mSv) for SPECT-CT, corresponding to a 21.2% dose reduction (P = 0.0004).ConclusionDECT imaging shows strong quantitative correlations and qualitative agreements with SPECT-CT for the evaluation of lung perfusion.     

Bladder endometriosis: Preoperative MRI analysis with assessment of extension to ureteral orifices

PurposeThe purpose of this study was to retrospectively evaluate the performance of magnetic resonance imaging (MRI) in locating endometriosis implants within the bladder wall with assessment of ureteral orifice extension using surgical findings as standard of reference.Materials and methodsMRI examinations of 39 consecutive women (mean age: 31.2 ± 5.5 [SD] years; age range: 22–42 years) operated in 3 university hospitals for bladder endometriosis over a 6-year period were reviewed by 2 independent readers. Interobserver agreement was assessed using Kappa tests. Results of consensus reading were used to calculate sensitivity, specificity and accuracy of MRI for the diagnosis, location and extent of endometriosis implants using surgical findings as the standard of reference.ResultsMean bladder repletion volume was 134 ± 110 [SD] mL (range: 21–479 mL). The mean largest endometriosis implant diameter was 30 ± 7 [SD] mm (range: 19–41 mm). On MR images, 34/39 (87%) endometriosis implants were present in the two anterior thirds of the dome (k = 0.45), 31/39 (79%) extended or were present in the posterior third pouch (k = 0.92) and 25/39 (64%) extended into the bladder base (k = 0.84) with sensitivities of 100% (31/31; 95% confidence interval [CI]: 89–100%), 100% (30/30; 95% CI: 88–100%) and 90% (19/21; 95% CI: 69–98%), respectively, specificities of 83% (5/6, 95% CI: 36–100), 88% (7/8, 95% CI: 47–100%), 87% (13/15; 95% CI: 52–96), respectively and accuracies of 97% (36/37, 95% CI: 86–100%), 97% (37/38; 95% CI: 86–100%), and 89% (32/36; 95% CI: 74–97%), respectively. In 9 (9/25; 36%) patients with bladder base involvement, a zero distance was reported between endometriosis implants and ureteral orifices, all but one presenting with low-to-moderate bladder volumes. In the two patients who needed ureteral resection-reimplantation, ureteral dilation was associated with a zero distance. External adenomyosis was reported in 26/39 (66%) patients (k = 0.94).ConclusionA dedicated preoperative MRI work-up for bladder endometriosis helps accurately depict and locate endometriosis implants. Adequate bladder filling is needed to improve appropriate estimate of the distance between endometriosis implants and ureteral orifices to better predict requirement of ureteral resection-reimplantation.     

Use of Second Window ICG in spinal cord biopsy of a mildly contrast-enhancing lesion: Technical note and review of the literature

IntroductionIndocyanine green (ICG) is commonly used to visualize cerebral vasculature, particularly in the management of cerebral aneurysms. There have also been attempts to use ICG for visualization of tumors. Injection of ICG followed by immediate fluorescence microscopy is limited by the short time window for imaging and administration and restricted depth of imaging. Second Window Indocyanine Green (SWIG) addresses these issues by allowing for longer contrast times and the imaging of deeper regions of brain tissue. Biopsy of spinal cord lesions is often difficult for a variety of reasons, including the delicate nature of the tissue and differentiating normal from lesional tissue visually, especially in lesions with heterogeneous enhancement.MethodsIn this case report, we describe the use of second window ICG to facilitate the visualization of a spinal cord lesion and subsequent biopsy of the lesion.ResultsThis patient is a 24-year-old female who had recurrence of a suprasellar germinoma. An MRI of the rest of the neuraxis was performed to assess for the presence of drop metastases. The spinal cord from C2-5 was expanded with areas of patchy enhancement; however, this lesion was asymptomatic. The patient's oncologist requested a biopsy of this lesion to help direct subsequent care of her recurrent germinoma. The day before surgery, the patient had an intravenous injection of ICG dye. She then underwent a C3-5 laminectomy for biopsy of her cervical intramedullary lesion. After opening of the dura, no visible abnormality of the spinal cord could be identified. A Stryker endoscope showed an area of ICG uptake in the cord at approximately the C3-4 level. A midline myelotomy was centered over the ICG demarcated area and several samples were taken for pathology. Final biopsy results determined the lesion to be spinal cord parenchyma with perivascular and intraparenchymal lymphocytes – not consistent with spinal cord tumor or germinoma.ConclusionSecond Window ICG is effective in visualizing otherwise visually unremarkable spinal cord lesions. This technology can facilitate biopsy of these lesions and possibly their surgical resection.     

The relevance of liquid biopsy in surgical oncology: The application of perioperative circulating nucleic acid dynamics in improving patient outcomes

BackgroundLiquid biopsy is gaining increasing clinical utility in the management of cancer patients. The main components of a liquid biopsy are circulating nucleic acids, circulating tumour cells and extracellular vesicles such as exosomes. Circulating nucleic acids including cell free DNA (cfDNA) and circulating tumour DNA (ctDNA) in particular have been the focus of recent attention as they have demonstrated excellent potential in cancer screening, provision of prognostic information and in genomic profiling of a tumour without the need for repeated tissue biopsies. The aim of this review was to explore the current evidence in relation to the use of liquid biopsy in the perioperative setting and identify ways in which liquid biopsy may be applied in the future.MethodsThis narrative review is based on a comprehensive literature search up to the 1st of June 2020 for papers relevant to the application of liquid biopsy in surgical oncology, focusing particularly on the perioperative period.ResultsRecent evidence has demonstrated that perioperative liquid biopsy can accurately stratify patients’ risk of recurrence compared to conventional biomarkers. Attention to the perioperative dynamics of liquid biopsy components can potentially provide new understanding of the complex relationship between surgery and cancer outcome. In addition, careful evaluation of liquid biopsy components in the perioperative window may provide important diagnostic and therapeutic information for cancer patients.ConclusionThe rapidly evolving concept of the liquid biopsy has the potential to become the cornerstone for decision making around surveillance and adjuvant therapies the era of personalised medicine.