The PEARL Approach for CT-guided Lung Biopsy: Assessment of Complication Rate.

Background Percutaneous CT-guided biopsy of lung nodules is an established method with high diagnostic accuracy but a high rate of pneumothorax and chest tube insertion compared with endobronchial methods. Purpose To investigate the effect of a protocol combining patient positioning biopsy-side down, needle removal during expiration, autologous blood patch sealing, rapid rollover, and pleural patching (PEARL) on complication rate after percutaneous CT-guided lung biopsy, especially chest tube insertion. Materials and Methods In a secondary analysis of both prospectively and retrospectively acquired data from December 2019 to November 2020, consecutive participants underwent biopsy with use of the PEARL protocol (prospective data) and were compared with patients who underwent biopsy at the same tertiary cancer center according to the standard method without any additional techniques (controls, retrospective data). Patient demographics, lesion characteristics, intraprocedural data, complications, and histologic results were recorded and compared. Results One hundred patients in the control group (mean age ± standard deviation, 63 years ± 12; 61 men) and 100 participants in the PEARL group (mean age, 64 years ± 12; 48 men) were evaluated. No differences were found in patient and lesion characteristics. The emphysema rate was 47 of 100 patients (47%) in both groups. The rate of pneumothorax was 37 of 100 patients (37%) in the control group versus 16 of 100 (16%) in the PEARL group (P = .001). Of the pneumothoraxes that occurred, fewer were during the intervention in the PEARL group, with 21 of 37 onsets (57%) in the control group versus three of 16 onsets (19%) in the PEARL group (P < .001). A chest tube was inserted in 13 of 100 patients (13%) in the control group and only in one of 100 (1%) in the PEARL group (P = .002). Histologic findings were diagnostic in 94 of 100 patients (94%) in the control group and 95 of 100 (95%) in the PEARL group (P > .99). Conclusion During CT-guided percutaneous lung biopsy, a protocol of positioning biopsy-side down, needle removal during expiration, autologous blood patch sealing, rapid rollover, and pleural patching, or PEARL, reduced rates of pneumothorax and chest tube insertion. © RSNA, 2021.

Combined local treatments for vertebral metastases with limited epidural extension.

OBJECTIVES: Vertebral metastases with limited epidural extension (VMLEE) are frequently encountered in cancer patients; they can cause severe and debilitating symptoms including pain and neurological impairment and are usually treated by radiotherapy. In this study, we mainly evaluated the safety of combined local treatments (CLT), associating radiofrequency ablation (RFA) with vertebroplasty and radiotherapy (RT) to treat VMLEE. Also, we aimed to evaluate the short-term efficacy of CLT on bone metastases palliation and long-term prevention of skeletal-related events. METHODS: We retrospectively reviewed treatment complications, pain palliation, and skeletal complications after combined local treatments (CLT) for vertebral metastasis with limited epidural extension (VMLEE). RESULTS: Eighteen consecutive patients had CLT for 24 VMLEE, between June 2016 and January 2021. No major post-treatment complication was recorded. Nine patients had pain before the initiation of CLT. One month after CLT, only 3 patients had residual pain with a significant decrease of visual analogue scale (VAS), from 7.3 ± 2.4 to 2 ± 0 (p = .008), as well as the mean morphine milligram equivalent dose from 196.6 ± 135.7 to 38.5 ± 26, p = .008. Mean follow-up was 16.7 ± 11.5 months. Only one vertebra showed an increase of a preexisting vertebral fracture. Nine VMLEE had evidence of residual disease, including 2 which resulted in spinal cord compression (2, 11 months). CONCLUSION: CLT was safe and effective for pain palliation and long-term prevention of skeletal-related events for treatment of patients with VMLEE. The effectiveness of this combined treatment on tumor control and epidural involvement on the long term needs further investigation.

Risk factors for local tumor progression after RFA of pulmonary metastases: a matched case-control study.

OBJECTIVES: Curative treatment of oligometastatic pulmonary disease aims at eradication of all metastases. Radiofrequency ablation (RFA) has been shown to be an efficient method and the frequency of local tumor progression (LTP) should be minimized. The objective of this study was to determine the morphological and treatment-related risk factors for LTP after RFA of pulmonary metastases. MATERIALS AND METHODS: All patients treated with RFA for pulmonary metastases from 2002 to 2014 were reviewed. All LTPs from 2011 to 2014 were individually matched on the basis of tumor size, number, and histology. In total, 48 LTPs and 112 controls were blindly analyzed for morphological factors including vicinity of bronchus and vessels as well as treatment-related factors such as the size of the ablation zone and ablation margins. RESULTS: In the simple regression analysis, the significant predictive variables were ≤ 5-mm distance to a large bronchus (OR = 4.94; p = 0.0095) or large vessel (OR = 7.09; p < 0.001), minimal ablation margin (≤ 5 mm (OR = 42.67; p < 0.001), and a central-peripheral ablation offset/ablation zone size > 0.36 (OR = 13.83; p = 0.013). In the multiple regression model, only a minimal ablation margin ≤ 5 mm remained a significant risk factor for LTP. CONCLUSION: Only the minimal ablation margin remains significant in the multiple regression analysis; the other factors are presumably surrogates of an insufficient ablation margin. Improvement of lung RFA outcomes can probably be obtained by immediate post RFA evaluation of ablation margins to ensure a minimal ablation margin of at least 5 mm. KEY POINTS: • A distance < 5 mm to a bronchus or vessel of over 3 mm diameter is associated with insufficient ablation margin and thus risk factors for local tumor progression after pulmonary radiofrequency ablation. • A minimal ablation margin of > 5 mm after pulmonary RFA is associated with significantly less local tumor progression and should be looked for at the end of treatment session before needle removal in order to decrease local tumor progression. • Tumor location, pleural contact, occurrence of intra-alveolar hemorrhage, pulmonary atelectasis, and pneumothorax are not associated with an increased risk of local tumor progression.

Variant filtering, digenic variants, and other challenges in clinical sequencing: a lesson from fibrillinopathies.

Genome-scale high-throughput sequencing enables the detection of unprecedented numbers of sequence variants. Variant filtering and interpretation are facilitated by mutation databases, in silico tools, and population-based reference datasets such as ExAC/gnomAD, while variants are classified using the ACMG/AMP guidelines. These methods, however, pose clinically relevant challenges. We queried the gnomAD dataset for (likely) pathogenic variants in genes causing autosomal-dominant disorders. Furthermore, focusing on the fibrillinopathies Marfan syndrome (MFS) and congenital contractural arachnodactyly (CCA), we screened 500 genomes of our patients for co-occurring variants in FBN1 and FBN2. In gnomAD, we detected 2653 (likely) pathogenic variants in 253 genes associated with autosomal-dominant disorders, enabling the estimation of variant-filtering thresholds and disease predisposition/prevalence rates. In our database, we discovered two families with hitherto unreported co-occurrence of FBN1/FBN2 variants causing phenotypes with mixed or modified MFS/CCA clinical features. We show that (likely) pathogenic gnomAD variants may be more frequent than expected and are challenging to classify according to the ACMG/AMP guidelines as well as that fibrillinopathies are likely underdiagnosed and may co-occur. Consequently, selection of appropriate frequency cutoffs, recognition of digenic variants, and variant classification represent considerable challenges in variant interpretation. Neglecting these challenges may lead to incomplete or missed diagnoses.

Mid-term results of MR-guided high-intensity focused ultrasound treatment for relapsing superficial desmoids.

PURPOSE: Desmoids are locally infiltrative, nonmalignant soft tissue tumors. Surgery, radiation therapy, and chemotherapy have been the mainstay of treatment, but relapse is common and side effects can result in significant morbidity. MR-HIFU is increasingly recognized as an alternative treatment modality. We assessed the success rate of MR-HIFU for the treatment of extra-abdominal desmoids at our institute. MATERIALS AND METHODS: Five patients with relapsing desmoid tumors (three males, two females; age range 40-79 years) were treated using the Sonalleve system in an outpatient setting without general anesthesia. Changes in total tumor volumes were measured with a tumor tracking software. Adverse events were documented. RESULTS: MR-HIFU was successful in all patients without severe side effects. Follow up ranged from 13 to 60 months. Three patients required more than one treatment session. In 3 patients with small lesions (mean = 9.7 mL), complete ablation was achieved with no evidence of viable tumor on follow up MRI at an average of 35.7 months, while in two patients with larger lesions (mean = 46 mL) the targeted tumor volumes decreased by 73% at 14 months. Skin injuries comprised first- and second-degree burns and were observed with short distance to skin (mean = 0.9 cm) and proximity to bone (i.e. ribs). Skin burns healed within weeks with topical treatment. CONCLUSION: MR-HIFU shows good mid-term result for extra-abdominal desmoids with complete response for small lesions and stabilization of larger lesions. MR-HIFU for desmoids can be performed under regional anesthesia/sedation as outpatients.

Long segment 3D double inversion recovery (DIR) hypersignal on MRI in glaucomatous optic neuropathy.

BACKGROUND: In this retrospective study the relationship between intraocular pressure (IOP), retinal nerve fiber layer (RNFL) thickness and pathologic hypersignal in optic nerve segments on 3D double inversion recovery (DIR) MR sequence in 21 patients with proven glaucoma of different origin was evaluated. METHODS: All patients were examined on a 3 T MR Philips® scanner. Pathologic optic nerve DIR hypersignal was determined in four different nerve segments. IOP was measured in mmHg by applanation tonometry. RNFL thickness was measured in µm with optical coherence tomography (OCT Heidelberg Engineering Spectralis® apparatus). Wilcoxon rank sum tests, student's t-tests and (multivariate) linear regression models were appied. RESULTS: 3D DIR hypersignal was present in 17 (41.5%) optic nerves. 3D DIR hypersignal was not related to ischemic or demyelinating optic nerve pathology but was associated with increased IOP (19.8 [24-18]; versus 15.45; [18.85-13.75] mmHg; p = 0.008) and decreased RNFL thickness (61.06 ± 12.1 versus 82.5 ± 21.6 µm; p < 0.001) in comparison to optic nerves of glaucoma patients without DIR hypersignal. Specifically, presence of DIR hypersignal in optic nerves in at least one optic nerve segment lowered RNFL thickness on average by 17.54 µm (p = 0.005) in comparison to optic nerves without DIR hypersignal. CONCLUSIONS: In patients with glaucomatous optic neuropathy (GON) and pathologic optic nerve DIR hypersignal, significantly increased IOP and significantly decreased RNFL thickness values are present. DIR hypersignal seems to be a marker for disease severity in GON related to decreased RNFL thickness and may thus represent long-segment severe axonal degeneration in optic nerves in patients with GON. Venous congestion and edema within the optic nerve related to high IOP may contribute to the DIR hypersignal as well.

Transfemoral hepatic vein catheterization reduces procedure time in double vein embolization.

BACKGROUND: Double vein embolization with simultaneous embolization of the portal and hepatic vein aims to grow the future liver remnant in preparation for major hepatectomy. Transvenous hepatic vein embolization is usually done via a transjugular access. The purpose of this study is to describe the transfemoral approach as an alternative option and to discuss potential advantages. RESULTS: Twenty-three patients undergoing hepatic vein embolization via a transjugular (n = 10) or transfemoral access (n = 13) were evaluated retrospectively. In all cases the portal vein embolization was done first. All procedures were technically successful. There were no peri-interventional complications. Only two patients were not able to proceed to surgery. Standardized future liver remnant hypertrophy was non-inferior with the transfemoral approach compared to the transjugular route. Procedure time was significantly shorter in the transfemoral access group (40 ± 13 min) compared to the transjugular group (67 ± 13 min, p < 0.001). CONCLUSION: Transfemoral hepatic vein embolization is feasible, safe, and faster due to easier catheterization, improved stability, and simpler patient preparation. These findings will need to be validated in larger studies.

Postinterventional Patient Comfort After Uterine Artery Embolization and Superior Hypogastric Nerve Block.

PURPOSE: To evaluate the duration and effect of superior hypogastric nerve block (SHNB) with ropivacaine and clonidine on postinterventional pain levels and opioid requirements in patients undergoing uterine artery embolization. MATERIALS AND METHODS: Postinterventional pain levels (numeric rating scale, NRS 0-10) and opioid doses were retrospectively analyzed in 53 patients undergoing transfemoral uterine artery embolization and intraprocedural superior hypogastric nerve block during 24 h. A mixture of 150 mg of ropivacaine and 150 µg of clonidine was used for the block. RESULTS: Postinterventional pain averaged between 1.4 and 2.0 during the first 9 h, after which a small but significant increase was observed (NRS 1.7 ± 1.6 vs. NRS 2.6 ± 2.2, p < 0.001). 70% of patients did not exceed a tolerable pain threshold of NRS 4 during the first 9 h after the intervention. Thirty-three patients (62%) did not require any opioid medication. Mean iv morphine dose was 3.1 ± 4.7 mg, whereas 71% of opioid doses were administered after 9 h. CONCLUSION: Superior hypogastric nerve block using a mixture of ropivacaine and clonidine provides good pain relief for 9 h after uterine artery embolization requiring only very low amounts of additional opioids.

Safety of Percutaneous Transmesenteric and Transsplenic Access for Portosystemic Shunt Creation in Patients with Portal Vein Obstruction: Single-Center Experience and Review of Literature.

PURPOSE: To evaluate the safety of ultrasound-guided percutaneous mesenteric vein access compared to transsplenic portal vein access for portosystemic shunt placement in patients with portal vein obstruction. MATERIALS AND METHODS: Eight patients underwent portosystemic shunt creation through either a transsplenic (n = 4) or transmesenteric (n = 4) approach. The superior or inferior mesenteric vein was percutaneously accessed under ultrasound guidance using a 21G needle and a 4F sheath. Hemostasis at the mesenteric access site was achieved with manual compression. For transsplenic access, sheath sizes between 6 and 8F were used and tract embolization with gelfoam was performed. RESULTS: Portosystemic shunt placement was successful in all patients. While there were no bleeding complications with transmesenteric access, hemorrhagic shock requiring splenic artery embolization occurred in one patient in which the transsplenic approach was used. CONCLUSION: Ultrasound-guided mesenteric vein access seems feasible and a valid alternative to the transsplenic access in case of portal vein obstruction. Level of Evidence Level 4, case series.

CIRSE Position Paper on Artificial Intelligence in Interventional Radiology.

Artificial intelligence (AI) has made tremendous advances in recent years and will presumably have a major impact in health care. These advancements are expected to affect different aspects of clinical medicine and lead to improvement of delivered care but also optimization of available resources. As a modern specialty that extensively relies on imaging, interventional radiology (IR) is primed to be on the forefront of this development. This is especially relevant since IR is a highly advanced specialty that heavily relies on technology and thus is naturally susceptible to disruption by new technological developments. Disruption always means opportunity and interventionalists must therefore understand AI and be a central part of decision-making when such systems are developed, trained, and implemented. Furthermore, interventional radiologist must not only embrace but lead the change that AI technology will allow. The CIRSE position paper discusses the status quo as well as current developments and challenges.

Transarterial Radioembolization to Impact Liver Volumetry: When and How.

Inadequate volume of the future liver remnant (FLR) renders many patients with liver malignancies not amenable to surgical resection. Depending on the health of the liver and the patient in general, an FLR of 25-40% is required to avoid acute post-hepatectomy liver failure. Transarterial radioembolization (TARE) of a diseased liver lobe leads to atrophy of the embolized lobe and compensatory hypertrophy of the contralateral lobe. Although the absolute degree of FLR hypertrophy seems to be comparable to portal vein embolization, the kinetic of hypertrophy is much slower after radioembolization. However, TARE has the unique advantages of simultaneously offering local tumor control, possibly downstaging disease, and providing biological test of time. Progressions in technique and personalized dosimetry allow for more predictable ablative treatment of liver malignancies and preparation for major liver surgery. This article provides an overview of the existing literature, discusses the evidence, and considers possible criteria for patient selection.

Prostate Cancer Detection with mpMRI According to PI-RADS v2 Compared with Systematic MRI/TRUS-Fusion Biopsy: A Prospective Study.

Background: mpMRI assesses prostate lesions through their PI-RADS score. The primary goal of this prospective study was to demonstrate the correlation of PI-RADS v2 score and the volume of a lesion with the presence and clinical significance of prostate cancer (PCa). The secondary goal was to determine the extent of additionally PCa in inconspicuous areas. Methods: All 157 patients underwent a perineal MRI/TRUS-fusion prostate biopsy. Targeted biopsies as well as a systematic biopsy were performed. The presence of PCa in the probes was specified by the ISUP grading system. Results: In total, 258 lesions were biopsied. Of the PI-RADS 3 lesions, 24% were neoplastic. This was also true for 36.9% of the PI-RADS 4 lesions and for 59.5% of the PI-RADS 5 lesions. Correlation between ISUP grades and lesion volume was significant (p < 0.01). In the non-suspicious mpMRI areas carcinoma was revealed in 19.7% of the patients. Conclusions: The study shows that the PI-RADS v2 score and the lesion volume correlate with the presence and clinical significance of PCa. However, there are two major points to consider: First, there is a high number of false positive findings. Second, inconspicuous mpMRI areas revealed PCa.

Impact of Acoustic Noise Reduction on Patient Experience in Routine Clinical Magnetic Resonance Imaging.

OBJECTIVES: Acoustic noise emission from MRI scanners is considered a major factor of patient discomfort during routine MRI examinations. We prospectively evaluated the impact of acoustic noise reduction using software implementations in routine clinical MRI on subjective patient experience and image quality. METHODS: Two-hundred consecutive patients undergoing one of four MRI examinations (brain, lumbar spine, shoulder, and knee) at a single center were prospectively randomized into two groups at a 1 to 1 ratio: standard MRI examination and MRI examination with acoustic noise reduction. After the examination, patients were asked to complete a questionnaire aimed at defining their subjective experience (primary endpoint). Two readers assessed subjective image quality of all patient studies in consensus (secondary endpoint). Nonparametric tests and logistic regression models were used for statistical analysis. RESULTS: Hundred-seventy-four patients were included in the final study. Patients in the intervention group felt less discomforted by the acoustic noise (p = 0.01) and reported increased audibility of music through the headphones (p = 0.03). No significant difference in subjective image quality was found. CONCLUSION: Our study indicates that the effects of acoustic noise reduction in routine clinical MRI can be translated into reduced patient discomfort from acoustic noise and improved audibility of music. Acoustic noise reduction thus significantly contributes to increased patient comfort during MRI examinations.

Combined simultaneous embolization of the portal vein and hepatic vein (double vein embolization) - a technical note about embolization sequence.

BACKGROUND: Simultaneous portal vein embolization (PVE) and hepatic vein embolization (HVE) has been shown to be feasible, safe and lead to a faster growth of future liver remnant (FLR) than PVE alone. The objective of this study is to highlight different technical aspects as well as importance of embolization order. MATERIALS AND METHODS: Seven patients were treated with simultaneous PVE and HVE. In three cases, HVE was performed first followed by PVE and in four cases the other way around. Portal vein branches were embolized using Glubran-Lipiodol mixture in all cases. Hepatic veins were embolized using Amplatzer II plugs sized 8-20 mm. Specific consideration was given to depth of glue penetration in the portal vein defined by visible branch order on the treated side. RESULTS: Six of seven patients were discharged home the same day. One patient with infected tumor necrosis died of liver failure 40 days later, otherwise there were no periprocedural clinical complications. Median glue penetration was to the 5th order (4th - 5th) when PVE was performed first and 3rd order (2nd - 4th) when PVE was performed after HVE. In one PVE first case, glue spillage was seen due to marked reduced flow in the right portal vein. There was sufficient FLR growth for subsequent surgical resection in the remaining six patients. CONCLUSION: PVE should be performed prior to HVE because the reduced flow in the portal vein after HVE leads to less deep glue penetration with presumably increased risk of contralateral spillage.

Evaluation of Cystic and Solid Renal Lesions with Contrast-Enhanced Ultrasound: A Retrospective Study.

Purpose Renal lesions are frequent random findings on CT, MRI, and conventional ultrasound. Since they are usually found accidentally, the respective examinations have not been performed optimally to provide a conclusive diagnosis, making additional multiphase contrast-enhanced examinations necessary. The aim of the study is to correlate CEUS findings with the final diagnosis and to determine whether it is a suitable method for the conclusive characterization of undetermined renal lesions. Materials and Methods All CEUS examinations of focal renal lesions performed at our institute between 2007 and 2014 were retrospectively examined. 437 patients with a total of 491 lesions and 543 examinations were included. 54 patients had bilateral lesions. One patient had three lesions in one kidney. Histology was available in 49 cases and follow-ups in 124 cases. The sensitivity, specificity, positive and negative predictive value as well as positive and negative likelihood ratios were calculated. Results There were 54 malignant and 437 benign lesions. The sensitivity and specificity were 0.981/0.954 overall, 1.000/0.956 for cystic lesions, 0.977/0.906 for solid lesions, and 0.971/0.071 for the histologically confirmed lesions. Bosniak classification was consistent in 289 of 301 lesions (96%). Only 12 lesions (3.9%) were falsely assessed as malignant. Conclusion CEUS is an appropriate method for the clarification of undetermined renal lesions. The characterization of cystic lesions according to Bosniak is adequately possible, especially for potentially malignant lesions (types III and IV).

Prophylactic Percutaneous Consolidation of Large Osteolytic Tumors of the Pelvic Ring Using Fixation by Internal Cemented Screws.

Purpose To evaluate the efficacy, durability, and safety of percutaneous fixation by internal cemented screw (FICS) for prophylactic consolidation of impending pathologic fractures of the pelvic ring. Materials and Methods In this single-institute retrospective study, patients with large, minimally symptomatic to asymptomatic osteolytic tumors of the pelvic ring that were treated with percutaneous cone-beam CT-guided FICS procedures were included (January 2014 to May 2019). Follow-up cross-section imaging and clinical reports were reviewed for procedural complications and assessment of the long-term consolidation efficacy on the basis of the development of pathologic fracture or need for additional surgical intervention. All continuous variables were expressed as a mean with standard deviation, and dichotomous variables were expressed as frequencies and percentages. Results Fifty consecutive patients (mean age, 60 years ± 12; 27 men) underwent prophylactic FICS for consolidation of 54 osteolytic tumors (mean size, 51 mm ± 21.5; range, 30-114 mm). Local tumor destruction was performed in association with FICS in 38 patients (76%) using percutaneous thermal and/or radiation therapy. Follow-up exceeded a year in 35 patients (70%), with mean follow-up of 22 months ± 18 (range, 1-67 months). Long-term consolidation efficacy was 98% (49 of 50), with the development of a pathologic fracture in only one patient 20 months after FICS. Procedural complications were limited to two patients with self-resolving hematoma, one patient with inflammatory sciatic pain, and one patient with focal pain at the ischial tuberosity. Conclusion Percutaneous FICS provides a safe and durable minimally invasive treatment for the prevention of pathologic fractures of the pelvic ring. Keywords: Interventional-MSK, Percutaneous, Skeletal-Axial, Metastases, Oncology Supplemental material is available for this article. © RSNA, 2020.

Angiographic Detection of Utero-Ovarian Anastomosis and Influence on Ovarian Function After Uterine Artery Embolization.

PURPOSE: To assess the detectability and frequency of the different types of utero-ovarian anastomosis, the correlation between type of anastomosis and ovarian failure after UAE, as well as the impact of coiling as a strategy for the prevention of ovarian failure. MATERIALS AND METHODS: We retrospectively studied a population of 92 women treated with uterine artery embolization at our institution between 2007 and 2017. Utero-ovarian anastomoses were categorized on angiographic sequences by two radiologists based on the classification published by Razavi et al. (Radiology 224(3):707-712, 2002), and Cohen's kappa was calculated. Ovarian failure was defined as an increase in serum FSH above 27 mIU/ml three months after embolization. RESULTS: Out of a total of 184 anastomoses, 27% were classified as type Ia, 45% as type Ib, 1% as type II and 24% as type III. Three percent of anastomoses could not be determined. There was very good inter-observer reliability on the classification of utero-ovarian anastomoses (κ = 0.847). Ovarian failure occurred in six out of 92 women (7%). Each had at least one type Ib (n = 4) or type III (n = 1) anastomosis, with the exception of one patient in whom the type of anastomosis could not be determined. All women presenting with ovarian failure were 45 years of age or older. No patient with protective coiling developed ovarian failure. CONCLUSION: Utero-ovarian anastomoses are more common than previously expected and can be reliably classified with very good inter-observer reliability. Patients with type Ib and type III anastomoses carry the risk of ovarian failure after uterine artery embolization. Protective coiling seems to be an adequate strategy for avoiding ovarian failure in those types of anastomoses.

Advanced multimodality MR imaging of a cerebral nocardiosis abscess in an immunocompetent patient with a focus on Amide Proton Transfer weighted imaging.

Cerebral nocardiosis abscess is a very rare entity in an immunocompetent patient. In this case report multiparametric and multimodality MR imaging characteristics of a pyogenic brain abscess caused by Nocardia Farcinica are discussed with a specific focus on amide proton transfer weighted imaging as a modern non-invasive, molecular MR imaging method which detects endogenous mobile protein and peptide concentration and tissue pH changes in pathologic brain lesions. The imaging characteristics are reviewed and discussed in respect to possible differential diagnoses, especially malignant tumorous lesions.

Lung Ablation - How I Do It.

Interventional oncology and the value of thermal ablation of small tumors is increasingly recognized by the oncological community. Primary lung cancers and lung metastases have been one of the most researched applications of percutaneous ablation and as interventional oncologists gain more experience and confidence, it is becoming a more effective treatment with expanding indications. Importantly, the current literature does not demonstrate major differences in survival between ablation, sublobar resection, and stereotactic body radiation. The advantages of percutaneous ablation over other local therapies like surgery or SBRT are significantly lower morbidity, mortality, and repeatability of treatments. The focus of this essay is to highlight technical and procedural aspects of lung ablation as well as management and follow-up in a practical fashion.