dual-test-gas-pulmonary-diffusing-capacity-measurement-during

Dual Test Gas Pulmonary Diffusing Capacity Measurement During Exercise in Humans Using the Single-Breath Method

The combined single-breath measurement of the diffusing capacity of carbon monoxide (DL,CO) and nitric oxide (DL,NO) is a useful technique to measure ...

Copenhagen University Hospital - Rigshospitalet

University of Copenhagen

Acute pulmonary embolism (PE) is diagnosed either by ventilation/perfusion (V/P) scintigraphy or pulmonary CT angiography (CTPA). In recent years both techniques have improved. Many nuclear medicine centres have adopted the single photon emission CT (SPECT) technique as opposed to the planar technique for diagnosing PE. SPECT has been shown to have fewer indeterminate results and a higher diagnostic value. The latest improvement is the combination of a low-dose CT scan with a V/P SPECT scan in a hybrid tomograph. In a study comparing CTPA, planar scintigraphy and SPECT alone, SPECT/CT had the best diagnostic accuracy for PE. In addition, recent developments in the CTPA technique have made it possible to image the pulmonary arteries of the lungs in one breath-hold. This development is based on the change from a single-detector to multidetector CT technology with an increase in volume coverage per rotation and faster rotation. Furthermore, the dual energy CT technique is a promising modality that can provide functional imaging in combination with anatomical information. Newer high-end CT scanners and SPECT systems are able to visualize smaller subsegmental emboli. However, consensus is lacking regarding the clinical impact and treatment. In the present review, SPECT and SPECT in combination with low-dose CT, CTPA and dual energy CT are discussed in the context of diagnosing PE.

SPECT/CT and pulmonary embolism.

Assessing nodules detected in lung cancer screening: the value of positron emission tomography.

Due to low counts in an (111)In single photon emission computed tomography (SPECT) scan, a large part of the head was missing in the reconstructed images on Philips Extended Brilliance Workspace (EBW) and IntelliSpace Portal (ISP) workstations. This problem occurred for the ordered subsets expectation maximization (OSEM) algorithm with and without resolution recovery (Astonish), but not for filtered backprojection (FBP) or maximum likelihood expectation maximization (MLEM). There were also underflow problems because the images are stored as integers resulting in a loss of intensity resolution and color banding.Philips EBW2.0 and ISP5.02 workstations upscale low-count images, but the result is not always optimal, for example, in the case of low counts in one part and more counts in another part of an image. On these workstations, the missing head artefact problem could be resolved by applying a Hann pre-filter (with a cutoff at the Nyquist frequency, which only influences the filtering) in the reconstruction process. Upscaling of the projection data prior to reconstruction did not recover the head in the images, neither did limiting the reconstructed volume to the low-count part of interest.Underflow problems were partially solved by the new version 2.0 of the Philips EBW and ISP stations, although situations could arise where underflow still poses a problem. A solution for the underflow problems is to upscale the raw projection data before reconstruction. While this results in a pure upscaling of the FBP reconstruction, the effect in iterative statistical reconstruction is not only upscaling of the intensities because the assumption of Poisson statistics of the data is violated. However, the influence of this last matter seems limited.Reconstruction of studies with low counts in relevant areas should be performed with care. Reconstruction artefacts and scaling issues can easily arise.

Missing head and color banding in low-count SPECT reconstructions.

CT-based attenuation correction (CT-AC) using contrast-enhancement CT impacts (111)In-SPECT image quality and quantification. In this study we assessed and evaluated the effect.

Intravenous contrast-enhanced CT can be used for CT-based attenuation correction in clinical (111)In-octreotide SPECT/CT.

The diagnosis of pulmonary embolism (PE) relies on clinical assessment, D-dimer test and diagnostic imaging. Modern CT pulmonary angiography (CTPA), ventilation/perfusion  single-photon emission computed tomography (SPECT) and SPECT/CT are rather equal in terms of sensitivity, specificity and inconclusive results for the diagnosis of PE, outper-forming planar lung scintigraphy. Furthermore, SPECT/CT and CTPA can both provide important information regarding differential diagnoses. Thus, the choice of primary diag-nostic modality relies on local expertise, availability and special circumstances like radiation dose, contraindications and the clinical urgency.

[The choice of diagnostic modality for acute pulmonary embolism].

Ventilation-perfusion scintigraphy is a functional imaging biomarker that has the potential of captivating the heterogeneity of chronic obstructive pulmonary disease (COPD). It specifically images the distribution of ventilation and perfusion within the lungs, which is a critical pathophysiological component of COPD. The extent of ventilation defects and ventilation inhomogeneity, as well as the ventilation-perfusion ratio distribution thus correlate with severity of disease. Furthermore, specific scintigraphic patterns, such as the "stripe sign" may detect centrilobular emphysematous lesions with a higher sensitivity than other imaging techniques. Although ventilation-perfusion scintigraphy may conceivably detect COPD before any specific changes can be detected by spirometry or high-resolution CT, it is currently mostly used in the workup of lung volume reduction treatment, and for diagnosing various complications and comorbidities of COPD when combined with low-dose CT.

Lung Scintigraphy in COPD.

Endoscopic lung volume reduction (ELVR) therapy using one-way valves is used to treat chronic obstructive pulmonary disease patients with severe heterogeneous emphysema. A successful treatment results in atelectasis of the treated pulmonary lobe with subsequent reduction of ventilation (V) and perfusion (Q).

Lobar Quantification by Ventilation/Perfusion SPECT/CT in Patients with Severe Emphysema Undergoing Lung Volume Reduction with Endobronchial Valves.

Lymph node yield (LNY) in neck dissection has been identified as a prognostic factor in oral cavity cancer. The purpose of this study was to investigate the impact of additional use of optical imaging on LNY in therapeutic ND in oral cancer.

Near-infrared fluorescence imaging improves the nodal yield in neck dissection in oral cavity cancer - A randomized study.

A wide catalogue of inhalers is available today as described in this review, but many patients and healthcare professionals do not know how to use inhalers correctly. However, knowledge of the working principles and pros and cons of the various inhaler types may improve patient education and the correct choice of device. Which inhaler is the best suited cannot be determined without measuring the patient's inspiration flow and controlling the ability to coordinate and handle a device. Extra-fine particles from pressurised metered dose inhalers, dry powder inhalers and soft mist inhalers give new perspectives on disease control as optimal coordination, and flow pattern is less crucial.

[Inhalers and inhalation techniques in the treatment of asthma and chronic obstructive pulmonary disease].

The sentinel node (SN) procedure is adopted in selected patients with early-stage vulva cancer (VC) in Denmark. Due to the low incidence of VC, large population-based studies on the safety of SN outside multicenter clinical trials are lacking. The current study evaluated the risk of recurrence and survival in SN- negative VC patients.

Recurrence and survival rates in node negative patients after sentinel node biopsy for early-stage vulva cancer - A nationwide study.

PET/computed tomography (CT) imaging increasingly is used in neuroendocrine neoplasms (NENs) for diagnosis, staging, monitoring, prognostication, and choosing treatment. Somatostatin PET analog tracers have added to the specificity by obtaining higher affinity to somatostatin receptors with Ga-labeled or Cu-labeled DOTA peptides compared with single-photon emission CT imaging isotopes. PET uptake correlates to tumor grade and is an essential part of theranostics with peptide receptor radionuclide treatment. This article focuses on the literature on head-to-head studies and meta-analyses of different combinations of peptide agonists and a few antagonists. Overall, the published data support the diagnostic capability of PET/CT imaging in NENs.

Somatostatin Receptor Imaging PET in Neuroendocrine Neoplasm.

What is the topic of this review? The use of proning for improving pulmonary gas exchange in critically ill patients. What advances does it highlight? Proning places the lung in its 'natural' posture, and thus optimises the ventilation-perfusion distribution, which enables lung protective ventilation and the alleviation of potentially life-threatening hypoxaemia in COVID-19 and other types of critical illness with respiratory failure.

Therapeutic benefits of proning to improve pulmonary gas exchange in severe respiratory failure: focus on fundamentals of physiology.

What is the central question in this study? How reliable is the combined measurement of the pulmonary diffusing capacity to carbon monoxide and nitric oxide (D ) during exercise and in the resting supine position, respectively? What is the main finding and its importance? The D technique is reliable with a very low day-to-day variability both during exercise and in the resting supine position, and may thus provide a useful physiological outcome that reflects the alveolar-capillary reserve in humans.

Pulmonary diffusing capacity to nitric oxide and carbon monoxide during exercise and in the supine position: a test-retest reliability study.

Lung neuroendocrine neoplasms (NEN) are a heterogeneous population of neoplasms with different pathology, clinical behavior, and prognosis compared to the more common lung cancers. The diagnostic work-up and treatment of patients with lung- NEN has undergone major recent advances and new methods are currently being introduced into the clinic. These Nordic guidelines summarize and update the Nordic Neuroendocrine Tumor Group's current view on how to diagnose and treat lung NEN-patients and are meant to be useful in the daily practice for clinicians handling these patients. This review reflects our view of the current state of the art of diagnosis and treatment of patients with lung-NEN. Small cell lung carcinoma (SCLC) is not included in these guidelines.

Nordic 2023 guidelines for the diagnosis and treatment of lung neuroendocrine neoplasms.

Lung volume reduction surgery (LVRS) has proven an effective treatment for emphysema, by decreasing hyperinflation and improving lung function, activity level and reducing dyspnoea. However, postoperative air leak is an important complication, often leading to reoperation. Our aim was to analyse reoperations after LVRS and identify potential predictors.

Article	Year
SPECT/CT and pulmonary embolism. European journal of nuclear medicine and molecular imaging\| PubMed ID: 24213621	2014
Assessing nodules detected in lung cancer screening: the value of positron emission tomography. The European respiratory journal\| PubMed ID: 25653263	2015
Missing head and color banding in low-count SPECT reconstructions. EJNMMI physics\| PubMed ID: 26501452	2014
Intravenous contrast-enhanced CT can be used for CT-based attenuation correction in clinical (111)In-octreotide SPECT/CT. EJNMMI physics\| PubMed ID: 26501805	2015
[The choice of diagnostic modality for acute pulmonary embolism]. Ugeskrift for laeger\| PubMed ID: 29493500	2018
Lung Scintigraphy in COPD. Seminars in nuclear medicine\| PubMed ID: 30545511	2019
Lobar Quantification by Ventilation/Perfusion SPECT/CT in Patients with Severe Emphysema Undergoing Lung Volume Reduction with Endobronchial Valves. Respiration; international review of thoracic diseases\| PubMed ID: 31167210	2019
Near-infrared fluorescence imaging improves the nodal yield in neck dissection in oral cavity cancer - A randomized study. European journal of surgical oncology : the journal of the European Society of Surgical Oncology and the British Association of Surgical Oncology\| PubMed ID: 31307814	2019
[Inhalers and inhalation techniques in the treatment of asthma and chronic obstructive pulmonary disease]. Ugeskrift for laeger\| PubMed ID: 31495355	2019
Recurrence and survival rates in node negative patients after sentinel node biopsy for early-stage vulva cancer - A nationwide study. Gynecologic oncology\| PubMed ID: 31711658	2020
Somatostatin Receptor Imaging PET in Neuroendocrine Neoplasm. PET clinics\| PubMed ID: 33648664	2021
Therapeutic benefits of proning to improve pulmonary gas exchange in severe respiratory failure: focus on fundamentals of physiology. Experimental physiology\| PubMed ID: 34242438	2022
Pulmonary diffusing capacity to nitric oxide and carbon monoxide during exercise and in the supine position: a test-retest reliability study. Experimental physiology\| PubMed ID: 36621806	2023
Nordic 2023 guidelines for the diagnosis and treatment of lung neuroendocrine neoplasms. Acta oncologica (Stockholm, Sweden)\| PubMed ID: 37194281	2023
Predictors of reoperation after lung volume reduction surgery. Surgical endoscopy\| PubMed ID: 38017156	2024

Jann Mortensen

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