Giordano Rafael Tronco Alves

PET/CT imaging in lung cancer: indications and findings

The use of PET/CT imaging in the work-up and management of patients with lung cancer has greatly increased in recent decades. The ability to combine functional and anatomical information has equipped PET/CT to look into various aspects of lung cancer, allowing more precise disease staging and providing useful data during the characterization of indeterminate pulmonary nodules. In addition, the accuracy of PET/CT has been shown to be greater than is that of conventional modalities in some scenarios, making PET/CT a valuable noninvasive method for the investigation of lung cancer. However, the interpretation of PET/CT findings presents numerous pitfalls and potential confounders. Therefore, it is imperative for pulmonologists and radiologists to familiarize themselves with the most relevant indications for and limitations of PET/CT, seeking to protect their patients from unnecessary radiation exposure and inappropriate treatment. This review article aimed to summarize the basic principles, indications, cancer staging considerations, and future applications related to the use of PET/CT in lung cancer.

Bilioma espontâneo: relato de caso e revisão da literatura

Biloma is defined as any collection of bile outside the biliary tree, usually resulting from surgery complications and abdominal trauma. Spontaneous occurrence of bilomas is rare, occasionally associated with choledocolithiasis. The present report describes a case of spontaneous biloma, whose diagnosis was radiologically confirmed. At laparotomy, the presence of a retroperitoneal biloma was observed. Intraoperative cholangiography has not demonstrated the presence of fistula. After drainage, the patient progressed well and was discharged.

Spontaneous pneumomediastinum (Hamman's syndrome)

A previously healthy, 21-year-old female nonsmoker sought emergency room treatment complaining of recent and progressive swelling of the face, neck, and chest (Figure 1). The patient reported no pain, dyspnea, or dysphagia at admission. She reported a brief history of odynophagia in the previous week, when, during an episode of cough, she felt intense (dissecting) retrosternal pain, which subsided within a few minutes after its onset. After that episode, she had no symptoms other than the abovementioned swelling.Physical examination revealed extensive subcutaneous emphysema, which extended from the xiphoid process to the temporal muscle and involved the entire neck and face. Pulmonary percussion and auscultation revealed no abnormalities. Cardiac auscultation revealed the presence of Hamman’s sign (crackles—as was the case in our patient—or bubbling sounds, synchronous with the heartbeat). Oral endoscopy revealed no abnormalities, and the remainder of the physical examination was normal.A CT scan of the skull, neck, and chest confirmed the presence of pneumomediastinum, pneumothorax (Figure is known as the Macklin effect or phenomenon, 2A), and extensive soft tissue emphysema in the cervical region (Figure having been named after Charles C. Macklin, 2B)—involving the face, periorbital tissues, and temporal muscles (Figure 2C)—as well as revealing the presence of pneumorrhachis (Figure in the case reported here, spontaneous 2D).From postadmission day two onward, the subcutaneous emphysema gradually improved. The patient received conservative treatment, including rest, unrestricted diet, and analgesia, if necessary. The results of routine laboratory tests, including blood workup and urinalysis, were normal. Follow-up chest X-rays revealed a sustained reduction in the abovementioned signs and symptoms. The patient remained under observation for another five days, being asymptomatic and showing nearly complete resolution of the clinical picture at discharge (Figure 1).Spontaneous pneumomediastinum, also known as Hamman’s syndrome, is defined as the presence of free air in the mediastinum, being unrelated to trauma or procedures (surgical or otherwise).

Thoracic lymphadenopathy in benign diseases: A state of the art review.

Lymphadenopathy is a common radiological finding in many thoracic diseases and may be caused by a variety of infectious, inflammatory, and neoplastic conditions. This review aims to describe the patterns of mediastinal and hilar lymphadenopathy found in benign diseases in immunocompetent patients. Computed tomography is the method of choice for the evaluation of lymphadenopathy, as it is able to demonstrate increased size of individual nodes, abnormalities of the interface between the mediastinum and lung, invasion of surrounding fat, coalescence of adjacent nodes, obliteration of the mediastinal fat, and hypo- and hyperdensity in lymph nodes. Intravenous contrast enhancement may be needed to help distinguish nodes from vessels. The most frequent infections resulting in this finding are tuberculosis and fungal disease (particularly histoplasmosis and coccidioidomycosis). Sarcoidosis is a relatively frequent cause of lymphadenopathy in young adults, and can be distinguished from other diseases - especially when enlarged lymph nodes are found to be multiple and symmetrical. Other conditions discussed in this review are silicosis, drug reactions, amyloidosis, heart failure, Castlemans disease, viral infections, and chronic obstructive pulmonary disease.

Interobserver agreement between radiologists and radiology residents and emergency physicians in the detection of PE using CTPA

OBJECTIVE To assess interobserver agreement between thoracic radiologists, radiology residents, and emergency physicians in diagnosing pulmonary embolism (PE). MATERIALS AND METHODS Emergency physicians, radiology residents, and thoracic radiologists evaluated 123 computed tomography pulmonary angiography images. Interobserver agreement was analysed using kappa statistics. RESULTS Very good agreements were observed between thoracic radiologists and radiology residents (0.81 and 0.82). Fair and moderate agreements (0.39 and 0.42) were demonstrated between emergency physicians and thoracic radiologists. CONCLUSIONS Important differences in interobserver agreement were found, with emergency physicians tending to overdiagnose PE.

Normal variance in emphysema index measurements in 64 multidetector-row computed tomography

The purpose of this study was to identify the normal variance of emphysema index (EI) measured in examinations acquired with 64 multidetector‐row computed tomography (64‐MDCT). A longitudinal, noninterventional study was performed retrieving all patients in our institution who are currently registered in our lung nodule protocol. All patients with clinical, functional, or significant radiological changes were excluded. We assumed that EI should remain unchanged within a short period of time. We reviewed 475 MDCTs in order to select 50 clinically stable patients who had two sequential chest MDCTs performed within a time interval of less than three months, and who presented at least one lung free of abnormalities but emphysema. CT densitovolumetry was used to calculate EI with thresholds set at −950 Hounsfield units (HUs) (EI‐950) and −970 HUs (EI‐970); on both studies from each patient. We observed the variation of total lung volume (TLV), mean lung density (MDL), and EI for measurements at the baseline and at follow‐up scans. Differences observed between baseline and follow‐up measurements were: TLVμ=149ml; IC=μ+1.96(133); EI−950=0.02%; p95=0.89%; EI−970μ=0.04%; p95=0.23% and MLDμ=15HU; IC=μ+1.96(18). The correlations obtained were the following: TLV r=0.96, EI−950r=0.79, EI−970r=0.85. Accepting that emphysema would remain unchanged within three months on stable patients, differences of less than 0.89% for EI‐950 and of less than 0.23% for EI‐970 are within the variance of the method. PACS number: 87.50.ct

The effects of dynamic hyperinflation on CT emphysema measurements in patients with COPD

OBJECTIVES Dynamic hyperinflation (DH) significantly affects dyspnea and intolerance to exercise in patients with chronic obstructive pulmonary disease (COPD). Quantitative computed tomography (QCT) of the chest is the modality of choice for quantification of the extent of anatomical lung damage in patients with COPD. The purpose of this article is to assess the effects of DH on QCT measurements. METHODS The study sample comprised patients with Global initiative for Chronic Obstructive Lung Disease (GOLD) stages III and IV COPD referred for chest CT. We examined differences in total lung volume (TLV), emphysema volume (EV), and emphysema index (EI) determined by QCT before and after DH induction by metronome-paced tachypnea (MPT). Initial (resting) and post-MPT CT examinations were performed with the same parameters. RESULTS Images from 66 CT scans (33 patients) were evaluated. EV and EI, but not TLV, increased significantly (p<0.0001) after DH induction. CONCLUSION QCT showed significant increases in EV and EI after MPT-induced DH in patients with GOLD stages III and IV COPD. For longitudinal assessment of patients with COPD using QCT, we recommend the application of a pre-examination rest period, as DH could mimic disease progression. QCT studies of the effects of DH-preventive therapy before exercise could expand our knowledge of effective measures to delay DH-related progression of COPD.

Índice de enfisema pulmonar em coorte de pacientes sem doença pulmonar conhecida: influência da idade

OBJECTIVE: To investigate the effects of age on pulmonary emphysema, based on the values of the emphysema index (EI) in a cohort of patients who had never smoked and who had no recognizable lung disease. METHODS: We reviewed the CT scans, reported as normal, of 315 patients. Exclusion criteria were a history of smoking, cardiorespiratory disease, and exposure to drugs that could cause lung disease. From this cohort, we selected 32 patients (16 men and 16 women), matched for gender and body mass index, who were divided equally into two groups by age ( 50 years). We quantified emphysema using a computer program specific to that task. The EI was calculated with a threshold of -950 HU. We also evaluated total lung volume (TLV) and mean lung density (MLD). RESULTS: The overall means for TLV, MLD, and EI were 5,027 mL, -827 HU, and 2.54%, respectively. Mean values in the older and younger groups, respectively, were as follows: for TLV, 5,229 mL vs. 4,824 mL (p > 0.05); for MLD, -846 HU vs. -813 HU (p < 0.04); and for EI, 3.30% vs. 1.28% (p < 0.001). Significant correlations were found between EI and age (r = 0.66; p = 0.001), EI and TLV (r = 0.58; p = 0.001), and EI and MLD (r = -0.67; p < 0.001). The predicted EI per age was defined by the regression equation (r2 = 0.43): p50(EI) = 0.049 × age - 0.5353. CONCLUSIONS: It is important to consider the influence of age when quantifying emphysema in patients over 50 years of age. Based on the regression analysis, EI values of 2.6%, 3.5%, and 4.5% can be considered normal for patients 30, 50, and 70 years of age, respectively.

Hemichorea-hemiballism: the role of imaging in diagnosing an unusual disorder in patients with nonketotic hyperglycemia.

An 81-year-old man presented to the emergency room with a 4-day history of progressive confusion followed by frontal headache and left-sided choreiform movements. His medical history was remarkable for smoking, dyslipidemia, and poorly-controlled hypertension, with no previous diagnosis of diabetes mellitus (DM). On laboratory investigation, his serum glucose was 460 mg/dL and his glycated hemoglobin was 17.4% (consistent with a prolonged period of undiagnosed DM). A computed tomography scan of the brain revealed hyperdensity of the right putamen without an associated mass effect (Figure 1), which suggested a diagnosis of hyperglycemic hemichorea-hemiballism (HCHB). The patient was started on insulin, and few hours following glucose correction there was great improvement in his mental status and a decrease in involuntary movements. On an unenhanced T1weighted spin-echo magnetic resonance imaging (MRI) sequence obtained two weeks after initial presentation, there were hyperintense lesions, consistent with hyperglycemic HCHB, located in right putamen. Diffusion-weighted imaging showed no corresponding signal alterations. T2*-weighted imaging demonstrated bilateral punctiform hypointensities in the globus pallidus, which were presumably physiological in nature and did not match the unilateral T1 abnormality (Figure 2). The patient completely recovered his previous cognitive and motor functions after glycemic control, being discharged without sequelae. Ballistic and choreic movements are characterized by hyperkinetic, random, involuntary movements in the proximal and distal extremities, respectively. Because they usually occur concomitantly, the term HCHB was created to unify these signs into a clinical syndrome when presented unilaterally. Although HCHB syndrome is secondary to lesions in the basal ganglia, the source of the neuronal damage is controversial, the putative mechanisms including disruption of the blood-brain barrier, decreased thalamic gamma-aminobutyric acid input secondary to anaerobic metabolism, small hemorrhages in the striatal region, hyperviscosity related to hyperglycemia, and Wallerian degeneration of putaminal white matter with protein desiccation. Vascular cerebral lesions constitute the most common cause of HCHB. Hyperglycemia is considered an important, albeit rare, risk factor for the development of HCHB, which is most commonly seen in elderly female patients with uncontrolled DM. The predominance of Asian patients in the published data suggests an ethnic predisposition. The clinical course tends to vary depending on the patient’s glycemic status—the hemiballism and hemichorea usually start together with the hyperglycemia, resolving after its correction. Computed tomography findings of hyperglycemic HCHB include unilateral hyperdensity in the basal ganglia contralateral to the affected site. On T1-weighted MRI scans, the most common finding is signal hyperintensity in the caudate nucleus and putamen, usually sparing the internal capsule. The apparent diffusion coefficient and diffusion-weighted MRI generally indicate

Influences in CT Scan Lung Nodule Volumetry

Lung nodule measurements made with CT imaging are used in clinical practice to assess size changes estimated from serial scans obtained over time to predict the likelihood of malignancy and to monitor the tumor response to treatment. 2 Size measurements need to be accurate and consistent to enable the assessment of nodule changes in a short time interval. Th e precision and accuracy of volume measurements depend on several factors, including the image-acquisition and reconstruction parameters, the nodule characteristics, and the performance of algorithms for nodule segmentation and volume estimation. 2 4