Body CT Research Articles

Correlation of CT measurements of total body gas volume and hounsfield units with post-mortem interval

Accurate estimation of the post-mortem interval (PMI) may be a matter of crucial importance in forensic investigations.A preliminary investigation to assess whether longitudinal changes in organ Hounsfield units (HU) and total body gas volume (TBGV), as measured from serial PMCT scans, correlate with postmortem interval (PMI).: Eight euthanised lambs each had five whole body CT scans performed over seven days and measurements were taken from the brain, heart, lungs, liver, kidneys and spleen. HU tissue density was measured directly from the PMCT images, while TBGV was calculated using ImageJ software. A random effect model was fitted with the subject fitted as a random intercept. Ethical and Animal Welfare approval was obtained. : The average increase in TBGV was 422 ml/Kg with a change of 77 ml/Kg per day. For each additional post-mortem day, the HU of the brain, heart, lung, liver and spleen decreased by per day since death, while HU for the kidneys increased by day since death. Expect for the kidney where it increased, there was clear and progressive decrease in tissue densities and for all organs there was an increase in TBGV over time. However, the overlap in values between cases indicates that more work is required before either HU or TBGV can be developed as non-invasive methods to reliably determine time of death in humans.

Comprehensive Management of Pelvic Trauma in Pregnant Patients

Pelvic fractures occur frequently due to traffic accidents and high-energy. Pregnant women are susceptible to trauma, with one in 12 pregnancies complicated by such incidents, making trauma the leading cause of non-obstetric maternal deaths during pregnancy. Pelvic fractures during pregnancy pose significant risks, potentially leading to adverse pregnancy outcomes such as preterm delivery, placental abruption, fetal distress, and even maternal or fetal death. The physiological changes that occur during pregnancy, including increased blood volume and altered cardiovascular dynamics, further complicate the management of pelvic trauma in pregnant patients. Prompt and appropriate management of pelvic trauma in pregnant patients is essential to optimize outcomes for both the mother and the fetus. Initial evaluation and stabilization of the mother take precedence, with close attention to airway, breathing, and circulation. Diagnostic imaging, including pelvic X-rays and, when feasible, body CT or MRI, aids in assessing the extent of pelvic injury and identifying associated injuries. Definitive treatment of pelvic fractures may involve a combination of surgical fixation, bed rest, traction, and pelvic slings, depending on the severity of the injury. The timing and approach to delivery in pregnant patients with pelvic fractures require careful consideration, with vaginal delivery being a viable option in many cases, provided that the pelvic architecture remains intact. Conclussions: The management of pelvic trauma in pregnant patients requires a multidisciplinary approach and careful consideration of maternal and fetal well-being. Further research is needed to establish clear treatment guidelines and preventive strategies to reduce the incidence of pelvic fractures during pregnancy and improve outcomes for both mother and fetus.

Tip of the iceberg: extracardiac CT findings in infective endocarditis.

Infective endocarditis (IE) is a disease with high morbidity and mortality rate, but diagnosis is confounded by diverse clinical presentations, which mimic other pathologies. A history of illicit intravenous drug use, previous cardiac valve surgery, and indwelling intracardiac devices increases the risk for developing infective endocarditis. The modified Duke criteria serve as the standard diagnostic tool, though its accuracy is reduced in certain cases. Radiologists in the Emergency Room setting reading body CT may be the first to identify the secondary extra-cardiac complications and facilitate expeditious management by considering otherwise unsuspected infective endocarditis. This review highlights common extracardiac complications of IE and their corresponding CT findings in the chest, abdomen, pelvis, and brain. If IE is suspected radiologists should suggest further investigation with echocardiography.

Hemoperitoneum Due to Dissection and Rupture of the Superior Mesenteric Artery in a Patient With COL3A1 Mutation.

Introduction: Vascular Ehlers-Danlos syndrome (vEDS) is an autosomal dominant disorder that results from mutations in the collagen type III gene. It is a risk factor for medium-sized artery aneurysms, dissections, and ruptures. We report a case of hemoperitoneum due to medial dissection and rupture of the superior mesenteric artery related to vEDS. Methods: A full body CT scan and full three cavity autopsy was performed in a 47-year-old man with a history of an intermittent abdominal cramping for one week rand complex past medical history that included a sigmoid bowel perforation at age 20, and previous popliteal artery pseudoaneurysm rupture. Histology and genetic testing were performed. Results: The postmortem computed tomography and autopsy showed a significant hemoperitoneum due to a ruptured dissection of the superior mesenteric artery and branches, and multiple splanchnic artery dissections with renal and small bowel infarctions. Genetic testing revealed a heterozygous COL3A1 gene variant associated with Ehlers-Danlos syndrome. Death was attributed to hemoperitoneum due to medial dissection and rupture of the superior mesenteric artery due to arteriopathy. Discussion: The relatively young age and medical history correlate with the autopsy findings and genetic testing towards the conclusion of an arteriopathy consistent with vEDS.

A Comprehensive Analysis of Metastatic Disease following Surgery for Clinically Localized Cutaneous Melanoma.

The NCCN considers "baseline staging" (whole body CT or PET scan +/- brain MRI) for all asymptomatic melanoma patients with a positive sentinel lymph node biopsy. The true yield of these workups is unknown. We created cohorts of adult malignant melanoma patients, using the National Cancer Database (2012-2020) to mimic three common scenarios: (1) clinically node negative, with positive sentinel lymph node(s) (SLNB[+]); (2) clinically node negative, with negative sentinel lymph node(s) (SLNB[-]); (3) clinically node positive with confirmed lymph node metastases (cN[+] and pN[+]). Multivariable regression, supervised decision trees, and nomograms were constructed to assess the risk of metastases based on key features. 10,371 patients were SLNB[+], 55,172 were SLNB[-], and 4,012 were cN[+] and pN[+]. The proportion of patients with any metastatic disease (brain metastases) were as follows: SLNB[+]: 1.4% (0.3%); SLNB[-] 0.3% (<0.1%); cN[+] and pN[+] 11.6% (1.6%). On multivariable regression, Breslow depth > 4, ulceration, and lymphovascular invasion were associated with greater risk of metastatic disease. A supervised decision tree for SLNB[+] and SLNB[-] patients found the only groups with >2% risk of metastases were T4 tumors or T2/T3 tumors with ulceration and LVI. Most groups had a negligible risk (<0.1%) of brain metastases. This is the first large analysis to guide the use of imaging for cutaneous melanoma. Among clinically node negative patients, metastatic disease is uncommon and brain metastases are exceedingly rare. Further investigation could promote a tailored approach to metastatic workups guided by individual risk factors.

Harnessing the Value of Incidental Tissue and Organ Data at Body CT.

Harnessing the Value of Incidental Tissue and Organ Data at Body CT.

Off-label use of fam-trastuzumab deruxtecan-nxki with early activity in a cohort of patients with desmoplastic small round cell tumor.

11584 Background: Desmoplastic small round cell tumor (DSRCT) is a rare and aggressive sarcoma occurring predominantly in pediatric, adolescent and young adult biologic males, and is molecularly characterized by the pathognomonic EWSR1-WT1 fusion. Despite aggressive multi-modality therapy outcomes for those with DSRCT remain poor, and more effective therapies are urgently required. Prior pre-clinical data and transcriptomic analyses of DSRCT patients has suggested the relevance of the ERBB2 pathway in this disease, prompting the off-label use of fam-trastuzumab deruxtecan-nxki (T-DXd) in the treatment of patients of DSRCT patient with relapsed and refractory disease. Methods: Patients with relapsed/refractory DSRCT received T-DXd 5.4 mg/kg intravenously in 21-day cycles. Whole body PET and CT of the chest, abdomen and pelvis were used for monitoring. Response was correlated with HER2 immunohistochemistry (IHC) status and transcriptomic analysis by RNA sequencing (RNAseq) when available. Results: Seven patients received the agent, and at the time of submission 3 patients had at least one follow up imaging test after receiving between 6 and 9 cycles of T-DXd. Treatment was overall well tolerated with the only grade 3 toxicity of transaminitis (in patients with known liver metastases), which self-resolved. All other toxicities including constipation, nausea, and fatigue were grade 2 or less. All 3 patients have experienced clinical benefit including one patient with a RECIST 1.1 partial response and two patients with stable disease. Additionally, favorable responses were noted by PET imaging. Four additional patients with relapsed/refractory DSRCT have initiated off-label treatment with T-DXd and are pending imaging responses. 7/7 and 4/7 patients have available IHC and ERBB2 RNA expression data available respectively. All ERBB2 RNA expression data is elevated when compared with the median across all evaluated pediatric tumors in our institutional series. Conclusions: The use of anti-HER2 therapy in a limited and unselected group of heavily pre-treated DSRCT patients is demonstrating an early signal of activity with minimal toxicity and suggests that formal assessment as monotherapy or in other relevant combinations in clinical trials is warranted. Further correlation with IHC and RNAseq expression data may help optimize correlatives and/or generate biomarkers for future clinical trials.

A phase II trial of nivolumab plus axitinib in patients with anti-PD1 refractory advanced melanoma.

TPS9600 Background: A significant portion of patients (pts) with advanced melanoma (mel) either do not respond or become refractory to immune checkpoint inhibitor (ICI) therapy, with no established second line treatment regimen. A key ICI resistance mechanism includes formation of an immunosuppressive tumor microenvironment (TME). We have shown that high oxidative metabolism (OXPHOS) of mel tumor cells is associated with a hostile TME (1). Furthermore, this is associated with high intra-tumoral hypoxia (ITH). In mel tumor cells with high OXPHOS, CD8+ tumor infiltrating lymphocytes (TIL) display increased exhaustion and decreased functionality (decreased IFN-γ and TNF-α production). Pts with metastatic mel who progressed on ICI had tumor cells with high OXPHOS and ITH. Axitinib is a VEGFR small molecule tyrosine kinase inhibitor with high inhibitory activity for VEGFR 1-3. We previously showed that low dose axitinib reduces ITH in B16 murine mel, and our pre-clinical data show that axitinib synergizes with ICI to produce an improved tumor response (2). We hypothesize that axitinib will re-sensitize mel to ICI by modulating angiogenesis and reducing ITH and resultant T cell dysfunction. Methods: This is an investigator-initiated, single arm phase II trial of nivolumab plus axitinib for pts with unresectable stage III or IV cutaneous, acral, or mucosal mel who have progressed on prior anti-PD1 based therapy in the adjuvant or metastatic setting (NCT04493203). Pts previously treated with concomitant anti-CTLA4, anti-LAG3, BRAF/MEK inhibitors, and/or pts with brain metastases (asymptomatic or stable treated disease x 2 weeks) are eligible. Pts will receive nivolumab 480 mg IV every 4 wks with axitinib PO 5 mg twice daily for up to 2 years, or until progression or unacceptable toxicity. Pts will undergo biopsy at baseline and at 12 wks, with optional biopsy at progression. Pts will receive an oral dose of pimonidazole 0.5 mg/m2 prior to each biopsy to permit in-vivo evaluation of ITH. Staging scans (full body PET-CT or CT and MRI brain) will be obtained at baseline, with restaging scans at 12 week intervals. Primary endpoint: overall response rate (ORR) by RECIST 1.1. Responses are determined by Blinded Independent Central Review (BICR). Secondary endpoints: safety analysis, progression-free survival (PFS) and overall survival (OS). Extensive correlative translational analyses will focus on immunophenotypic changes in the TME, ITH, profiling of tumor cell metabolism, and TIL function. The null hypothesis that the true ORR is 10% will be tested versus a one-sided alternative hypothesis of ≥25%, using Simon’s minimax two-stage design. This design has a type I error rate 0.08 and power 0.81 when the true response rate is 0.25. PFS and OS will be estimated via Kaplan-Meier method. 31 of planned 31 pts have been enrolled in January 2024, with no data analysis yet available. 1. Najjar et al., JCI Insight 2019. 2. Scharping et al., Nat Immunol 2021. Clinical trial information: NCT04493203 .

Extracellular volume measured by whole body CT scans predicts chronic cardiotoxicity in breast cancer patients treated with neoadjuvant therapies based on anthracyclines: A retrospective study

IntroductionNeoadjuvant chemotherapies for breast cancer (BC) are effective but potentially cardiotoxic, and expose long survivors at risk of chemotherapy-related cardiac dysfunction (CTRCD). Unfortunately, early screening for CTRCD has actual diagnostic limits. Myocardial extracellular volume (mECV) is a radiological marker used in cardiac CT scans and cardiac magnetic resonance for diagnosis and follow-up of CTRCD. It can be measured in whole-body CT (WB-CT) scan, routinely performed in patients at high risk of relapse, to evaluate CTRCD occurrence during oncological follow-up. Methods82 WB-CT scans were examined at baseline (T0) and during oncological follow-up at first year (T1) and fifth year (T5) after the end of neoadjuvant treatment. mECV was measured at 1 min (PP) and 5 min (DP) after contrast injection. 31 echocardiograms were retrieved in T1 to perform a linear correlation between mECV and left ventricular ejection fraction (LVEF). ResultsmECV values in T0 were similar between the two groups both in PP and in DP. Significant results were found for PP values in T1 (37.0 % vs 32 %, p = 0.0005) and in T5 (27.2 % vs 31.2 %, p = 0.025). A cut-off value of 35 % in PP proved significant in T1 (OR = 12.4, p = 0.004), while mECV was inversely correlated with LVEF both in PP (adj-S = −3.54, adj-p = 0.002) and in DP (adj-S = −2.51, adj-p = 0.0002), suggesting a synergistic action with the age at diagnosis (p < 0.0001, respectively). ConclusionsWB-CT scans performed during oncological reassessment in patients at high-risk of recurrence could be used for CTRCD screening in cardiovascular low-risk patients, especially in aging patients with mECV values above 35 %.

LYME AND DENGUE FEVER: FROM BANGLADESH TO ITALY

Abstract Background Dengue fever (Flavivirus) and Lyme disease (Borrelia burgdorferi) are rare tropical infectious diseases transmitted by hematophagous vectors (Aedes mosquitoes and ticks, respectively), and they are extremely uncommon in Italy. In European countries, both represent a public health concern as they manifest as imported diseases. Case Report A 54–year–old man from Bangladesh was admitted with symptoms of fever, dyspnea, and pericarditic chest pain. Laboratory and imaging examinations revealed severe acute respiratory failure secondary to left lower lobe pneumonia and pleuropericardial effusion. Broad–spectrum antibiotic therapy and anti–inflammatory treatment were initiated, suspecting para–pneumonic pleuropericarditis. During hospitalization, there was a gradual improvement with a reduction in inflammatory indices and resolution of lung consolidation. The patient was discharged after 14 days with anti–inflammatory therapy (ibuprofen and colchicine). Approximately 7 days later, the patient returned to the emergency department complaining of a recurrence of symptoms and fatigue. The EKG showed phases of 2:1 AV block, EAS and EPS, complete de novo left bundle branch block (LBBB), alternating with an escape atrial rhythm, not evident in previous EKG. During hospitalization, complete AV block emerged with prolonged asystolic phases, requiring urgent placement of a temporary pacemaker. Concurrently, blood tests revealed anemia and increased levels of inflammatory markers, troponin, creatinine, transaminases, cholestatic indices, LDH, and lipase, indicative of multiple organ failure (MOF). Acute pathologies or active bleeding were ruled out by total body CT with contrast. Blood cultures and serological tests were performed to exclude infections by Trichinella, Mycoplasma, Borrelia, Dengue, and other rare infectious diseases. Due to progressive deterioration, the patient was transferred to a tertiary care hospital. In the following days, laboratory results showed positive IgG and IgM for Dengue (without serological evidence of viral RNA) and positive IgG and IgM antibodies for Borrelia burgdorferi. Conclusion In Italy, the incidence of these diseases is low, and their coexistence in the same host is even rarer (if not anecdotal). However, coinfection cannot be excluded in patients from areas where these diseases are endemic, such as Bangladesh.

HALF DOSE THROMBOLYSIS IN INTERMEDIATE – HIGH RISK PULMONARY EMBOLISM WITH TRICUSPID VALVE MOBILE MASS: A BAIL OUT STRATEGY

Abstract A 82–year–old previously healthy male was referred to the emergency department complaining sudden onset dyspnea and witnessed syncope complicated by head trauma. Recurrent dizziness occurred previously. No history or drug consumption noted. On admission: heart rate 90 beats/min, blood pressure 110/60 mmHg, respiratory rate 25 breaths/min, oxygen saturation 87% in room air, normal body temperature. No lower extremities tenderness or swelling reported. Consistent with peripheral blood oxygen saturation levels, arterial blood gas analysis showed hypoxemia and respiratory alkalosis. Laboratory exams were significant for thrombocytopenia (89.000 cells/L), elevated cardiac troponin T levels (222 ng/L) and natriuretic peptide (NT pro–BNP 3944 pg/mL). Head CT excluded acute cerebral hemorrhage. At the electrocardiogram, signs of RV strain were present (biphasic T–waves in V1–V3 leads, S1–Q3–T3). Transthoracic echocardiography (TTE) showed dilated RV with hypokinetic free wall, “D–shaped” LV, “60/60” sign and a mobile filiform mass crossing the tricuspid valve plan in the right atrium (fig. 1). The patient did not present structural valvular abnormalities or endocarditis–related risk factors. CT pulmonary angiography detected a “saddle” PE and extensive thrombosis in inferior vena cava. After unfractioned heparin (UFH) bolus, the patient was transferred to our intensive care unit and balancing risks and benefits the chosen treatment option consisted in half dose systemic thrombolysis (50 mg rtPA in 60’’; 10 mg as loading dose in 2’). Because of potential harmful effects in thrombocytopenia and recent head trauma, UFH was temporarily withheld and started again after 1 hour. The day after, a beside TTE showed complete tricuspid thrombus resolution, a significant decrease in RV/LV ratio and systolic pulmonary artery pressure (fig. 2). Apart from small hematomas, no bleedings were reported. The patient was shifted to the ward on the next day and following course was uneventful. On day 4 a direct oral anticoagulant (Dabigatran 110 mg) was started. Abdominal and inferior limb–deep–venous ultrasound were both negative for pathological reports. A total body CT was scheduled to exclude silent malignancies at discharge. Take home message: in intermediate–high risk PE, half dose systemic fibrinolysis strategy is controversial since its potential benefit is counterbalanced by concerns about major bleedings, but increasing data suggest its efficacy with low risk profile.

Atypical psychosis in a patient with intracranial hypertension: clinical case and review

IntroductionSeveral neurologic conditions can produce or mimic psychotic symptoms. It is important to make an exhaustive differential diagnosis between a psychiatric manifestation of an underlying neurological condition and a primary psychiatric one. We explore through the present clinical case of a young woman admitted to neurology the relationship between intracranial hypertension and a case of atypical psychosis that resolved itself with the treatment of the intracranial hypertension, without the need for antipsychotic medication.ObjectivesTo explore through the presented clinical case and the concerning literature the concept and management of psychotic-like symptoms in patients with intracranial hypertension.MethodsWe present a clinical case and a review of the existing literature concerning atypical psychosis or psychosis-like symptoms in cases of intracranial hypertension.ResultsWe report the case of a 24 year old woman with no relevant medical history hospitalised in the neurology unit due to suspected encephalitis. Native to New Zealand, she is brought from the airport due to behavioural alterations. During the last few days before admission she had presented with incoherent speech, derailment, religious and persecutory delusions, and erotomania towards her cousin. She described feelings of strangeness with her surroundings and of time moving at a different speed than usual, either faster or slower. She also had a headache and visual alterations, as well as memory errors concerning recent events, clouding of consciousness and inattention.No fever or other relevant physical symptoms. A lumbar puncture is done, which shows an opening pressure of 37mmHg but no other anomalies. Body CT scan shows no relevant findings. Empirical treatment with dexamethasone is initiated for suspected encephalitis, progressively reducing the dosage until suspension in the following days. During her stay at the hospital she is assessed by ophthalmology, which finds no abnormalities in the eye fundus examination, and psychiatry. A second evacuating lumbar punture is done to reduce intracraneal hypertension. No antipsychotic treatment is initiated: the symptomatology remitted with the lowering of intracranial pressure. At time of discharge, the patient remained asymptomatic without treatment and was able to return home to continue outpatient neurologic study of the etiology of the intracranial hypertension.Finally, we conduct a review ot the existing literature concerning psychotic and psychosis-like symptoms in patients with intracranial hypertension, to explore the diagnostic and management options of this rare finding.ConclusionsOur findings point to the existing relationship between intracranial hypertension and psychosis-like symptoms. Further studies on pathogenic mechanisms and therapeutic management are required.Disclosure of InterestNone Declared

Preparing for the Worst: Management and Predictive Factors of Open Conversion During Minimally Invasive Renal Tumor Surgery (UroCCR-135 Study)

Background and objectiveData regarding open conversion (OC) during minimally invasive surgery (MIS) for renal tumors are reported from big databases, without precise description of the reason and management of OC. The objective of this study was to describe the rate, reasons, and perioperative outcomes of OC in a cohort of patients who underwent MIS for renal tumor initially. The secondary objective was to find the factors associated with OC. MethodsBetween 2008 and 2022, of the 8566 patients included in the UroCCR project prospective database (NCT03293563), who underwent laparoscopic or robot-assisted minimally invasive partial (MIPN) or radical (MIRN) nephrectomy, 163 experienced OC. Each center was contacted to enlighten the context of OC: “emergency OC” implied an immediate life-threatening situation not reasonably manageable with MIS, otherwise “elective OC”. To evaluate the predictive factors of OC, a 2:1 paired cohort on the UroCCR database was used. Key findings and limitationsThe incidence rate of OC was 1.9% for all cases of MIS, 2.9% for MIRN, and 1.4% for MIPN. OC procedures were mostly elective (82.2%). The main reason for OC was a failure to progress due to anatomical difficulties (42.9%). Five patients (3.1%) died within 90 d after surgery. Increased body mass index (BMI; odds ratio [OR]: 1.05, 95% confidence interval [CI]: 1.01–1.09, p = 0.009) and cT stage (OR: 2.22, 95% CI: 1.24–4.25, p = 0.008) were independent predictive factors of OC. Conclusions and clinical implicationsIn MIS for renal tumors, OC was a rare event (1.9%), caused by various situations, leading to impaired perioperative outcomes. Emergency OC occurred once every 300 procedures. Increased BMI and cT stage were independent predictive factors of OC. Patient summaryThe incidence rate of open conversion (OC) in minimally invasive surgery for renal tumors is low. Only 20% of OC procedures occur in case of emergency, and others are caused by various situations. Increased body mass index and cT stage were independent predictive factors of OC.

The role of 18F-FDG PET/CT in Neurolymphomatosis: A Comprehensive Imaging Approach.

Neurolymphomatosis (NL) is an uncommon and rare neurologic disorder characterised by extranodal lymphoma, where the tumour cells invade the cranial nerves, nerve plexus, nerve root, spinal nerve roots, trunk nerves or peripheral nerves. MRI is the modality of choice, but is often challenging in detection of early recurrence, assessing residual disease and response evaluation. 18FFDG PET/CT has superior diagnostic performance compared with body CT in the evaluation of NL. 18F-FDG PET-CT is helpful in evaluation of disease extent and potential to guide biopsy. 18F-FDG PETCT is a highly sensitive technique for early localisation of NL than MRI or CT alone. Besides diagnostic and prognostic value in NL, it might be very helpful in response assessment.

The Contribution of 18F FDG PET-CT for the Investigation of Fever of Unknown Origin and Inflammation of Unknown Origin

BackgroundFever of unknown origin and inflammation of unknown origin are highly challenging diagnostic conditions. The current practice for evaluating patients is to conduct a positron emission tomography-computed tomography (PET-CT) scan as either a first- or a second-line modality. We aimed to assess the contributory effect of PET-CT to the diagnosis and compare it with the contributory effect of CT alone. MethodsWe performed a systematic review and meta-analysis. We included all cohorts that examined the contribution of PET-CT to the investigation of classical fever of unknown origin and inflammation of unknown origin. The primary outcome was the contribution of PET-CT to the final diagnosis. Secondary outcomes were sensitivity and specificity of PET-CT and CT scans, and contribution of a CT scan. We pooled the results of all studies and calculated the pooled contributory effect of PET-CT. ResultThirty-six studies (3516 patients) were included in the systematic review. The pooled contribution of PET-CT was 75.4%. The compiled sensitivity and specificity values for all studies were 85.9% and 59.5%, respectively. Five studies (405 patients) compared between the PET-CT component and the total body CT component. The pooled contribution of a CT scan was 68%. The summed sensitivity and specificity values of a CT scan for all studies were 63.1% and 84.4%, respectively. ConclusionsPET-CT has a contributory effect of 75% for the diagnosis of fever of unknown origin and inflammation of unknown origin. PET-CT had superior sensitivity and inferior specificity vs the CT scan.

Comparative analysis of osteoderms across the lizard body.

Osteoderms (ODs) are mineralized tissue embedded within the skin and are particularly common in reptiles. They are generally thought to form a protective layer between the soft tissues of the animal and potential external threats, although other functions have been proposed. The aim of this study was to characterize OD variation across the lizard body. Adults of three lizard species were chosen for this study. After whole body CT scanning of each lizard, single ODs were extracted from 10 different anatomical regions, CT scanned, and characterized using sectioning and nanoindentation. Morphological analysis and material characterization revealed considerable diversity in OD structure across the species investigated. The scincid Tiliqua gigas was the only studied species in which ODs had a similar external morphology across the head and body. Greater osteoderm diversity was found in the gerrhosaurid Broadleysaurus major and the scincid Tribolonotus novaeguineae. Dense capping tissue, like that reported for Heloderma, was found in only one of the three species examined, B. major. Osteoderm structure can be surprisingly complex and variable, both among related taxa, and across the body of individual animals. This raises many questions about OD function but also about the genetic and developmental factors controlling OD shape.

Body CT examinations in oncologic patients: the impact of subspecialty radiology on radiation exposure in the clinical practice. A quality care study

PurposesThe primary objective of this retrospective study was to assess whether the CT dose delivered to oncologic patients was different in a subspecialty radiology department, compared to a general radiology department. The secondary explorative objective was to assess whether the objective image quality of CT examinations was different in the two settings.Materials and methodsChest and abdomen CT scans performed for oncologic indications were selected from a general radiology department and a subspecialty radiology department. By using a radiation dose management platform, we extracted and compared CT dose index (CTDIvol) and dose length product (DLP) both for each phase and for the entire CT exams. For objective image quality evaluation, we calculated the signal-to-noise ratio (SNR) and the contrast-to-noise ratio (CNR) at the level of the liver and of the aorta. A P-value < 0.05 was considered significant.ResultsA total of 7098 CT examinations were included. CTDIvol was evaluated in 12,804 phases; DLP in 10,713 phases and in 6714 examinations. The CTDIvol and DLP overall were significantly lower in the subspecialty radiology department compared to the general radiology department CTDI median (IQR) 5.19 (3.91–7.00) and 5.51 (4.17–7.72), DLP median and IQR of 490.0 (342.4–710.6) and 503.4 (359.9–728.8), p < 0.001 and p = 0.01, respectively. The objective image quality showed no significant difference in the general and subspecialty radiology departments, with median and IQR of 4.03 (2.82–5.51) and 3.84 (3.09–4.94) for SNRLiv (p = 0.58); 4.81 (2.70–7.62) and 4.34 (3.05–6.25) for SNRAo (p = 0.30); 0.83 (0.20–1.89) and 1.00 (0.35–1.57) for CNRLiv (p = 0.99); 2.23 (0.09–3.83) and 1.01 (0.15–2.84) for CNRAo (p = 0.24) with SNRLiv (p = 0.58), SNRAo (p = 0.30), CNRLiv (p = 0.99) and CNRAo (p = 0.24).ConclusionIn a subspecialty radiology department, CT protocols are optimized compared to a general radiology department leading to lower doses to oncologic patients without significant objective image quality degradation.

O-13 Parathyroid carcinoma - a rare and challenging entity

Abstract Background Parathyroid carcinoma is a rare malignancy, accounting for less than 1% of all cases of primary hyperparathyroidism (HPT). This entity affects both men and women equally and is usually diagnosed in the fourth or fifth decade of life. It can occur sporadically or be associated with genetic syndromes such as hyperparathyroidism-jaw tumor syndrome. Its clinical presentation can overlap with that of primary HPT, with hypercalcemia that can lead to a range of symptoms, such as fatigue, weakness, bone pain, kidney stones, and gastrointestinal disorders. Distinguished by its rarity and clinical challenges, this condition requires a high level of suspicion and its initial surgical approach correlates with long-term prognosis. Clinical Case This is the case of a male patient, 39 years old, Caucasian, with a previous history of hypertension diagnosed 5 months earlier, deep vein thrombosis (DVT) diagnosed 2 months earlier, and active tobacco use. Additional study performed after the DVT episode found severe hypercalcemia (14.3 mg/dL, N 8.6-10.0), hypophosphatemia (2.2 mg/dL, N 2.5-4.5), and renal dysfunction (Creatinine 1.43 mg/dL). The patient was asymptomatic and was admitted to the Internal Medicine department, to correct the hypercalcemia and further investigation. Increased PTH levels (1555 pg/mL, N 15-65) were found, and a cervical ultrasound revealed, on the left thyroid lobe, a bilobed nodule, mainly solid, hypoechogenic, with irregular margins and macrocalcifications, with 34×22 mm. Full body CT showed osteolytic lesions on several ribs and both iliacs and kidney stones. A bone scintigraphy was also done, showing a diffuse fixation on the axial and appendicular skeleton, compatible with diffuse osteomedullary infiltration. Due to these findings, the collaboration of the Endocrinology department was requested. Based on the PTH levels and the characteristics of the cervical mass, suspicion arose regarding a potential case of parathyroid carcinoma. Subsequently, a parathyroid scintigraphy using Sestamibi was conducted, whose report revealed an intense hyperfixation at a nodular formation projecting on the lower two-thirds of the thyroid left lobe, without unequivocal identification of its origin - thyroid nodule vs. parathyroid tissue. Based on intraoperative findings and clinical suspicion, en bloc resection of the tumor along with the thyroid lobe and unilateral neck exploration was performed by the Surgery department, with the pathological assessment confirming the malignancy diagnosis. The patient was referred to an oncologic tertiary center, for follow-up and genetic testing. Conclusion We want to shed light on this rare entity and the importance of multidisciplinary critical thinking, alongside imaging. Markedly elevated PTH and/or calcium levels on a patient with a cervical mass should arouse suspicion of a parathyroid carcinoma, which must not be biopsied and warrants a more extensive surgery to ensure the best possible prognosis.

Role of 18F-fluorodeoxyglucose positron-emission tomography/computed tomography in restaging of adrenocortical carcinoma.

The objective was to retrospectively evaluate the contribution of fluorodeoxyglucose [18F] positron emission tomography/computed tomography (18FDG-PET/CT) to the re-staging of adrenocortical carcinoma (ACC). A total of 16 patients (10 males and 6 females), who underwent adrenalectomy due to adrenocortical carcinoma and 18FDG-PET/CT scan to re-stage the tumor between July 2007 and April 2013, were included in the present study. The mean age was 53.37 ± 13.91 years (min: 30, max: 74) The patients were required to fast for six hours prior to scanning, and whole-body PET scanning from the skull base to the upper thighs was performed approximately 1 h after the intravenous injection of 555 MBq of F-18 FDG. Whole body CT scanning was performed in the cranio-caudal direction. FDG-PET images were reconstructed using CT data for attenuation correction. Suspicious recurrent or metastatic lesions were confirmed by histopathology or clinical follow-up. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 18FDG-PET/CT were 100%, 83.3%, 90.9%, 83.3%, and 93.7%, respectively. 18FDG-PET/CT detects local recurrence and/or distant metastases with high accuracy in the re-staging of operated adrenocortical carcinoma. It is considered that the procedure could play an important role in treatment decision after the operation and post-operative follow-up and could influence the entire decision-making process.

Simultaneous Learning of Erector Spinae Muscles for Automatic Segmentation of Site-Specific Skeletal Muscles in Body CT Images

Simultaneous Learning of Erector Spinae Muscles for Automatic Segmentation of Site-Specific Skeletal Muscles in Body CT Images