Anatomical Variations of the Left Adrenal Vein Encountered During Venous Sampling.

PURPOSE: To identify anatomical variations in the left adrenal vein (LAV) and to evaluate the role of preprocedural contrast-enhanced computed tomography (CT) planning. METHODS: The length of the left adrenal central vein (LACV), the vessel that receives blood from all tributaries of the left adrenal gland, was measured using venograms of patients who had undergone adrenal venous sampling (AVS) for the diagnosis of primary aldosteronism between October 2017 and December 2019. The anatomical variants of the LAV were described and classified. Contrast-enhanced CT was used to evaluate the detection rate of the following: (a) confluence of the left inferior phrenic vein and the LAV and (b) the last tributary flowing into the LAV. RESULTS: In total, 311 patients (143 men, 168 women; mean age: 49.3 years ± 11.0) were enrolled. Of them, 9 (2.9%) patients had anatomical variants lacking a LACV. In patients with a LACV (n = 302), the venographic LACV length was 9.0 mm ± 3.9 (<1 mm in 9 patients). The detection rate of the confluence of the left inferior phrenic vein and LAV, as determined using contrast-enhanced CT, was high (96.2%), whereas that of the last tributary flowing into the LAV was low (0.8%). In 4 of 18 patients with short or absent LACV, the variant was visualized using contrast-enhanced CT. CONCLUSIONS: In some patients, the LACV is absent or short, which is an anatomical variation. Understanding venographic anatomical variations can help avoid misleading results resulting from a suboptimal sampling site in AVS. For some subtypes, contrast-enhanced CT may also help in planning the AVS procedure.

Comparison of image quality between synthetic and patients' electrocardiogram-gated 320-row pediatric cardiac computed tomography.

BACKGROUND: Pediatric cardiac computed tomography (CT) can be acquired without electrode placement by using synthetic electrocardiogram (ECG). OBJECTIVE: To determine whether the depiction of gross cardiac structures and coronary arteries in 320-row pediatric CT is not inferior when CT is gated with synthetic ECG at 150 beats per minute (bpm), compared to the patients' own ECG. MATERIALS AND METHODS: Sixty 320-row CT examinations performed in children younger than 3 years old with congenital cardiac anomaly were enrolled in this retrospective study. Thirty examinations were scanned using the children's own ECG for gating and 30 examinations were scanned using synthetic ECG at 150 bpm. The image quality was compared between the two gating modes using a 3-point scale to delineate the following anatomical structures: atrial septum, ventricular septum, right atrium, right ventricle, left atrium, left ventricle, main pulmonary artery, ascending aorta, aortic arch including the patent ductus arteriosus, descending aorta, right coronary artery and left main trunk. Beam-hardening artifacts from contrast enhancement material were evaluated using a 3-point scale, and the overall image quality was evaluated using a 5-point scale. RESULTS: Synthetic ECG was not inferior to the patients' ECG in depicting each structure, beam-hardening artifact and overall image quality. Average indices were clinically acceptable imaging quality, except for subjective image quality of mid and distal coronary arteries. CONCLUSION: Pediatric cardiac CT in patients younger than 3 years old can be acquired using synthetic ECG gating, with image quality not inferior to the patients' ECG.

The pseudo-SAH sign: an imaging pitfall in postmortem computed tomography.

Postmortem computed tomography (PMCT) of the brain has an important role in detection of subarachnoid hemorrhage (SAH), which has a high mortality rate. However, a phenomenon known as "pseudo-SAH," or high-attenuation areas along the cisterns mimicking SAH, may be seen on CT. The aim of this study was to evaluate the diagnostic accuracy of brain PMCT for SAH and to identify the characteristics of pseudo-SAH. Findings on PMCT (sulcal effacement, asymmetry, maximum thickness of SAH signs, presence of acute/subacute intraventricular/intraparenchymal hemorrhage) and clinical history (left ventricular assist device [LVAD] implantation, anticoagulation therapy/coagulation disorder, global ischemia) were compared between subjects with true SAH and those with pseudo-SAH. Twenty eight of 128 enrolled subjects had positive signs of SAH on PMCT, 20 (71.4%) had SAH on autopsy, and 8 (28.6%) did not. The sensitivity, specificity, positive predictive value, and negative predictive value of SAH signs seen on PMCT were 95.2, 94.6, 71.4, and 99.3%, respectively. Asymmetry of SAH signs and acute/subacute intraventricular and intraparenchymal hemorrhage were significantly more common in true SAH cases than in pseudo-SAH cases. The maximum thickness of SAH signs was significantly greater in true SAH cases. A history of LVAD implantation, anticoagulation therapy, and/or a coagulation disorder were more common in true SAH cases but not significantly so. A history of global ischemia was significantly more common in pseudo-SAH cases. If signs of SAH are observed on PMCT, it is important to look for other signs on PMCT and carefully review the clinical history to avoid a diagnostic error.

Pediatric 320-row cardiac computed tomography using electrocardiogram-gated model-based full iterative reconstruction.

BACKGROUND: Full iterative reconstruction algorithm is available, but its diagnostic quality in pediatric cardiac CT is unknown. OBJECTIVE: To compare the imaging quality of two algorithms, full and hybrid iterative reconstruction, in pediatric cardiac CT. MATERIALS AND METHODS: We included 49 children with congenital cardiac anomalies who underwent cardiac CT. We compared quality of images reconstructed using the two algorithms (full and hybrid iterative reconstruction) based on a 3-point scale for the delineation of the following anatomical structures: atrial septum, ventricular septum, right atrium, right ventricle, left atrium, left ventricle, main pulmonary artery, ascending aorta, aortic arch including the patent ductus arteriosus, descending aorta, right coronary artery and left main trunk. We evaluated beam-hardening artifacts from contrast-enhancement material using a 3-point scale, and we evaluated the overall image quality using a 5-point scale. We also compared image noise, signal-to-noise ratio and contrast-to-noise ratio between the algorithms. RESULTS: The overall image quality was significantly higher with full iterative reconstruction than with hybrid iterative reconstruction (3.67±0.79 vs. 3.31±0.89, P=0.0072). The evaluation scores for most of the gross structures were higher with full iterative reconstruction than with hybrid iterative reconstruction. There was no significant difference between full and hybrid iterative reconstruction for the presence of beam-hardening artifacts. Image noise was significantly lower in full iterative reconstruction, while signal-to-noise ratio and contrast-to-noise ratio were significantly higher in full iterative reconstruction. CONCLUSION: The diagnostic quality was superior in images with cardiac CT reconstructed with electrocardiogram-gated full iterative reconstruction.

Comparison of volume and attenuation of the spleen between postmortem and antemortem computed tomography.

OBJECTIVES: The purpose of this study is to compare the postmortem changes in computed tomography (CT) findings between normal spleen, splenic infarct, and splenic tumor infiltration. METHODS: The institutional review board approved this study, and informed consent was obtained from the next of kin. We studied 63 consecutive subjects who underwent antemortem CT, postmortem CT, and autopsy between February 2012 and December 2013. Postmortem CT was performed within 1678 min after death and was followed by pathological studies. The subjects were divided into three groups based on the pathological findings: normal, splenic infarct, and splenic tumor infiltration. The volume and attenuation of the spleen were compared between antemortem and postmortem CT using paired t tests. Gender, age, time elapsed since death, and the causes of death were examined as potential confounding factors of the postmortem changes in volume and attenuation. RESULTS: In all groups, the spleen decreased in volume and attenuation increased on postmortem CT compared with antemortem CT. The postmortem changes in spleen volume and attenuation were not significantly associated with sex, age, time elapsed since death, or causes of death. CONCLUSIONS: Spleen volume decreased and attenuation increased on postmortem CT compared with antemortem CT in subjects with a normal spleen, splenic infarct, or splenic tumor infiltration. These results should caution us against underestimating the significance of splenomegaly on postmortem CT, misinterpreting reduced splenic volume as the presence of hypovolemic or distributive shock in the subject while alive, and confusing postmortem splenic hyperattenuation with diseases characterized by this finding.

Can postmortem computed tomography detect antemortem hypoxic-ischemic encephalopathy?

The purpose of this study was to evaluate the usefulness of brain postmortem computed tomography (PMCT) findings for the detection of global hypoxia or hypoperfusion leading to hypoxic-ischemic encephalopathy (HIE) prior to death. Cadavers of individuals who died from non-traumatic causes were subjected to PMCT and pathological autopsy. Cases with an episode of cardiopulmonary arrest, hypoxia, or hypoperfusion that required intensive respiratory management at least 24 h before death and exhibited findings of HIE in conventional autopsy (HIE group, n = 6) were compared with those without such episodes prior to death (control group; overall, n = 37; age-matched, n = 8) with regard to four parameters: (1) width of the central sulcus (CS), (2) attenuation difference at the basal ganglia (BG) level, (3) attenuation difference between cerebral gray matter (GM) and cerebral white matter (WM), and (4) attenuation difference between cerebellar GM and cerebral GM. The results revealed significant differences in the width of the CS (P < 0.001), attenuation difference at the BG level (P < 0.001), and attenuation difference between cerebral GM and cerebral WM (P = 0.009) between the HIE group and the overall control group. When the age-matched control group and the HIE group were compared, there was a significant difference in the width of the CS (P = 0.026) and attenuation difference at the BG level (P < 0.001). Our results suggest that effacement of the sulcus of the cerebral hemisphere and the loss of contrast at the BG level on brain PMCT indicate the existence of HIE prior to death.

Early postmortem volume reduction of adrenal gland: initial longitudinal computed tomographic study.

We aimed to confirm whether postmortem adrenal volumetric changes occur by measuring adrenal volumes on computed tomography (CT). Fifty-five adrenal glands from 28 subjects who died were included. All subjects underwent antemortem CT (AMCT) and postmortem CT (PMCT) within 94-1,191 min after death, followed by conventional autopsy. CT volumetry was performed using freely-available software. Differences between AMCT and PMCT adrenal volumes were evaluated statistically along with differences in the degree of volume change, elapsed time to PMCT, and presence of underlying malignant disease. The mean volume of the right adrenal gland decreased from 3.8 cm(3) on AMCT to 2.6 cm(3) on PMCT (P < 0.001); the left adrenal gland decreased from 4.2 cm(3) on AMCT to 3.1 cm(3) on PMCT (P < 0.001). Conventional autopsy revealed decreased intracellular lipid components in portions of the adrenal glands. No correlation between the adrenal gland reduction rate and the elapsed time from AMCT to death or from death to PMCT was observed (P = 0.99 and 0.79; P = 0.28 and 0.59 for the right and left adrenal glands, respectively). Significant differences in both the bilateral adrenal gland reduction rates and underlying malignant disease were found for the left adrenal gland (P = 0.015), but not for the right (P = 0.74). Adrenal volume reduction was observed on PMCT compared to AMCT. This highlights the need to further elucidate the mechanism of adrenal shrinkage during the agonal stage and after death. This may be explained by pathological findings of intracellular lipid depletion.

Transarterial radioembolization vs transarterial chemoembolization with drug-eluting beads for treating hepatocellular carcinoma: a cost-effectiveness analysis in Japanese healthcare system.

PURPOSE: Transarterial radioembolization (TARE) is effective for unresectable hepatocellular carcinoma; however, it awaits approval in Japan. This study aimed to simulate the cost-effectiveness of TARE over chemoembolization when TARE is approved in Japan and identify the requirements for cost-effectiveness. MATERIALS AND METHODS: A Markov model was constructed to analyze the costs and effectiveness associated with TARE and transarterial chemoembolization with drug-eluting beads (DEB-TACE) for 2-month cycles over 5 years. In the primary analysis, the intention-to-treat survival data were used to calculate transition probabilities, whereas the ancillary analysis assessed the per-protocol survival data. DEB-TACE costs were calculated using the Japanese nationwide claims Diagnosis Procedure Combination database between April 2018 and March 2022, whereas TARE costs were estimated using database and international sources. The incremental cost-effectiveness ratio (ICER) was determined based on the payer's perspective and compared with the Japanese willingness-to-pay threshold of 5 million Japanese yen (JPY) (31,250 USD) per quality-adjusted life years (QALY). RESULTS: From the claims database, 6,986 patients with hepatocellular carcinoma who received DEB-TACE were identified. In the primary analysis, the ICER was 5,173,591 JPY (32,334 USD)/QALY, surpassing the Japanese willingness-to-pay threshold. However, the ancillary analysis showed a lower ICER of 4,156,533 JPY (25,978 USD)/QALY, falling below the threshold. The one-way deterministic sensitivity analysis identified progression-free survival associated with TARE and DEB-TACE, DEB-TACE costs, and radioactive microsphere reimbursement price as key ICER influencers. The primary analysis suggested that setting the reimbursement price of radioactive microspheres below 1.399 million JPY (8,744 USD), approximately 2.8% lower than the price in the United Kingdom, would place the ICER below the Japanese willingness-to-pay threshold. CONCLUSIONS: Under specific conditions, TARE can be a more cost-effective treatment than DEB-TACE. If the reimbursement price of radioactive microspheres is set approximately 2.8% lower than that in the United Kingdom, TARE could be cost-effective compared with DEB-TACE.

Diagnostic Performance of GPT-4o and Claude 3 Opus in Determining Causes of Death From Medical Histories and Postmortem CT Findings.

INTRODUCTION: This study evaluates the diagnostic performance of the latest large language models (LLMs), GPT-4o (OpenAI, San Francisco, CA, USA) and Claude 3 Opus (Anthropic, San Francisco, CA, USA), in determining causes of death from medical histories and postmortem CT findings. METHODS: We included 100 adult cases whose postmortem CT scans were diagnosable for the causes of death using the gold standard of autopsy results. Their medical histories and postmortem CT findings were compiled, and clinical and imaging diagnoses of both the underlying and immediate causes of death, as well as their personal information, were carefully separated from the database to be shown to the LLMs. Both GPT-4o and Claude 3 Opus generated the top three differential diagnoses for each of the underlying or immediate causes of death based on the following three prompts: 1) medical history only; 2) postmortem CT findings only; and 3) both medical history and postmortem CT findings. The diagnostic performance of the LLMs was compared using McNemar's test. RESULTS: For the underlying cause of death, GPT-4o achieved primary diagnostic accuracy rates of 78%, 72%, and 78%, while Claude 3 Opus achieved 72%, 56%, and 75% for prompts 1, 2, and 3, respectively. Including any of the top three differential diagnoses, GPT-4o's accuracy rates were 92%, 90%, and 92%, while Claude 3 Opus's rates were 93%, 69%, and 93% for prompts 1, 2, and 3, respectively. For the immediate cause of death, GPT-4o's primary diagnostic accuracy rates were 55%, 58%, and 62%, while Claude 3 Opus's rates were 60%, 62%, and 63% for prompts 1,2, and 3, respectively. For any of the top three differential diagnoses, GPT-4o's accuracy rates were 88% for prompt 1 and 91% for prompts 2 and 3, whereas Claude 3 Opus's rates were 92% for all three prompts. Significant differences between the models were observed for prompt two in diagnosing the underlying cause of death (p = 0.03 and <0.01 for the primary and top three differential diagnoses, respectively). CONCLUSION: Both GPT-4o and Claude 3 Opus demonstrated relatively high performance in diagnosing both the underlying and immediate causes of death using medical histories and postmortem CT findings.

Cutoff CT value can identify upper gastrointestinal bleeding on postmortem CT: Development and validation study.

This study aimed to establish the diagnostic criteria for upper gastrointestinal bleeding (UGIB) using postmortem computed tomography (PMCT). This case-control study enrolled 27 consecutive patients with autopsy-proven UGIB and 170 of the 566 patients without UGIB who died in a university hospital in Japan after treatment and underwent both noncontrast PMCT and conventional autopsy between 2009 and 2020. Patients were randomly allocated to two groups: derivation and validation sets. Imaging findings of the upper gastrointestinal contents, including CT values, were recorded and evaluated for their power to diagnose UGIB in the derivation set and validated in the validation set. In the derivation set, the mean CT value of the upper gastrointestinal contents was 48.2 Hounsfield units (HU) and 22.8 HU in cases with and without UGIB. The optimal cutoff CT value for diagnosing UGIB was ≥27.7 HU derived from the receiver operating characteristic curve analysis (sensitivity, 91.7%; specificity, 81.2%; area under the curve, 0.898). In the validation set, the sensitivity and specificity in diagnosing UGIB for the CT cutoff value of ≥27.7 HU were 84.6% and 77.6%, respectively. In addition to the CT value of ≥27.7 HU, PMCT findings of solid-natured gastrointestinal content and intra/peri-content bubbles ≥4 mm, extracted from the derivation set, increased the specificity for UGIB (96.5% and 98.8%, respectively) but decreased the sensitivity (61.5% and 38.5%, respectively) in the validation set. In diagnosing UGIB on noncontrast PMCT, the cutoff CT value of ≥27.7 HU and solid gastrointestinal content were valid and reproducible diagnostic criteria.

[Infantile meningitis caused by respiratory syncytial virus].

Respiratory syncytial (RS) virus commonly causes infantile respiratory tract infection causing significant morbidity and mortality, but rarely meningitis. We report a case of meningitis caused by RS virus subgroup B in a 56-day-old boy admitted for high fever who underwent blood examination and lumbar puncture. Empirical chemotherapy was started with intravenous ampicillin, gentamicin, and cefotaxime based on laboratory data on CSF cells (84/microL) and serum CRP (13.8mg/dL) data. RS virus subgroup B was only detected using real-time PCR comprehensive reverse transcription from the first CSF, but no bacterial gene was detected. No bacteria grew from his CSF, urine, or blood. Fever and serum CRP dropped in a few days. He had neither seizures nor disturbance of consciousness and was discharged on day 11 after admission. No evidence of encephalopathy was detected in brain MRI or electroencephalography. RS virus rarely causes meningitis, but a percentage of RS-virus-infected infants exhibit symptoms such as seizure and disturbance of consciousness. We should recognize that the RS virus may cause neurological complications associated with high morbidity and mortality.

Pitfalls in chest CT findings of COVID-19 patients infected during hospitalisation.

OBJECTIVE: This study evaluated the differences in the appearance of COVID-19 pneumonia on chest computed tomography (CT) images of outpatient and cases that developed during hospitalisation. METHOD: Chest CT images of 66 patients (median age, 76 years; range, 29-94 years) who underwent the severe acute respiratory syndrome coronavirus-2 reverse-transcription polymerase chain reaction (RT-PCR) test were included in this retrospective study. The chest CT appearance was categorised as "typical," "indeterminate," "atypical," or "negative" in accordance with the recommendations of the Radiological Society of North America for COVID-19 pneumonia and compared among the following four subgroups: PCR-positive outpatient (n = 14); PCR-positive hospitalised (n = 7); PCR-negative outpatient (n = 9); and PCR-negative hospitalised (n = 36). FINDINGS: The frequency of "typical" findings in the PCR-positive outpatient cases (13/14, 92.9%) was significantly higher than that of those in the PCR-positive hospitalised cases (2/7, 28.6%, P = 0.022). There was no significant difference between the frequency of the "typical" appearance in PCR-positive hospitalised cases and that of those in the PCR-negative hospitalised cases (1/36, 2.8%, P = 0.192). CONCLUSIONS: When COVID-19 patients acquire infections while hospitalised, their chest CT images are less likely to show typical findings than those of outpatient cases. Comprehensive and careful assessments of CT findings and consideration of the possibility of concomitant infections with other pathogens and clinical information, such as underlying diseases, background lung structure, and time course of the infection, are required for the management of such cases.

Longitudinal comparison of ascites attenuation between antemortem and postmortem computed tomography.

OBJECTIVE: To investigate the changes in ascites attenuation between antemortem (AMCT) and postmortem computed tomography (PMCT) analyses of the same subjects. METHODS: Thirty-five subjects who underwent unenhanced or enhanced AMCT within 7 days before death, unenhanced PMCT, and autopsy were evaluated. In each subject, ascites attenuation was measured at similar sites on AMCT and PMCT. Attenuation changes were evaluated in 42 unenhanced AMCT/PMCT site pairs (23 subjects) and 20 enhanced AMCT/PMCT site pairs (12 subjects). Factors contributing to CT attenuation changes were also assessed, including the time interval between AMCT and PMCT, serum albumin level, estimated glomerular filtration rate, and ascites volume. RESULTS: Significantly elevated CT attenuation was observed between enhanced AMCT and PMCT (12.2 ± 6.3 vs. 18.7 ± 10.4 Hounsfield units; paired t-test, p = 0.006), but not between unenhanced AMCT and PMCT (13.5 ± 8.9 vs. 13.4 ± 9.3; p = 0.554). A significant inverse association was observed between the degree of CT attenuation change and the time interval between enhanced AMCT and PMCT (Spearman's rank correlation coefficient, r = -0.56, p = 0.01). CONCLUSIONS: We confirmed an elevated level of ascites attenuation on PMCT relative to AMCT in subjects who underwent enhanced AMCT shortly before death.

Pulmonary postmortem computed tomography of bacterial pneumonia and pulmonary edema in patients following non-traumatic in-hospital death.

In this study, we compared the postmortem computed tomography (PMCT) findings among nonpathological lungs, lungs with bacterial pneumonia, and lungs with pulmonary edema in patients following non-traumatic in-hospital death. We studied 104 consecutive adult patients (208 lungs) who died in our tertiary care hospital and underwent PMCT and pathological autopsy (both within 2.5 days after death), and were pathologically diagnosed with nonpathological lungs, bacterial pneumonia, and pulmonary edema. Thirteen pulmonary features were assessed on the CT scans. We also examined the association between the time elapsed since death and the pulmonary findings. We observed increased lung opacities with horizontal plane formation, diffuse opacities, diffuse bronchovascular bundle thickening, symmetric opacities to the contralateral lung, and decreased segmental opacities with time elapsed since death (Cochran-Armitage test for trend). Multiple logistic regression revealed that the presence of opacities without horizontal plane formation or centrilobular opacities, and the absence of diffuse bronchovascular bundle thickening were associated with histopathological pneumonia, whereas the presence of opacities with horizontal plane formation, diffuse opacities, and interlobular septal thickening were associated with histopathological pulmonary edema. In conclusion, specific pulmonary PMCT findings increased with time elapsed since death, and some lung findings may facilitate the diagnosis of bacterial pneumonia and pulmonary edema.

Utility of unenhanced postmortem computed tomography for investigation of in-hospital nontraumatic death in children up to 3 years of age at a single Japanese tertiary care hospital.

To evaluate the utility of unenhanced postmortem computed tomography (PMCT) for the investigation of in-hospital nontraumatic death in children up to 3 years of age.This study included the cadavers of children who died from intrinsic diseases before 3 years of age. The major underlying disease and the main organ-disease systems associated with the immediate causes of death were determined by clinical evaluation, PMCT, and autopsy, which were used as a reference standard. The rates of concordance between the former two methods and autopsy were calculated for all cases.In total, 22 cadavers (12 male and 10 female; mean age, 6.1 ±â€Š8.2 months) were included. The rates of concordance between clinical evaluation/PMCT and autopsy for diagnosis of the major underlying disease and main organ-disease systems associated with the immediate causes of death were 100%/36% (P = .0015) and 59%/41% (P = .37), respectively. In cases where the respiratory system was associated with the immediate cause of death, PMCT showed greater diagnostic sensitivity (90%) than did clinical evaluation (20%). In contrast, the diagnostic sensitivity of PMCT was lower than that of clinical evaluation in cases involving disorders of the cardiac system and multiple organ systems (0% vs 100% for both).The findings of this study suggest that the use of unenhanced PMCT with clinical evaluation can result in improved detection of the immediate cause of death in select cases of in-hospital nontraumatic death before 3 years of age.

Intrahepatic Carcinosarcoma With Cholangiocarcinoma Elements and Prominent Bile Duct Spread.

Carcinosarcomas with elements of cholangiocarcinoma and sarcoma are rare and have a poor prognosis. The spreading pattern and radiological findings of these lesions remain unclear. A 74-year-old man presented with a high γ-glutamyl transferase level. Magnetic resonance imaging revealed dilation of the right intrahepatic and common bile ducts, consistent with an intraductal papillary neoplasm of the bile duct (IPNB), and diffusion-weighted imaging (DWI) indicated an area of high signal intensity in the intrahepatic bile duct. Bile duct biopsy yielded a small amount of atypical spindle cells, and the patient underwent a right hepatectomy. Microscopically, the tumor contained cholangiocarcinoma and sarcomatous components, including osteosarcoma and leiomyosarcoma, leading to a diagnosis of intrahepatic carcinosarcoma. The tumor spread primarily through the intrahepatic bile duct. An accurate radiological diagnosis of carcinosarcoma was challenging, given the apparent similarities with IPNB. The findings from DWI and pathology of a bile duct biopsy may assist with preoperative diagnosis.

Comparison of the cardiothoracic ratio between postmortem and antemortem computed tomography.

As postmortem imaging has gained prominence as a supplement to traditional autopsy, it is important to understand the normal postmortem changes to enable the accurate evaluation of postmortem imaging. No studies have evaluated the postmortem changes in cardiothoracic ratio (CTR) compared with antemortem images in the same subjects. We studied 147 consecutive subjects who underwent antemortem and postmortem CT, and autopsy. Postmortem CT was performed <23h after death and was followed by autopsy. The subjects were divided into three groups: normal heart, old myocardial infarction, and CPR-treated hearts. CTR was compared between antemortem and postmortem CT using paired t tests, which revealed that the CTR was greater on postmortem CT than on antemortem CT in all groups (mean CTR: 0.53±0.06vs. 0.50±0.06, respectively; P<0.01). Sex, age, time elapsed since death, and the causes of death were examined as potential confounding factors for the postmortem changes in CTR, but no significant associations were found. Receiver-operating characteristic (ROC) curves were used to determine CTR values for cardiomegaly, which was defined according to the autopsy weight of the heart. The area under the ROC curve was 0.71 (95% confidence interval 0.63-0.79). The CTR threshold of 0.54 identified cardiomegaly with the greatest accuracy, compared with the general threshold of 0.50. In conclusion, the CT-determined CTR increases after death, irrespective of the heart's condition. We should be cautious of overdiagnosis of cardiomegaly on postmortem CT, and new criteria for interpreting cardiomegaly on postmortem CTR are needed.

Brain Swelling and Loss of Gray and White Matter Differentiation in Human Postmortem Cases by Computed Tomography.

The purpose of this study was to evaluate the brain by postmortem computed tomography (PMCT) versus antemortem computed tomography (AMCT) using brains from the same patients. We studied 36 nontraumatic subjects who underwent AMCT, PMCT, and pathological autopsy in our hospital between April 2009 and December 2013. PMCT was performed within 20 h after death, followed by pathological autopsy including the brain. Autopsy confirmed the absence of intracranial disorders that might be related to the cause of death or might affect measurements in our study. Width of the third ventricle, width of the central sulcus, and attenuation in gray matter (GM) and white matter (WM) from the same area of the basal ganglia, centrum semiovale, and high convexity were statistically compared between AMCT and PMCT. Both the width of the third ventricle and the central sulcus were significantly shorter in PMCT than in AMCT (P < 0.0001). GM attenuation increased after death at the level of the centrum semiovale and high convexity, but the differences were not statistically significant considering the differences in attenuation among the different computed tomography scanners. WM attenuation significantly increased after death at all levels (P<0.0001). The differences were larger than the differences in scanners. GM/WM ratio of attenuation was significantly lower by PMCT than by AMCT at all levels (P<0.0001). PMCT showed an increase in WM attenuation, loss of GM-WM differentiation, and brain swelling, evidenced by a decrease in the size of ventricles and sulci.

Common Postmortem Computed Tomography Findings Following Atraumatic Death: Differentiation between Normal Postmortem Changes and Pathologic Lesions.

Computed tomography (CT) is widely used in postmortem investigations as an adjunct to the traditional autopsy in forensic medicine. To date, several studies have described postmortem CT findings as being caused by normal postmortem changes. However, on interpretation, postmortem CT findings that are seemingly due to normal postmortem changes initially, may not have been mere postmortem artifacts. In this pictorial essay, we describe the common postmortem CT findings in cases of atraumatic in-hospital death and describe the diagnostic pitfalls of normal postmortem changes that can mimic real pathologic lesions.

Comparison of attenuation of striated muscle between postmortem and antemortem computed tomography: results of a longitudinal study.

OBJECTIVE: We evaluated the postmortem changes of striated muscle by comparing computed tomography (CT) images obtained postmortem and antemortem in the same patients. MATERIALS AND METHODS: We studied 33 consecutive patients who underwent antemortem CT, postmortem CT, and pathological autopsy in our tertiary care hospital between April 2009 and December 2010. Postmortem CT was performed within 20 h after death and was followed by pathological autopsy. Pathological autopsy confirmed the absence of muscular diseases such as amyotrophic lateral sclerosis, muscular dystrophy, myositis, and myasthenia, in all of the patients. The CT attenuation values of four cardiac muscle sites (anterior wall of the left ventricle, left ventricular free wall, posterior wall of the left ventricle, and the ventricular septum) and two skeletal muscle sites (the pectoralis major muscle and the erector spinae muscle) were compared between antemortem and postmortem CT using paired t test. RESULTS: Striated muscle had significantly greater attenuation on postmortem CT than on antemortem CT (P<0.001) in all six tissue sites. No significant association was found between postmortem change in the CT attenuation of striated muscle and gender, age, or elapsed time since death. CONCLUSION: This is the first longitudinal study to show hyperattenuation of striated muscle on postmortem CT images compared with antemortem CT images in the same patients.