Enlarged mediastinal air cyst in a patient with bronchial diverticula localized in the left main bronchus: a case report with surgical and bronchoscopic findings.

BACKGROUND: A mediastinal air cyst is a rare computed tomography (CT) finding. Once the lesion is identified, it is difficult to diagnose and treat. Meanwhile, bronchial diverticula have been reported as a CT finding observed in certain pulmonary pathologic conditions. We encountered the case of an enlarged mediastinal air cyst accompanied with bronchial diverticula and upper lobe-dominant fibrous changes of the lung. CASE PRESENTATION: A 69-year-old man with a chronic cough who had regularly visited a chest physician for upper lobe-dominant pulmonary fibrosis was referred to our hospital for the examination of an enlarged mediastinal air cyst. Chest CT exhibited an air cyst (size, 30 mm) connected to the lumen of the left main bronchus (LMB) and multiple tiny outpouches only on the LMB. Flexible bronchoscopy showed bubbling from slits or indentations of the bronchial mucosa only in the LMB but not in the right main bronchus or lobar bronchus. For therapeutic diagnosis, we removed the air cyst. Based on clinical, surgical, and pathological findings, we diagnosed the air cyst as an enlarged bronchial diverticulum. CONCLUSIONS: This is the first case wherein bronchoscopic and surgical findings of bronchial diverticula and an enlarged bronchial diverticulum are reported. There are possible pathogenic mechanisms in cases of pulmonary disease that are attributable to enlargement of the bronchial diverticula.

Hepatic Relaxation Times from Postmortem MR Imaging of Adult Humans.

PURPOSE: To measure T1 and T2 values of hepatic postmortem magnetic resonance (PMMR) imaging. MATERIALS AND METHODS: We performed hepatic PMMR imaging of 22 deceased adults (16 men, 6 women; mean age, 56.3 years) whose deaths were for reasons other than liver injury or disease at a mean of 27.7 hours after death. Before imaging, the bodies were kept in cold storage at 4°C (mean rectal temperature, 17.6°C). We measured T1 and T2 values in the liver at two sites (the anterior segment of the right lobe and the lateral segment of the left lobe). We also investigated the influence of the body temperature and postmortem interval on T1 and T2 values. RESULTS: In the anterior segment of the right lobe and the lateral segment of the left lobe, T1 values of PMMR imaging were 524 ± 112 ms and 472 ± 104 ms (mean ± standard deviation), respectively; while T2 values were 42 ± 6 ms and 43 ± 8 ms, respectively. T1 and T2 values did not differ significantly between the two sites (P ≧ 0.05). Regarding temperature, the T2 values of hepatic PMMR imaging were linearly correlated with the body temperature, but the T1 values were not. The T1 and T2 values of the two sites in the liver did not correlate with the postmortem interval. CONCLUSION: Reduction in body temperature after death is considered to induce T1 and T2 value changes in the liver on PMMR imaging.

Possibility of visualization of gastrothorax based on unenhanced postmortem computed tomography/PMCT.

We present a fatal case of a gastrothorax due to an acute gastric volvulus resulting from a Bochdalek hernia. A 5-year-old boy without previous medical history was brought to our institution in a state of cardiopulmonary arrest and was subsequently pronounced dead. Postmortem computed tomography (PMCT) of the torso showed abdominal organs involving the lower section of the esophagus up to the entire stomach, the left side of the transverse colon, the entire spleen, and the tail of the pancreas herniated into the left thoracic cavity. The stomach was markedly expanded and a mesentero-axial (rotation along the short axis) volvulus was observed, displacing mediastinal structures to the right side and depressing the diaphragmatic contour. A PMCT of the thorax at the lung window setting revealed displacement of bilateral lungs. The bilateral lungs were severely atelectatic and congested. The PMCT findings mentioned above were consistent with the autopsy findings. PMCT can provide useful information for the diagnosis in cases we initially cannot predict any significant changes, for example, organ displacement.

Clinical evaluation of the need for carbapenems to treat community-acquired and healthcare-associated pneumonia.

Carbapenems have an overall broad antibacterial spectrum and should be protected against from the acquisition of drug resistance. The clinical advantages of carbapenem in cases of pneumonia have not been certified and the need for antipseudomonal antimicrobial agents to treat healthcare-associated pneumonia (HCAP) remains controversial. We introduced an antimicrobial stewardship program for carbapenem and tazobactam/piperacillin use and investigated the effects of this program on the clinical outcomes of 591 pneumonia cases that did not require intensive care unit management, mechanical ventilation or treatment with vasopressor agents [221 patients with community-acquired pneumonia (CAP) and 370 patients with HCAP]. Compared with the pre-intervention period, age, comorbidities and the severity and etiology of pneumonia did not differ during the intervention period. Carbapenems were rarely used during the intervention period in cases of pneumonia (CAP: 12% vs. 1%, HCAP: 13% vs. 1%), while antipseudomonal beta-lactam use was reduced from 33% to 8% among cases with HCAP. This reduction in the rate of carbapenem administration did not have an impact on the prognosis in the cases of CAP, and the in-hospital mortality was lower among the patients with HCAP during the intervention period (15% vs. 5%, p = 0.013). The causes of death in the cases of HCAP were not directly related to pneumonia during the intervention period. The current study shows that carbapenem use can be avoided in cases of CAP or HCAP that are not in a critical condition. The frequent use of antipseudomonal beta-lactams does not improve the clinical outcomes of HCAP.

Optimization of Inversion Time for Postmortem Fluid-attenuated Inversion Recovery (FLAIR) MR Imaging at 1.5T: Temperature-based Suppression of Cerebrospinal Fluid.

PURPOSE: Signal intensity (SI) and image contrast on postmortem magnetic resonance (MR) imaging are different from those of imaging of living bodies. We sought to suppress the SI of cerebrospinal fluid (CSF) sufficiently for fluid-attenuated inversion recovery (FLAIR) sequence in postmortem MR (PMMR) imaging by optimizing inversion time (TI). MATERIALS AND METHODS: We subject 28 deceased patients to PMMR imaging 3 to 113 hours after confirmation of death (mean, 27.4 hrs.). PMMR imaging was performed at 1.5 tesla, and T1 values of CSF were measured with maps of relaxation time. Rectal temperatures (RT) measured immediately after PMMR imaging ranged from 6 to 32°C (mean, 15.4°C). We analyzed the relationship between T1 and RT statistically using Pearson's correlation coefficient. We obtained FLAIR images from one cadaver using both a TI routinely used for living bodies and an optimized TI calculated from the RT. RESULTS: T1 values of CSF ranged from 2159 to 4063 ms (mean 2962.4), and there was a significantly positive correlation between T1 and RT (r = 0.96, P < 0.0001). The regression expression for the relationship was T1 = 74.4 * RT + 1813 for a magnetic field strength of 1.5T. The SI of CSF was effectively suppressed with the optimized TI (0.693 * T1), namely, TI = 0.693 * (77.4 * RT + 1813). CONCLUSION: Use of the TI calculated from the linear regression of the T1 and RT optimizes the FLAIR sequence of PMMR imaging.

Dialister pneumosintes bacteremia caused by dental caries and sinusitis.

A 62-year-old Japanese woman was hospitalized at the Department of Senology for positive signals on two sets of blood cultures obtained in the Emergency Department. The initial physical examination with enhanced computed tomography of the chest and abdomen did not identify the infectious source. Dialister pneumosintes was identified on 16S rRNA sequencing, and dental caries with sinusitis were subsequently diagnosed based on a dental examination and magnetic resonance imaging. History taking with respect to dental hygiene and oral examinations should be performed in daily clinical practice, especially in immunosuppressed patients.

Can ruptured abdominal aortic aneurysm be accurately diagnosed as the cause of death without postmortem computed tomography when autopsies cannot be performed?

PURPOSE: This study aimed to conduct a multicentre retrospective review of cases to clarify how many ruptured abdominal aortic aneurysms (RAAAs) as the cause of death could be diagnosed without post-mortem computed tomography (PMCT) when autopsies cannot be performed. METHODS: We collected consecutive PMCT data from January 2002 to December 2009 from three institutes where PMCT examinations are performed on a routine basis for deceased patients with unknown causes of death. A total of 19 cases were identified where PMCT revealed RAAAs. Ante-mortem clinical presentations, post-mortem external examinations, and peri-mortem ultrasonography findings were assessed for their diagnostic accuracy. RESULTS: The correct diagnosis based on the classic triad of shock, acute abdominal pain, and pulsatile abdominal mass was made in only one of 19 (5.3%) patients. Shock, acute abdominal pain, and abdominal swelling were found in five of 19 (26%) patients. Shock and acute abdominal pain or abdominal swelling were found in two of 19 (10%) patients. Ten of 19 (53%) patients only had shock. Peri-mortem ultrasonography was performed in seven of 19 patients; one was diagnosed with RAAA (14%). No patients had pre-mortem CT examinations. CONCLUSIONS: Post-mortem diagnosis of RAAA is difficult to make based on ante-mortem clinical presentation, post-mortem external examinations, or peri-mortem ultrasonography. PMCT is recommended for diagnosing RAAA as the cause of death if pre-mortem CT examinations are not carried out when autopsies cannot be performed.

Pericardial tear as a consequence of cardiopulmonary resuscitation (CPR) involving chest compression: a report of two postmortem cases of acute type A aortic dissection with hemopericardium.

We present two cases of a pericardial tear as a consequence of cardiopulmonary resuscitation involving chest compressions in fatal acute type A aortic dissection (AoD) with hemopericardium. For each case, postmortem computed tomography revealed a hematoma in the false lumen of the ascending aorta with a slight hemopericardium and a large left hemothorax, as well as focal pericardial dimpling and discontinuity around the left ventricle. At autopsy, we confirmed a convex lens-shape gaping pericardial tear at the left posterolateral site of the pericardium and a massive volume of bloody fluid in the left thoracic cavity. It has been hypothesized that the pericardium ruptured due to chest compressions during resuscitation in these cases of acute type A AoD with hemopericardium and that intrapericardial blood leakage through the pericardial tear resulted in a hemothorax.

Pseudo-Hirschsprung's disease with rectal hypoganglionosis: an autopsied case of circulatory failure due to severe constipation.

We report a 21-year-old female patient who suddenly died of circulatory failure due to pressure from megacolon allied with pseudo-Hirschsprung's disease. Since 3 years before her death, she had exhibited the feeling of abdominal distention, which was diagnosed as constipation. However, her constipation did not respond well to the prescribed oral administration of laxatives and enemas. She was found dead at home in the morning, lying on her back. An autopsy revealed a decreased number of ganglion cells in the rectum, suggesting hypoganglionosis. In cases of intractable chronic constipation, careful investigation of the cause of such symptoms is important.

Cerebral relaxation times from postmortem MR imaging of adults.

PURPOSE: We measured T1 and T2 values of cerebral postmortem magnetic resonance (PMMR) imaging and compared the data of cadavers with that of living human subjects. MATERIALS AND METHODS: We performed PMMR imaging of the brains of 30 adults (22 men, 8 women; mean age, 58.2 years) whose deaths were for reasons other than brain injury or disease at a mean of 29.4 hours after death. Before imaging, the bodies were kept in cold storage at 4°C (mean rectal temperature, 15.6°C). We measured T1 and T2 values in the brain bilaterally at 5 sites (bilateral caudate nucleus, putamen, thalamus and gray matter and white matter of the frontal lobe) and compared the data of PMMR imaging with that from MR imaging of the corresponding sites in 24 healthy volunteers (9 men, 15 women; mean age, 51.8 years). We also investigated the influence of body temperature on T1 and T2 values. RESULTS: Compared with MR imaging findings in the living subjects, PMMR imaging showed significantly shorter T1 values in the caudate nucleus, putamen, thalamus and gray matter and white matter of the frontal lobe and significantly longer T2 values in the gray matter and white matter of the frontal lobe; T2 values in the caudate nucleus, putamen, and thalamus showed no such differences. T1 values correlated significantly with body temperature in all 5 brain sites measured, but T2 values did not. CONCLUSION: Compared with findings of cerebral MR imaging in living adult subjects, those of PMMR imaging tended to demonstrate shorter T1 values and longer T2 values. We attribute this to increased water content of tissue, reduced pH, and reduced body temperature after death.

High-resolution 3D-MRI of postmortem brain specimens fixed by formalin and gadoteridol.

PURPOSE: The purpose of this investigation was to compare magnetization-prepared rapid gradient echo (MP-RAGE) images with T1-weighted images (T1WI) and T2-weighted images (T1W2) of postmortem brain tissue fixed by admixtures of formalin and gadoteridol. We additionally sought to explore the feasibility of using fixed brain magnetic resonance imaging (MRIs) in forensic practices. METHODS: Specimens included in the study were eight whole brains that had been removed during forensic autopsy. Brain specimens were randomly divided into three groups and MRIs were performed either (A) the day of autopsy (n=2) on unfixed tissue, (B) after immersion fixation in 20% formalin (n=3), or (C) after immersion fixation in 20% formalin mixed with 4 mL/L ProHance® (gadoteridol) (n=3). T1WI, T2WI, and MP-RAGE images of all group samples were acquired with a 3T clinical MR scanner. Gray and white matter contrasts of the cortex and basal nucleus in every fixation group and image sequence were then visually compared. RESULTS: Gray/white matter contrasts of the cortex were good in all images obtained by MP-RAGE, and T1WIs of specimens fixed by formalin and gadoteridol-mixed formalin. Additionally, gray/white matter contrast in the basal nucleus was sufficient in the MP-RAGE sequence of specimens fixed by gadoteridol-mixed formalin. CONCLUSIONS: MRI of brains immersion-fixed in formalin and gadolinium could serve as a promising tool for neuropathological assessment in forensic practices.

Optimization of inversion time for postmortem short-tau inversion recovery (STIR) MR imaging.

PURPOSE: Signal intensity and image contrast differ between postmortem magnetic resonance (PMMR) images and images acquired from the living body. We sought to achieve sufficient fat suppression with short-tau inversion recovery (STIR) PMMR imaging by optimizing inversion time (TI). MATERIAL AND METHODS: We subjected 37 deceased adult patients to PMMR imaging at 1.5 tesla 8 to 60 hours after confirmation of death and measured T1 values of areas of subcutaneous fat with relaxation time maps. Rectal temperature (RT) measured immediately after PMMR ranged from 6 to 31°C. We used Pearson's correlation coefficient to analyze the relationship between T1 and relaxation time (RT). We compared STIR images from 4 cadavers acquired with a TI commonly used in the living body and another TI calculated from the linear regression of T1 and RT. RESULTS: T1 values of subcutaneous fat ranged from 89.4 to 182.2 ms. There was a strong, positive, and significant correlation between T1 and RT (r = 0.91, P < 0.0001). The regression expression for the relationship was T1 = 2.6*RT + 90 at a field strength of 1.5T. The subcutaneous fat signal was suppressed more effectively with the optimized TI. CONCLUSION: The T1 value of subcutaneous fat in PMMR correlates linearly with body temperature. Using this correlation to determine TI, fat suppression with PMMR STIR imaging can be easily improved.

Thrombus formation in the pulmonary vein stump after left upper lobectomy: a report of four cases.

Left upper lobectomy may be followed by complications such as thrombus formation in a stump of the left superior pulmonary vein (LSPV), which may cause systemic embolization. We have encountered four such cases, which account for 3.4% of all left upper lobectomies performed at our institution. Right renal infarction was observed in one of these four cases; the remaining cases were asymptomatic, with the thrombus incidentally detected by enhanced computed tomography (CT). The postoperative duration for the detection of the thrombus varied from 4 days to 24 months. Even in a case in which the superior pulmonary vein (PV) was divided by posterolateral thoracotomy, CT showed that the stump was long enough intrapericardially for thrombus formation. Anticoagulant therapy was administered in all the cases, resulting in dissipation of the thrombus. Therefore, when a thrombus is detected in a pulmonary stump, an anticoagulant should be administered.

Feasibility of resuscitation contrast-enhanced postmortem computed tomography using cardiopulmonary resuscitation technique with chest compression immediately after death.

PURPOSE: Our purpose was to evaluate image delineation ability of contrast-enhanced post-mortem computed tomography (CEPMCT) using cardiopulmonary resuscitation technique of chest compression, named "resuscitation CEPMCT". MATERIALS AND METHODS: Non-traumatically-deceased 15 subjects (7 men; 8 women) aged 19-87 years (mean 61 years) underwent resuscitation CEPMCT. The contrast-enhanced technique, while injecting 100 ml of contrast media from the right cubital vein at a rate of 1 ml/s, chest compression was performed for 2 minutes at a rate of 100 times/min (a total of 200 times). CT attenuation values (Hounsfield Unit: HU) were measured in 8 target vessels: 1) pulmonary artery, 2) coronary artery, 3) ascending aorta, 4) abdominal aorta, 5) celiac trunk, 6) common iliac artery, 7) superior vena cava, and 8) inferior vena cava. One-sided Student's t-test was performed to assess whether measured values were higher than 140 HU by setting p-value at 0.05. RESULTS: Measured CT values in the 8 vessels were 1) pulmonary artery: 325 ± 140 HU, 2) coronary artery: 240 ± 73 HU, 3) ascending aorta: 321 ± 127 HU, 4) abdominal aorta: 286 ± 96 HU, 5) celiac trunk: 233 ± 62 HU, 6) common iliac artery: 260 ± 114 HU, 7) superior vena cava: 422 ± 187 HU, and 8) inferior vena cava: 301 ± 142 HU, showing significantly higher values than the threshold value of 140 HU. Resuscitation CEPMCT detected one case of pulmonary arterial thromboemboli death. CONCLUSION: Resuscitation CEPMCT using chest compression immediately after death has the possibility of detecting thromboembolus in major vessels, despite the simplicity of the technique.

[Spontaneous tension hemothorax due to rupture of a solitary fibrous tumor of the posterior mediastinum].

A 37-year-old man was transported by ambulance to our hospital due to abrupt chest pain. The pain began when he was practicing a combative-type sport. He denied any impact or blunt trauma. A chest radiograph revealed massive left pleural effusion with a mediastinal shift. Thoracentesis revealed a hemothorax;therefore, we performed an emergency thoracotomy. The intraoperative findings revealed a rupture of a posterior mediastinal tumor itself located between the descending aorta and the thoracic vertebra. After we identified the artery of Adamkiewicz that originates away from the tumor and evaluated the degree of tumor extension into the inter-vertebral foramen, we safely performed an elective tumor resection 1 month after the initial emergency operation. In patients with a hemothorax caused by rupture of the tumor itself, an elective tumor resection after detailed investigation should be considered if hemostasis can be achieved in the emergency thoracotomy.

Immediate non-traumatic postmortem computed tomographic demonstration of myocardial intravascular gas of the left ventricle: effects from cardiopulmonary resuscitation.

An 87-year-old man was found in a state of cardiopulmonary arrest. Despite cardiopulmonary resuscitation (CPR) for over 1 hour by emergency technicians and physicians, the patient died. Immediate postmortem computed tomography showed cardiovascular gas in the right atrium, right ventricle, and left ventricle. Cardiovascular gas in the left ventricle was located in the myocardium and appeared as linear or branch-shaped suggesting the presence of myocardial intravascular gas. This is the first report describing the appearance and significance of myocardial intravascular gas of the left ventricle as a CPR-related change.

Background and current status of postmortem imaging in Japan: short history of "Autopsy imaging (Ai)".

There is a low autopsy rate and wide distribution of computed tomography (CT) and magnetic resonance imaging (MRI) scanners in Japan. Therefore, many Japanese hospitals, including 36% of the hospitals with in-patient facilities and 89% of large hospitals with ER facilities conduct postmortem imaging (PMI), use clinical scanners to screen for causes in unusual deaths as an alternative to an autopsy or to determine whether an autopsy is needed. The Japanese PMI examination procedure is generally referred to as "autopsy imaging" (Ai) and the term "Ai" is now commonly used by the Japanese government. Currently, 26 of 47 Japanese prefectures have at least one Ai Center with scanners that are dedicated for PMI. Here, we briefly review the history of Japanese PMI (Ai) from 1985 to the present.

Sudden death as a late sequel of Kawasaki disease: postmortem CT demonstration of coronary artery aneurysm.

Kawasaki disease (KD) is an acute, self-limited vasculitis of unknown etiology that primarily affects the coronary artery (CA) and presents during childhood. The characteristic coronary arterial lesion of KD is an aneurysm. Ischemic heart disease derived from a CA aneurysm is experienced approximately two decades after the onset of acute KD. In recent years, the primary issue of concern has been asymptomatic adults with a CA aneurysm caused by undiagnosed KD. We present a case of sudden death as a late KD sequel in a young adult. A postmortem CT scan revealed a coarse calcification of a left anterior descending CA aneurysm, which was confirmed at the time of autopsy. A postmortem CT scan is useful in cases of sudden death where the detection of a calcified CA aneurysm would suggest to the forensic pathologist that the deceased suffered from a late sequel of KD. The use of screening postmortem CT scans for young people may detect cases of unsuspected CA aneurysms, raising the possibility of untreated KD.