Burned bodies: post-mortem computed tomography, an essential tool for modern forensic medicine.

Currently, post-mortem computed tomography (PMCT) has become an accessible and contemporary tool for forensic investigations. In the case of burn victims, it provides specific semiologies requiring a prudent understanding to differentiate between the normal post-mortem changes from heat-related changes. The aim of this pictorial essay is to provide to the radiologist the keys to establish complete and focused reports in cases of PMCT of burn victims. Thus, the radiologist must discern all the contextual divergences with the forensic history, and must be able to report all the relevant elements to answer to the forensic pathologist the following questions: Are there tomographic features that could help to identify the victim? Is there evidence of remains of biological fluids in liquid form available for toxicological analysis and DNA sampling? Is there another obvious cause of death than heat-related lesions, especially metallic foreign bodies of ballistic origin? Finally, what are the characteristic burn-related injuries seen on the corpse that should be sought during the autopsy? TEACHING POINTS: • CT is highly useful to find features permitting the identification of a severely burned body. • PMCT is a major asset in gunshot injuries to depict ballistic foreign bodies in the burned cadavers. • CT is able to recognise accessible blood for tests versus heat clot (air-crescent sign). • Heat-related fractures are easily differentiated from traumatic fractures. • Epidural collections with a subdural appearance are typical heat-related head lesions.

Failure of Conservative Treatment of Acute Diverticulitis with Extradigestive Air.

BACKGROUND: Medical management for perforated diverticulitis without abscess or peritonitis (PDwAP) has a success rate of 40-70%. Identifying patients with a risk of medical treatment failure would improve outcomes. The aim of this study was to identify the risk factors for failure of medical treatment in patients admitted with PDwAP. METHODS: This multicenter retrospective observational study included all consecutive patients admitted for PDwAP and not surgically treated over a 7-year period. Peritonitis classified on the Hinchey scale was excluded. Potential clinical, biological and radiological risk factors for medical treatment failure were collected and compared between the group of patient with a failure of medical treatment (F) and the group in which treatment did not fail. Data were collected at referral. RESULTS: Ninety-one patients were included, and 29 had a failure of treatment (31.9%). The median heart rate was different between the two groups (p < 0.001), at approximately 100/min in the F group. A blood level of C-reactive protein (CRP) ≥150 mg/mL was associated with a higher rate of failure (p = 0.021), but it was not confirmed in multivariate analysis. Pneumoperitoneum ≥5 mm and intraperitoneal liquid located in the pouch of Douglas were more likely to be present in the F group (respectively, p = 0.001 and p < 0.001). A multivariate analysis showed independent risk factors as being the highest pneumoperitoneum diameter >5 mm (OR 5.193; p = 0.015) and peritoneal fluid location in the pouch of Douglas (OR 4.103; p = 0.036). CONCLUSION: The severity of sepsis (tachycardia and CRP ≥150 mg/mL) and of imaging signs (pneumoperitoneum ≥5 mm and peritoneal fluid in the pouch of Douglas) were risk factors for medical treatment failure of PDwAP requiring special supervision so as not to lose time in undertaking surgical management.

CT findings of complications after abdominal wall repair with prosthetic mesh.

Postoperative complications following prosthetic mesh repair are relatively rare and depend on the type and location of prosthetic mesh. They include abscess, hematoma, seroma, fistula, bowel obstruction, mesh retraction, granuloma and recurrent hernia. Computed tomography (CT) is the imaging examination of choice for the diagnosis of such complications. This pictorial review illustrates the CT presentation of the most and less common postoperative complications following prosthetic mesh repair of the abdominal wall.

Evaluation of unenhanced post-mortem computed tomography to detect chest injuries in violent death.

PURPOSE: The aim of this study was to assess the performances of unenhanced post-mortem computed tomography (CT) to detect thoracic injuries in violent death. MATERIALS AND METHODS: Retrospectively, we conducted a review of unenhanced CT scans of 67 victims of violent deaths with thoracic injuries and compared CT findings with the results of clinical autopsy. Our gold standard was a comparison of CT scans with autopsy discussed in a monthly forensic radiology multidisciplinary team meeting (MDTM). The data were collected by organ system: heart, pericardium, aorta, lungs, pleura, bone, and diaphragm and performance indices (sensitivity, specificity, accuracy) were calculated. RESULTS: Pleural (59/67) and bone (55/67) injuries detected on CT were also found at autopsy and confirmed by the MDTM (sensitivity and specificity 100%). Seventeen out of 67 diaphragmatic lesions were visible on CT. Eighteen out of 67 were confirmed during MDTM after autopsy, yielding overall sensitivity of 94% and specificity of 98%. Forty out of 67 lung contusions were found on CT with two false positives and one false negative yielding 95% sensitivity for CT with a specificity of 96%, and accuracy of 95%. Fourteen out of 67 aortic injuries were found on CT compared to 19 confirmed during MDTM (sensitivity 74%, specificity 85%, accuracy 82%). In terms of pericardial lesions, 19/67 were found on CT and 20 on autopsy and confirmed during MDTM (sensitivity 80%, specificity 94%, accuracy 85%). Ten out of 10/67 cardiac lesions were visible on CT imaging and 15 found on autopsy and confirmed during MDTM (sensitivity 57%, specificity 94%, accuracy 81%). CONCLUSION: Unenhanced post-mortem CT performs well to detect pleural, pulmonary, bone and diaphragmatic injuries but less well to identify cardiac and aortic injuries, for which the use of indirect signs is essential.

Simultaneous CT angiography and whole-body CT is an effective imaging approach before multiorgan retrieval.

PURPOSE: To assess the role of whole-body computed tomography (CT) for determining morphological suitability before multiorgan retrieval (MOR) in brain dead patients. MATERIALS AND METHODS: Fifty-one clinically brain dead patients (21 women, 30 men; mean age 61 year±15) were included in this prospective, single center study. All patients had CT angiography of the brain and whole-body CT examination. CT images were evaluated for the presence of morphological abnormalities of lungs, liver and other abdominal organs and presence of vascular anatomical variants. The results of CT examinations were compared to intraoperative findings observed during organ harvesting and/or the results of histopathological analysis of biopsy specimens. The impact of whole-body CT examination on the harvesting process was evaluated. RESULTS: Ninety-five percent of vascular anatomical variants that were found intraoperatively were depicted on CT. CT density measurements predicted surgical finding of steatosis in 80% of patients. Whole-body CT changed the MOR strategy in 21/51 patients (41%) including 3 MOR cancellations and 8 grafts refusals, whereas organ harvesting was continued in 10 patients after histopathological analysis was performed. CONCLUSION: Selection of potential graft donors using whole-body CT is reliable and improves graft selection during MOR.

Sigmoid stricture associated with diverticular disease should be an indication for elective surgery with lymph node clearance.

BACKGROUND: The literature concerning stricture secondary to diverticulitis is poor. Stricture in this setting should be an indication for surgery because (a) of the potential risk of cancer and (b) morbidity is not increased compared to other indications for colectomy. The goal of this report is to study the post-surgical morbidity and the quality of life in patients after sigmoidectomy for sigmoid stricture associated with diverticular disease. METHOD: This is a monocenter retrospective observational study including patients with a preoperative diagnosis of sigmoid stricture associated with diverticular disease undergoing operation between Jan 1, 2007 and Dec 31, 2013. The GastroIntestinal Quality of Life Index was used to assess patient satisfaction. RESULTS: Sixteen patients were included of which nine were female. Median age was 69.5 (46-84) and the median body mass index was 23.55kg/m(2) (17.2-28.4). Elective sigmoidectomy was performed in all 16 patients. Overall, complications occurred in five patients (31.2%) (4 minor complications and 1 major complication according to the Dindo and Clavien Classification); none resulted in death. Pathology identified two adenocarcinomas (12.5%). The mean GastroIntestinal Quality of Life Index was 122 (67-144) and 10/11 patients were satisfied with their surgical intervention. CONCLUSION: Sigmoid stricture prevents endoscopic exploration of the entire colon and thus it may prove difficult to rule out a malignancy. Surgery does not impair the quality of life since morbidity is similar to other indications for sigmoidectomy. For these reasons, we recommend that stricture associated with diverticular disease should be an indication for sigmoidectomy including lymph node clearance.

Water-enema multidetector computed tomography for planning surgery.

PURPOSE: Water-enema multidetector computed tomography (WE-MDCT) is a technique for the localization and preoperative T- and N-stage assessments of colon cancer. It may be a useful tool for planning surgery. The primary aim of this study was to evaluate the diagnostic accuracy of WE-MDCT for T-staging and its ability to locate tumors for laparoscopy planning. The secondary aim was to assess reading reproducibility and diagnostic accuracy for the preoperative determination of N-stage. METHODS: We performed a study to evaluate preoperative WE-MDCT for surgical planning in patients with symptomatic colon adenocarcinomas who underwent surgery between June 2010 and January 2014. A radiologist and a surgeon read the WE-MDCTs separately. Results were compared with colonoscopy and the surgical specimen. RESULTS: Seventy-one patients (42 men (59.1%); mean age 73.1 years (range 45 to 95)) were included. Seventy-six tumors were assessed. The intraclass correlation coefficient (ICC) for location as determined by surgery and that determined by WE-MDCT was 1, and the ICC for location between colonoscopy and WE-MDCT was 0.85 (95% CI 0.75-0.91). For T-stage determination, sensitivity was 96 and 94% and specificity 83 and 88% for readers 1 and 2, respectively. The T-stage assessment allowed for the programing of surgical access and showed good sensitivity and specificity for the assessment of invasion in adjacent organs. CONCLUSION: WE-MDCT is relatively easy to perform, and its results can be read effectively by radiologists and surgeons. WE-MDCT indicated the location of tumors perfectly and permitted a good determination of their T-stage. The technique is thus pertinent for the planning of laparoscopic surgery for colon cancer.

Imaging in colonic cancer.

Whilst the diagnosis of colonic cancer is always based on visually guided flexible colonoscopy, which is the only technique that provides a histological diagnosis, the pre-treatment assessment of the cancer involves computed tomography. This can determine the exact site of the cancer in the colon, its dimensions and juxta-colonic extension and is used to investigate for liver, mesenteric or lung metastases.

Tomodensitometric survey of the distance between thoracic and abdominal vital organs and the wall according to BMI, abdominal diameter and gender: proposition of an indicative chart for the forensic activities.

INTRODUCTION: Forensic doctors are frequently asked by magistrates when dealing principally with knife wounds, about the depth of the blade which may have penetrated the victim's body. Without the use of imaging, it is often difficult to respond to this question, even in an approximate way. Knowledge of the various distances between organs and the skin wall would allow an assessment to be made of the minimum blade length required to obtain the injuries observed. The objective of this study is thus to determine average distances between the vital organs of the thorax and abdomen, and the skin wall, taking into account the person's body mass index (BMI). MATERIALS AND METHODS: This is a prospective single-center study, carried out over a 2-month period at University Hospital in Angers. A sample of 200 people was studied. The inclusion criteria were as follows: all patients coming to the radiology department and the emergency department for an abdominal, thoracic or thoraco-abdominal scan with injection. The exclusion criteria included patients presenting a large lymphoma, a large abdominal or retroperitoneal tumor, a tumor in one of the organs targeted by our study and patients presenting ascites. The organs focused on were: the pericardium, pleura, aorta, liver, spleen, kidneys, abdominal aorta and femoral arteries. The shortest distance between the organ and the skin wall was noted. Median distances were calculated according to gender, abdominal diameter and BMI. RESULTS: We associated these values to propose an indicative chart which may be used by doctors in connection with their forensic activities. DISCUSSION: The problem of the depth of a wound is frequently exposed to the expert. Without a reliable tool, it is difficult to value and a personal interpretation is often done. Even if, in current days, tomodensitometry is frequently done in vivo or after death, measurement can be difficult because of the local conditions. We classified values according to the different factors of fat repartition (BMI, abdominal diameter, gender). These tables, collectively used, permit evaluation of the distance between wall and thoracic or abdominal vital organs. CONCLUSION: We suggest an indicative chart designed for forensic doctors in their professional life to help determine the minimum penetration length for a knife, which may wound a vital organ.

Benefit of the Vittel criteria to determine the need for whole body scanning in a severe trauma patient.

OBJECTIVE: To evaluate the use of the Vittel criteria in addition to a clinical examination to determine the need for a whole body scan (WBS) in a severe trauma patient. MATERIALS AND METHODS: Between December 2008 and November 2009, 339 severe trauma patients with at least one Vittel criterion were prospectively evaluated with a WBS. The following data were collected: the Vittel criteria present, circumstances of the accident, traumatic injury on the WBS, and irradiation. The original intent to prescribe a computed tomography (CT) scan (whole body or a targeted region), based solely on clinical signs, was specified. RESULTS: Injuries were diagnosed in 55.75% of the WBS (n=189). The most common Vittel criteria were "global assessment" (n=266), "thrown, run over" (n=116), and "ejected from vehicle" (n=94). The multivariate analysis used the following as independent criteria for predicting severe traumatic injury on the WBS: Glasgow score less than 13, penetrating trauma, and colloid resuscitation greater than 11. Based solely on clinical factors, 164 patients would not have had any scan or (only) a targeted scan. In that case, 15% of the severe injuries would have been missed. CONCLUSION: Using the Vittel criteria to determine the need for a WBS in a severe trauma patient makes it possible to find serious injuries not suspected on the clinical examination, but at the cost of an increased number of normal scans.

CT colonography: Why? When? How?

Although optical colonoscopy is still the gold standard for diseases of the colon, radiologic examination of the colon is now being performed by CT scan. Evaluation of the colon is enhanced by distension, which "de-folds" the intestinal wall, thus facilitating its examination for abnormalities of the mucosa, the wall as a whole, and the diameter of the bowel lumen. Water or gas (CO(2)) may be used for the distension, depending on the suspected lesions. The water enema method of colonography combines filling the bowel lumen with water and intravenous injection of a contrast medium. It is indicated when there is a clinical suspicion of colon cancer, or for initial discovery of liver metastases, and for staging of colon tumors. This technique, which requires little or no colon cleansing preparation, can be performed with no special equipment and has a short learning curve. The gas enema method of colonography, or virtual colonoscopy, is performed by distending the colon with CO(2), without any intravenous injection of contrast medium. Its purpose is to detect polyps as part of a screening for precancerous growths. This technique, which does require bowel cleansing preparation, uses a dedicated console for reading and requires specific training.

[Imaging features and evaluation of liver lesions after non-surgical therapy]. / Aspects et évaluation post-thérapeutiques des lésions du foie après traitement non chirurgical.

The main non-surgical treatments for liver lesions include chemotherapy, targeted treatments, chemoembolization and radiofrequency ablation. The post-treatment imaging features are variable and depend on the initial appearance of the lesion, the type of treatment and the imaging modality. Evaluation of tumour response to treatment is important. RECIST criteria based on unidimensional lesion measurements may not always be appropriate. Other evaluation criteria (Choi for GIST, EASL for HCC or Chun criteria.) may be more relevant.

[Peritoneal parasitic teratoma and chemical dermoid peritonitis]. / Tératomes parasitiques péritonéaux et péritonites chimiques dermoïdes.

Chemical peritonitis occurs following intraperitoneal rupture of a mature ovarian dermoid. Rupture may be acute and spontaneous, typically during pregnancy, or iatrogenic. Low grade ruptures lead to parasitic peritoneal dermoid cysts, usually involving the greater omentum, cul-de-sac of Douglas and perihepatic region. Radiologists should be familiar with their appearance to correctly diagnose the condition and not mistake the disease for peritoneal carcinomatosis.

Accuracy of computed tomographic colonography in a nationwide multicentre trial, and its relation to radiologist expertise.

OBJECTIVE: Reports on the accuracy of computed tomographic colonography (CTC) mainly involve series from expert institutions. The aims of this study were to assess CTC accuracy in a nationwide population and to relate it to radiologist performance in their initial training. DESIGN: Nationwide multicentre trial. SETTING: Twenty-eight radiologists, working in 26 mostly academic clinical units, were involved in the study after having attended a formal specialised 2-day training session on CTC. They worked through a training set of 52 cases with automatic feedback after an attempt at each case. PATIENTS: The study enrolled 845 patients with average and high risk of colorectal cancer, 737 of whom had both complete CTC and videocolonoscopy data, which constituted the dataset. INTERVENTIONS: Patients underwent same-day CTC followed by videocolonoscopy with segmental unblinding of CTC results. MAIN OUTCOME MEASURES: Sensitivity, specificity and positive and negative predictive values for detection of polyps ≥ 6 mm in per-patient and per-lesion analyses of CTC without computer-aided detection. RESULTS: Sensitivity, specificity and positive and negative predictive values for patients with polyps ≥ 6 mm were 69% (95% CI 61% to 77%), 91% (95% CI 89% to 94%), 67% (95% CI 59% to 74%) and 92% (95% CI 90% to 94%), respectively. Univariate analysis showed that the detection rate for polyps ≥ 6 mm was linked to neither radiologist case volume nor number of polyps, but was related to sensitivity achieved in the training set. Pooled sensitivity was 72% (95% CI 63% to 80%) versus 51% (95% CI 40% to 60%) for radiologists achieving above and below median sensitivity in the training set (61%), respectively. Multivariate analysis showed that sensitivity for polyps ≥ 6 mm in the training set was the only remaining significant predictive factor for subsequent performance. CONCLUSIONS: Radiologist sensitivity CTC for detection of polyps ≥ 6 mm in training was the sole independent predictor for subsequent sensitivity in detection of such polyps.

[Postoperative imaging of the cardia and stomach]. / Imagerie post-opératoire du cardia et de l'estomac.

In addition to treatment of complications from peptic ulcer disease, gastroesophageal reflux and gastric cancer, bariatric surgical procedures have increased over the recent years. Complications after gastric surgery are imaged with upper gastrointestinal contrast studies and CT. This imaging is not always easy and it is important for radiologists to know the different types of surgical techniques and to be familiar with normal postoperative anatomical and pathological findings.

[Abdominal trauma: spectrum of lesions]. / Traumatismes abdominaux: les lésions élémentaires.

Abdominal injuries are more often observed in the setting of polytrauma. Detection and accurate description of hemoperitoneum, solid organ injuries (contusion, hematoma, laceration, fracture), bowel perforation and arterial bleeding allow optimal multidisciplinary management. Mesenteric and bowel injuries are often difficult to diagnose and may be masked by the presence of more frequent injuries (spleen, liver). MDCT is the gold standard imaging modality for severe blunt abdominal trauma.

[Image-guided percutaneous gastrostomy]. / Gastrostomie Percutanée Radiologique.

Gastrostomy is mainly used to provide longterm enteral nutrition. Percutaneous techniques are generally preferred to surgery except for specific cases. Image-guided percutaneous gastrostomy, currently used less than the gastroscopy-guided technique, is a simple, reliable and advantageous technique in managing these frequently debilitated patients. The different aspects of the procedure will be described: indications, contraindications, technique, follow-up, main complications and technical variations.