Hepatobiliary diseases in small animals: a comparison of ultrasonography and multidetector-row computed tomography

Ultrasonography (US) is an essential imaging tool for identifying abnormalities of the liver parenchyma, biliary tract and vascular system. US has replaced radiography as the initial imaging procedure in screening for liver disease in small animals. There are few reports of the use of conventional and helical computed tomography (CT) to assess canine or feline parenchymal and neoplastic liver disease and biliary disorders. In human medicine the development of multidetector- row helical computed tomography (MDCT), with its superior spatial and temporal resolution, has resulted in improved detection and characterization of diffuse and focal liver lesions. The increased availability of MDCT in veterinary practice provides incentive to develop MDCT protocols for liver imaging in small animals. The purpose of this study is to assess the rule of MDCT in the characterization of hepatobiliary diseases in small animals; and to compare this method with conventional US. Candidates for this prospective study were 175 consecutive patients (dogs and cats) referred for evaluation of hepatobiliary disease. The patients underwent liver US and MDCT. Percutaneous needle biopsy was performed on all liver lesions or alterations encountered. As for gallbladder, histopatological evaluation was obtained from cholecystectomy specimens. Ultrasonographic findings in this study agreed well with those of previous reports. A protocol for dual-phase liver MDCT in small animals has been described. MDCT findings in parenchymal disorders of the liver, hepatic neoplasia and biliary disorders are here first described in dogs and cats and compared with the corresponding features in human medicine. The ability of MDCT in detection and characterization of hepatobiliary diseases in small animals is overall superior to conventional US. Ultrasonography and MDCT scanning, however, play complementary rules in the evaluation of these diseases. Many conditions have distinctive imaging features that may permit diagnosis. In most instances biopsy is required for definitive diagnosis.

[The thoracoscopic talc pleurodesis with intraoperative pleural biopsy - a retrospective analysis in patients with malignant pleural effusion]

The thoracoscopic pleurodesis with talc is an established therapy in case of malignant pleural effusion. With the instillation of talc a -localised inflammation is induced. However, some-times it turns into a severe systemic reaction. In this study of the postoperative course, the -question is examined whether a pleural biopsy is an additional risk factor for morbidity and mortality after talc pleurodesis.

Virtobot--a multi-functional robotic system for 3D surface scanning and automatic post mortem biopsy

The Virtopsy project, a multi-disciplinary project that involves forensic science, diagnostic imaging, computer science, automation technology, telematics and biomechanics, aims to develop new techniques to improve the outcome of forensic investigations. This paper presents a new approach in the field of minimally invasive virtual autopsy for a versatile robotic system that is able to perform three-dimensional (3D) surface scans as well as post mortem image-guided soft tissue biopsies.

Primary tuberculosis of the TMJ: presentation of a case and literature review

Tuberculosis (TB) is a frequent health problem. The prevalence of extrapulmonary TB has increased in the last couple of years. Head and neck tuberculosis forms nearly 10% of all extrapulmonary manifestations of the disease. TB of the temporomandibular joint (TMJ) is rare; only a few cases have been reported. The clinical appearance of TB infection of the TMJ has been described as unspecific, resembling arthritis, osteomyelitis, cancer or any kind of chronic joint diseases. This article describes a 22-year-old woman with pain and left preauricular swelling. Magnetic resonance imaging and computed tomography showed an expansive process with destruction of the left condyle and condylar fossa. A fine needle aspiration examination of the swelling showed non-specific granulomatous inflammation. In the following days, a preauricular fistula developed, of which a swab and biopsy specimens were taken. Histological and microbiological examinations revealed an infection with Mycobacterium tuberculosis. The initial antituberculosis treatment consisted of a combination of four antibiotics and could be reduced to two antibiotics in the course of treatment. The treatment was completed successfully after 9 months.

Diagnostic performance and accuracy of 3-D spoiled gradient-dual-echo MRI with water- and fat-signal separation in liver-fat quantification: comparison to liver biopsy

To prospectively evaluate a 3-dimensional spoiled gradient-dual-echo (3D SPGR-DE) magnetic resonance imaging (MRI) sequence for the qualitative and quantitative analysis of liver fat content (LFC) in patients with the suspicion of fatty liver disease using histopathology as the standard of reference.

Postmortem imaging-guided biopsy as an adjuvant to minimally invasive autopsy with CT and postmortem angiography: a feasibility study

Although postmortem CT suffices for diagnosing most forms of traumatic death, the examination of natural death is, to date, very difficult and error prone. The introduction of postmortem angiography has led to improved radiologic diagnoses of natural deaths. Nevertheless, histologic changes to tissues, an important aspect in traditional examination procedures, remain obscure even with CT and CT angiography. For this reason, we examined the accuracy of a minimally invasive procedure (i.e., CT angiography combined with biopsy) in diagnosing major findings and the cause of death in natural deaths.

Air suctioning during colon biopsy forceps removal reduces bacterial air contamination in the endoscopy suite

Bacterial contamination of endoscopy suites is of concern; however studies evaluating bacterial aerosols are lacking. We aimed to determine the effectiveness of air suctioning during removal of biopsy forceps in reducing bacterial air contamination.

Blood aspiration as a vital sign detected by postmortem computed tomography imaging

Blood aspiration is a significant forensic finding. In this study, we examined the value of postmortem computed tomography (CT) imaging in evaluating findings of blood aspiration. We selected 37 cases with autopsy evidence of blood in the lungs and/or in the airways previously submitted to total-body CT scanning. The CT-images were retrospectively analyzed. In one case with pulmonary blood aspiration, biopsy specimens were obtained under CT guide for histological examination. In six cases, CT detected pulmonary abnormalities suggestive of blood aspiration, not mentioned in the autopsy reports. CT reconstructions provided additional data about the distribution and extent of aspiration. In one needle-biopsied case, the pulmonary specimens showed blood in the alveoli. We suggest the use of CT imaging as a tool complementary to traditional techniques in cases of blood aspiration to avoid misdiagnosis, to guide the investigation of lung tissue, and to allow for more evidence-based inferences on the cause of death.

Multimodal target correction by local bone registration: a PET/CT evaluation

PET/CT guidance for percutaneous interventions allows biopsy of suspicious metabolically active bone lesions even when no morphological correlation is delineable in the CT images. Clinical use of PET/CT guidance with conventional step-by-step technique is time consuming and complicated especially in cases in which the target lesion is not shown in the CT image. Our recently developed multimodal instrument guidance system (IGS) for PET/CT improved this situation. Nevertheless, bone biopsies even with IGS have a trade-off between precision and intervention duration which is proportional to patient and personnel exposure to radiation. As image acquisition and reconstruction of PET may take up to 10 minutes, preferably only one time consuming combined PET/CT acquisition should be needed during an intervention. In case of required additional control images in order to check for possible patient movements/deformations, or to verify the final needle position in the target, only fast CT acquisitions should be performed. However, for precise instrument guidance accounting for patient movement and/or deformation without having a control PET image, it is essential to be able to transfer the position of the target as identified in the original PET/CT to a changed situation as shown in the control CT.

Reproducibility of sensory nerve conduction studies of the sural nerve using ultrasound-guided needle positioning

In this study we sought to evaluate the reproducibility of sensory nerve conduction studies (NCS) using ultrasound-guided needle positioning (USNP).

Evaluation of a novel needle guide for ultrasound-guided phantom vessel cannulation

We evaluated a novel, sled-mounted needle guide for ultrasound-guided vessel cannulation. Fifty medical students were randomly assigned to use ultrasound with the sled (sled group, n = 23) or ultrasound without the sled (control group, n = 27) for vessel cannulation in a phantom. For each of 15 attempts we recorded cannulation time and designated a successful cannulation as 1 and a failure as 0. Our primary outcome was the mean overall success rate. The median (IQR [range]) number of successes in the sled group and control group were 15.0 (13.0-15.0 [11.0-15.0]) and 11.0 (9.0-13.0 [6.0-15.0]), respectively (p < 0.001). Cannulation time decreased from the first to the last attempt in the sled group from 7.0 s (6.0-10.0 [4.0-16]) s to 4.0 s (3.0-4.0 [1.0-6.0]) s and in the control group from 35.0 s (27.0-35.0 [11.0-35.0]) s to 7.0 s (5.0-10.0 [3.0-25.0]) s. The sled group demonstrated a shorter cannulation time at each attempt (p < 0.001). The novel sled improved the success rate and efficiency of ultrasound-guided phantom vessel cannulation.

Indocyanine green fluorescence-guided sentinel lymph node biopsy in dermato-oncology

Sentinel lymph node biopsy (SLNB) for cutaneous malignancies usually carried out with radioactive nanocolloids (Tc-99m). The SLNE is controversially discussed internationally. This is especially given to the high false-negative rate up to 44 %. An alternative could be the fluorescent dye indocyanine green (ICG).

A navigation system for percutaneous needle interventions based on PET/CT images: design, workflow and error analysis of soft tissue and bone punctures

Percutaneous needle intervention based on PET/CT images is effective, but exposes the patient to unnecessary radiation due to the increased number of CT scans required. Computer assisted intervention can reduce the number of scans, but requires handling, matching and visualization of two different datasets. While one dataset is used for target definition according to metabolism, the other is used for instrument guidance according to anatomical structures. No navigation systems capable of handling such data and performing PET/CT image-based procedures while following clinically approved protocols for oncologic percutaneous interventions are available. The need for such systems is emphasized in scenarios where the target can be located in different types of tissue such as bone and soft tissue. These two tissues require different clinical protocols for puncturing and may therefore give rise to different problems during the navigated intervention. Studies comparing the performance of navigated needle interventions targeting lesions located in these two types of tissue are not often found in the literature. Hence, this paper presents an optical navigation system for percutaneous needle interventions based on PET/CT images. The system provides viewers for guiding the physician to the target with real-time visualization of PET/CT datasets, and is able to handle targets located in both bone and soft tissue. The navigation system and the required clinical workflow were designed taking into consideration clinical protocols and requirements, and the system is thus operable by a single person, even during transition to the sterile phase. Both the system and the workflow were evaluated in an initial set of experiments simulating 41 lesions (23 located in bone tissue and 18 in soft tissue) in swine cadavers. We also measured and decomposed the overall system error into distinct error sources, which allowed for the identification of particularities involved in the process as well as highlighting the differences between bone and soft tissue punctures. An overall average error of 4.23 mm and 3.07 mm for bone and soft tissue punctures, respectively, demonstrated the feasibility of using this system for such interventions. The proposed system workflow was shown to be effective in separating the preparation from the sterile phase, as well as in keeping the system manageable by a single operator. Among the distinct sources of error, the user error based on the system accuracy (defined as the distance from the planned target to the actual needle tip) appeared to be the most significant. Bone punctures showed higher user error, whereas soft tissue punctures showed higher tissue deformation error.

Massive Systemic Fat Embolism Detected by Postmortem Imaging and Biopsy

Postmortem computed tomography (pmCT) and pmCT angiography (pmCTA) provide a minimally invasive method to determine the cause of death. Postmortem image-guided biopsy allows for precise sampling of histological specimens. This case study describes the findings of lethal systemic fat embolism (FE) on whole-body unenhanced pmCT, pmCTA, and image-guided biopsy, with autopsy and histopathologic correlation. Unenhanced pmCT revealed a distinct fat level on top of sedimented layers of corpuscular blood particles and serum in the arterial system and pulmonary trunk. Subsequent pmCTA showed reproducible results, and image-guided biopsy confirmed fatal FE. pm CT/pmCTA combined with image-guided biopsy established the cause of death as right heart failure as a result of systemic fatal FE prior to autopsy. All imaging findings were consistent with traditional autopsy and histological specimens. This unique case demonstrates new imaging findings in massive, fatal FE and highlights that postmortem imaging, supplemented by image-guided biopsy, may detect the cause of death prior to traditional autopsy.