Biomedical subjects

Robert M Abbott

Publications and source records attributed to Robert M Abbott.

10 recordsLinked to original sources

PubMed2006

Virtual autopsy: preliminary experience in high-velocity gunshot wound victims.

PURPOSE: To retrospectively assess virtual autopsy performed with multidetector computed tomography (CT) for the forensic evaluation of gunshot wound victims. MATERIALS AND METHODS: The institutional review board approved this HIPAA-compliant study and did not require informed consent of the next of kin. Thirteen consecutive male gunshot wound victims (mean age, 27 years) were scanned with 16-section multidetector CT prior to routine autopsy. Retrospectively, the total-body nonenhanced scans were interpreted at a three-dimensional workstation by radiologists blinded to autopsy findings. Images were evaluated for lethal wound, number and location of wound tracks, injured structures, and metal fragment location. After image review, autopsy reports and photographs were compared with the images and interpretations to validate the multidetector CT determinations. RESULTS: Multidetector CT aided in correct identification of all lethal wounds, and metallic fragment location was always precise. In four cases, multidetector CT aided in accurate assessment of organ injuries and lethal wounds but led to underestimation of the number of wounds if comingling paths occurred. In two cases of a chest wound, multidetector CT aided in accurate assessment of the chest as having the lethal wound but failed to help identify specific sites of hemorrhage. In two cases of craniofacial injury, the path of the wound was not clear. Autopsy revealed a total of 78 wound tracks (mean, 6; range, 1-24). Ten (13%) wound tracks were not identified at multidetector CT (six upper extremity wounds and four thigh wounds). In two cases, findings missed at autopsy (fracture of the cervical spine, bullet fragments in the posterior area of the neck) were identified at multidetector CT. CONCLUSION: Multidetector CT can aid prediction of lethal wounds and location of metallic fragments.

Adult↗

PubMed2005

Duodenal carcinoids: imaging features with clinical-pathologic comparison.

PURPOSE: To retrospectively evaluate the imaging features of duodenal carcinoids with clinical-pathologic comparison. MATERIALS AND METHODS: The institutional review board approved this study; informed consent was not required. The study was HIPAA compliant. The authors retrospectively reviewed the barium studies (n = 20), computed tomographic (CT) scans (n = 16), magnetic resonance (MR) images (n = 2), pathology reports (n = 33), gross pathology photographs (n = 15), and clinical data (n = 33) from 33 patients (16 men and 17 women; age range, 19-90 years; mean age, 52.6 years) with a confirmed diagnosis of duodenal carcinoid admitted into our institution during a 52-year period. The imaging studies were evaluated by consensus of two abdominal radiologists for the number of masses and their location and morphologic characteristics (polypoid or mural). The CT and MR images were also assessed for contrast enhancement characteristics. RESULTS: Most carcinoids were located in the proximal duodenum (10 in the bulb, 19 in the second portion, two in the third portion, and two in the fourth portion). Seventeen patients (52%) had focal intraluminal polypoid masses and 13 (39%) had mural masses; in three patients (9%), the tumor was not visualized at CT. Five of the 33 patients (15%) had multiple carcinoids. CT showed heterogeneous contrast enhancement in all patients who received intravenous contrast material in the arterial or portal venous phases of enhancement. Nonenhancing masses were present in patients who underwent CT during the equilibrium phase. Two patients had Zollinger-Ellison syndrome. Five patients (15%) had neurofibromatosis type 1 (NF-1); four of the five patients (80%) were women, and four patients were African American. In all five patients with NF-1, the carcinoids were located in the periampullary region. CONCLUSION: Duodenal carcinoids are uncommon tumors with a wide clinical-pathologic spectrum. They occur most commonly in the proximal duodenum and manifest as an intraluminal polyp or a mural mass.

Adult↗

PubMed2005

Angiosarcoma of the spleen: imaging characteristics in 12 patients.

PURPOSE: To retrospectively review clinical, pathologic, and imaging features of angiosarcoma of the spleen in 12 patients. MATERIALS AND METHODS: Institutional review board approval was obtained, and informed consent was not required. Records of 12 cases of proved angiosarcoma of the spleen were accessed from the files of the Armed Forces Institute of Pathology. Clinical, pathologic, and imaging findings were reviewed. Presenting signs and symptoms were recorded, and the pathologist confirmed the diagnosis and determined gross and microscopic morphologic findings in each spleen. Radiologists reviewed available images to determine the size of the spleen and mass, amount of splenic involvement by the tumor (if enhanced at computed tomography [CT] and magnetic resonance [MR] imaging), and amount of nonviable tumor determined as decreased echogenicity at ultrasonography (US) and lack of enhancement at CT and MR imaging. Imaging and pathologic findings were compared. Five US, 10 CT, three MR, and two angiographic images were reviewed by two experienced abdominal radiologists. RESULTS: There were seven men and five women (age range, 36-86 years; mean, 55 years). The most common symptom was upper abdominal pain in eight (67%) patients: Pain was acute for 24 hours prior to admission in one patient and chronic (range, 1-6 months) in seven patients. At imaging, the spleen was enlarged (>12 cm in length) in nine patients. The most common finding, seen in seven (58%) patients, was a complex mass or masses in an enlarged spleen. Four of these patients had evidence of metastases and one had intraperitoneal hemorrhage. Two patients had solitary hypervascular tumors and liver metastases. One patient had a normal-sized spleen with multiple lesions that ranged 2-3 cm in size, as well as metastases to the spine. The 11th patient had two small lesions, with small calcifications in the periphery of one lesion. The 12th patient had intraabdominal hemorrhage around the spleen and no obvious mass at CT. Tumor necrosis was confirmed at histologic evaluation in nine patients. CONCLUSION: The most common clinical finding was upper abdominal pain. Angiosarcoma of the spleen could be suggested in the majority of cases (83%) by using the imaging features of splenic mass with evidence of metastatic disease.

Adult↗

PubMed2004

Littoral cell angioma of the spleen: CT features with clinicopathologic comparison.

PURPOSE: To evaluate the clinical, pathologic, and computed tomographic (CT) features of littoral cell angioma of the spleen in eight patients. MATERIALS AND METHODS: Two abdominal radiologists retrospectively reviewed the contrast material-enhanced CT images obtained in six, the contrast-enhanced and nonenhanced CT images obtained in two, and the photographs of gross pathologic specimens resected from seven patients. They also retrospectively reviewed clinical data (ie, demographic data, presenting signs and symptoms, physical findings, and medical histories). Histopathologic specimens from the eight patients were reviewed by a hematopathologist. The CT images were reviewed for the presence of splenomegaly. The number, size, and enhancement characteristics of the splenic masses at CT were compared with the histopathologic and gross pathologic specimen findings. RESULTS: All patients had laboratory evidence of hypersplenism. Seven patients (88%) had splenomegaly and innumerable splenic masses ranging from 0.2 to 6.0 cm in diameter at CT. The single patient with a normal spleen size had four splenic masses. The splenic masses were hypoattenuating relative to the normal spleen at CT in all patients and correlated with blood-filled nodules at gross pathologic examination and with blood-filled vascular channels of littoral cell angioma at histopathologic examination. The early and late portal venous phase CT images that were available in one case demonstrated progressive homogeneous contrast enhancement of the masses such that they were indistinguishable from the normal splenic parenchyma. CONCLUSION: Littoral cell angioma is a primary splenic neoplasm that most commonly manifests at CT as multiple hypoattenuating masses in an enlarged spleen. Histopathologically, these masses represent blood-filled vascular channels.

Adult↗

PubMed2004

Frequency and CT patterns of bowel wall thickening proximal to cancer of the colon.

OBJECTIVE: This study was performed to determine the frequency and patterns of colon wall thickening seen on CT of patients with adenocarcinoma of the colon. MATERIALS AND METHODS: Preoperative abdominal and pelvic CT scans of 185 patients with surgically proven adenocarcinoma of the colon were retrospectively evaluated by three abdominal radiologists for the presence of colon obstruction and colon wall thickening proximal to the colon adenocarcinoma. The distributions and patterns of colon wall thickening were categorized by consensus. CT findings were compared with pathologic findings. Fisher's exact test was used to determine the statistical significance of any associations. RESULTS: Of 185 patients, CT findings of 20 (10.8%) showed colon wall thickening. Of these, the adenocarcinoma obstructed the colon in 19 patients (p < 0.01). Colon obstruction was partial in 10 patients (53%) and complete in nine (47%). Colon wall thickening was contiguous to the tumor in 14 (70%) patients and noncontiguous in six (30%). Segmental and pancolonic, patchy and diffuse, and dependent and nondependent colon wall thickening was observed in 10 patients (50%) in each category. Associated small-bowel wall thickening was shown in 10 (50%) of the 20 patients. Pathologic examination showed colon wall thickening to be due to edema in all cases. CONCLUSION: Colon wall edema can occur proximal to colon adenocarcinoma, is almost always associated with colon obstruction, and is predominantly contiguous with the obstructing adenocarcinoma.

Adenocarcinoma↗

PubMed2004

Gastrointestinal stromal tumors in patients with neurofibromatosis: imaging features with clinicopathologic correlation.

OBJECTIVE: The purpose of this study was to evaluate the clinical, pathologic, and imaging features of gastrointestinal stromal tumors that occur in patients with neurofibromatosis. CONCLUSION: Gastrointestinal stromal tumors that occur in patients with neurofibromatosis commonly originate from the proximal small intestine and are often multiple. The cross-sectional imaging appearance of gastrointestinal stromal tumors that occur in patients with neurofibromatosis is similar to that of gastrointestinal stromal tumors that occur in the general population.

Adult↗

PubMedDate not supplied

From the archives of the AFIP. Benign tumors and tumorlike lesions of the gallbladder and extrahepatic bile ducts: radiologic-pathologic correlation. Armed Forces Institute of Pathology.

A diverse spectrum of benign tumors and tumorlike lesions arises from the gallbladder and bile ducts, and despite their diversity, these lesions share common embryologic origins and histologic characteristics. Although these lesions are relatively uncommon, their importance lies in their ability to mimic malignant lesions in these locations. Benign neoplasms are derived from the epithelial and nonepithelial structures that compose the normal gallbladder and bile ducts. The epithelium gives rise to adenomas, cystadenomas, and the unusual condition of biliary papillomatosis. Granular cell tumors, neurofibromas, ganglioneuromas, paragangliomas, and leiomyomas are examples of benign tumors that may originate from nonepithelial structures. Tumorlike lesions are more commonly found in the gallbladder and include xanthogranulomatous cholecystitis, adenomyomatous hyperplasia, cholesterol polyps, and heterotopias. In the clinical setting of a patient with nonspecific abdominal complaints or symptoms of biliary obstruction, the discovery of a gallbladder or bile duct polyp or mass, gallbladder wall thickening, or biliary stricture is most often indicative of malignancy. However, the differential diagnosis should include benign tumors and tumorlike lesions. The preoperative determination of a benign lesion may significantly alter therapy and patient prognosis.

Bile Duct Diseases↗

PubMedDate not supplied

Emphysematous infections of the abdomen and pelvis: a pictorial review.

Emphysematous (gas-forming) infections of the abdomen and pelvis represent potentially life-threatening conditions that require aggressive medical and often surgical management. The initial clinical manifestation of these entities may be insidious, but rapid progression to sepsis will occur in the absence of early therapeutic intervention. Conventional radiography and ultrasonography are often the initial imaging modalities used to evaluate patients with abdominopelvic complaints. However, when a differential diagnosis remains, or if further localization or confirmation of tentative findings is needed, computed tomography (CT) should be considered the imaging modality of choice. CT is both highly sensitive and specific in the detection of abnormal gas and well suited to reliable depiction of the anatomic location and extent of the gas. Of equal importance may be the capability of CT to help reliably identify benign sources of gas, because treatment (if any) varies dramatically depending on the source. Knowledge of the pathophysiologic characteristics, common predisposing conditions, and typical imaging features associated with gas-forming infections of the gallbladder, stomach, pancreas, and genitourinary system will help make early diagnosis and successful treatment possible. In addition, such knowledge will aid in further diagnostic work-up, surveillance of potential complications, and evaluation of therapeutic response.

Aged↗

PubMedDate not supplied

From the archives of the AFIP: primary vascular neoplasms of the spleen: radiologic-pathologic correlation.

Primary vascular neoplasms of the spleen constitute the majority of nonhematolymphoid splenic tumors. The benign primary vascular tumors include hemangioma, hamartoma, and lymphangioma, whereas those of variable or uncertain biologic behavior include littoral cell angioma, hemangioendothelioma, and hemangiopericytoma. The primary malignant vascular neoplasm of the spleen is angiosarcoma. Peliosis is a rare lesion of unknown cause that is usually found incidentally in asymptomatic patients but may be associated with hematologic or metastatic disease. Although these vascular neoplasms of the spleen are uncommon, their importance lies in that they must be differentiated from the more common neoplastic disorders of the spleen, such as lymphoma and metastasis. The most common echogenic solid or complex cystic mass in an asymptomatic patient is splenic hemangioma. However, the imaging appearance of splenic hemangiomas may be complex, and differentiation of these lesions from malignant disease may not be possible. The diagnosis of splenic hamartoma may be suggested when findings of increased blood flow on color Doppler images are seen in association with a homogeneous solid echogenic mass. A large subcapsular solitary cystic abnormality discovered incidentally in a child in association with internal septations and tiny mural nodules favors the diagnosis of lymphangioma. Any invasion of the surrounding splenic parenchyma by a splenic lesion should indicate a more aggressive or malignant process. Evaluation of a focal splenic abnormality identified on sonograms should be followed up with computed tomography or magnetic resonance imaging with and without contrast material enhancement. Splenectomy may be required for definitive evaluation of a splenic mass with atypical features.

Adult↗

PubMedDate not supplied

From the archives of the AFIP: abdominal neoplasms in patients with neurofibromatosis type 1: radiologic-pathologic correlation.

Neurofibromatosis type 1 (NF1) is one of the most common genetic disorders. NF1 is a complex disease resulting from a spectrum of mutations that may occur at many locations along the large, complex NF1 gene, which is located on chromosome 17. Mutations of the NF1 gene lead to abnormal tumor suppression. Consequently, patients with NF1 have an increased prevalence of benign and malignant neoplasms throughout the body. There are five categories of NF1 tumors that occur in the abdomen: neurogenic, neuroendocrine, nonneurogenic gastrointestinal mesenchymal, embryonal, and miscellaneous. Many of these tumors are age related, occur at specific anatomic locations, and have unique imaging features. Notably, many patients have a variety of organs affected because there is a high prevalence of multiple tumors occurring in the same patient. Neurofibromas are the most common benign neoplasms and may occur in the retroperitoneum or visceral organs. Malignant peripheral nerve sheath tumor is an aggressive malignancy that is the most common malignant tumor of the abdomen in patients with NF1. Interpreting abdominal imaging studies in patients with NF1 can be challenging because of the wide spectrum and diverse nature of tumors that occur in this disease.

Abdominal Neoplasms↗