Biomedical subjects

Randy D Ernst

Publications and source records attributed to Randy D Ernst.

12 recordsLinked to original sources

PubMed2006

Revisiting MRI for appendix location during pregnancy.

OBJECTIVE: The purpose of this study is to determine the location of the appendix in pregnant patients by MRI and to investigate the possibility of gradual upward displacement of the appendix during pregnancy. CONCLUSION: The gradual upward displacement of the appendix during pregnancy was confirmed. MRI can be used for determination of the appendix localization in pregnant patients. Further studies with a larger number of patients will be helpful to answer this clinically relevant question.

Appendix↗

PubMed2006

Localization of appendix with MDCT and influence of findings on choice of appendectomy incision.

OBJECTIVE: The purpose of this study was to show the relation between McBurney's point and the appendix in patients undergoing 3D MDCT and to investigate the effect of this information on a surgeon's choice of appendectomy incision. MATERIAL AND METHODS: Among 142 adults undergoing consecutive MDCT studies, 100 patients (35 women, 65 men; mean age, 52.1 years) with an identifiable appendix on abdominopelvic MDCT examinations were selected for the study group. The presence of intraabdominal mass or a history of abdominal surgery were the exclusion criteria. Three-dimensional reconstruction of the CT data was performed with a surface shaded display algorithm. The locations of the base of the appendix and McBurney's point were marked on a single 3D image that allowed display of the skin surface markings for each patient. The superoinferior and mediolateral distances from the level of the appendix to the level of McBurney's point were measured, and the radial distance was calculated from these measurements. A surgeon experienced in emergency abdominal surgery reviewed 3D CT images and one axial image showing the appendix, and his choice of incision for each patient based on the CT information was recorded. The influence of the superoinferior and mediolateral distances of the appendix from McBurney's point on the surgeon's decision was analyzed with a multivariate logistic regression model. RESULTS: The appendix was exactly at McBurney's point in only 4% of the patients. In 36% of the cases, the appendix was within 3 cm, in 28% of cases it was 3-5 cm, and in 36% of the cases it was more than 5 cm away from McBurney's point. Mean +/- SD superoinferior, mediolateral, and radial distances between the appendix and McBurney's point were 33.0 +/- 24.1, 20.8 +/- 19.3, and 42.1 +/- 26.7 mm, respectively. After reviewing the images, the surgeon would have altered his incision site in 35% of the cases. The surgeon preferred a higher incision in 28% and a lower incision in 7% of the cases. Both positive and negative superoinferior displacement away from McBurney's point were significant factors regarding the surgeon's decision to alter the incision (p = 0.005), and the superoinferior distance was more than 3 cm in 94% of the cases in which the surgeon would have altered the incision. CONCLUSION: The location of the appendix varies widely among individuals, and McBurney's point has limitations as an anatomic landmark. Three-dimensional MDCT findings can be useful to surgeons customizing appendectomy incisions. Additional information about the location of the appendix in the CT report (if possible, together with a 3D image showing the location of the appendix) may be beneficial for surgeons performing appendectomy.

Appendectomy↗

PubMed2006

Medical qualification of a commercial spaceflight participant: not your average astronaut.

BACKGROUND: Candidates for commercial spaceflight may be older than the typical astronaut and more likely to have medical problems that place them at risk during flight. Since the effects of microgravity on many medical conditions are unknown, physicians have little guidance when evaluating and certifying commercial spaceflight participants. This dynamic new era in space exploration may provide important data for evaluating medical conditions, creating appropriate medical standards, and optimizing treatment alternatives for long-duration spaceflight. CASE: A 57-yr-old spaceflight participant for an ISS mission presented with medical conditions that included moderately severe bullous emphysema, previous spontaneous pneumothorax with talc pleurodesis, a lung parenchymal mass, and ventricular and atrial ectopy. The medical evaluation required for certification was extensive and included medical studies and monitoring conducted in analogue spaceflight environments including altitude chambers, high altitude mixed-gas simulation, zero-G aircraft, and high-G centrifuge. To prevent recurrence of pneumothorax, we performed video-assisted thoracoscopic pleurodesis, and to assess lung masses, several percutaneous or direct biopsies. The candidate's 10-d mission was without incident. CONCLUSION: Non-career astronauts applying for commercial suborbital and orbital spaceflight will, at least in the near future, challenge aerospace physicians with unknowns regarding safety during training and flight, and highlight important ethical and risk-assessment problems. The information obtained from this new group of space travelers will provide important data for the evaluation and in-flight treatment of medical problems that space programs have not yet addressed systematically, and may improve the medical preparedness of exploration-class missions.

Aerospace Medicine↗

PubMed2005

Rapid CT diagnosis of acute appendicitis with IV contrast material.

The purpose of this study was to determine the sensitivity and specificity of computed tomography (CT) without administration of oral contrast in confirming suspected acute appendicitis. One hundred seventy-three patient studies were retrieved by a computer-generated search for the word "appendicitis" in radiology reports. Patients presenting to the emergency department over an 8-month period were examined for acute abdominal pain or suspected acute appendicitis. IV-contrast-enhanced CT scans of the abdomen and pelvis were obtained without oral or rectal contrast. Criteria for diagnosis of acute appendicitis included a dilated appendix (>6 mm), periappendiceal inflammation, or abscess. Final diagnoses were established with surgical/clinical follow-up, histopathological analysis or both. The standard time (1 h) for the administration of oral contrast prior to the CT scan was eliminated. Fifty-nine CT diagnoses were made of acute appendicitis, 56 of which were histologically verified and three of which resulted in another diagnosis. One hundred fourteen CT diagnoses were negative for appendicitis. This corresponds to a sensitivity of 100% and specificity of 97%, a positive predictive value of 95%, and a negative predictive value of 100%. CT with IV contrast is sensitive and specific for the confirmation or exclusion of acute appendicitis. By eliminating the time required to administer oral contrast, the diagnosis might be made more rapidly.

Abdomen, Acute↗

PubMed2004

Right-lower-quadrant pain and suspected appendicitis in pregnant women: evaluation with MR imaging--initial experience.

PURPOSE: To determine if there is a role for magnetic resonance (MR) imaging in evaluation of pregnant women with acute right-lower-quadrant pain in whom acute appendicitis is suspected. MATERIALS AND METHODS: Informed consent and institutional review board approval were obtained. Images obtained with a 1.5-T MR imager and medical records of 23 pregnant women (age range, 19-34 years; mean age, 24.7 years) who presented with acute right-lower-quadrant pain were retrospectively reviewed. MR protocol included use of transverse, coronal, and sagittal noncontiguous T2-weighted single-shot fast spin-echo (SE) sequences; transverse fat-suppressed T2-weighted fast SE sequences; transverse T1-weighted gradient-recalled-echo sequences; and transverse and coronal short inversion time inversion-recovery sequences performed through the lower abdomen and pelvis. MR findings were evaluated by two radiologists and compared with surgical and pathologic findings and clinical follow-up data. RESULTS: Appendix was detected in 20 (86.9%) of 23 patients. Seven patients underwent surgery; four had acute appendicitis, and three had ovarian torsion. Two patients with pelvic abscesses not related to appendicitis underwent percutaneous drainage. Fourteen patients were treated medically. Dilated thick-walled appendix and periappendiceal inflammation were detected in three (75%) of four patients with acute appendicitis. In one patient with appendicitis, the appendix could not be visualized, but inflammation was present in the right lower quadrant. In three patients with ovarian torsion, MR imaging demonstrated right adnexal mass or inflammation. MR imaging was used to correctly identify pelvic abscesses and healthy appendix in two patients. A healthy appendix was depicted in 17 (89.5%) of 19 patients without acute appendicitis. CONCLUSION: MR imaging shows promise for evaluation of pregnant women in whom acute appendicitis is suspected by enabling diagnosis of other possible causes of right-lower-quadrant pain, including ovarian torsion or pelvic abscesses, and demonstrating a healthy or unhealthy appendix.

Abdominal Abscess↗

PubMed2004

Alternative diagnoses to stone disease on unenhanced CT to investigate acute flank pain.

Acute flank pain is a common problem in emergency medicine. The most frequent cause is urolithiasis, but many other entities can cause the same clinical presentation. In many institutions unenhanced computed tomography (CT) of the abdomen is used in this setting. One of the major advantages of unenhanced CT is its ability to detect other pathologies causing flank pain. In this pictorial review, we present the CT findings of pathologies other than stone disease in patients with acute flank pain.

Adult↗

PubMed2004

Traumatic diaphragmatic rupture: can oral contrast increase CT detectability?

Traumatic diaphragmatic rupture is a frequently missed diagnosis. We present a patient with traumatic diaphragmatic hernia. Diagnosis was suggested by a emergent computed tomography (CT) examination without oral contrast. Diaphragmatic rupture and herniation of stomach were confirmed by repeating CT examination after the administration of oral contrast and using multiplanar reconstruction.

Administration, Oral↗

PubMed2003

Computerized tomographic colonography: performance evaluation in a retrospective multicenter setting.

BACKGROUND & AIMS: No multicenter study has been reported evaluating the performance and interobserver variability of computerized tomographic colonography. The aim of this study was to assess the accuracy of computerized tomographic colonography for detecting clinically important colorectal neoplasia (polyps >or=10 mm in diameter) in a multi-institutional study. METHODS: A retrospective study was developed from 341 patients who had computerized tomographic colonography and colonoscopy among 8 medical centers. Colonoscopy and pathology reports provided the standard. A random sample of 117 patients, stratified by criterion standard, was requested. Ninety-three patients were included (47% with polyps >or=10 mm; mean age, 62 years; 56% men; 84% white; 40% reported colorectal symptoms; 74% at increased risk for colorectal cancer). Eighteen radiologists blinded to the criterion standard interpreted computerized tomography colonography examinations, each using 2 of 3 different software display platforms. RESULTS: The average area under the receiver operating characteristic curve for identifying patients with at least 1 lesion >or=10 mm was 0.80 (95% lower confidence bound, 0.74). The average sensitivity and specificity were 75% (95% lower confidence bound, 68%) and 73% (95% lower confidence bound, 66%), respectively. Per-polyp sensitivity was 75%. A trend was observed for better performance with more observer experience. There was no difference in performance across software display platforms. CONCLUSIONS: Computerized tomographic colonography performance compared favorably with reported performance of fecal occult blood testing, flexible sigmoidoscopy, and barium enema. A prospective study evaluating the performance of computerized tomography colonography in a screening population is indicated.

Colonic Neoplasms↗

PubMedDate not supplied

Mimicks of pancreatic malignancy in patients with chronic pancreatitis: correlation of computed tomography imaging features with histopathologic findings.

Differentiation of chronic pancreatitis and pancreatic carcinoma can be a clinical and radiologic dilemma. Several patients with chronic pancreatitis can undergo unnecessary major abdominal surgery for benign lesions. This pictorial review illustrates the computed tomographic findings and histopathologic features of lesions mimicking pancreatic neoplasm in patients with chronic pancreatitis. Several benign lesions can simulate pancreatic malignancy in patients with chronic pancreatitis. Knowledge of the computed tomographic appearance of these benign entities is important to prevent unnecessary surgeries.

Diagnosis, Differential↗

PubMedDate not supplied

Magnetic resonance imaging of maternal diseases causing acute abdominal pain during pregnancy: a pictorial review.

Evaluation of acute abdominal pain in a pregnant patient is a clinical challenge. In these patients, magnetic resonance imaging (MRI) can allow a systematic cross-sectional evaluation of the entire abdomen and can provide clinically useful information in a short enough time for emergent diagnosis. This pictorial essay demonstrates MRI findings of various maternal diseases that can present as acute abdominal pain in pregnant patients. Familiarity with these findings is important for the radiologist to make an accurate and prompt diagnosis.

Abdominal Pain↗

PubMedDate not supplied

Development of a teaching file by using a DICOM database.

A teaching file of Digital Imaging and Communications in Medicine (DICOM) images was developed. Selected computed tomographic, magnetic resonance, angiographic, nuclear medicine, and ultrasonographic images were transferred to a personal computer (PC) with a 75-GB hard drive. The database created from the DICOM header information was modified to include American College of Radiology (ACR) Learning File categories. Database modification allowed cases to be searched by diagnosis, by findings, and by patient age, sex, and demographics. Technologists inputted ACR codes into the DICOM headers before the images were acquired, thereby reducing database maintenance time. Images were manipulated and reviewed and were used for case presentations, board review, and conferences. Selected images were transferred via a hospital network to workstations for consultation, saving time for referring clinicians. The teaching file is reliable, cost-effective, and easy to install and takes advantage of recent technologic advances in computer hardware and software. Rapid cost reductions and increases in PC storage capacity allow maintenance of the teaching file in DICOM format without intermediate steps involving automation or manual conversion. This setup rivals any of the proprietary software currently available from other vendors.

Computer Communication Networks↗

PubMedDate not supplied

Paleoradiology: advanced CT in the evaluation of nine Egyptian mummies.

Axial thin-collimation state-of-the-art spiral computed tomography (CT) was combined with sagittal and coronal reformatting, three-dimensional (3D) reconstruction, and virtual "fly-through" techniques to nondestructively study nine Egyptian mummies. These techniques provided important paleopathologic and historical information about mummification techniques, depicted anatomy in the most informative imaging plane, illustrated the soft-tissue preservation and physical appearance of mummies in superb detail, and generated an intriguing virtual tour through hollow mummified remains without harming the specimens themselves. Images generated with these methods can help archaeologists and Egyptologists understand these fascinating members of mankind and can serve as adjunct visual aids for laypersons who are interested in mummies. CT has emerged as the imaging modality of choice for the examination of Egyptian mummies due to its noninvasive cross-sectional nature and inherently superior contrast and spatial resolution. As multi-detector row CT and postprocessing tools evolve, the capabilities and applications of CT will continue to proliferate, attesting to the expanded versatility and utility of CT as a noninvasive research tool in the multidisciplinary study of Egyptian mummies.

History, Ancient↗