Israel Medical Association Journal

Background: Aural cholesteatoma is an epidermal cyst of the middle ear or mastoid that can only be eradicated by surgical resection. It is usually managed with radical or modified radical mastoidectomy. Clinical diagnosis of recurrent cholesteatoma in a closed postoperative cavity is difficult. Thus, the accepted protocol in most otologic centers for suspected recurrence consists of second-look procedures performed approximately 1 year after the initial surgery. Brain herniation into a post-mastoidectomy cavity is not rare and can be radiologically confused with cholesteatoma on the high resolution computed tomographic images of temporal bones that are carried out before second-look surgery.

Objectives: To present our experience with meningoceles that were confused with recurrent disease in patients who had undergone primary mastoidectomy for cholesteatoma and to support the use of magnetic resonance imaging as more suitable than CT in postoperative follow-up protocols for cholesteatoma.

Methods: We conducted a retrospective chart review of four patients.

Results: Axial CT sections demonstrated a soft tissue mass in the middle ear and mastoid in all four patients. Coronal reconstructions of CT scans showed a tympanic tegmen defect in two patients. CT failed to exclude cholesteatoma in any patient. Each underwent a second-look mastoidectomy and the only finding at surgery was meningocele in all four patients.

Conclusions: Echo-planar diffusion-weighted MRI can differentiate between brain tissue and cholesteatoma more accurately than CT. We recommend that otolaryngologists avoid unnecessary revision procedures by using the newest imaging modalities for more precise diagnosis of the patients who had undergone mastoidectomy for cholesteatoma in the past.
 

Background: Venous thromboembolism is a well-recognized and relatively frequent complication of malignancy, whereas tumor thrombosis is a rare complication of solid cancers. Correct diagnosis of tumor thrombosis and its differentiation from VTE[1] can alter patient management and prevent unnecessary long-term anticoagulation treatment.

Objectives: To evaluate the contribution of 18F-fluorodeoxyglucose positron emission tomography/computed tomography to the diagnosis of tumor thrombosis and its differentiation from VTE.

Methods: PET/CT[2] scans from 11 patients with suspected tumor thrombosis were retrospectively evaluated. Suspicion arose from positive PET/CT in eight cases, or from findings on contrast-enhanced CT in three patients. Criteria for positivity of PET/CT included increased focal or linear uptake of 18F-FDG[3] in the involved vessel. Findings were categorized as PET/CT positive, or PET/CT negative and compared to contrast-enhanced or ultrasound Doppler, pathology where available, and clinical follow-up.

Results: Eight occult tumor thromboses were identified by PET/CT-positive scans. Underlying pathologies included pancreatic, colorectal, renal cell, and head-neck squamous cell carcinoma, as well as lymphoma (4 patients). Three thrombotic lesions on contrast-enhanced CT were PET/CT negative, due to VTE (2 patients) and leiomyomatosis. Accuracy of PET/CT to differentiate between tumor thrombosis and benign VTE was 100% in this small study.

Conclusions: Contrast-enhanced CT defines the extent of thrombotic lesions, while the functional information from PET/CT characterizes the lesions. It appears that PET/CT may be helpful in the diagnosis of occult tumor thrombosis and its differentiation from VTE.

Background: Cardiac computed tomography scans influde several extra-cardiac structures such as mediastinum, lung parenchyma and upper abdominal organs. A variety of abnormalities in those structures might be clinically important and in some cases might explain the patient's complaints.

Objectives: To analyze consecutive cardiac computed tomography examinations for the prevalence and clinical significance of extra-cardiac findings.

Methods: Cardiac CT scans of 134 sequential patients (104 males, 30 females) aged 20–77 years (mean 54 years) with suspected coronary artery disease were prospectively and independently reviewed by a consensus of two radiologists for the presence of lung, mediastinal, pleural, upper abdominal and skeletal abnormalities. CT scans with extra-cardiac abnormalities were divided into two groups: group A – defined as "clinically significant" or "potentially significant findings" – consisted of patients requiring further evaluation or follow-up, and group B – "clinically non-significant findings."

Results: Extra-cardiac abnormalities were found in 103 of the 134 patients (76.8%). Group A abnormalities were found in 52/134 patients (39%), while group B abnormalities were seen in 85/134 (63%). The most common abnormalities in group A were non-calcified lung nodules (> 4 mm) noted in 17/134 patients (13%), followed by enlarged mediastinal lymph nodes (> 10 mm) in 14/134 (10%), diaphragmatic hernia (2 cm) in 12/134 (9%), moderate or severe degenerative spine disease in 12/134 (9%), and emphysema and aortic aneurysm in 6 patients each (4.5%). A malignant lung tumor was noted in one patient.

Conclusions: There is a high prevalence of non-cardiac abnormalities in patients undergoing CCT[1]. Clinically significant or potentially significant findings can be expected in 40% of patients who undergo CCT, and these will require further evaluation and follow-up. The reporting radiologist should be experienced in chest imaging and aware of the large variety of non-cardiac findings in CCT that might explain the patient's complaints. 

Background: Computed tomographic colonography, also known as virtual colonoscopy, is a rapid, non-invasive imaging technique for the detection of colorectal masses and polyps that is becoming increasingly popular.

Objectives: To evaluate the availability, technique, standards of performance and indications for CT colonography in Israel.

Methods: A questionnaire on CT colonography was sent to all radiology departments and private institutions that perform CTC[1] in Israel. We evaluated multiple technical parameters regarding the performance and interpretation of CTC as well as radiologists' training and experience.

Results: Fourteen institutions – 7 hospitals and 7 private clinics – participated in the study. Most of the small radiology departments and nearly all of the more peripheral radiology departments do not perform CTC studies. Since 2000 and until March 2007, a total of 15,165 CTC studies were performed but only 14% (2123 examinations) were performed at public hospitals and 86% (13,042 exams) at private clinics. CTC was performed after an incomplete colonoscopy or for various contraindications to endoscopic colonoscopy in up to a third of cases. In the various institutions patients were self-referred in 20–60% of cases, more commonly in private clinics. All CTC examinations were performed on 16–64 slice CT scanners and only a small minority was performed on 4-slice scanners in 2001. All but one center used low radiation protocols. Nearly all facilities used a 2 day bowel-cleansing protocol. All except one facility did not use stool tagging or computer-aided diagnosis. All facilities inflated the colon with room air manually. All institutions used state-of-the-art workstations, 3D and endoluminal navigation, and coronal multi-planar reconstructions routinely. There are 18 radiologists in the country who perform and interpret CTC studies; half of them trained abroad. Ten of the radiologists (56%) have read more than 500 CTC studies.

Conclusions: In Israel, CTC examinations are performed by well-trained and highly experienced radiologists using the latest CT scanners and workstations and adhering to acceptable CTC guidelines.  

A thorough medical inquiry is included in every aviation mishap investigation. While the gold standard of this investigation is a forensic pathology examination, numerous reports stress the important role of computed tomography in the postmortem evaluation of trauma victims. To characterize the findings identified by postmortem CT and compare its performance to conventional autopsy in victims of military aviation mishaps, we analyzed seven postmortem CT examinations. Musculoskeletal injuries accounted for 57.8% of traumatic findings, identified by postmortem CT. The most frequent findings were fractures of the rib (47%), skull (9.6%) and facial bones (8.6%). Abnormally located air accounted for 24% of findings, for which CT was superior (3.5% detected by autopsy, 100% by postmortem CT, P < 0.001).  The performance of autopsy in detecting injuries was superior (autopsy detected 85.8% of all injuries, postmortem CT detected 53.9%, P < 0.001), especially in the detection of superficial lesions (100% detected by autopsy, 10.5% by postmortem CT, P < 0.001) and solid organ injuries (100% by autopsy, 18.5% by postmortem CT, P < 0.001), and in the detection of musculoskeletal injuries (91.3% for autopsy, 90.3% for postmortem CT, P = not significant). Postmortem CT and autopsy have distinct performance profiles, and although the first cannot replace the latter it is a useful complementary examination.

Background: Emergency room triage of patients presenting with chest pain syndromes may be difficult. Under-diagnosis may be dangerous, while over0diagnosis may be costly.

Objectives: To report our initial experience with an emergency room cardiologist-based chest pain unit in Israel.

Methods: During a 5 week pilot study, we examined resource utilization and ER [1] diagnosis in 124 patients with chest pain of uncertain etiology or non-high risk acute coronary syndrome. First assessment was performed by the ER physicians and was followed by a second assessment by the CPU[2] team. Assessment was based on the following parameters: medical history and examination, serial electrocardiography, hematology, biochemistry and biomarkers for ACS[3], exercise stress testing and/or 64-slice multi-detector cardiac computed tomography angiography. Changes in decision between initial assessment and final CPU assessment with regard to hospitalization and utilization of resources were recorded.

Results: All patients had at least two cardiac troponin T measurements, 19 underwent EST[4], 9 echocardiography and 29 cardiac MDCT[5]. Fourteen patients were referred for early cardiac catheterization (same/next day). Specific working diagnosis was reached in 71/84 patients hospitalized, including unstable angina in 39 (31%) and non-ST elevation myocardial infarction in 12 (10%). Following CPU assessment, 40/124 patients (32%) were discharged, 49 (39%) were admitted to Internal Medicine and 35 (28%) to the Cardiology departments. CPU assessment and extended resources allowed discharge of 30/101 patients (30%) who were initially identified as candidates for hospitalization after ER assessment. Furthermore, 13/23 (56%) of patients who were candidates for discharge after initial ER assessment were eventually hospitalized. Use of non-invasive tests was significantly greater in patients discharged from the ER (85% vs. 38% patients hospitalized) (P < 0.0001). The mean ER stay tended to be longer (14.9 ± 8.6 hours vs. 12.9 ± 11, P = NS) for patients discharged. At 30 days follow-up, there were no adverse events (myocardial infarction or death) in any of the 40 patients discharged from the ER after CPU assessment. One patient returned to the ER because of chest pain and was discharged after re-assessment. 

Conclusions: Our initial experience showed that an ER cardiologist-based chest pain unit improved assessment of patients presenting to the ER with chest pain, and enhanced appropriate use of diagnostic tests prior to decision regarding admission/discharge from the ER.

Multidetector-row computed tomography has been validated as a useful non-invasive diagnostic method in patients with various cardiac diseases.

Background: Acute renal infarction is an oft-missed diagnosis. As a result; its true incidence, although presumed to be low, is actually unknown. Surprisingly, the medical literature on the subject, other than anecdotal case reports, is scarce.

Objectives: To increase physician awareness of the diagnosis and to identify predictive clinical and laboratory features of the entity.

Method: Between 1 November 1997 and 31 October 2000, 11 cases of acute renal infarction in 10 patients were diagnosed in our center by contrast-enhanced computerized tomography. The medical charts of these patients were reviewed regarding risk factor, clinical presentation, possible predictive laboratory examinations, and out-come.

Results: During the 36 month observation period, the incidence of acute renal infarction was 0.007%. The mean age of the patients (5 men and 5 women) was 67.4 + 21.1 (range 30-87 years). In four cases the right and in five the left kidney was involved; in the other. two cases bilateral:involvement was seen. In 7/10 patients, an increased risk for thromboembolic events was found. Six had chronic atrial fibrillation and one had a combined activated protein C resistance and protein S deficiency, Three patients had suffered a previous thromboembolic event. Two cases were receiving anticoagulant therapy with an INR of 1.6 and 1.8, respectively. On admission, flank pain was recorded in 10/11, fever in 5 and nausea/vomiting in 4 cases. Hematuria was detected in urine reagent strips in all cases; Serum lactate dehydrogenase and white blood cell count were elevated in all cases (1,570 + 703 IU/L and 12,988 + 3,841/ l, respectively). In no case was the diagnosis of acute renal infarction  initially entertained. The working diagnoses were .renal colic in 2 pyelonephritis in 3, renal carcinoma, digitails intoxication, and suspected endocarditis in one patient each, and an acute abdomen in 3. Time from admission to definitive CT diagnosis ranged from 24 hours to 6 days; Three patients were treated with intravenous heparin and another with a combination of IV heparin and renal intra-arterial urokinase infusion with, in the latter case, no recovery of function of the affected kidney. With the exception of this one patient (with a contralateral contracted kidney) who required maintenance dialysis, in all other cases serum creatinine levels. remained unchanged or reverted to the baseline mean of 1.1 mg/dl (0.9-1.2).

Conclusions: Acute renal infarction is not as rare as previously assumed. The entity is often misdiagnosed. Unilateral flank pain in a patient with an increased risk for thromboembolism should raise the suspicion of renal infarction. In such a setting, hematuria, leuaocytosis and an elevated LDH level are strongly supportive of the diagnosis.