Panos Prassopoulos

Assessment of Crohn's disease activity in the small bowel with MR and conventional enteroclysis: preliminary results

Every single imaging finding that can be disclosed on conventional and MR enteroclysis was correlated with the Crohn’s disease activity index (CDAI). Nineteen consecutive patients with Crohn’s disease underwent colon endoscopy and both conventional and MR enteroclysis examinations. Seventeen MR imaging findings and seven conventional enteroclysis findings were ranked on a four-point grading scale and correlated with CDAI, with a value of 150 considered as the threshold for disease activity. Six patients had active disease in the colon according to colon endoscopy. In the remaining 13 patients, the presence of deep ulcers (P=0.002), small bowel wall thickening (P=0.022) and gadolinium enhancement of mesenteric lymph nodes (P=0.014) identified on MR enteroclysis images were strongly correlated to disease activity. The product of deep ulcers and enhancement of lymph node ranks identified on MR enteroclysis were the optimum combination for discriminating active from non-active disease (F-test: 55.95, P<0.001). Additionally, the ranking of deep ulcers on conventional enteroclysis provided statistically significant differences between active and non-active patients (F-test: 14.12, P=0.004). Abnormalities strongly suggestive of active Crohn’s disease can be disclosed on MR enteroclysis examinations and may provide pictorial information for local inflammatory activity.

Determination of normal splenic volume on computed tomography in relation to age, gender and body habitus

Abstract The purpose of our study was to examine variations in normal splenic size in relation to age, gender and body habitus in vivo, and to determine normative data for splenic volume on CT. The width (W), length (L), thickness (Th), cross-sectional areas and volume (Vol) of the spleen were obtained from abdominal CT examinations of 140 patients who underwent CT for indications unrelated to splenic disease. Splenic volume did not vary significantly (–0.04 < r < 0.05, p > 0.10) with the patients age, gender, height, weight, body mass index or the diameter of the first lumbar vertebra, the latter considered as representative of body habitus on CT. The mean value of the measured splenic volume (S Vol) was 214.6 cm3 with a range from 107.2 to 314.5 cm3. S Vol correlated well with all the linear and the maximal cross-sectional area measurements and could be calculated using the formula: S Vol = 30 + 0.58 (W × L × Th.). Employing the same formula splenic volume was reliably assessed in 47 patients with clinically evident splenomegaly. Quantitative assessment of splenic volume might be of value in assessing mild variations in splenic size, because splenomegaly is the most common manifestation of splenic involvement in many disorders.

MR enteroclysis: technical considerations and clinical applications.

Abstract. Magnetic resonance enteroclysis (MRE) is an emerging technique for the evaluation of small bowel abnormalities. Adequate luminal distention, achieved by the administration of iso-osmotic water solution through a nasojejunal catheter, in combination with ultrafast sequences, such as single-shot turbo spin echo, true fast imaging with steady precession, half-Fourier acquired single-shot turbo spin echo, and 3D fast low-angle shot, results in excellent anatomic demonstration of the small bowel. Magnetic resonance fluoroscopy can be performed during MRE examination and might be useful in studying low-grade stenosis or motility-related disorders. Magnetic resonance enteroclysis is very promising in detecting the number and extent of involved small bowel segments in patients with Crohn’s disease, and in disclosing lumen narrowing and extramural manifestations and complications of the disease. Initial experience shows that MRE is very efficient in the diagnosis of small bowel tumors and can be used in the evaluation of small bowel obstruction.

Imaging of small intestinal Crohn’s disease: comparison between MR enteroclysis and conventional enteroclysis

The purpose of this study was to compare MR enteroclysis (MRE) with conventional enteroclysis (CE) in patients with small intestinal Crohn’s disease. Fifty-two consecutive patients with known or suspected Crohn’s disease underwent MR and conventional enteroclysis, which was considered the gold standard. Eleven imaging features, classified in three groups, mucosal, transmural and extraintestinal, were subjectively evaluated by two experienced radiologists. MRE and CE were in full agreement in revealing, localizing and estimating the length of all involved segments of the small bowel. The sensitivity of MRE for the detection of superficial ulcers, fold distortion and fold thickening was 40, 30 and 62.5%, respectively. The sensitivity of MRE for the detection of deep ulcers, cobble-stoning pattern, stenosis and prestenostic dilatation was 89.5, 92.3, 100 and 100%, respectively. Additional findings demonstrated on MRE images included fibrofatty proliferation in 15 cases and mesenteric lymphadenopathy in 19 cases. MRE strongly correlates with CE in the detection of individual lesions expressing small intestinal Crohn’s disease. It provides additional information from the mesenteries; however, its capability to detect subtle lesions is still inferior to conventional enteroclysis.

Acute abdomen due to torsion of wandering spleen: CT diagnosis

Abstract. Two adults and a child with acute abdomen and surgically confirmed torsion of wandering spleen are presented. Computed tomography provided a spectrum of findings including an ovoid or comma-shaped abdominal mass, hypertrophy of the livers left lobe, a whirled appearance of hyperdense, nonenhancing splenic vessels, and an enlarged spleen, exhibiting minimal or no enhancement. Computed tomography also indicated the point of torsion and the viability of splenic parenchyma.

Comparison of two volumetric techniques for estimating liver volume using magnetic resonance imaging

To compare the conventional technique of manual planimetry with the point counting technique for estimating liver volume from magnetic resonance imaging (MRI) data.

Extracranial venous hemodynamics in multiple sclerosis: A case-control study

Objectives: A chronic state of impaired cerebral and cervical venous drainage, termed chronic cerebrospinal venous insufficiency (CCSVI), has recently been implicated in the pathogenesis of multiple sclerosis (MS). We performed a color-coded Doppler sonography case-control study to externally validate the CCSVI criteria. Methods: We prospectively evaluated consecutive patients with clinically definite MS and healthy volunteers using extracranial and transcranial color-coded Doppler sonography. The recently developed neurosonology criteria for CCSVI detection were used for interpretation of ultrasound assessments. The presence of venous reflux in cervical veins was assessed both in the sitting and upright position during a short period of apnea and after Valsalva maneuver. Results: We recruited 42 patients with MS (mean age 39 ± 11 years, 17 men) and 43 control individuals (mean age 38 ± 12 years, 16 men). Very good/excellent intrarater and interrater agreement (κ values 0.82–1.00) was documented in 3 out of 5 CCSVI criteria. There was no evidence of stenosis or nondetectable Doppler flow in cervical veins in patients and controls. Reflux in internal jugular vein (IJV) was documented in 1 patient (2%) and 1 control subject (2%), both in sitting and supine posture during apnea. After performing Valsalva maneuver, we documented the presence of IJV valve incompetence in 3 patients with MS (7%) and 4 healthy volunteers (9%; p > 0.999). Conclusions: With established reproducibility of venous ultrasound testing, our data argue against CCSVI as the underlying mechanism of MS. Without further independent validation of CCSVI, potentially dangerous endovascular procedures, proposed as novel therapy for MS, should not be performed outside controlled clinical trials.

Groove pancreatitis: a diagnostic challenge

Groove pancreatitis is a distinct form of chronic pancreatitis characterized by inflammation and fibrous tissue formation, affecting the groove area between the head of the pancreas, the duodenum and the common bile duct. It is manifested on imaging by a sheet-like mass in the groove area near the minor papilla. Thickening of the duodenal wall and cystic transformation in the duodenal wall also represent common imaging features. Pathogenesis is still unclear, and clinical presentation is not specific. Endoscopic ultrasonography (EUS), computed tomography (CT) and magnetic resonance imaging (MRI) demonstrate imaging findings consistent with the disease in typical cases, but specific diagnosis is challenging in a number of patients where biopsy is required. The disease may mimic pancreatic, common bile duct or duodenal wall cancer that requires prompt and excessive surgical intervention, as opposed to groove pancreatitis where initial conservative treatment is suggested. The clinical, histopathological and radiological features on cross-sectional imaging of this entity are discussed in this review, and differential diagnostic clues are given.

CT imaging of blunt chest trauma

BackgroundThoracic injury overall is the third most common cause of trauma following injury to the head and extremities. Thoracic trauma has a high morbidity and mortality, accounting for approximately 25% of trauma-related deaths, second only to head trauma. More than 70% of cases of blunt thoracic trauma are due to motor vehicle collisions, with the remainder caused by falls or blows from blunt objects.MethodsThe mechanisms of injury, spectrum of abnormalities and radiological findings encountered in blunt thoracic trauma are categorised into injuries of the pleural space (pneumothorax, hemothorax), the lungs (pulmonary contusion, laceration and herniation), the airways (tracheobronchial lacerations, Macklin effect), the oesophagus, the heart, the aorta, the diaphragm and the chest wall (rib, scapular, sternal fractures and sternoclavicular dislocations). The possible coexistence of multiple types of injury in a single patient is stressed, and therefore systematic exclusion after thorough investigation of all types of injury is warranted.ResultsThe superiority of CT over chest radiography in diagnosing chest trauma is well documented. Moreover, with the advent of MDCT the imaging time for trauma patients has been significantly reduced to several seconds, allowing more time for appropriate post-diagnosis care.ConclusionHigh-quality multiplanar and volumetric reformatted CT images greatly improve the detection of injuries and enhance the understanding of mechanisms of trauma-related abnormalities.

T2 relaxation time analysis in patients with multiple sclerosis: correlation with magnetization transfer ratio

The aim of the current study was to perform T2 relaxation time measurements in multiple sclerosis (MS) patients and correlate them with magnetization transfer ratio (MTR) measurements, in order to investigate in more detail the various histopathological changes that occur in lesions and normal-appearing white matter (NAWM). A total number of 291 measurements of MTR and T2 relaxation times were performed in 13 MS patients and 10 age-matched healthy volunteers. Measurements concerned MS plaques (105), NAWM (80), and “dirty” white matter (DWM; 30), evenly divided between the MS patients, and normal white matter (NWM; 76) in the healthy volunteers. Biexponential T2 relaxation-time analysis was performed, and also possible linearity between MTR and mean T2 relaxation times was evaluated using linear regression analysis in all subgroups. Biexponential relaxation was more pronounced in “black-hole” lesions (16.6%) and homogeneous enhancing plaques (10%), whereas DWM, NAWM, and mildly hypointense lesions presented biexponential behavior with a lower frequency(6.6, 5, and 3.1%, respectively). Non-enhancing isointense lesions and normal white matter did not reveal any biexponentional behavior. Linear regression analysis between monoexponential T2 relaxation time and MTR measurements demonstrated excellent correlation for DWM(r=−0.78, p<0.0001), very good correlation for black-hole lesions(r=-0.71, p=0.002), good correlation for isointense lesions(r=−0.60, p=0.005), moderate correlation for mildly hypointense lesions(r=−0.34, p=0.007), and non-significant correlation for homogeneous enhancing plaques, NAWM, and NWM. Biexponential T2 relaxation-time behavior is seen in only very few lesions (mainly on plaques with high degree of demyelination and axonal loss). A strong correlation between MTR and monoexponential T2 values was found in regions where either inflammation or demyelination predominates; however, when both pathological conditions coexist, this linear relationship is lost.