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Purpose: The aim of this study was to identify and classify the ultrasonographic and computed tomography (CT) signs of simple and complicated acute cholecystitis and to define the correct diagnostic protocol., Materials and Methods: We retrospectively reviewed 35 patients (23 men and 12 women; mean age 66.6 years) presenting with acute cholecystitis who were assessed by emergency ultrasonography (US) (30/35 cases) and spiral CT (12/35 cases); all patients underwent emergency surgery. The US signs were analysed and classified as major criteria (wall thickening and stratification, distension, Murphy's sign), minor criteria (bile stones, sludge, and biliary tract dilatation), and complication signs (gas collections, aerobilia, fluid collection, difficult or missed identification of the gallbladder). Imaging results were compared with histological findings (gold standard), and accuracy, sensitivity, specificity, and positive and negative predictive values (PPVs and NPVs) were assessed for each modality. Concordance between the US and CT findings was also evaluated for cases undergoing both examinations; additional findings provided by one or the other modality were also assessed., Results: US had an accuracy of 66.6%, a sensitivity of 37.5%, a specificity of 70%, a PPV of 100%, and an NPV of 58.3%. CT had 100% accuracy, sensitivity, and specificity. Concordance between US and CT was observed for diagnosis of complications, but CT provided additional findings in all cases. The majority of complicated cases undergoing US examination (68.7%) revealed more than two major criteria and one minor criterion or at least one sign of complication., Conclusions: If more than two major signs associated with one minor sign or at least one sign of complication are present at US, CT is mandatory to recognise and thoroughly evaluate the type of complication and indicate appropriate treatment.

Purpose: One the main reasons for the limited use of MRI in the evaluation of aortic dissection in emergency conditions is its long execution time. The authors report their experience regarding a new MRI sequence that reduces execution time and avoids the use of contrast medium., Materials and Methods: Eighteen haemodynamically stable patients with suspected (16 cases, 3 with confirmed diagnosis of aneurysm) or known aortic dissection (2 cases) underwent in emergency conditions 1.5T MRI with Steady-State sequence (Fast Imaging Employing Steady-State Acquisition: GRE 2D; TR 3.5, TE 1.6; Flip Angle 45, bandwidth 125, matrix 224x224, NEX 1, acquisition time per slice 7 s, thickness 6-8 mm, FOV 38; 2D-GE breath-hold sequence requiring cardiac triggering). The results obtained were compared in terms of diagnostic accuracy and execution time with those of classical MRI examination (black blood T1, FSE T2 and 3D MR-angiography) or multislice CT., Results: The diagnostic accuracy of MRI, both with Steady-State sequence and the ''classical'' technique, and multislice CT in the diagnosis of dissection or aneurysm is equal (100%), whereas execution time is 6, 25 and 6 minutes, respectively. Multislice CT proved to be more accurate than Steady-State MRI in evaluating the renal parenchyma and the extension of the dissection to the renal arteries., Conclusions: The Steady-State MRI sequence provides a diagnosis of aortic dissection or aneurysmal dilatation in a short time and may represent a valuable alternative to CT in emergency settings, especially in patients with reported contraindications to iodinated contrast media.

Purpose: To establish the additional value of MR Spectroscopy (3D CSI MRS Three-dimensional Chemical Shift Imaging Magnetic Resonance Spectroscopy) to endorectal MR in the diagnosis and grading of prostate cancer., Materials and Methods: MR and 3D CSI MR spectroscopy were performed in 53 patients with suspicion of prostate cancer on the basis of rectal exploration and/or transrectal ultrasound and/or the PSA levels. All the examinations were performed with a 1.5 T imager using an endorectal coil. We acquired axial and coronal T2-weighted FSE sequences, axial T1-weighted SE sequences and PRESS 3D CSI (Point Resolved Spectroscopy 3D Chemical Shift Imaging) sequences localized on the axial T2 images so as to include the prostatic gland while excluding the periprostatic fat. The MR examinations were evaluated by two radiologists unaware of the clinical data, transrectal ultrasound findings, PSA levels and histological findings. The MR and 3D CSI MRS findings were compared with the biopsy findings in 22 cases and with material obtained from laparoscopic prostatectomy in 31 cases., Results: The histological examination revealed adenocarcinoma in 37 cases, prostatitis in 2 cases and no alterations in the remaining 14 cases. The morphologic MR scan showed a sensitivity of 76%, a specificity of 56%, an accuracy of 70%, a PPV of 80% and a NPV of 50%. By combining MR and 3D CSI MRS we obtained a sensitivity of 95%, a specificity of 81%, an accuracy of 91%, a PPV of 92% and a NPV of 87%. Elevated choline concentrations were found both in tumours with a low Gleason score (18 cases) and in those with a high Gleason score (19 cases); instead we found markedly reduced (n=9) or absent (n=4) citrate only in the tumours with a high Gleason score, while we found normal citrate levels in the 18 tumours with a low Gleason score., Conclusions: The 3D CSI MRS improved the reliability of endorectal MR in the diagnosis and characterisation of prostatic cancer. Moreover, the 3D CSI MRS findings demonstrated a linear correlation with tumour grade.

Purpose: We investigated the comparative sensitivity of virtual and conventional cystoscopy in patients with urinary bladder cancer., Material and Methods: Twelve patients (8 men and 4 women; mean age: 61 years, range: 49-73) with findings of bladder cancer at conventional cystoscopy were submitted to volumetric spiral CT of the urinary bladder. Before the examination, the urinary bladder was distended with 180-200 mL of air. CT findings were then sent to an independent workstation to generate interactive intraluminal views of the bladder. The findings of virtual cystoscopy were compared with those of conventional cystoscopy in 11 patients and with the findings of transurethral resection after urethrotomy in one patient. All lesions had pathologic confirmation., Results: Eighteen (90%) of 20 masses detected on conventional cystoscopy were visualized with virtual cystoscopy. The latter allowed readers to identify 13 of 13 masses (100%) > 1 cm and only 5 of 7 (71%) < 1 cm; three 4-mm masses were missed. Although only a subjective evaluation of lesion size was possible on conventional cystoscopy, there seemed to be good agreement on mass size and site with both techniques., Discussion: Cystoscopy plays a key role in the diagnosis of urinary bladder carcinoma. However cystoscopy is invasive, has a limited field of view and lacks an objective scale; moreover, it is not indicated in patients with severe urethral strictures or active vesical bleeding. In our study, virtual cystoscopy depicted all the masses > 1 cm, and a lesion in a diverticulum with a small opening. Virtual cystoscopy was also very useful in a patient with urethral stricture (who could no be submitted to conventional cystoscopy) where it showed the lesion before transurethral resection after urethrotomy. The virtual technique could also be complementary to conventional cystoscopy in evaluation of bladder base and anterior bladder neck, as well as for postchemotherapy follow-up. Unfortunately virtual cystoscopy does not allow biopsy of suspicious lesions.

Purpose: The purpose of this study was to investigate if Triphasic Spiral CT (arterial, portal and equilibrium phases) can improve the characterization of noncystic focal lesions., Material and Methods: Sixty-six patients with suspected focal liver disease underwent Triphasic Spiral CT. After the injection of 120-140 ml contrast material at 3 ml/s the liver was imaged in the arterial (scanning delay: 20-27 s), portal (scanning delay: 45-80 s) and equilibrium (scanning delay: 5-8 min) phases. The enhancement of each lesion was evaluated in each phase and the lesions were grouped by enhancement pattern (11 patterns in all). The reference standards in our 66 patients were surgery (12), biopsy (43), MRI (9), follow-up (9), somatostatin receptor scintigraphy (6)., Results: One hundred and twenty-six liver lesions were detected in 66 patients, four of 11 enhancement patterns (hypo/hyper/hyper, hyper/iso/iso, hyper/hyper/iso, hyper/hyper/hyper) were always referrable to benign disease (hemangioma, focal nodular hyperplasia-FNH-adenoma). Four of 11 enhancement patterns (iso/hypo/hypo, iso/iso/hypo, hyper/hypo/hypo, hyper/hyper/hypo) were always referrable to malignant disease (hepatocellular carcinoma-HCC-metastases). The other two patterns (hypo/hypo/hypo, hypo/hypo/hyper) were seen in both benign and malignant diseases., Conclusions: Triphasic Spiral CT improves the characterization of HCC, FNH, adenoma and hemangioma. The arterial and the equilibrium phases add no information to the yield of the portal venous phase in metastases, except for those from pancreas neuroendocrine tumors in the arterial phase. In our experience, patients with unclassified lesions at US or conventional CT, suspected HCC and metastases from pancreas neuroendocrine tumors should be submitted to Triphasic CT of the liver. This technique however does not appear to be indicated in the study of liver metastases from hypovascular tumors, while it improves the detection of FNH and adenoma.

Introduction: We investigated the accuracy of MRI of the prostate with an endorectal surface coil in determing penetration of the prostatic capsule and invasion of seminal vescicles in prostate carcinoma., Material and Methods: Endorectal coil MRI (1 Tesla) was performed in 300 patients with biopsy-proved cancer. The PSA levels were always calculated and all the patients were examined with transrectal ultrasound. The imaging protocol included Turbo Spin Echo T2-weigthed (3900/150 TR/TE) axial and coronal images and T1-weigthed (650/15 TR/TE) axial images, 4 mm thick interleaved sections with .4 mm intersection gap, FOV 180 mm, 256 x 256 matrix (reconstruction 512). Seventy-five patients underwent radical prostatectomy and MR images were compared with pathologic findings of capsular penetration and invasion of seminal vescicles. The MR signs specific for capsular penetration were: deformation (irregularity) of capsular profile, capsular retraction with irregular margins, capsular interruption, obliteration of periprostatic adipose tissue, asymmetry of neurovascular bundles., Results: MRI correctly depicted 37 of 45 pathologic stage T2 lesions and correctly depicted macroscopic capsular penetration (T3) in 18 of 23 cases. Microscopic capsular penetration was overestimated in all 7 cases. Sensitivity, specificity, accuracy, for microscopic and macroscopic capsular penetration were 60, 82, 73% respectively. Sensitivity, specificity, accuracy for macroscopic capsular penetration were 78, 82, 80% respectively. Sensitivity, specificity, accuracy for depiction of seminal vesicle involvment were 80, 100, 93%, respectively. The most reliable signs of capsular penetration were capsular interruption and invasion of periprostatic adipose tissue, while asymmetry of the neurovascular bundle was not seen., Conclusions: MRI provides accurate preoperative local staging. The two main limitations of MRI were the high rate of microscopic capsular penetration and the difficulty in detecting capsular penetration of tumor when the lesions are in the prostate apex. Prostate enlargement also made diagnosis more difficult.

Thirty-three patients with mediastinal masses were examined by means of MRI to obtain elements for lesion characterization, to evaluate lesion extent, and to assess the relationship of the mass to the surrounding structures, especially the great vessels (accuracy: 84.84%), mediastinal structures (accuracy: 76.78%), and lung parenchyma (accuracy 69.69%). MR data were compared to CT findings; sensitivity, specificity and accuracy were subsequently compared to surgical and histologic findings. The results have shown MRI to be a very reliable method in the evaluation of mediastinal masses.

Fourteen patients, who had undergone surgery for rectal carcinoma, were studied by MR imaging to evaluate the presence of recurrences. MR results were compared to those obtained by needle biopsy or laparotomy. MR imaging proved to be a valuable method in diagnosing tumor recurrences on the basis of tissular morphology, whereas its capabilities were poor in differentiating recurrence from fibrosis on the basis of the signal intensity on T2-weighted images.

This study was aimed at assessing MR utility in the evaluation of cerebral-medullar malformative pathologic conditions in infants. Among 274 patients 2 months to 15 years old examined by means of MR imaging, 51 (18.6%) were affected with cerebral-medullar abnormalities. Seventeen different types of pathologic conditions were identified, some of which single and some multiple; tethered cord was the most frequent finding. 45/51 patients affected with malformative pathologic conditions required sedation. The high incidence of malformative pathologic conditions in pediatrics highlights the importance of this subject for all the radiologists dealing with MR imaging in pediatrics. MR imaging appears to be the method of choice for the evaluation of cerebral-medullar abnormalities.

Forty eight patients surgically treated for carcinoma of the rectum were by computed tomography (CT) during routine follow up to test the value if this procedure in the early diagnosis of pelvic recurrences. We used a protocol which schedules controls at different intervals for Dukes A e B and for Dukes C patients; CT showed pelvic recurrences in 13.3% of the Dukes A e B and in 50% of Dukes C cases. CT seems to be the most reliable presently available test in detecting early extraluminal recurrence after radical resection for rectal cancer.

Twenty-two patients with bladder carcinoma were examined by MR imaging and CT to determine the degree of parietal involvement. The results were then compared with the surgical and histological findings. A classification in CT and MR stages was elaborated in order to supply corresponding models to clinical TNM staging. Three groups were thus formed, corresponding to the evolutive phases of the tumor. The first MR group included T1-T2 forms (accuracy: 75%); the second group included T3a forms (accuracy: 75%), and the third T3b-T4 forms (accuracy: 90%). Overall MR accuracy was 81.81%. The first CT group included T1 forms (acc. 71.42%), the second group T2-T3a forms (acc. 60%), and the third group included T3b-T4 forms (acc. 90%). Overall CT accuracy was 77.27%. MR imaging proved thus more accurate than CT in the staging of bladder tumors, especially thanks to its allowing deep muscular involvement to be assessed.