Unenhanced whole-body MRI versus PET-CT for the detection of prostate cancer metastases after primary treatment.

OBJECTIVE: The aim of this study was to evaluate the accuracy of unenhanced whole-body MRI, including whole-body Diffusion Weighted Imaging (DWI), used as a diagnostic modality to detect  pathologic lymph nodes and skeletal metastases in patients with prostate cancer (PCa) undergoing restaging after primary treatment. PATIENTS AND METHODS: 152 male patients with biochemical recurrence after radical prostatectomy (RP) or external beam radiation therapy (EBRT) underwent MRI at a 1.5 Tesla magnet with whole spinal sagittal T2-weighted, sagittal T1-weighted, sagittal STIR images, axial T1 and T2-weighted and STIR images of the pelvis and whole-body. 18Fcholine-PET/CT exam was used as the reference standard. RESULTS: MRI protocol including whole-body combined T1-weighted+T2-weighted+STIR+DWI showed a sensitivity (Se) of 99%, a specificity (Spe) of 98%, a positive predictive value (PPV) of 98%, a negative predictive value (NPV) of 96%, an accuracy of 98% and an area under the receiver operating characteristic curve (AUC) of 0.971 for identification of bone metastatic lesion. The same protocol, displayed a Se of 98%, a Spe of 99%, a PPV of 97%, a NPV of 98%, an accuracy of 98 % and an AUC of 0.960 in the detection of pathologic lymph nodes. CONCLUSIONS: Unenhanced whole-body MRI, including whole-body-DWI, is an accurate and cost-effective diagnostic tool which is able to detect lymph node involvement and bone metastases in patients with biochemically recurrent PCa after RP or EBRT. Thanks to its lack of ionizing radiation, excellent soft tissue contrast, high spatial resolution, no need of contrast agent, high Se and Spe, it could play a role in the restaging procedure of such patients.

Pitfalls in Interpreting mp-MRI of the Prostate: A Pictorial Review with Pathologic Correlation.

OBJECTIVES: The purpose of this pictorial review is to present a wide spectrum of prostate multiparametric MRI (mp-MRI) pitfalls that may occur in clinical practice, with radiological and pathological correlation. METHODS: All examinations were performed according to ESUR Guidelines protocols. RESULTS AND CONCLUSION: mp-MRI imaging of the prostate often leads to interpreting doubts and misdiagnosis due to the many interpretative pitfalls that a tissue, whether healthy or treated, may cause. These "false-positive" findings may occur in each stage of the disease history, from the primary diagnosis and staging, to the post-treatment stage, and whether they are caused by the tissue itself or are iatrogenic, their recognition is critical for proper treatment and management. Knowledge of these known pitfalls and their interpretation in the anatomical-radiological context can help radiologists avoid misdiagnosis and consequently mistreatment. MAIN MESSAGES: • Some physiological changes in the peripheral and central zone may simulate prostate cancer. • Technical errors, such as mispositioned endorectal coils, can affect the mp-MRI interpretation. • Physiological changes post-treatment can simulate recurrence.

Preoperative staging of colorectal cancer using virtual colonoscopy: correlation with surgical results.

OBJECTIVE: The aim of this study was to evaluate the clinical usefulness of computed tomography colonography (CTC) in the preoperative staging in patients with abdominal pain for occlusive colorectal cancer (CRC) and to compare the results of CTC with the surgical ones. PATIENTS AND METHODS: 127 patients with abdominal pain, iron deficiency anemia and occlusive CRC underwent a CTC examination in prone position without intravenous contrast agent and in prone position after administration of intravenous contrast medium. All the patients underwent surgery after CTC. Two radiologists with different experience analyzed the images first independently and then by consensus. They evaluated the location of the lesion, the depth of the invasion of the colon-rectal wall (T stage), lymph node involvement (N stage) and the presence or absence of distant metastasis (M stage). CTC findings were correlated with surgical outcomes. RESULTS: The overall accuracy values for tumour localization according to consensus reading of CTC examinations in comparison to surgical results were 100% (K = 1, p = 0.0001). The overall accuracy values of agreement for T staging of reader 1, reader 2 and consensus reading of CTC examinations in comparison to surgical results were respectively 95.5% (K = 0.876, p = 0.0035), 93.3% (K = 0.858, p = 0.0037) and 97.7% (K = 0.926, p = 0.0014) for ≤ T2; 91.3% (K = 0.839, p = 0.0027), 88.3% (K = 0.817, p = 0.0031), and 92.9% (K = 0.894, p = 0.0025) for T3; 89.6% (K = 0.825, p = 0.0037), 86.2% (K = 0.837, p = 0.0032) and 89.6% (K = 0.821, p = 0.0023) for T4. The overall accuracy values for N staging for reader 1, reader 2 and consensus reading was 90.2% (K = 0.865, p = 0.0029). The overall accuracy values for M staging of reader 1, reader 2 and consensus reading was 92% (K = 0.875, p = 0.0019). CONCLUSIONS: CTC with is a very useful tool for accurate pre-treatment staging and localization of occlusive CRC.

Imaging biomarkers in prostate cancer: role of PET/CT and MRI.

Prostate-specific antigen (PSA) is currently the most widely used biomarker of prostate cancer (PCa). PSA suggests the presence of primary tumour and disease relapse after treatment, but it is not able to provide a clear distinction between locoregional and distant disease. Molecular and functional imaging, that are able to provide a detailed and comprehensive overview of PCa extension, are more reliable tools for primary tumour detection and disease extension assessment both in staging and restaging. In the present review we evaluate the role of PET/CT and MRI in the diagnosis, staging and restaging of PCa, and the use of these imaging modalities in prognosis, treatment planning and response assessment. Innovative imaging strategies including new radiotracers and hybrid scanners such as PET/MRI are also discussed.

Static and dynamic MR imaging in the evaluation of temporomandibular disorders.

OBJECTIVE: The aim of this study is to prove if dynamic HASTE (half-Fourier acquisition single-shot turbo spin-echo) sequences can be used in the diagnosis of internal derangement disorders of temporomandibular joint (TMJ) as an alternative to static proton density (PD) weighted/turbo spin echo (TSE) T2-weighted sequences which are considered up to now as the gold standard in the evaluation of TMJ disorders (TMDs). PATIENTS AND METHODS: 194 patients for a total of 388 TMJs were examined with a 1.5 Tesla field strength superconducting magnet. Sagittal static PD-weighted/TSE T2-weighted and dynamic HASTE sequences have been used. Three experts in the field of oral radiology (specialist A, B and C) independently and blinded to clinical symptoms and any treatment, assessed the articular disc position in each TMJ (rated as normal or disc displacement with reduction or disc displacement without reduction). The agreement between static and dynamic images and between the three different specialists in the assessment of the articular disc position was evaluated using kappa statistic. RESULTS: The agreement between static and dynamic images is: for specialist A, K = 0.862; for specialist B, K = 0.870 and for specialist C, K = 0.862. CONCLUSIONS: Since there is no complete agreement between these two MR techniques, dynamic sequences can not be used as a reliable alternative to static sequences in the evaluation of internal derangement disorders of TMJ.

3.0 Tesla MRI in the early evaluation of inferior alveolar nerve neurological complications after mandibular third molar extraction: a prospective study.

OBJECTIVES: To evaluate the use of 3.0 T MRI in the prognosis of inferior alveolar nerve (IAN) sensory disorders after mandibular third molar extraction, in the early post-operative period. METHODS: 343 IANs were examined before and 3 days after surgery. Two radiologists evaluated the course of the nerve and the relative signal intensity (RSI). Cohen's kappa coefficient (κ) and intraclass correlation coefficient (ICC) were used to evaluate the interobserver (k = 0.891) and intra-observer variability (ICC = 0.927; 0.914, respectively). The IANs were divided into four groups on the basis of neurosensory disorders recovery time. ANOVA was used to evaluate the differences among the RSIs of the four groups, and multiple comparisons were performed with Tukey's range test. RESULTS: No differences in the course of IANs were found before and after surgery. In 280 IANs, no iatrogenic paraesthesia was found (Group A). 63 IANs showed a neurosensory impairment. 38 IANs showed recovery of post-operative paraesthesia at 3-month follow-up (Group B). 16 IANs showed a full recovery of iatrogenic paraesthesia at 6-month follow-up (Group C). Seven IANs displayed a full recovery at 12-month follow-up and two IANs showed persistence of neurosensory disorders at 18-month follow-up (Group D). The one-way ANOVA results indicated statistically significant difference among all groups (p < 0.05), except between Groups C and D (p = 0.504). CONCLUSIONS: The early evaluation of RSI values represents a valid tool to determine the prognosis of IAN sensory disorders after mandibular third molar extraction.

Densitometric kneecap changes after unilateral knee arthroplasty.

PURPOSE: To assess bone density of kneecaps in subjects with femoro-tibial prosthesis before and after surgery by means of DEXA examination. SUBJECTS AND METHODS: We examined 34 patients with unilateral femoro-tibial prosthesis, 20 healthy subjects of the same age and non-carriers of knee replacement and 14 healthy young adult subjects. All the data sets were analysed by two radiologists (AS and AM). The coincidence of the results between the two specialists was evaluated by means of Cohen's Kappa index and the results were considered statistically significative if p value is < of 0.05. RESULTS: The values of patellar BMD in the group of 34 patients, were: a minimum of 0.386 g/cm(2) (K = 0.879, p = 0.0012), a maximum 1.707 g/cm(2) (K = 0.886, p = 0.0016). The comparison between the left and right knee showed the following data: minimum difference 0.034 g/cm2 (K = 0.901, p = 0.0015), maximum difference of 0.622 g/cm(2) (K = 0.908, p = 0.0017), the average was found to be of 0.277 g/cm(2) (K = 0.894, p = 0.0018). But this difference tends to decrease 6 months after surgery. In the group of healthy young adults, we obtained the following values: a minimum of 0.782 g/cm(2) (K = 0.907, p = 0.0025), maximum 1.503 g/cm(2) (K = 0.932, p = 0.0012). Between both knees, the difference was minimal 0.006 g/cm(2) (K = 0.951, p = 0.0035) and maximum 0.096 g/cm(2) (K = 0.926, p = 0.0007) with an average difference of 0.058 g/cm(2) (K = 0.954, p = 0.0026). In the group of healthy subjects of the same age and non-carriers of knee replacement the values were average higher. A maximum value of 1.134 g/cm(2) (K = 0.894, p = 0.0028) and a minimum value of 0.944 g/cm(2) (K = 0.892, p = 0.0023) were found; between both knees a minimum difference of 0.010 g/cm(2) (K = 0.918, p = 0.0047) and a maximum of 0.090 g/cm(2) (K = 0.937, p = 0.0017) were found, with an average difference of 0.052 g/cm(2) (K = 0.956, p = 0.0024). CONCLUSIONS: DEXA examination of the patellar is recommended as a supplementary study to the clinical and radiological standard exams because it is able to provide additional information to determine when to intervene surgically, on the basis of patellar bone density values.

Comparing proton density and turbo spin echo T2 weighted static sequences with dynamic half-Fourier single-shot TSE pulse sequence at 3.0 T in diagnosis of temporomandibular joint disorders: a prospective study.

OBJECTIVES: The aim of this prospective study was to compare dynamic and static sequences in the evaluation of temporomandibular joint disorders using a 3.0 -T imaging unit. METHODS: 194 patients were evaluated by static (double echo proton density weighted/turbo spin echo T2 weighted sequences) and dynamic (half-Fourier single-shot turbo spin echo sequences)imaging. Two radiologists evaluated in consensus the quality of images, the disc position and morphological alterations. The Kendall rank correlation coefficient (τ-b) was used to compare the qualitative rating between static and dynamic sequences. Cohen's kappa coefficient (k) was used to assess the agreement of disc position and morphological alterations between both sequences. The intraclass correlation coefficient was used to calculate the intraobserver variability. The significance was set at p ≤ 0.05. RESULTS: The correlation between both sequences in the qualitative evaluation was τ-b = 0.632. The agreement between both techniques in the evaluation of disc position was k = 0.856. The agreement between both techniques in assessing the morphological alterations was k = 0.487. In the static sequences, the intraclass correlation coefficient was 0.915 in the qualitative evaluation, 0.873 in the evaluation of disc position and 0.934 in the assessment of morphological alterations. In the dynamic sequences, the intraclass correlation coefficient was 0.785 in the qualitative evaluation, 0.935 in the evaluation of disc position and 0.826 in the assessment of morphological alterations. CONCLUSIONS: Static imaging remains the gold standard in the evaluation of the temporomandibular joint. Dynamic imaging is a valuable tool that can provide additional information about topographic changes in the disc-condyle relationship.

High resolution 3-T MR imaging in the evaluation of the facial nerve course.

OBJECTIVES: To assess the value of 3-Tesla (3-T) MR imaging (MRI) in the evaluation of the course of the intracranial and extra-cranial tracts of the facial nerve. PATIENTS AND METHODS: 83 patients were studied by MRI in order to detect the course of facial nerve; a total of 166 facial nerves were examined. T2-weighted 3D Fast imaging employing steady-state acquisition (FIESTA) and T1-weighted Fast spoiled gradient recalled echo (fast SPRG) sequences were used. Two radiologists (reader A and B), independently, evaluated the course of the tracts of the facial nerve according to a qualitative scale (excellent, good, fair, poor). The Intraclass Correlation Coefficient (ICC) and Pearson correlation coefficient were used to assess the intra-observer and interobserver variability in the nerve course evaluation. RESULTS: Reader A evaluated 35 facial nerves as excellent, 94 as good, 33 as fair and 4 as poor. Reader B rated 31 facial nerves excellent, 89 good, 43 fair and 3 poor. The intraobserver variability was ICC = 0.919 in reader A and ICC = 0.842 in reader B. The interobserver variability (Pearson correlation coefficient) was 0.713 (p ≤ 0.01). CONCLUSIONS: According to the preliminary results of our study the use of 3-T MRI with FIESTA and fast SPGR sequences may allow the study of the course of the facial nerve and its branches. The knowledge of the course and of the anatomic relationships of these nerve bundles with surrounding structures, as well as of the anatomical variants, provide useful informations for a prompt neurosurgery and maxillofacial surgical planning.

High resolution 3-T MR imaging in the evaluation of the trigeminal nerve course.

BACKGROUND: The evaluation of the trigeminal course and his anatomical relationships with surrounding structures, is important for the assessment of the injury that may occur in tumors and several orofacial trauma and for avoiding the damage during surgeries. AIM: The aim of this retrospective study was to assess the use of 3-T MRI in the evaluation of the course of the four segments of the trigeminal nerve: cisternal and Meckels's cave, cavernous sinus, skull base and mandibular extracranial segments. PATIENTS AND METHODS: 78 patients were studied, for a total of 156 trigeminal nerves examined. T2-weighted 3D Fast imaging employing steady-state acquisition and T1-weighted Fast spoiled gradient recalled echo sequences were used. Two radiologists (reader A and B), independently, evaluated the course of the four segments of the trigeminal nerve according to a qualitative scale. The Intraclass correlation coefficient (ICC) and Pearson correlation coefficient were used to assess the intraobserver and interobserver variability in the nerve course evaluation. RESULTS: Reader A evaluated 47 trigeminal nerves excellent, 94 good, 12 fair and 3 poor. Reader B rated 43 trigeminal nerves excellent, 92 good, 16 fair and 5 poor. The intraobserver variability was ICC = 0.937 in reader A and ICC = 0.894 in reader B. The interobserver variability was 0.734 (p ≤ 0.01). CONCLUSIONS: High resolution 3-T MRI imaging allows an accurate study of the trigeminal nerve and especially of its mandibular branch. The knowledge of the course and of the anatomic relationships of these nerve bundles with surrounding structures, as well as of the anatomical variants, allow oral and maxillofacial surgical plannings thus reducing the risk of nerve damage.

Incidental discovery of testicular microlithiasis: what is the importance of ultrasound surveillance? Two case reports.

Many studies have demonstrated an association between diffuse bilateral testicular microlithiasis (TM) and gonadal and extragonadal germ cell tumors. Nevertheless, it is still uncertain whether ultrasound surveillance is really necessary in patients with TM in the absence of other risk factors such as previous testicular cancer, a history of cryptorchidism or testicular atrophy. We report the cases of a 33- and a 39-year-old man presenting with a retroperitoneal extragonadal tumor. The first patient underwent an MRI examination in order to rule out a lumbosacral hernia: MRI images showed no slipped disks but a voluminous retroperitoneal solid mass. The histological analysis revealed an immature teratoma. The second patient came to the emergency department complaining of abdominal pain, vomiting, weight loss and mild jaundice: ultrasound examination showed a large, ill-defined heterogeneous abdominal mass, confirmed by CT and MRI examination. The histology diagnosed a yolk sac tumor. In both patients, the testicular sonography was performed to rule out a focal lesion, but it displayed bilateral TM without a focal testicular mass. Based on our direct experience, we highlight the importance of annual ultrasonographic surveillance of the testis and the retroperitoneal space in patients with occasionally detected TM.

Surveillance of patients affected by Peutz-Jeghers syndrome: diagnostic value of MR enterography in prone and supine position.

INTRODUCTION: Peutz-Jeghers syndrome (PJS) is a familial polyposis syndrome characterized by multiple hamartomatous polyps throughout the gastrointestinal tract. The aim of our study was to retrospectively determine the diagnostic value of MR enterography (MRE), performed in supine and prone position, in the detection of small bowel polyps in PJ patients. MATERIALS AND METHODS: We retrospectively reviewed MRE examinations of 8 PJS patients who underwent MRE, pushed-double-ballon enteroscopy, laparoscopic endoscopy or surgery, within 3 months. Polietilenglicole was orally administered before the examination. True FISP and HASTE sequences were acquired in supine and prone position; 3D VIBE Gd-enhanced sequences in prone position only. RESULTS: Concordance between MRE and endoscopy was 72.6% for polyps <15 mm, 93% for polyps >15 mm. In supine and prone position concordance with endoscopy for polyps <15 mm was 63% and 66.8%, respectively. In the detection of smaller polyps the difference between supine position only and supine plus prone position was statistically significant (P < 0.027). DISCUSSION: MRE performed by combining prone and supine position was accurate in the detection of PJS polyps, with 93% concordance with enteroscopy for larger and more risky polyps. MRE offers a promising and non invasive alternative to capsule endoscopy, suggesting the possibility of an effective yearly surveillance in PJ patients.

Giant lipoma of descending colon diagnosed at CT: report of a case.

Colonic lipomas are rare benign lesions, detected accidentally. These are often asymptomatic, but large lipoma may produce symptoms as abdominal pain, nausea, weight loss, diarrhea, constipation, hemorrhage, and intussusception. Colonic lipomas are more often localized in the ascending colon: literature reports less than 20 symptomatic cases situated in the descending colon. We report the case of a young man with a colonic giant lipoma diagnosed at Computed Tomography, who presented with rectum bleeding and 5-kg weight loss. The case was interesting because of the patient's young age, the tumor's location in the left side of the colon and the giant size (5.5 cm).