Durable radiologic and molecular complete response following nivolumab in an HNSCC patient with UV signature and HIV.

Cancer patients living with HIV (CPLWH) may experience increased mortality risk. Furthermore, they have been historically excluded from clinical trials due to safety concerns. Our patient with squamous cell carcinoma of the lower lip received radiotherapy and platinum-based chemotherapy but declined by multiple centers due to his accidental HIV status. Genomic profiling revealed CDKN2A/B, PBRM1, TP53, and TERT alterations corresponding to UV signature, and high tumor mutational burden with positive PD-L1 staining. Accordingly, we report a durable radiologic and molecular complete response upon nivolumab plus IVC and antiretroviral therapy (ART). We demonstrated the safety and efficacy of ICIs, and feasibility of managing adverse events caused by antitumor, antiviral, and integrative therapies.

Is 3D Volumetric Evaluation Consistent with Postoperative Renal Parenchymal Preservation in Open and Robot-Assisted Laparoscopic Partial Nephrectomy?

Introduction: To evaluate by using 3D renal volumetric assessment and compare renal parenchymal preservation between patient who underwent open partial nephrectomy (OPN) and robot assisted laparoscopic partial nephrectomy (RALPN). Methods: We retrospectively reviewed the records of the patients to evaluate the effect of OPN (23 patients) or RALPN (19 patients) partial nephrectomy on renal parenchymal preservation. The CT or MRI were examined using 3D-Slicer image processing software. The tumor volume and preoperative and postoperative non-tumor bearing parenchymal volumes were evaluated with the segmentation. The preoperative and postoperative parenchymal volumes, serum creatinine levels, and estimated glomerular filtration rates (eGFRs) were compared between the surgical techniques. Results: The data of 42 patients were included in the final analysis. The patient and tumor characteristics were similar between the two groups. Postoperative renal parenchymal volumetric changes were seen similar between groups. Although the serum creatinine levels and eGFRs did not change postoperatively in the RALPN group (P = .145 and P = .085, respectively), creatinine increased while eGFR decreased in the OPN group (P = .003 and P = .002, respectively). Conclusions: Our analysis showed that RALPN could be considered similar to OPN in terms of parenchymal volume preservation, but the rate of parenchymal volume preservation was not associated with the change in functional parameters. These results should be supported by further research.

Navigating uncharted territory: a case report and literature review on the remarkable response to personalized crizotinib containing combinational therapy in a pazopanib refractory patient with novel alterations.

This paper presents a patient with a novel Ig-like-III domain fibroblast growth factor receptor (FGFR2) alteration (W290_P307>C) along with CDKN2A/B alterations and a cadherin 1 (CDH1) alteration. Initial responsiveness to pazopanib monotherapy was encouraging, yet progression occurred after 7.5 months. Following progression, the molecular tumor board recommended a combination therapy approach comprising pazopanib, crizotinib, and palbociclib to target all of the changed pathways at the same time. Pazopanib was chosen to specifically target the FGFR2 alteration, while crizotinib was selected due to its potential synthetic lethality with the CDH1 alteration. In addition, the CDK4/6 inhibitor palbociclib was administered to address the CDKN2A/B alterations. The patient exhibited a remarkable and sustained response to this innovative combination. This case not only underscores the potential of tyrosine kinase inhibitors, exemplified by pazopanib, as a viable alternative for patients without access to pan-FGFR inhibitors, but it also emphasizes their efficacy beyond commonly detected point mutations and rearrangements. Notably, the outstanding response to combination therapy, including crizotinib, in a patient with a CDH1 alteration, further substantiates the preclinical evidence of synthetic lethality between crizotinib and CDH1 alterations. To our knowledge, this represents the first clinical evidence demonstrating the efficacy of crizotinib in a patient with a CDH1 alteration. Through careful dosage adjustments and consideration of individualized genomic information, this case exemplifies the power of personalized medicine in achieving favorable treatment outcomes.

In-vivo or in-vitro stone attenuation: what is more valuable for the prediction of renal stone composition in non-contrast-enhanced abdominal computed tomography?

OBJECTIVES: To compare the efficacy of in-vivo and in-vitro stone attenuation in the prediction of stone composition using non-contrast-enhanced abdominal computed tomography (NCCT). METHODS: This study included a total of 104 patients with renal stones who received percutaneous nephrolithotomy treatment for renal stones between December 2016 and December 2019 and underwent NCCT before the procedure. Preoperative (in-vivo) and postoperative (in-vitro) kidney stone attenuations were compared using the NCCT images of the patients. Renal stone fragments were analysed with the infrared spectrophotometer method. RESULTS: The mean age of the 104 patients was 49.5 (interquartile range: 37-61) years. According to the receiver operating characteristics analysis, the cut-off values for the prediction of uric acid stones were determined to be 556 HU for the in-vivo and 774 HU for the in-vitro attenuation measurement. Sensitivity and specificity were 100% and 96.6%, respectively, for the in-vivo and 90.9 and 91%, respectively, for the in-vitro images. The cut-off values for the prediction of calcium stones were determined to be 824 HU and 1065 HU for the in-vivo and in-vitro attenuation measurements, respectively. Sensitivity and specificity were 97.3 and 96% for the in-vivo and 96 and 96% for the in-vitro images. CONCLUSIONS: In-vivo stone attenuation measurement in NCCT was slightly superior to in-vitro measurement due to the reduction in the composition and size of the stone. Our findings show that NCCT in-vivo stone attenuation might differentiate uric acid and calcium stones from the other stone types.

The association between ureteral wall thickness and need for additional procedures after primary ureteroscopy in patients with ureteral stones above the iliac crest.

PURPOSE: To examine the parameters affecting the need for additional procedures in the primary ureteroscopy treatment in patients with ureteral stones above the iliac crest level. METHODS: Seventy-one patients were included in the study who were ≥ 18 years old and had undergone ureteroscopy (URS) for ureteral stones above the iliac crest level between 2018-2020 and had a non-contrast-enhanced abdominal computed tomography before the procedures were included in the study. Patients and stone characteristics were prospectively collected. The results were evaluated six weeks after URS. The absence of any residual fragment was thought to indicate stone-free status. The patients with failure were referred for the additional procedures. RESULTS: The median patient age was 51 years [interquartile range (IQR): 18-66]. The median transverse stone diameter was 9.5 mm (IQR: 7.1-11.4), and the median ureteral wall thickness (UWT) was 5.8 mm (IQR: 4.3-6.5). In the univariate analysis, UWT (p < 0.001), presence of multiple stones (p = 0.008), and stone length (p = 0.022) affected stone-free status. The multivariate analysis revealed UWT as the only independent factor affecting the need for additional procedures after URS (p = 0.028). In the receiver operating characteristic curve analysis, the best threshold value for UWT according to the outcomes was identified as 5.8 mm. CONCLUSION: Ureteral wall thickness was the only independent parameter determining the need for additional procedures and affecting the treatment outcomes after the URS procedure.

Comparison and ensemble of 2D and 3D approaches for COVID-19 detection in CT images.

Detecting COVID-19 in computed tomography (CT) or radiography images has been proposed as a supplement to the RT-PCR test. We compare slice-based (2D) and volume-based (3D) approaches to this problem and propose a deep learning ensemble, called IST-CovNet, combining the best 2D and 3D systems with novel preprocessing and attention modules and the use of a bidirectional Long Short-Term Memory model for combining slice-level decisions. The proposed ensemble obtains 90.80% accuracy and 0.95 AUC score overall on the newly collected IST-C dataset in detecting COVID-19 among normal controls and other types of lung pathologies; and 93.69% accuracy and 0.99 AUC score on the publicly available MosMedData dataset that consists of COVID-19 scans and normal controls only. The system also obtains state-of-art results (90.16% accuracy and 0.94 AUC) on the COVID-CT-MD dataset which is only used for testing. The system is deployed at Istanbul University Cerrahpasa School of Medicine where it is used to automatically screen CT scans of patients, while waiting for RT-PCR tests or radiologist evaluation.

Ureteral wall thickness at the stone site: A critical predictor of success and complications in children undergoing semi-rigid ureteroscopy.

INTRODUCTION: We retrospectively assessed the role of ureteral wall thickness (UWT) at the ureteral stone site in predicting the stone-free status and the complication rates in children undergoing semi-rigid ureterorenoscopy (URS). PATIENTS AND METHODS: The children who underwent URS and had undergone non-contrast abdominal computerized tomography before the URS were included in the study. The following protocol was used to determine the outcome. Immediately before removing the stent, all children were evaluated by ultrasound (US) and plain film (KUB) for residual stones in the upper urinary tract and after removing the double J stent, the presence of stone fragments in the ureter was checked with URS. The children were considered stone-free if no residual fragments were identified in radiologic imaging and the evaluation of the ureter by URS. The case was accepted as a failure if any fragments were seen on immediate US, KUB, and/or during URS just after the stent removal. The patients who could not complete the standard primary URS procedure due to stone-related reasons (patients for whom we could not pass the safety guidewire behind the stone and/or the procedure was terminated due to pyuria during the procedure) were also accepted as a failure. The possible factors related to the patient, stone, ureter, and the operation that could affect the outcome and the complications following the URS were evaluated. RESULTS: The children's median age was six years (1-17 years). Among the 89 children included in the study, 69 (78%) were stone-free, and 20 (22%) presented residual stone after the first URS session. The ROC analysis revealed that a UWT value of 4.5 mm (sensitivity 60%, specificity 92%) was the optimal cut-off value predictive of the URS outcome. The regression analysis revealed UWT >4.5 mm (p = 0.006) and multiple stone presentation (p = 0.005) as independent risk factors for residual stone. Complications were detected in 15 (17%) children. Thick ureteral wall (p = 0.012) and longer operative time (p = 0.016) were defined as the independent risk factors for complications. DISCUSSION: Increased UWT is associated with the adverse outcomes of URS due to tissue hypertrophy, edema, and mucosal bleeding may cause difficulty in removing the stone. The thick ureteral wall might increase the risk of complications due to the necessity of manipulating the instruments or the involuntary forceful use of instruments while removing the stone. CONCLUSION: UWT was the only independent variable affecting both increased failure and complication rates in children undergoing URS.

Ureteral wall thickness is an independent parameter affecting the success of extracorporeal shock wave lithotripsy treatment in ureteral stones above the iliac crest.

BACKGROUND: To investigate the relationship between ureteral wall thickness (UWT) and other variables of patients who underwent extracorporeal shock wave lithotripsy (SWL) in the primary treatment of the ureteral stone above the iliac crest level. MATERIAL AND METHODS: A total of 147 patients aged 18 years and older, who underwent SWL in our clinic between December 2016 and December 2019 for the treatment of ureteral stones above the iliac crest level and had non-contrast enhanced abdominal computed tomography scans before the procedure were included in the clinical study. The results were evaluated at 3 months after SWL. The absence of residual fragments was considered as stone-free status, and the existence of any size residual fragment was considered as treatment failure. RESULTS: In our study, the mean age of the patients was 42.4 ± 12.8 years, and the stone-free rate was 92.5%. The median transverse stone size was 7.5 mm (min 2.8-max 15), and the median UWT was 4.2 mm (1-8.7). In the multivariate analysis, UWT (P = .002) and multiple stone presence (P = .027) were found to be independent factors affecting stone-free status. In the receiver operating characteristic curve analysis, the optimal threshold value for UWT was determined as 5.25 mm. CONCLUSIONS: We found that UWT was the most important independent variable associated with increased failure in SWL treatment. The presence of multiple stones was another independent factor that increased the failure rates. Using SWL technology through experience accumulated with the mechanical hardware of the machine, we can select patients who are more suitable for this treatment and improve treatment outcomes.

Use of volumetric CT scanning to predict tumor staging and survival in pancreatic cancer patients that are to be administered curative resection.

BACKGROUND: This study evaluates the achievability of CT volumetry of pancreatic cancer and its correlation with pTNM stage and survival. METHODS: Tumor volume was measured from contrast enhanced CT images of 58 patients who undergo curative resection for pancreatic cancer using the Segment Editor module implemented in 3D-Slicer-a free open source software platform. Receiver operating characteristic (ROC) analysis was used to evaluate correlation between Tvol and pTNM staging. RESULTS: The preoperative images of 58 pancreatic adenocarcinoma patients were included. The mean Tvol of pancreatic cancer is an increasing trend with T stage (The mean T1vol = 1.75 cm3 , the mean T2vol = 11.43 cm3 , the mean T3vol = 14.98 cm3 , the mean T4vol = 19.6 cm3 ). There were statistical differences between volumes (p = .000). On ROC analysis, the area under the ROC curve (Az) of Tvol to differentiate T1 stage from ≥T2 stage was 0.966 (p = .000). At a cut-off value of 3.050 cm3 , sensitivity of 92.3%, and specificity of 83.3% were achieved. Az value of Tvol to differentiate ≤T2 from ≥T3 stage was 0.750 (p = .010). At a cut-off value of 10.250 cm3 , sensitivity of 72.7% and specificity of 66% were achieved. In addition Az value of Tvol to differentiate ≤T3 from ≥T4 stage was 0.652 and was not significant (p = .380). At a cut-off value of 11.2 cm3 , sensitivity of 66.7% and specificity of 63.6% were achieved. CONCLUSION: CT volumetry in pancreatic cancer is feasible with excellent reproducibility. It is one of the prognostic factors affecting survival in operated patients with pancreatic cancer.

Chest Computed Tomography Findings of Eight Patients With Covid-19 Diagnosis: Case Series.

COVID-19 is an infectious disease caused by the virus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and declared a pandemic on March 11, 2020, by the world health organization. In Turkey, the first cases began to appear on March 11, 2020. After the cases in China, the appearance of ground glass with or without consolidation in the posterior and periphery of the bilateral lung is determined as the main finding of COVID-19. In this article, we wanted to share the tomography findings of eight patients who were diagnosed with COVID-19 in our emergency department and who had lung involvement.

Comparison of automated versus hand-held breast US in supplemental screening in asymptomatic women with dense breasts: is there a difference regarding woman preference, lesion detection and lesion characterization?

PURPOSE: To compare automated breast volumetric scanning (ABVS) with hand-held bilateral whole breast ultrasound (HHUS) prospectively in regards to patient workflow, woman preference, efficacy in lesion detection, and characterization. MATERIALS AND METHODS: Supplemental screening was performed with both ABVS and HHUS to 345 women with dense breasts and negative mammograms. Acquisition and evaluation times were recorded. Lesions were classified according to BIRADS US criteria and compared one to one. Women were recalled for a secondary HHUS examination if ABVS showed any additional lesions. Findings were compared based on biopsy results and/or 36-48 months of follow-up. RESULTS: Findings could be compared for 340 women. There were two carcinomas which were detected by both methods, with no interval cancers in the follow-up period. Recall rate was 46/340 (13.05%) for ABVS and 4/340 (1.18%) for HHUS. ABVS recalls decreased with experience. HHUS had more true negative (BIRADS 1-2) results, while ABVS had more false positive ones (p < 0.001). Positive predictive value was 4.17% for ABVS and 50% for HHUS. ABVS overdiagnosed shadowings (p < 0.01), distortions (p < 0.034), and irregular nodules (p < 0.001) in comparison to HHUS. At ABVS, 10.6% of women experienced severe pain. 59.7% stated that they would choose HHUS if they had the chance. CONCLUSION: ABVS is as good as HHUS in lesion detection. However, the recall rate is higher and positive predictive value is lower with ABVS, which could result in more follow-ups, and more anxiety for the women. More than 50% women stated they would prefer HHUS if they were given the chance.

Does median nerve translate pre- and postoperatively in carpal tunnel syndrome?

OBJECTIVES: This study aims to evaluate the distance between the median nerve and the hook of the hamate pre- and postoperatively in patients with carpal tunnel syndrome and to investigate the efficiency of magnetic resonance imaging in diagnosis and postoperative follow-up. PATIENTS AND METHODS: Median nerve decompression was performed by releasing the carpal tunnel in 15 patients (4 males, 11 females; mean age 51 years; range, 41 to 66 years) with carpal tunnel syndrome. The shortest distance between the median nerve and the hook of the hamate was measured with magnetic resonance imaging preoperatively and at three months after the operation and radial and ulnar translations were assessed. Findings were compared to those of a control group of 15 subjects (5 males, 10 females; mean age 52.2 years; range, 40 to 65 years). RESULTS: Median nerve shifted ulnarwards in patients with carpal tunnel syndrome. An intragroup evaluation of five patients with thenar atrophy revealed that as disease severity increased, the degree of the nerve's medial translation increased. Compared to preoperation, the median nerve significantly shifted to the radial side after decompression. CONCLUSION: In carpal tunnel syndrome patients, we observed significant ulnar translation of the median nerve and lateral translation after releasing the carpal tunnel. Magnetic resonance imaging may be used to establish a diagnosis and to assess operation success in advanced carpal tunnel syndrome patients who may recover slowly postoperatively.

Bladder cancer in an inguinal vesical hernia.

A 60-year-old male patient presented with intermittent right-sided scrotal swelling for the last 4 months. On ultrasonography, a fluid-filled cavity extending through the right inguinal canal into the scrotum was noted with inferior displacement of the right testis. Multiple papillary hyperechoic lesions with internal vascularity on Doppler ultrasound were protruding into the fluid-filled cavity. Computed tomography showed herniation of the bladder through the right inguinal canal into the scrotum with mural components in the herniated segment. Hernioplasty followed by transurethral tumor resection showed urothelial carcinoma with invasion into the muscular layer. Vesical herniation through the inguinal canal is uncommon. Additionally, the presence of bladder carcinoma within a herniated portion of the bladder is exceedingly rare.

A dilemma at gray scale thyroid ultrasound: microcalcification or not? Differentiation with Acoustic Radiation Force Impulse Imaging-Virtual Touch Imaging.

AIMS: To evaluate the capacity of virtual touch imaging (VTI) of the acoustic radiation force impulse (ARFI) techniquein the differential diagnosis of micro-echogenicities in thyroid nodules. MATERIAL AND METHODS: The study comprised 28patients. Gray scale and ARFI displacement maps were used during ultrasound examination.In the same session, fine needleaspiration biopsy (FNAB) samples were obtained from the dominant nodule hav-ing micro-echogenicities. Two radiologists blinded to the FNAB results and clinical data of the patients evaluated these images and rated ARFI echogenicities according to the degree of shining points on the displacement maps and classified them as isohypoechogenic, isohyperechogenic, and obvious hyperechogenic. To differentiate between benignancy and malignancy, "a new sign" was defined as follows: in the ARFI maps obtained by VTI, iso-echogenic or hyper-echogenic appearance of micro-echogenic foci was evaluated as benignancy and hypo-echogenic appearance of micro-echogenic foci was evaluated as malignancy. RESULTS: The FNAB results indicated 14 cases and benign nodules in the other 14 cases. Interobserver agreement between the two radiologists was highly significant for the classification of the micro-echogenic foci (Kappa=0.659, p<0.001). When we reclassified the hyperechoic and isohyperechoic foci as "benign" and isohypoechoic foci as "malignant", the interobserver agreement between the two radiologists increased (Kappa=0.772, p<0.001). The evaluation of the first and second radiologists were highly concordant with the gold standard pathology results (Kappa=0.786, p<0.001 and Kappa=0.714, p<0.001, respectively). CONCLUSIONS: ARFI method with specific VTI features could be a very useful tool in the differentiation of malignant microcalcifications in thyroid nodules.

Vacuum-assisted stereotactic breast biopsy in the diagnosis and management of suspicious microcalcifications.

PURPOSE: We aimed to present our biopsy method and retrospectively evaluate the results, upgrade rate, and follow-up findings of stereotactic vacuum-assisted breast biopsy (VABB) procedures performed in our clinic. METHODS: Two hundred thirty-four patients with mammographically detected nonpalpable breast lesions underwent VABB using a 9 gauge biopsy probe and prone biopsy table. A total of 195 patients (median age 53 years, range 32-80 years) with 198 microcalcification-only lesions with a follow-up of at least one year were included in the study. The location of the lesion relative to the needle was determined from the postfire images, and unlike the conventional technique, tissue retrieval was predominantly performed from that location, followed by a complete 360° rotation, if needed. RESULTS: The median core number was 8.5. Biopsy results revealed 135 benign, 24 atypical, and 39 malignant lesions. The total upgrade rate at surgery was 7.7% (6.1% for ductal carcinomas in situ and 10.5% for atypical lesions). Patients with benign lesions were followed up for a median period of 27.5 months, with no interval change. At the follow-up, scar formation was seen in 23 patients (17%); three of the scars were remarkable for resembling a malignancy. CONCLUSION: Our biposy method is fast and practical, and it is easily tolerated by patients without compromising accuracy. Patients with a diagnosis of atypia still need to undergo a diagnostic surgical procedure and those with a malignancy need to undergo curative surgery, even if the lesion is totally excised at biopsy. VABB may leave a scar in the breast tissue, which may resemble a malignancy, albeit rarely.

A Very Rare Complication of Acute Appendicitis: Appendicovesical Fistula.

Appendicovesical fistula (AVF) is an uncommon type of enterovesical fistula and a very rare complication of acute appendicitis. Herein, we report a case of 39-year-old male patient who presented with persistent urinary tract infection, recurrent abdominal pain, and pneumaturia. Imaging techniques including ultrasonography (USG), computed tomography (CT), and magnetic resonance imaging (MRI) were performed to identify the abnormality. However, definitive diagnosis of AVF was made by cystoscopy.

Defining the Collateral Flow of Posterior Tibial Artery and Dorsalis Pedis Artery in Ischemic Foot Disease: Is It a Preventing Factor for Ischemia?

BACKGROUND: Critical limb ischemia, a worldwide prevalent morbidity cause, is mostly secondary to vascular insufficiency due to atherosclerosis. The disease presents with intermittent claudication, which can progress to critical limb ischemia requiring amputation. Research has emphasized that the quality or existence of the pedal arch have a direct effect on wound healing and, therefore, on limb salvage, through the mechanism of collateral vascularization to the ischemic regions. OBJECTIVES: This study aimed to determine the existence and, if present, grade of retrograde blood flow from plantar arch to dorsal foot artery (dorsalis pedis artery, DPA). The correlation between clinical symptoms and presence of collateral flow were also investigated. PATIENTS AND METHODS: Study group consisted of 34 cases, which included patient group (n = 17, all male, mean age: 68 years) and control group (n = 17, all male, mean age: 66 years). After physical examination and lower extremity Doppler examination, spectral morphology of DPA flow was recorded, before and during manual compression of posterior tibial artery (PTA), for a period of 5 seconds. At the end, findings of Doppler ultrasound, computed tomography angiography, magnetic resonance angiography and, physical examination finding and symptomatology were gathered and analyzed. RESULTS: In the patient group, 31 lower limb arteries, of total of 17 cases, were included. After compression maneuver, DPA in 11 cases (six right, five left) showed retrograde filling from plantar arch. This retrograde flow support was triphasic in three cases, biphasic in five cases, and monophasic in three cases. In other DPAs of these 20 limbs, PTA based retrograde collateral flow was not determined. In nine of these 20 limbs, with no or diminished retrograde filling, symptoms were worse than in other cases. Contrarily, only two of 11 limbs, with retrograde collaterals, have claudication during walking. CONCLUSION: In cases with critical atherosclerotic disease of anterior tibial artery, PTA-based biphasic or triphasic retrograde collateral flow prevents ischemia, whereas monophasic support or no retrograde flow remains incapable.

Vein of foramen caecum: imaging findings.

Vein of foramen caecum has been classically described as a vein that connects nasal mucosa to the superior sagittal sinus in classic anatomy textbooks. However, its existence is controversial in literature. Herein, we demonstrated computed tomography and contrast enhanced magnetic resonance imaging findings of a tubular vascular structure extending to nasal mucosa and superior sagittal sinus.

Perianal Fistula With and Without Abscess: Assessment of Fistula Activity Using Diffusion-Weighted Magnetic Resonance Imaging.

BACKGROUND: Magnetic resonance imaging (MRI) is highly accurate for the depiction of both the primary tract of fistula and abscesses, in patients with perianal disease. In addition, MRI can be used to evaluate the activity of fistulas, which is a significant factor for determining the therapeutic strategy. OBJECTIVES: This study aimed to determine the usefulness of diffusion-weighted (DW) MRI for assessing activity and visibility of perianal fistula. PATIENTS AND METHODS: Fifty-three patients with 56 perianal fistulas were included in the current retrospective study. The T2-weighted imaging (T2WI) and DWMRI were performed and apparent diffusion coefficient (ADC) values of fistulas were measured. Fistulas were classified into two groups: only perianal fistulas and fistulas accompanied by abscess. Fistulas were also classified into two groups, based on clinical findings: positive inflammatory activity (PIA) and negative inflammatory activity (NIA). RESULTS: Mean ADC value (mm(2)/s) of PIA group was significantly lower than that of NIA group, regarding lesions in patients with abscess-associated fistulas (1.371 × 10(-3) ± 0.168 × 10(-3) vs. 1.586 × 10(-3) ± 0.136 × 10(-3); P = 0.036). No statistically significant difference was found in mean ADC values between PIA and NIA groups, in patients with only perianal fistulas (P = 0.507). Perianal fistula visibility was greater with combined evaluation of T2WI and DWMRI than with T2WI, for two reviewers (P = 0.046 and P = 0.014). CONCLUSION: The DWMRI is a useful technique for evaluating activity of fistulas with abscess. Perianal fistula visibility is greater with combined T2WI and DWMRI than T2WI alone.